WHat's your guys' carb setup for the Go-Tech?

[3pointX]

I think I've got the HSN turned about as far as it should go, but it seems like it still bogs until it gets up into the RPMs and I'm afraid to go too far and run it lean. Once it gets up there it just screams, but I guess I was expecting a bit more punch in the low end. I've got the HSN turned right about 3/4 turn from the factory setting and I haven't touched the LSN at all. It idles well and there's smoke when I get on it but not an excessive amount of unburned fuel spitting out the pipe - just a little bit, so I wonder, how much does it have left?

[Mr Fusion]

Cam has been digging up a lot of info on that. It depends on which carb you have on it... the stock carb needs a weird setup.

[3pointX]

Yeah it's the stock RTR stuff. I mean, it's weird. Most carbs you don't turn more than 3/4 from flush, and with this one, 3/4 from flush, it takes it forever to get up to speed, so you keep leaning it a little at a time, and it just gets better and better every little bit I turn it. But I'm at that point where I'm scared to keep leaning it out. I can tell it's got a lot more left to give, but I'm afraid to ask it for any more until I know for sure.

[vnmsgt]

Get a temp gauge. As long as the temps are fine and you are happy with the performance then leave it alone.

[3pointX]

Yeah I've been using a meat thermometer lol. I just stick the probe inside the head and it seems like it reads pretty close lol. I've been getting readings between 220-240 after warming it up a bit, depending on the time of day. It's cool in the mornings but the afternoons are starting to get warmer here, so I'm sure that's making a difference. And the old spit test shows it's still running somewhat rich (cool) for teh most part so that's what got me thinking there was something funny going on. Once my tax incentive check comes in this month I'll pick up an actual thermometer along with some other things.

[Lee_Jones]

You can't tune a motor with Temps. This will help. For you people that don't know, this was written by Ron Paris.

ENGINE TUNING TECH TIPS

First off i did not write any of this i found out there and after reading it thought alot of pepole here may find it useful. All sounded good and seemed to make sense, hopefully this will be the begining of a good tuning thread.

Tuning tech: carb Needle balance We get dozens of tuning questions from around the world at Paris racing daily, The number one questions is, were do I set my needles on the carb?

Unfortunately there is no such thing as a definitive universal setting for any engine! Every application will have it’s own unique requirements, even two IDENTICAL set ups can and most likely will have at least slightly different settings.

Please see tech tips following the article below [from our web site] I would like to address what seems to be the # 1 mistake we encounter in engine tuning:

Carburetor Needle balance:

It has come to our attention some racers are making the mistake of setting the idle speed opening to wide [high idle] and setting the bottom end too rich!

This will give a false normal idle speed even though the speed is set to high because it “loads up” the engine with excess fuel causing the idle to be lower than set! The end result is a very unstable idling engine that surges and may cut out as full throttle is applied because the over rich bottom end can disguise a too lean TOP end setting!!!

Let’s address this a little more in depth! Idle speed opening set too wide:

It is possible too set the idle screw adjustment in to far but yet the idle speed is not high! Even though the air regulation [carb barrel or slide] may be set to a position that would normally equal a vary fast idle, the idle is low because the low speed mixture adjustment is set so rich that the engine loads up with excess fuel and the engine goes into what’s commonly called a four cycle idle. One tell tail sign of this is if after revving up the completely warmed up engine it tends to idle fast for a few seconds then drops to lower idle speed. [Here we go again with the written sound effects :-)]

Something like da..da..da..da..da..da..da..da then it drops to da….da….da….da [if it were sheet music it would be like dropping from 8 beats per measure to 4 beats per measure] If you start leaning the bottom end a little at a time [then repeat the reving up and idle test] and it takes longer before the idle drops your going in the right direction! Eventually as you keep leaning the bottom the idle will stay to high, now it is time to lower the idle to were it belongs by re adjusting the idle screw! CAUTION!!!! Now that you have the idle set correctly the top end may be too lean!!! Keep in mind the fuel does not directly enter the cylinder area like a 4 stroke engine, it enters the crankcase area first then is transferred or pumped up to the cylinder area by the piston movement. Simply put, the crank case volume can hold much more capacity than the cylinder so it takes some time to burn off the residual fuel.

In other words if the bottom end is to rich the engine will be supplied by this residual fuel briefly and depending on the demand you may be actually be experiencing a lean condition on the top end that can range from:

1. Seems to run well but engine life is short

2. Seems to run well but car continues to get hotter the longer you run to the point of overheat!

3. Seems to run ok on the bottom but sputters starves or strains to gain rpm

4. Seems to run ok on the bottom but when I give full throttle it cuts out or stalls [An overly rich top end can act the same as 3 & 4 but excessive smoke and oil are usually present with a distinct blubbering sound] There is no reason for an engine to continually get hotter unless the tune is wrong [classic #2. symptom] or there is a mechanical problem causing more load or drag on the engine as the run continues.

Exception Note: if the weather or track conditions change DRAMATICALLY.

{Examples** A light drizzle starts and the off road track goes from a very dry loose to high traction condition, or during a race a rapid weather front like a ten degree change! It is very important to fully warm up your engine, clutch and chassis before making finale adjustments.

The chassis in most applications also works like a heat sink to the engine so it is important to fully saturate the chassis!!! I like to start the engine at least 3 or 4 minutes before our qualifier to get some heat in the engine. [Operate the throttle by hand until you have radio frequency clearance] It still takes at least 2 to 3 minutes of hard running on the track to fully saturate the chassis! There is a series of restrictions to control fuel flow at different throttle/air flow positions called needles These are the five basic parts of the carb to concern yourself with:

1.The slide or barrel [regulates the amount of air to enter the engine controlled by the servo] It simply blocks off the airflow to the engine proportional to how far it is open or closed.

2. The idle/air speed screw [sets the absolute minimum air the barrel/slide can control to maintain idle speed] It simply is an adjustment screw that comes in contact with the side at the nearly closed/idle position.

3. The high speed needle [regulates maximum fuel flow allowed to enter engine at any throttle position] It simply is a tapered needle that screws into the fuel flow orifice [an adjustable restriction] This maximum fuel flow ideally is adjusted to the correct mixture ratio for the surrounding conditions at WIDE OPEN THROTTLE or WOT There are two more devices’ the low speed or minimum spray bar and the mid range needle that restrict or control the fuel further at less than full throttle.

4. The low speed needle [regulates fuel to engine at idle] The low speed adjustment simply restricts the flow at idle speed. If you look down the bore of the carb you will see a long tapered needle [except for Picco torque carbs] When the carb barrel/slide is closed the larger part or diameter portion of the long tapered needle is inserted into the spray bar, this is what’s adjusted when you turn the low speed/minimum adjustment. It literally moves either the tapered needle OR spray bar farther in or out changing the restriction independent of the barrel/side position. This leans [more restriction] or richens [less restriction] the flow from the spray bar at idle. NOTE: some carbs the spray bar is moved and others the needle assembly is moved, both have the same effect.

5. The mid range needle [regulates fuel to engine after idle and before full fuel position. Notice as you open and close the carb the tapered needle [mentioned above in item 4.] enters into a small tube this is called the spray bar/jet. This spray bar is were ALL the fuel enters the airflow stream regulated by the high speed, mid range and idle/minimum adjustments! Normally somewhere between ½ and ¾ throttle open position the needle is completely out of the spray bar, This is what is called full fuel position or FFP [at this point 100% of the mixture is controlled by the high speed needle. On many carbs the low speed and midrange are not independently adjustable so the mid rage is a factor of the needle taper and is engineered by the factory.

On some SLIDE carbs there is both independent spray bar and mid range needle adjustments. CAUTION: be very careful with these type carbs!!! You can identify them easily because there are four adjusting screws! {Continued on page 2** Page 1 One each for the: High speed/top end [normally sticks up some what vertical] Idle/air speed [normally a much smaller screw entering the carb at an angle] Low speed/minimum [located in the end of the slide OR on the opposite end of the carb body] Midrange [also located in the end of the slide OR on the opposite end of the carb body] Note: if there are adjustments on both the slide and the carb body one is an adjustable mid range and the other the low speed!!! Check with the engine manufacture before attempting to adjust these types of carbs!

It is very important not to use the mid screw to adjust the low end by mistake it is very easy to get the carb way out of sync. Normally I recommend not attempting to adjust the mid range even if your carb is so equipped, the gains are VERY small and mostly limited to minute midrange drivability/economy changes that only the most sophisticated driver will recognize!

The negative is a carb that is so screwed up only an expert can get it back in tune! Please note the above descriptions will apply to 99% of the modern car carbs being manufactured as of this writing with the exception of the Picco TORQUE carb that use’s no mid range needle at all.

It utilizes a fuel management ramp built into the slide the carb also has two completely independent fuel delivery spray bars/jets. I wish I could tell every one exactly how to tune their engine but I cannot! My hope with this article is if I can help racers to more understand How your carb works, all the other instructions and guides will make more sense! Best Regards, Ron Paris Engine Tuning Tech Tips From Our Web Site: Should I seal the carb with silicone? Many racers find this a must! [Particularly in off road] Here are a few tips.

1** Be sure to use ONLY non-volatile silicone [it should say oxygen sensor safe on the tube!] you can find it at any auto parts store.

2** Use sparingly, apply a thin bead on the carb neck just below the main carb body [even if there is an o-ring present. Do not put it in the engine case bore or all around the carb neck. [That would glue the carb into the engine for good!] You just want a thin bead to squish out from between the engine case and carb body just as you fully insert the carb.

3** After positioning the carb were you want it tighten the pinch bolt assembly that holds the carb very snug! Then add a dab of silicone to both ends of the pinch bolt assembly.

4** Let fully cure before staring engine. Optimal carburetor settings: There is no such thing with any size or brand engine that has a predetermined optimal carb. Setting! If there were, all engines would come without adjustments. There are many variables that must be taken into consideration. Glow plug, fuel type and nitro, manifold type and length, pipe type and were the pressure filing is, clutch adjustment, gear ratios, tire size, ambient humidity, temperature and altitude etc, etc, etc.

The point I'm trying to make is no one can tell you were to “set the Carb” only some one they’re with you can fine-tune it! BUT IT IS NOT THAT HARD IT ONLY SOUNDS COMPLICATED. 95% of all problems are that the directions were not followed correctly. Ideal engine temperature: First let me say that there is no IDEAL temperature for any engine. There are many variables that affect it Ambient temp, fuel type and nitro content, altitude & barometric pressure, Pipe/manifold type and setting, clutch setting, glow-plug, gear ratio, available traction, How hard your driving, on road or off road Etc. Etc.

All information is based on the Paris/Exergin probe it is the only probe designed for model engines and has worldwide patented Emisivity compensation. We tested dozens of devices before we started working with Exergin and introduced infrared tuning to the model industry. All of the following conditions MUST be met before any temperature can be considered correct, the engine is assumed to be in good shape.

1** There must be a visible trail of smoke when accelerating from EVERY corner.

2** The idle is stable.

3** The glow plug wire stays somewhat shiny and the coil stays round [UN-distorted]

4** The performance is good. Picco on road average conditions 20 to 40% nitro 205 to 230 degrees f Picco off road average conditions 20 to 30% nitro 215 to 250 degrees f Nova on road average conditions 20 to 40% nitro 220 to 260 degrees f Nova off road average conditions 20 to 30% nitro 230 to 270 degrees f How to “READ” your glow plug: OS and Turbo glow plugs go gray sooner [easier] than McCoy plugs this is not necessarily bad.

Actually when A new plug wire just goes slightly gray after a 5 or 10 minute hard run it means your very close to an optimal horsepower tune, but be careful the next step is TOO LEAN! My rule of thumb.

1** Wire and surrounding bottom of plug wet, with like new shiny wire = rich side of optimum power 85%

2** Wire and surrounding bottom of plug starting to dry and wire starting to gray = Very close to optimum power 95%

3** Wire and surrounding bottom of plug dry, wire totally gray but not distorted optimum power 100%

4** Wire and surrounding bottom of plug dry, wire distorted = slightly lean DANGER!

5** Wire and surrounding bottom of plug dry, wire broken and distorted or burnt up = extremely lean possible engine damage! Note: You can only “Read” your plug in a nearly new state [Wire like new and shiny] A gray plug can still operate well.

After it has totally gone gray, performance can start to fall off. To test just put in a new plug and if there is no difference in performance save the gray one or put it back in. If your engine does not feel or run right tray a new plug before making major tune changes Effects of changing manifold to pipe length: Rule of thumb: Longer manifold = more bottom end torque. [At the expense of some rpm] Shorter manifold = more top end rpm [at the expense of some torque] BUT you can go to far with either direction causing the engine to run erratic or HOT!

You must keep it in the “sweet spot” Bottom line: there is no set length for every engine or pipe, experiment with the length to suit your driving style or track needs. Does it mater were you put the pressure fitting in your pipe: If you’re talking about a single chamber pipe like the Associated or Paris AL12T no big deal. But if you’re talking a two-chamber pipe, and you go from one chamber to the other you will have to re tune the engine. Even then it is not a big deal once it is tuned for that location there is little if any performance difference. [It is all relative to available pressure Vs needle setting]

I recommend tapping into the first chamber on two chamber pipes [the intake side] were the pipe is at its largest diameter. The second chamber has more constant pressure but can be more difficult to tune in high altitude or fast changing weather conditions {Continued on page 3** Page 2 How to shut off you engine and stop runaways: If the engine is out of control and at high RPM DO NOT USE YOUR HAND on the flywheel! Some guy’s flip the car over and stick the toe of their shoe on the flywheel! I have seen it work but 50% of the time the engine lets go before you can stop it!

The method I like is as follows: Try and hold the car down hard so the wheels can’t spin [this may waste the clutch shoes but it is cheaper than an engine!] Yank the body if you can’t get to the air cleaner, then yank the air cleaner and put your finger on the carb intake. It is kind of like handling a wild animal but it is a good method. Do not just push your finger down on the foam air cleaner, which will suck all the dirt into the engine! Holding a rag on the exhaust works too [if you happen to have one handy] but, Be sure there is several layers of rag it will take more than a few seconds to choke it And it will be HOT HOT HOT! If the engine is idling normally, I just touch the flywheel with the handle of an old screwdriver!

Ron’s tips for healthy Fuel: I always shake my fuel because some oil separation is common especially with higher nitro but I mostly shake it to re oxygenate the nitro [old habit from topfuel/funny car days] Water absorption Is the #1 reason for “Bad” fuel! And is little affected by any nitro or oil/additive package.

The methanol is what’s so hydroscopic [Water magnet] My advice as always.

1. Never leave the bottle open any longer than it takes to fill your fuel bulb.

2. Never leave the FUEL BULB uncapped any longer than it takes to fill the car.

3. Always rinse out you fuel bulb at the start of each day with a little fresh fuel.

4. NEVER draw fuel back into your bulb or put it back in the jug.

5. keep your fuel out of direct sunlight and off the ground.

6. store your fuel in a stable temperature.

7. I like to squeeze the extra air out of the bottle before tightening the lid.

8. Some times it is handy to save some 1/2 gallon or quart bottles to transfer to as you the Gallon remember to rinse them out with a little fresh fuel first. If you follow these simple steps your day will never be ruined by bad fuel. Will it hurt my engine to run it out of fuel: My opinion is if your engine was tuned correctly, to start with it will not harm it running out of fuel!

I have done this hundreds of times with no damage even in our killer engines. If just before running out of fuel the car was tuned:

1** Tuned Slightly rich, it will speed up for a brief moment just before it dies as you pass through the “Ideal performance” mixture stage.

2** Tuned for ideal performance, it will fall off in power just before it dies as it passes through the too lean stage.

3** Tuned too lean to start with, it will bog down noticeably and may blow the plug as it pass though the “way to lean you just screwed up stage”. This can cause some damage to the piston and sleeve if the element wire breaks and falls in to the engine. However, the brief lean moment should not hurt the bearings, bushings, rod, crank etc. if you’re using high quality fuel [especially a high castor blend like Blue thunder race formula] Is it ok to switch nitro content or brands of fuel?

There are many opinions on this subject I feel there are no problems doing either! The most important thing is to use a good quality fuel! Personally, I break our engines in on the same nitro we race with, but have had equally good results either way! The only recommendation I would make is, if you do switch brands it would not hurt to:

1** Let the engine idle a few minutes before you go out on the track.

2** Run ½ to 1 tank of fuel on the rich side.

3** Check your glow plug and if it looks good fine tune and go for it.

The reason I say to check the plug is that different fuels have different oil additives and detergent packages. This may wash away some of the built up oil deposits and platelets or bonding agents [As the oil companies call them] and foul the plug. After a few runs your new fuel will leave deposits of there own, some brands you can see the residue because of its blue or red color.

Other brands you can’t see because they’re a light yellow or amber color but rest assured it's there! It is normal to have these build-ups and it cause’s no harm! What is the best Fuel? Blue Thunder Race Formula [Paris/Blend] Has a High castor to synthetic ratio. Castor oil is simply the best lube available for model engines [Alberto Picco and Mario Rossi agree] but not all castors are the same!

We use the finest ultra Pure Triple A refined castor. Then we add a synthetic supplement package, which includes anti foaming and rust properties. There is also a wetting agent to aid in Lubricity and reduce storage dry out. The fuel is manufactured with the latest high tech computer controlled mixing equipment using the freshest lab tested and certified USA made nitro and methanol by the largest manufacture of model fuel in the world.

Should I use after run oil: Race Formula Blue Thunder is a high castor blend that includes 3% Synthetic with anti gumming agents. It is always a good idea to use some after run oil. First let the tank run completely empty at idle until it runs out of fuel [try re-starting it several times]

Next put a few drops down the carb [open] and a few drops down the glow Plug hole [leave the plug out and put a rag over the top of the engine] And spin it over for 5 seconds on the starter box. Last put a few more drops down the carb re install the glow pug and spin The engine over 5 more seconds.

That will do it! We May be releasing a after run oil but in the meantime Marvel Mystery oil works great and can be had at any automotive or hardware store. Other substitutes would be automatic Trans fluid, 3in1 oil or Mineral oil from the drug store! NEVER USE ANY OILS THAT CONTAIN SILICONES!!!

Cleaning your Engine: First, follow the after run oil instructions above! Remove the engine from the car, you can then wash it off just be careful not to wash dirt into the front bearing [even if it has a rubber sealed type]

I brush it off behind the flywheel then rap a strip of cloth around the crank, “wedging” it between the front of the engine and back of the flywheel. I then plug the carb and exhaust [be sure there is a glow plug installed] then squirt it off with methanol or denatured alcohol [Not Isopropyl it is 30% water] I do not recommend brake cleaner or motor spray.

Then blow of off with compressed air if you do not have compressed air shake the engine vigorously and blow it off until dry with a hair dryer, being careful not to get it HOT just warm to the touch. Last I remove the strip of cloth let the engine come to ambient temp [so there is no condensation formed inside] and put it in a zip lock bag or re- install in your car! You can see many other useful tech tips at the Paris web site http://parisracing.com [go to tech tips on third page] Good luck and enjoy your new Paris Racing Engine,

Ron Paris Page 3 Engine Break In And Tuning For The New and Experienced Racer:

Revised 12-30-99 Engine Break in for the for the New Racer:

I was honored when the gang at R/C Car magazine asked if I would collaborate on a tuning article geared to the new and hobby racers! With the continued growth of 1/10 off road and Explosion of sedan racers, there was a need for a generic tuning guide. Well here it is, it was very informative as written by the gang at the magazine, I simply added a few tips and clarifications based on the hundreds of tech questions we receive. Enjoy,

Ron How to Break In your New Engine Patience is the secret to success!

If you’ve read a few issues of this magazine, you’ve probably noticed that we devote quite a few pages each month to nitro-powered vehicles and accessories.

Critics might say that we prefer nitro over electric powered, but the truth is that we are simply covering what’s going on in the R/C industry—nitro is hot at the moment, and we’d be failing you if we didn’t provide comprehensive coverage! Surely, one of the reasons for nitro’s popularity rests in the quality of the engines themselves. Most of today’s engines are manufactured to be easy to use and to maintain, and many sport-level power plants have been designed to be incredibly user-friendly. For absolute novices, we still recommend electric-power over nitro, but if you should decide to take the plunge, you’ll find that most engines are quite easy to get running.

Above all else, your success or failure with a nitro engine depends on how well it’s been broken in—and this is entirely up to you and the amount of patience you have.

The more time you take to properly break-in your new engine, the better it will run. A well broken-in engine will develop more power and higher rpm, and will run much more consistently than an engine that had been rushed into race settings. .

It’s all in the carb Everything that’s needed to ensure your engine’s long life is contained in its carburetor. Most carbs have three adjustments that you’ll need to familiarize yourself with: The first, and most important, is the high-speed needle setting.

This needle valve controls the mixture of fuel and air that enters the engine’s combustion chamber during high-rpm running. More fuel in this mixture causes a “rich” condition, while less fuel (more air) causes a “lean” condition. A richer high-speed needle setting will actually help keep the engine running cooler as it reduces rpm, and because there is more fuel passing through the combustion chamber, a bit of “liquid cooling” actually takes place.

A leaner setting will allow the engine to achieve higher rpm, but will also cause it to run hotter. A properly set high-speed needle will provide a compromise between a cool temperature and high rpm. Needless to say (but we’ll remind you anyway), extremes in either direction aren’t good, but nobody ever blew up their engine by running it too rich! Many racing engines also have a secondary needle- valve adjustment that is used to control the engine’s low-speed fuel/air mixture.

This needle is used to adjust the way the engine makes the transition from low to high rpm. It also helps control the fuel mixture when the engine is idling. A low-speed needle setting that is rich will reduce throttle response at low rpm, and may make the car sluggish coming out of tight turns. A leaner setting will allow the engine to make more power during low rpm operation.

Many modern sport-type nitro engines have eliminated the low-speed needle entirely. While this doesn’t allow for the highest level of tuning for the experience racer, having one fewer needle to fuss with does make these engines much more user-friendly to the beginner, who only need set the high-speed needle. Finally, there’s the idle-stop screw. Basically, this screw is used to keep the carb’s slide or barrel from becoming totally closed (which would stop the engine from running). A small opening of the carb allows just enough air and fuel to mix and keep the engine running.

Setting the idle is usually done after you’ve properly set both the high- and low-speed needles. Where to begin? Read the book! Before you even place your nitro car on a starter box or yank its pull-starter, read the instruction manual that came with your engine or car kit. Most nitro kits’ manuals have a section that will tell you approximately where the carburetor’s needle settings should be for initial start up. We have found that higher-end (more expensive) engines tend to follow the instruction’s settings more closely, which means that when the manual says to set the high-end needle at three turns out from closed, this is almost exactly where the engine will run best for break-in. For sport-type engines, the needle position that allows the engine to fire and run may be quite different from what’s recommended in the manual.

In our experience, if a sport engine won’t fire, leaning the high-speed needle in small increments will get it going. Once the engine fires and runs consistently, we will usually richen the needle back to where the instructions recommend. Never run a new engine, or even an older one, too lean! Your new engine’s first run We know that you want to go out and do some hot laps the instant your new engine fires to life— but don’t!

The first few runs of your new engine are critical. Once your engine starts, place the car on a stand so that its wheels can’t touch the ground. Let the engine idle at low rpm for a few minutes (two or three minutes will do), then shut the engine down and let it cool. During this procedure, it’s also important that the piston not be at the top of the cylinder while the engine is cooling. Part of what’s taking place during break-in is that the engine’s mating parts are being heat-cycled—they’re expanding when the engine is hot and contracting when it cools.

Heat cycling stabilizes the metal and allows mating parts to fit better against each other. Keeping the piston out of the upper portion of the cylinder (which is smaller in diameter than the lower portion in order to create a better seal during combustion) will allow the cylinder to properly contract as it cools—without interference from the piston. To figure out where the piston is in relation to the cylinder, just turn the flywheel—it will become difficult to turn when the piston is at the top of the cylinder, where the fit between the piston and cylinder is its tightest. Just turn the flywheel until the piston is in the middle of its “easy turning” part. Now you’re ready to lay down some horsepower, right? Wrong!

Repeat the above steps three or four more times. Yes, you can drive it now After you’ve heat-cycled your engine, you can finally put it on the track. But don’t get too excited yet—you must run it with a very rich high- speed needle setting. Some engine experts recommend that, during break-in, the engine be set rich enough so that it will actually four- cycle instead of two (our nitro engines are two- cycle, which means that the fuel/air mixture is ignited once for every two strokes of the piston).

Four cycling means that the engine is actually only firing one time for every four strokes of the piston. In this condition, all of the unburned fuel passing through the combustion chamber takes heat (and any tiny metal particles created during the breaking-in process) right out to the exhaust pipe! Do you really need to run the engine this rich? Well, the experts know their stuff, but we have broken in dozens of new engines without actually allowing them to four stroke. Whether or not you four-stroke your engine during break-in is entirely up to you—just make absolutely certain that the high-speed needle is set very rich: lots of blue smoke should be coming from the exhaust, and the engine should sound “blubbery.”

During this procedure, it’s vital that you avoid prolonged use of full throttle, which could strain the engine. You should instead “blip” the throttle as you drive the car to avoid spending too much time in one particular rpm range. Run the engine using these settings for three or four tankfuls of fuel, allowing the engine to cool in between runs. Now comes the good part! Once you’ve put about six to eight tanks of fuel through the engine (as outlined above), it’s time to begin leaning the high-speed needle and making some power! Begin by leaning the high-speed needle (by turning it inward, or clockwise) by about one-hour (if you imagine the needle as a clockface, one full turn of the needle would equal 12 hours). Run the car for a minute or so, then bring it back in and lean the needle by another one hour increment.

Repeat this process until the engine begins to achieve good rpm, but it shouldn’t be allowed to “scream” quite yet. The engine should still be creating lots of blue smoke from its exhaust. Before you achieve that screaming race setting, we recommend that you run your engine for a few more tankfuls in this “almost race” setting.

Once you get the needle set to where your engine is making good rpm, richen it (by turning the needle counter-clockwise) by about a quarter of a turn— this is your final setting. The final steps Once you’ve found a good setting for the high- speed needle that allows the engine to make good power yet still push plenty of blue smoke from the exhaust (especially when the car exits a turn), it’s time to set the low-end needle and the idle-stop screw. Most engine manufacturers recommend a specific setting for the idle-stop screw, and they’re usually well within the ballpark.

For now, set the idle-stop screw so that the engine will idle at a moderate rpm without stalling. Bring the engine up to operating temperature by driving it for a few minutes. Now stop the car and listen to the engine’s idle speed. If the engine idles fast but then slows down in just a few seconds, the low-speed needle is probably set too rich. Lean the low-speed needle (by turning it clockwise in one-hour increments) until, after running a few more laps, the idle stays high for about twenty seconds or so when you stop the car. Once you’ve done this, use the idle-stop screw to make the final adjustment of the idle speed. For sport engines which lack a low-speed needle, the idle-stop screw is the only method of adjusting the engine’s idle speed. For these engines, simply turn the idle-screw clockwise to increase idle speed, and counterclockwise to reduce the idle speed.

Setting your engine’s idle speed isn’t a contest to see how low you can get it without stalling the engine! Your goal when setting the idle should be to allow the engine to run at moderate rpm without the clutch being engaged whatsoever. Your car should be able to sit at a standstill when idling.

If you have to hold the brake, the idle is too high. If you have to blip the throttle to prevent stalling the engine, the idle it too low. Enjoy your new engine! Nitro powered R/C vehicles can be tons of fun, or they can cause tons of frustration. The difference between success or failure lies with the break-in process.

If you follow these steps, have patience, and use your noggin, you’re assured of success. Rushing through the break-in procedure or worse, forgettting it altogether, is a recipe for disaster. Tuning your engine is the hardest part of nitro racing. But once you’ve learned how the carburetor works, and which screw does what, it will all become second nature. So when you’re running your car, you’ll always know exactly what to adjust to gain the highest level of performance possible. (sidebar) THE FOUR RULES OF ENGINE TUNING

1. Rich is good. Blue smoke should always be coming from the exhaust.

2. Always set the high-speed needle first

3. Never try to tune a cold engine—wait for it to get up to operating temperature.

4. Always begin your engine tuning from a rich high-speed needle setting. Never start out with a lean setting.

Tuning all carburetors and Engines for the experienced racer:

1 when starting a new engine follow the set up instructions first! Start the engine and let idle at a moderate speed for two or three minutes. Then shut it down and let it cool for a few minutes. Be sure the piston is not at the top. Repeat this procedure three or four times.

2 Now run the engine on the track, making sure the engine is rich. You should hear a “four cycle” sound. Be sure to let off the throttle going down the straightaway once or twice so the engine is not straining in its rich condition. Repeat this procedure for three or four tanks of fuel, letting the engine cool several minutes between tanks. Also, check the glow plug often. It should look new (shiny wire that is not distorted).

3 You can now start leaning [turn clockwise] the maximum needle a little at a time in one hour increments [imagine the needle like the hour hand of a clock] checking the glow plug often. [I use a glow igniter with a meter on it] I recommend running a few more tanks a little on the rich side before “Race tuning” When tuning for maximum performance [Race tune] adjust until engine will reach Good RPM then open needle 1/8 to 1/4 turn.

4 set the low end or idle: 4.1 After getting top end set close, bring model in, listen to the idle. If it is idling fast then it slows down in a few seconds, it is probably too RICH on the bottom (minimum spray bar). In that case, make it more lean (turn clockwise ¼ turn), then run another lap and bring the car in again.

4.2 Repeat this procedure until the idle stays high for at least 10 to 20 seconds at this point readjust the aircrew so the idle is at a moderate speed. The wheels should not turn, and the clutch should be fully disengaged.

4.3 If you had to turn the minimum spray bar in more than two or three more turns recheck the slide adjustment! [Picco Torque carburetor only]

5 you may need to repeat steps 3 and 4 several times to achieve the “perfect tune” Be patient. Tuning is the hardest part of gas racing, and is the first secret to race winning results. If you are a beginner, it is highly recommended that you ask your hobby shop or an experienced modeler for help.

Three last tips

1 Be sure engine is warmed up before tuning

2 always tune from rich to lean. When in doubt, richen up the maximum needle (top end)

3 If you have to turn minimum spray bar (low end) in more than three to four turns from flush, it is a indication the slide adjustment is too loose and needs resetting (Picco Torque carburetor only).

[Mr Fusion]

WOW... I'm going to come back tomorrow and read that post!!! I'm too tired now... lol

did you type all that or cut and paste???

[Lee_Jones]

cut and paste. this is off of his old web page.

[3pointX]

Wow. Yeah I'm going to have to read the rest of that tomorrow. I know I can't tune by temps alone, I take into consideration temps, exhaust condition (amount of unspent fuel/oil, coloration, etc), throttle response, air temp, all of that.

It just seemed odd to me that the carb would be set THAT rich from the factory, even for break-in. If that were the case, I'm amazed it started at all, let alone the glow plug lasting for what, six tanks of fuel before finally giving out lol.

[razzor]

Guys you need to use temps as a reference.
Only time you worry is when you go over/higher than 270deg/f
What you will notice as you tune a engine is that when very rich it wont smoke a lot and that makes guys worry about leaning it out.
I tune for a decent top speed first and then small adjustments at a time start leaning out teh bottom.
As it gets closer to the ideal tune i always notice that the smoke gets more before it start to lean out.
Besides temp you need to see a good smoke trial and you will also hear what the engine is doing this is the one thing that seperates the guys when learning to tune.

Ron Paris article is good so read it a couple of times.
Here is another for reference.

===========================================

By Steve Pond
MAXIMIZE YOUR ENGINE'S POWER POTENTIAL
So now you can get your engine started on a regular basis, but you’re still struggling with the fine-tuning that will score you a win at the racetrack (or bragging rights at the parking lot). Properly tuning a nitro engine can make that difference without jeopardizing its health. It takes time to learn how to really tune your engine, however. There’s a certain “feel” to how your car drives and a certain sound you’ll come to know when your engine has been ideally tuned. Other cues that you feel and hear tell you what to adjust when your engine isn’t running properly. When it’s time to tune your engine, there’s no substitute for plain old experience. Reading about engine tuning is helpful, but you need to experiment with your engine to improve your tuning skills. The good news is that the following tips will help you avoid some of the pitfalls of fine-tuning and achieve tuning proficiency more quickly.

BASE-LINE MIXTURE SETTINGS
Engine manufacturers often include base-line settings for the mixture needles, so it’s wise to start with these. If this information is not provided, then you must arrive at needle settings that will get the engine started. A universal starting point is usually about 1 turn open (counterclockwise) on the low-speed needle and somewhere in the 2- to 3-turn range on the high-speed needle. This varies among engines, but it gets you started running, and then you can make the necessary corrections. After the initial startup, follow the proper break-in procedure, then worry about performance tuning!

The proper sequence for adjusting the mixture needles is hotly debated. When you start to fine-tune the engine, it’s generally best to start with the high-speed needle, then set the low-speed. First, however, get your engine running, and keep it running before you worry about race tuning.

During break-in, the engine typically idles a long time, so it’s best to adjust the low-speed setting first so the engine runs slightly rich (loading up every 30 seconds or so). It requires an occasional “blip” of the throttle to clear out any raw fuel that has accumulated in the engine. Once break-in is finished, then get the high-speed needle in the ballpark.

Place the car on the ground and accelerate smoothly to give the engine a chance to build some heat. With the high-speed needle in the proper range, the engine should be able to rev relatively well up to full speed once it has been running for a few minutes on the track or parking lot.

FINE-TUNING
A word of caution first: there’s a fine line between the perfect tune and a blown or damaged engine. Nitro-engine fuel also contains engine lubricant, so as you get close to dialing in the mixture to where there is just enough fuel to burn and deliver maximum power, you also are close to having just enough oil to keep the engine lubricated. Anyone with experience in tuning 2-stroke engines can tell you that they run best right before they seize or blow up. Our engines are a little tougher and more capable of taking some abuse than bigger 2-strokes, but there’s no sense in pushing the mixture settings so lean that you risk damage to the engine. I can’t say this too often: get the engine up to full running temperature by running the car exactly as you would on the track or parking lot. The high-speed needle setting depends on the type of driving you do. I’ll start with a racing setup.

HIGH-SPEED NEEDLE
Racers will tune the high-speed setting to get from point A to point B as quickly as possible. (Performance also depends on a proper low-speed needle setting, but for now, let’s concentrate on the high-speed setting.) The best place to race tune your engine is on the track where you run. I prefer to set the high-speed mixture so the car can leg out the track’s longest straight section in the shortest time. Estimate the time by “feel” and gut instinct, or use a stopwatch for more accuracy. The high-speed mixture should be set to maximize engine performance for that particular track configuration. A short, tight track may require a main mixture setting just a shade on the lean side to provide maximum power out of the corners. You needn’t be concerned about high-rpm performance because the track is too small for the engine to ever reach peak rpm. A long, high-speed track may require a slightly rich main-needle setting. If an engine constantly revs at the upper limits of the rpm range, the fuel mixture should be richened to ensure proper lubrication across the entire rpm range. This slightly rich setting might reduce bottom-end acceleration to a degree, but longer tracks require a slightly richer mixture setting to let the engine rev to its limits without running dry of fuel and oil.

Why is it important to tune the engine to the track? A mixture needle can only provide optimum performance within a relatively narrow rpm range. Anywhere below this hypothetical rpm range, the engine runs slightly rich; anywhere above, it gets progressively leaner. Until we have fuel injection that constantly optimizes fuel mixture throughout the rpm range, there needs to be a degree of compromise with the mixture settings. So, ideally, set the mixture to provide the most power in an rpm range that is best suited to the track on which you run.

WIDE-OPEN RUNNING
Running in parking lots, particularly larger ones with a lot of breathing room, requires unique mixture settings. It’s a common mistake to establish mixture settings for maximum punch—as though the car will be run within the confines of a tight racetrack—and then to go out and run at wide-open throttle (WOT) in a huge parking lot for 5 minutes. This type of running is incredibly unhealthy for an engine to begin with, and compounding the problem with an excessively lean main-needle setting is a recipe for disaster. If you still insist on torturing your engine, the high-speed mixture setting needs to be as much as 1/4 turn richer than typical to provide optimum fuel for the upper rpm range. The engine will be a little softer when accelerating from a standstill, but it’s the only way to ensure there is an adequate supply of fuel and oil when running at the upper end of the rpm range. The inherent danger is that this type of running taxes the connecting rod and other engine components to their limits, but having the proper mixture setting will at least delay the inevitable.

LOW-SPEED NEEDLE
The high-speed needle is dialed in, so now let’s properly set the low-speed needle. It’s important to set it last because it simply regulates the fuel that flows from the main needle at low throttle settings. Lean out the main needle, and you automatically lean the low-speed needle as well. For this reason, it’s wise to finish with the low-speed setting.

Again, it’s imperative for the engine to be at full operating temperature. There are many methods of testing the low-speed needle setting; one is to pinch the fuel line. When you pinch the fuel line, the engine rpm increase slightly. Keep pinching it, and the engine will eventually stall. If the engine rpm increase dramatically, it indicates that the low-speed setting may be too rich. Or, if the low-speed setting is already too lean, the engine rpm may not increase much at all, and the engine will stall rather quickly. It’s a somewhat crude method and doesn’t tell you what to expect from the engine on the track, but it will get you into the ballpark.

Another common way is the “see-how-long-it-will-idle” method. The low-speed needle adjustment affects how long the engine will idle. A too lean fuel mixture causes the engine to race and possibly stall, limiting the duration of a steady idle. A too rich low-speed-mixture setting causes the engine idle to steadily drop and eventually stall. The ideal setting allows the engine to hold a smooth, steady idle for 10 to 20 seconds (max), and then the engine rpm decrease steadily because the crankcase loads up with fuel. Why? There are no awards given for the longest-idling engine. If the engine is able to idle steadily for a longer time, then it may start to lean out and heat up during a race and make it difficult to drive the car and keep the engine running. The only flaw in this method is that it doesn’t tell you whether you have an artificially rich mixture to compensate for an idle speed that’s too high.

A common mistake is to set the idle-speed screw to keep the carburetor open too far. The low-speed needle must then be artificially rich to bring the idle down to a reasonable rpm. The symptoms are similar to a too rich low-speed-mixture setting; there’s just a delay in the loss of engine rpm. How do you avoid this? This is also something that becomes easier with experience, but just continue to reduce the idle speed and lean the mixture until you know you can’t go any further. Bottom line: adjust the idle-speed screw to suit the fuel-mixture setting, not the other way around.

The simplest and most foolproof method to properly set the low-speed mixture is, again, to do it on the track. Set the low-speed needle so your car gets the strongest launch after sitting still for about 10 seconds. The engine should be able to pull strongly off the line without hesitation. A noticeable hesitation might be the result of either a rich or a lean low-speed mixture; knowing the difference takes experience, but look for signs that help point you in the right direction. How an engine decelerates can tell you as much as how it accelerates. If the engine spools down and rpm drops uncharacteristically low, it indicates that the low-speed-mixture setting is too rich. Or, if the engine takes too long to reach a steady idle and seems to want to keep revving, that tells you the low-speed-mixture setting is too lean. It can also indicate a lean high-speed-mixture setting, but that setting should have been addressed by properly setting the high-speed mixture first.

It will take a little time to get it right. If you make small adjustments and are patient, you really can’t do anything wrong. An adjustment you make in the wrong direction is reflected in engine performance; to correct the problem, simply go the other way.

CHANGING FUEL
Changing to a higher percentage of nitro fuel sounds like an easy method of developing more horsepower, but it isn’t always that simple. Without getting into all the particulars of nitro fuel, I’ll just say that there is a point where you can have too much nitro. Adding up to 10 percent more nitro than is typical produces more power, but you have to know how to adjust your engine to accommodate the extra nitro. Fuel-mixture settings need to be slightly richer when nitro content is increased. Also, you may have to increase head clearance by adding an extra head shim. The extra fuel introduced into the combustion chamber increases compression by adding non-compressible matter; this also increases cylinder pressure during the combustion process, which may cause detonation. Detonation occurs when the fuel explodes instead of burning, and that can cause internal engine damage. The extra head shim will likely prevent detonation when fuel with higher nitro content is used.

A final note about fuel: fuel with a lower oil content (for manufacturers that actually disclose the amount of oil in their fuels) should be run with a richer mixture setting. This doesn’t so much relate to performance as it does to the benefit of the engine. Conversely, fuels with higher oil content have the extra lubrication that allows a leaner mixture setting with less risk of engine damage. Fuels with a lower concentration of lubricant are intended for competition use by experienced engine tuners. These fuels will make marginally more power because the lubricant that’s removed is replaced with power-producing nitro and methanol. Evaluate your tuning ability honestly before you run out to buy fuel with a lower oil content.

GLOW PLUG
A glow plug’s temperature range is critical to proper performance. Small-block engines generally use warm to hot glow plugs, while big-block engines use plugs in the colder range. If you choose a plug in the wrong temperature range, you could be chasing the tune of your engine till the sun goes down. Changes of the relative temperature of the glow plug can be beneficial, however.

A combination of compression, heat and a catalytic reaction between the platinum in the glow-plug coil and the methanol in the fuel creates combustion in a nitro engine. Altering the heat range of your glow plug can alter the timing of the combustion process. Nitro engines don’t have an ignition system that can be used to advance or retard combustion timing, but a hotter plug that causes ignition a little earlier in the combustion process can have the same effect. “Advancing” the ignition timing can increase overall power output, especially at higher rpm. There are limits, however, and installing too hot a plug causes pre-ignition (detonation) and risks damaging your engine.

It’s a challenge to figure out a glow plug’s temperature range. Manufacturers don’t use a consistent and universal standard to rate the temperature ranges of their glow plugs. You will probably know the temperature of a plug relative to others within a given product line, but currently, no rating system allows comparisons among manufacturers. Here again, plain old experience with a variety of glow plugs will help you to know which are best for the effect you want.

“Reading” the glow plug is a tuning technique advanced by Ron Paris. It suggests that looking at the glow plug tells you something about how your engine is running. The element in a glow plug will turn gray in an engine that is close to the optimum fuel mixture. This method requires a new glow plug, as the element will eventually turn gray regardless of the needle settings; the length of time it takes to turn gray is the issue. Plugs that turn gray in just a tank or two of fuel (running at race pace, not diddling around) indicate a fuel mixture close to ideal—but also close to trouble. If the plug stays wet and shiny for a few tanks of fuel, you’re in the safe zone; a little rich but safe. When the plug wire gets distorted or broken, however, you’re in real trouble. It’s a sure sign that the mixture is way too lean, or that there is too much compression and the engine is detonating.

HEAD SHIMS

Engines are essentially air pumps. The engine takes air in, mixes it with fuel, and then the mixture is compressed and ignited. The additional pressure created by the burning fuel increases by a factor directly related to the amount of compression: increasing compression increases power output. But there are limits to the compression an engine tolerates. Too much causes the fuel mixture to combust too quickly, and that returns us to the same detonation scenario of an excessively hot glow plug.

The amount of compression is determined by the number and thickness of the shims (gaskets) between the cylinder head and the top of the piston sleeve. Well, it’s determined by many other factors, but the only one easily changed is the head clearance via head shims. More shims = less compression; less shims = more compression. Removing or replacing shims with thinner ones increases compression. Some engines have only one shim, so it isn’t advisable to run without a shim at all. Moderation is the key. Go slowly, and make small, not drastic, changes that will minimize the risk of damage to your engine. First and foremost, be sure the piston won’t hit the cylinder head if you remove a shim (or shims).

You can also change compression with glow plugs. Some manufacturers make a longer glow plug that protrudes slightly into the combustion chamber, effectively reducing the area in which the fuel mixture is compressed. This area is already small, and the little extra space occupied by a longer glow plug will raise compression. This is not the most desirable method, but it can be used on engines that have only one thin head shim. It’s unlikely that the longer plug will even come into contact with the piston, but just to be safe, check the head clearance before you install a long plug.

WEATHER CONDITIONS

It’s a simple fact: for optimum performance, you must retune your nitro engine every time you run it. Anyone who assumes that the needles can be left alone once they have been set is sadly mistaken. An overnight change in weather conditions may prevent an engine from running or may put it at risk of some damage if adjustments aren’t made to the fuel-mixture settings. Ignoring an engine’s tuning needs compromises its ability to make horsepower. In response to certain changes in weather, equipment and other variables, nitro engines must be regularly retuned.

Temperature. Hot weather requires a leaner mixture setting; cold weather requires a richer setting. Most people assume the opposite because they treat the mixture needle like a thermostat. It is wrong to assume that colder weather requires a leaner setting to keep heat in the engine and vice versa. Cold air is denser than hot air. The denser, colder air packs more oxygen into the engine, so going from hot weather to cold needs a commensurate increase of fuel to balance ratio of fuel-burning oxygen and the fuel itself. The opposite is true in hotter weather. Going from cold to hot weather requires a leaner mixture setting.

Humidity. Humidity is the amount of moisture (water vapor) in the air. Moisture in the air takes up volume that would otherwise be occupied by fuel-burning oxygen. Less oxygen means less fuel is required to maintain a proper ratio of air and fuel. High humidity requires a leaner mixture setting than dry conditions.

Barometric pressure. A barometer measures the atmospheric pressure (generally listed in the local newspaper or on the local weather forecast on TV). Higher barometric pressure readings mean more air is getting into the engine, requiring a richer mixture setting to balance the air/fuel ratio.

Altitude. Altitude is an important factor that most of us ignore, yet it affects the engine’s performance possibly more than any other element. The general formula for power loss with increases in altitude is 3 percent for every 1,000 feet above sea level. If you race in Colorado at 5,000 feet instead of in California at sea level, you can expect to lose about 15 percent of the engine’s potential power output, if the engine is tuned properly.
Air is thinner at higher altitudes, which means there’s less fuel-burning oxygen than at sea level. You might sense a common theme here: less air (oxygen) means less fuel to maintain the proper air/fuel ratio. So, running at higher altitudes requires a leaner mixture setting than running at sea level.

TUNING

This chart indicates the direction in which you should adjust the fuel mixture when faced with changing weather and other conditions. It assumes the engine is currently well tuned. You could face any combination of conditions listed in the chart; knowing which way to go with the mixture adjustments is half the battle.

Higher air temperature: Lean
Lower air temperature: Rich
Higher humidity: Lean
Lower humidity: Rich
Higher barometric pressure: Rich
Lower barometric pressure: Lean
Higher altitude: Lean
Lower altitude: Rich
Higher nitro content: Rich
Lower nitro content: Lean
Higher oil content: Lean
Lower oil content: Rich
Hotter glow plug: Rich
Colder glow plug: Lean

TUNED PIPE AND HEADER

Anyone who has been around 2-strokes knows that the exhaust system plays a major role in engine performance. Pipes and how they affect performance is a complete article in itself. I don’t want to get into the science of tuned pipes here, I’ll simply suggest that volume (assuming the pipe doesn’t stray too far from convention) determines where the pipe will go to make the best power. Smaller pipes with lower overall volume make the best top-end power, while the fatter, longer pipes with greater volume provide the best bottom-end punch. Selecting the proper tuned pipe can have a very noticeable impact on your application.

Headers can be modified by almost any enthusiast. The length of the header is important to squeezing more power out of your engine. Longer headers deliver better bottom-end power, while shorter headers make better top end. Shorten a header by cutting it with a hacksaw or a Dremel tool. Cut it in 1/8-inch increments, and measure the performance to determine whether any improvement has occurred. Continue cutting until performance levels off. If you need to add back on to the length of the header because you’ve cut too much and performance is suffering, simply increase the gap between the header and pipe, but don’t expose more than 1/4 inch of coupler. If the header is too short by greater than 1/4 inch, just get a new one.

CLUTCH
I’ve spent lots of time trying to chase away a nasty bog in the engine as it came off the line or out of a corner, only to find later that the problem was the clutch. Some clutches are built properly at the factory, but in my experience, most engage too early, which hobbles the engine coming out of every corner. Tuning the clutch to engage at the proper rpm puts more power to the ground than most could imagine.

TEMPERATURE GAUGE
You’ll notice that I have not once mentioned a temperature gauge. The worst thing you can do is to tune an engine to run at a specific temperature. Engine temperature is affected by a number of factors, only one of which is fuel mixture. Weather and many other factors play a role in engine temperature, so tuning to run at the same temperature every time shortchanges the engine’s potential to make power. Yes, most engines run in the 200- to 300-degree range, so checking that the engine stays within this range is valuable to a certain extent. As a result of different weather conditions and other variables, however, the same engine—when tuned for peak power output—can vary as much as 50 degrees. A temp gauge is a reference tool that you should use only to build a data bank of tuning information. A temp gauge should not be used as a tuning tool. Don’t tune an engine to run at 230 degrees all the time. Prevailing conditions may require a mixture setting that causes the engine to make maximum power while running at 270 degrees. You’ll never know that if you always target the same temperature.

CONCLUSION
Engine tuning is not a black art; it just takes time to learn the particulars so you can maximize your power plant's performance. Take the time to read and learn, and you will avoid the mistakes most of us made in learning the ropes. I thought I had it licked 10 years ago, but I’m still learning. We never really stop learning; sometimes, we just get too smart for our own good. Experiment a little with some of the tips, and you’ll find there’s more power to be made with less effort than you thought. Some of the modifications involve a bit of risk; just take it slowly, and use your “noodle.” It’s hard to make a mistake you can’t correct.

===============================================

http://www.youtube.com/watch?v=OwEptwegJqU

[razzor]

Check out this vid and the 23 that follow it.

http://www.youtube.com/watch?v=iYVKmJx65xg

[vnmsgt]

I did not mean to use only temps to tune, I did mention that if you are happy with the performance of your engine AND then temps are good that you could be ok. Just for some newer guys that might not fully understand all of this stuff above. It was some good reading though. I remember doing alot of that stuff (wrong stuff) when I first started LOL!