Anyone have any tips for tuning for bracket racing? I've tried eliminating some of the variables, but any advice would be much appreciated. My car used to be real consistent, but since I put a Ford 9" rear end in, it wants to jump all over the place (doesn't make sense to me). Just when I think it is going to start running the number, it will jump .05 in either direction. I'm currently using a program that runs open loop and speed density mode, but that didn't seem to help much. If anyone knows any "magic tricks," I'd sure like to know. Thanks.

 

I'm pretty tired and not in a very intelligent state of mind but wouldn't a speed density setup be more suspect to varying atmospheric variables such as barometric pressure, temperature, and air density than a MAF setup? I am not familiar with speed density so that may have been an ignorant question.

Also, have you already looked into your WOT AFR vs Coolant temp table? If your coolant is at 104*C one run and 116*C the next run, the stock tune probably has different % for those two values. If .05 is the largest difference you are seeing, I wouldn't get too excited--although I do realize that certainly can be the difference between winning and losing.

 

For Racing - here's what I do

Lock the PE BLM's to 128
Eliminate all knock retard and burst knock retard- assuming you're no where near detonation
Make sure your at a constant temp - in the
Eliminate Canister purge line to intake manifold

Steve

 

Thanks for the replies. I have "flattened out" the tables that involve anything with temperature, but will look at them one more time to make sure. And I will take out the knock retard. Was wondering about that, actually. Thanks for the tips, keep 'em coming.

Bill

PS - Closed loop vs. Open loop?

 

Don't forget you need some of that temperature stuff for cold starts. When you're racing, unless you push the car all the way to the burnout box, your coolant temp is going to be atleast 80*C. I would just make the % the same for each of the 80* through 116*C cells (assuming that is the temp range you race in) and leave the other cells alone.

 

I let mine run long enough to make sure it's in Closed Loop.