px33transam

I have a 2000 TA A4 car with a vigilate 3500 stall borla catback hypertech programing and mickey thompson drag radials that I have got running low 13's in thr 1/4. My question is the car runs very inconsistent from one run to another. I have been racing for years on and in everything from trucks cars motorcycles you name it and have done very well so I dont really think its driver error. I stage the car the same every time do the same burnout and even installed an aftermarket digital temp gauge to confirm the same starting line temp within a few degrees. I bought a weather station to try to moniter the inconsistencies with different weather conditions and cant find any patterns. It may run 13.03 one run than an hour later run 13.30's or 13.40's with no warning at all and sometimes it goes the other way and runs way faster.Oh and one other thing I know someone will ask my 60' times are fairly consistent compared to ET. Any ideas would be greatly appreciated. THANKS!

Coach 02 A3 Z/28

iTrader: (10)

You need to go to a speed/density tune. Works great for us.

Coach

px33transam

Please forgive me I'm new to computer cars. What exactly is a speed/density tune? sorry for my ignorance to this topic but like I said I'm very unschooled in the way of computer cars. I always ran a carb with no computers at all but always was in love with the f bodies and now I finally own one!!!

Dan

iTrader: (1)

My car does that sometimes but it's in the 60'..What to look for is having your car at the same temperature for each run(pic a spot on the water temp gauge & keep it consistent) Air temp, humidity, wind..those are about the only things..I raced last month & ran 12.96, 12.98, 12.97..go in eliminations & the cars spins the wheels off, Talk about being pissed off..

TWS

iTrader: (63)

Many times during a bracket competition, you cannot control how much time you have between rounds, so it throws off any control you wanted to have over things like coolant, oil, or tranny temp. (although a manual fan switch can help somewhat)

I would advise some of the things you already listed, but pay very careful attention to them: same burnout and staging technique, same launch technique, monitor tire pressure, keep a logbook and jot notes in it about what tires you were running, at what pressure, ambient air temp, DA (if you can get it), etc. etc. etc.

I have a "ritual" as I am preparing for a bracket pass and it helps me be pretty consistent.

Check into speed density tuning as Coach suggested. I know only a little about doing it on LS1 cars and since my only bracket cars are my '94 (LT4 motor) and my wife's nearly stock '00 B4C, I haven't really delved into it. However, Coach is an experienced and very successful bracket racer, so I would check out any advice he gives you.

px33transam

I have done alot of the other things you have mentioned. I keep a very detailed log book, I have a manual fan switch,keep the tires the same pressure and still it runs off. Do you guys run with the traction control on or off?

Coach 02 A3 Z/28

iTrader: (10)

The traction control is off, as a matter of fact it has been long gone. The 02's are what cause your car it run inconsistent. Until we went to the SD tune we ran off also. Now we run dead nuts on everytime.

Coach

px33transam

thanks for the info coach. I quit running the traction control a while ago thinking that was the problem. I was planning on headers and y pipe in the near future but I was going to go with a catted y pipe due to local emission laws but if it is the O2 sensor making my car run off should I go with an ory? Wait unless you mean the front O2's because I'm still not sure what you mean by speed/density tune and is the tune something a shop has to program into my car because I've read you guys talking about getting a tune after various mods. I'm trying very hard to learn about the computer in my car because I love to bracket race and I love my TA. Thanks

jswhite

iTrader: (1)

Get rid of torque management.

ninetres

iTrader: (35)

Not sure why no one has anwered you yet, they must have read right past it!

A speed desity tune is a tune that does not use your Mass air flow sensor (between your intake lid and throttle body) to measure air intake and determine fuel accordingly.

I am not 100% sure on the details of how a SD tune works....but that is the gist (sp?) of it.