Raceology - Science of Auto Racing

10 tips for shaving ET this weekend



10 tips for shaving ET this weekend
by Don Terrill ©2000

1.) More RPM - I've found that it’Äôs just about impossible to have too much (higher number) gear in your car if your goal is the lowest ETs. Just keep adding gear ratio until you stop gaining ET, even if the MPH falls off. Remember: racing is usually ET not MPH.

2.) Jetting - If I had to guess I'd say that 80% of all race engines are jetted too rich. Some of the signs of a rich setting are an engine that misses or surges. Try jetting down two sizes and see what happens. Learning how to read spark plugs is my best advice.

3.) Ignition Timing ’Äì Go up or down two degrees and make a test. I’Äôve seen engines tuned with just a couple of degrees too much timing lose 30hp, so don’Äôt think you can’Äôt have too much.

4.) Oil ’Äì If you aren’Äôt using synthetic oil already, try it, it’Äôs worked every time for me. The other big thing is oil level, on a wet sump engine too much oil is a killer. No engine needs more than 6gts, no matter what the pan manufacture says. In fact; too much oil is bad.

5.) Shift Points ’Äì If you’Äôre going to miss your shift point, miss it early. A late shift is an ET killer, especially in the lower gears. Here’Äôs a test: If you seem to really be knocked back into the seat after the shift, you’Äôre late. The Reason? Your body went forward before the shift because of lack of acceleration.

6.) More Traction ’Äì Obvious subject I know, but here’Äôs one I’Äôve seen missed more than any other traction aid: Weight. So many people are afraid to add weight to their car, but I would guess that 80% of cars could benefit from weight in the trunk. Don’Äôt take my word for it, give it a try.

7.) Lower Coolant Temp ’Äì With all other variables being the same, lower coolant almost always makes more power. There are a lot of ways to lower the temp and I can’Äôt mention them all here, but a problem I’Äôve seen more often than not is low coolant level. Make sure the radiator is full.

8.) Kill The Accessories ’Äì A water pump takes 10hp to drive, an oil pump takes 10hp and the alternator can take up as much as 35hp. Use a low drag water pump or electric drive and put a switch on the field of your alternator to turn off the drag during the run.

9.) Aerodynamics ’Äì Now I know changing aerodynamics of your car is not a simple thing to do, but there is one quick modification that I’Äôve seen work more than once; Lowering the front end of your car. I’Äôve seen drag cars pick up as much as .01 of a second in ET and 3 MPH in speed by just lowering the car two inches.

10.) Test Different Carbs ’Äì Carburetors all have their own personality and some just seem to work better than others. Buy two carbs that are exactly the same and you’Äôll have different results. My advice: test ever carb you can get your hands on and never get rid of a good one.

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