I wonder if anyone else with a C5 automatic has noticed this?

I have an 02 A4 coupe. When I put it into competition mode it seems like the throttle sensitivity decreases - I have to put my foot further into it to get the same response as I would when traction control is full on. Is it just me, or is there some programming in the ECU that kicks in to change throttle action to keep you from shredding tires in competition mode?

I would also like to hear from A4 owners who have had a tune without a torque converter change: who did your tune? What do you think of the outcome? Did you eliminate torque management or just modify it? Did you get changes to shift points, anything else you can think of and what about a transmission kit such as Transgo - results, recommendations. All knowledgeable input gratefully received.

 

The 1st time I had my car tune, the only thing it has was a cut airbox lid. A4 with 2.73 gears. They turned torque management completely off. Noticeable change but I felt the shifts were pretty harsh during normal cruising. After LT headers, vararam and 2.42 gear intall tune was tweaked to feed some torque management in for "softer" part throttle shifts. Stil have torgue management off for WOT. Much better.

 

I have an '04 A4 with work performed by Dynotech Engineering (DTE) in Ft. Wayne, IN. In 2005 they installed a small cam and headers, tuned the car, and I drove home with 367 rwhp and 356 rwtq. The work and tune was excellent, but what I found is that the car downshifted too easily (given the increased power), the car would kick out to the right after downshifting, and it was a little hard to control at times.

The next year I went back for AFR 205 heads and a Fast 90 intake. Power increased to 423 rwhp and 391 rwtq. I told Phil about the behavior and asked if he could tune the shift points so the car would not downshift so easily. He did his magic and life is great. I can now accelerate pretty hard (maybe 50% throttle) without downshifting.

Phil turned the torque management (TM) way down but left it on. To be honest I can't even tell that it is on. When the car was completely stock I could barely spin the tires from a dead stop, even with traction control turned off. I later learned that this was due to TM. I don't remember any other throttle sensitivity changes when the car was stock. So, minimizing or disabling TM will probably help.

http://www.comp-soln.com/Dyno3Run.jpg

 

good post

 

Here's how it works......C5 and C6 Corvettes have an electronic throttle....On C5's there's a "throttle actuator controller' or "TAC MODULE" and C6's have the "TAC" module built into the ECM as one of the 3 internal processors.....

Due largely in part to the incredible performance of the lightning fast electronic throttle and the LSx series of engines incredible low end torque, the throttle has to be "curved" so that it isn't too responsive...#1) cause you could break parts and #2) cause you could EASILY spin the tires causing a VERY unsafe condition.

If you are driving a car with a CABLE throttle, the engine's response to the manual throttle cable or pedal is "linear" meaning that 5% throttle using your foot equals 5% throttle body opening and that 100% (floored) throttle is roughly equal to WOT or 100% throttle body opening. Hence they are about the same and more importantly, LINEAR.

Welcome to ELECTRONIC THROTTLE. When your foot is at 25% of the way into the throttle the engine's throttle blade is about 3.1% open! and at 50% throttle of foot travel, the engine's throttle is about 15.1% open!

The throttle is especially curved in the "below 50%" area and dosen't begin to get more "natural or linear" till above that point. Below 50% it is horrendous which causes unwanted side effects with respect to how GM tuned the cars originally (especially with automatics).

Unfortunately, most tuners can't or don't address this. ALL of my LS1/LS6 tunes have corrected this problem while maintaining a smooth throttle transition.

The problem is that with LS2/LS3/LS7 controllers, NOBODY can fix it.....yet. Until now, I'm the only guy that has ever even seen it for the LS2 family of controllers. I was testing it for a time for one of the companies, but while I got it working....it also caused problems and was unreliable.TRUST ME THOUGH.....I'M RIDING THEM TO CONTINUE WORKING ON IT.

As an example....The 06 and later ZO6 (due to it's huge power) has a MUCH MORE SUBDUED throttle than LS2's of the same year and for all controllers and vehicles (believe this or not!) When you decide to "GET ON IT" with the car in "competitive mode" (thinking that you're "getting on it") the throttle response curve is DISGUSTINGLY more conservative than in normal mode....HOW STUPID IS THAT????

Trust me, I'm the "GM ELECTRONIC THROTTLE SCIENTIST" and have spent zillions of hours messing with the system... While I'm still at it....it will be a while before it's working.....it if happens.

Realize the disaster and troubles if "just once" a GM electronic throttle stuck open....For this reason there are dozens of redundant safety checks which have delayed the release of this very powerful tuning feature for LS2 family controllers.

Also realize that some of what you are feeling is also "torque management" if it's not turned off...

I'm on your side and I'm still at it... WE NEED THIS FEATURE...but, PLEASE be patient.

This has been a public service announcement from:
CHUCK COW

 

Thank you Chuck for that informative response. I drove a big horsepwer C4 with a 700R4 as an autocross car for years with a linear cable throttle and when I moved to the C5 it really seemed like the C5 throttle curve would alter depending on the TC mode. Glad to know its not my imagination. I would like to approach you for a tune, but this is a daily driver - when is the autocal system going to be available for a mail order tune without mailing my ECU? Or do you want to make a trip to Vancouver Canada?

 

Interesting post. I notice the speed of which you floor it is a determining factor also. STOMP IT FAST and see what happens.

 

You can see by the list my mods that we have done alot of work on the car. Our tuner, Mike Norris, re-programmed the up-shift & down-shift points based on optimizing the HP/TQ curve. The car is very responsive, shifts fast & hard at WOT, and is extremely fast at the track. A good tuner can program the car to suit your driving needs.

 

Nice info .