tuning for road racing.. interesting

[user539]

No matter what system you use to tune your car, whether it be a simple piggyback, reflash, complete piggyback system or a stand-alone engine management system, these suggestions apply to you.

I talked to about a dozen of the best tuners in the entire country to develop this list of suggestions (and franky, things you must do unless you plan on buying a new engine)

These are general ideas/concepts/suggestions, not specifics - let your tuner handle the specifics. But, the more you know, the better your car will run.

1) Finding a tuner
There are a lot of great tuners out there, you don't have to drive 2000 miles to find a competent person to tune your car. Find someone who is familiar with the system your using. Explain to them what your going to do with the car in detail. Let them sell you, they should be experts, they should be able to answer all your questions - so if they can't, don't have them tune your car.

2) Autocross and Roadracing require different tuning approaches
**And your tuner may not know the difference**
Your car is under great stess whenever you are on boost and at WOT throttle, there is a huge difference between 12 seconds of WOT and 45 minutes. The main difference is simple physics. Your turbo is spooled by exhaust gases, these gases happen to be very hot. So, the air is compressed by your turbo, but subsequently it is compressed and very hot. Your intercooler is designed to cool this air down before it enters your combustion chambers. If you roadrace or autocross, you will be under WOT for a long time, thus making your turbo extremly hot (hot enough to glow red), and eventually your intercooler will surpass it's efficiency and become very hot. This is an extremely bad thing - you then begin pumping extremely hot compressed air into your combustion chambers. If you have a tune designed for drag racing or daily driving (and apply tip #1, if your tuner has never autocrossed or roadraced think twice about going with him) your engine may be destroyed.

3) Take every safeguard to combat the heat problems with tuning
Tune your car with a large safety margin, the harder you plan on driving, the more safety margin you need. Use a very safe air/fuel ratio and timing - ie. a 10.5 air/fuel; it may not make as much power, but it is safer than anything above 11:1. Don't use too much boost - boost creates heat. This will also make less power, but if you want to make big power use race gas. Most tuners I talked to didn't advise anything above 20psi on 93 octane. Pump gas varies from store to store, so don't expect 93 octane to always be 93 octane. So, in short, you want your tune to be conservative.

4) Use knock control and have a full set of gauges/warning lights
**Your tuner might not have it enabled - turn it on**
Use knock control, period. It works, it may save you a motor. The only reason not to use it is if you run straight racefuel and have tuned your car extremely rigorously (less than 5% of us). You can cheaply and easily wire knock warning lights to alert you. The more gauges you have the better, in the event of a problem you can get answers fast. Gauges may cost money and give you zero hp, but they can save your motor and help you get answers to your problems fast. Don't assume that knock control is turned on, so if you have already been tuned, check and see if it's on. If your EMS system has a datalogger, learn how to use it. This can help you spot a problem well before it happens, and your factory sensors can tell you quite a bit, much more than a set of three gauges can. If you don't want to take a computer with you at the track, consider other alternatives (AEM EMS Specific). Gauge-tech.com makes a stand-alone monitoring system for the AEM EMS and it has a built in warning light which you can have triggered with EGT, knock of a/f warnings.


5) Fuel and spark run your engine - use the right gas and right spark plugs
$30 dollars of racegas may save you thousands on a engine rebuild. Racegas is added assurance. It works. If your tuned for 93 octane, add 3-4 gallons of leaded gas for extra safety. You can't stop heat unless you stop racing, so the extra octane and lead will stop or help to combat detonation. Water or Alcohol injection can work wonders, but keep in mind that you can have fuel slosh, pump failures or run out of water/alcohol with these systems also. Alcohol injection, in most cases, will not pass a road course tech inspection (think twice before putting something highly flammable in your windshield washertank). If you want to make more power, tune your car for straight race gas. A pump gas tune won't make as much power as a race gas tune, for a simple reason besides octane - 93 octane isn't always 93 on the other hand Sunoco GT100 is always 100 Octane. Leaded gas can ruin your 02 sensors, but it's much less expensive than a $3000 dollar motor. Change your spark plugs often, NGKs are inexpensive. And more importantly, inspect your spark plugs, they will show detonation spots and other signs. Run the correct heat range plugs. You may want to run a different (colder) heat range for road racing (BPR7ES for daily driving/BPR8ES for road racing). Ask your tuner for recommendations for spark plugs, if he/she doesn't seem to know, go somewhere else.

6) Overbuild your cooling and fueling
Read AEM EFI basics (available on the aem forums at www.aempower.com). Make sure your fuel pump, injectors and lines are up to the task of fueling. I wouldn't recommend doing any roadracing without a Walbro 255 pump. Make sure your injectors can supply enough fuel for your power levels. Most of the other parts of the fuel system can support very high horsepower, but it's always better to be safe than sorry. Roadrace on a full tank of gas, if your gas gets low, don't go out. If your serious and competitive, buy a fuel cell and or full fuel system with a surgetank. A larger intercooler is an excellent safety mod, if designed properly it will cool more efficently and help prevent heat induced detonation. If you do extremely long road racing events in extremely hot weather, consider an upgraded radiator. Heat in your engine can cause detonation.

7) Dynos lie (and so do knock sensors)
Refer back to the heat induced detonation failures. A dyno pull in 3rd gear with ample cooldown time does not stress your engine, your intercooler may still be operating at full efficiency and you may get zero knock with too much boost, too low of an air/fuel ration and/or too much timing. If your dyno operator uses a huge fan/sprays water on your engine/intercooler and gives you a 20 minute cooldown between runs, you may not be safe even if you get zero knock (I wasn't). Don't add racegas and get a reflash unless you plan on running racegas all the time. Keep in mind, you can strap your car on the dyno and run it through all the gears at WOT, it may not make huge numbers but it will make you feel better when your on the road course for 45 minutes. Road tuning can also be used, but be safe. A load bearing dyno is also a nice thing, but any type of dyno, if properly used, can do an adequate job. When you get tuned: Get a print out of your dyno sheet, but more importantly, find out how much boost your running, timing and your a/f. And it's not a bad thing to tune your car in extremely hot weather, nor is it bad to skip cooldown runs, nor is it bad to have low dyno numbers - after all, do you want to beat someone on the racetrack or the dyno?

Interesting read!

[Karl3]

8)pa very interesting to knowl