Gents,
Went to the drag strip Friday for the first time in probably 10 years. Obviously the first time with the E55. I read all the threads on getting the most out of the car but track prep was horrible and traction was about nil. Temp was around 87 degrees

Launching with the car raised, rear conti's at 27psi and trying all sorts of different techniques helped very little. Best 60' of the day was 2.2 sec. Actually what I found was that traction was even worse around the 120-150ft mark than in the first 60 ft. No matter what I tried the car would spin, axle hop, etc in first and I could not get to full throttle until 2nd gear.

My biggest concern was MPH. It ran 112-113 on all of the passes. I can't help but think that it was likely more because I had to keep getting out of the throttle to get rid of the rear axle hop than lack of power. The car feels strong once it hooks in second gear. However I remember from back in the day that a car should have a pretty consistant MPH no matter what. I also never properly cooled down the car to really get a "flier" since traction was soo bad. I just went out and had fun and hot lapped the thing and still had a blast.

Mods: Renntech stage I, CM30, K&N.

Should I worry about the MPH...or you think it's more a product lifting and not being able to go full throttle until 2nd gear? No supercharger cut thanks to the CM30.

Andy

**edit**. It's best run was 12.7 @ 113 with a 2.21 60'

 

Have you datalogged your car, checked IAT's? Check that and if that is fine then I would search somewhere else. Heat soak is a big factor. Another issue many have air in their intercooler system. It is a power killer.

 

I don't currently have anything to datalog the car with. I did the CM30 when I got the car because it was shutting down after a few pulls but never verified before and after results. I just assumed it was better because I was no longer getting the supercharger shut-off. Seemed to pull fine though once I was able to go full throttle.

Do the '55 cars have many issues with belt slip? I know about the chirp issue and my car has this when the supercharger initially kicks in, but I never thought about the possibility of belt slip beyond that. The renntech pulley / belt have been on the car for 20K miles.

 

Until and unless your traction problem is resolved you cannot predict performance. Launch and low speed acceleration is very important to both ET and MPH. Every car combination is different but you will get 1x to 3x the result of 60ft times... IOW a drop of 2 tenths could mean from 2 tenths to as much as 6 tenths quicker times. MPH is another issue loss of traction reduces the length of track left to accelerate and the time available to accelerate both reducing trap speeds.

You mentioned 27psi tire pressure. What was this based on? Some tires work better at higher pressure and some at lower. Start with recommended inflation and work to get your best traction from their you can then try both higher and lower pressures to judge gain/loss. Better yet get an extra set of wheels and mount some drag radials. That said you will need to experiment with pressure on those as well.

Finally, 87 degrees is not ideal race temp. Did you check the barometer? A low barometer and high humidity are performance killers.

Don't forget suspension. A lowered car with stiffer shocks/springs will not transfer weight as well which hurts low speed traction. Cars will often launch best with shocks set at softest settings which helps weight transfer to the rear increasing traction.