Jeff Eikenberry

In a previous thread, I asked questions about which would be the best C6 to autocross. After a lot of good input, I've decided to go with a GS, due to a compelling case made by many people re cost/performance. My question in this thread is whether to go with an A6 or standard 6 speed. I was all set to go for a stanard 6 speed, as I had really bad luck with my current A6 (2006). That car also has F55, which the GS will NOT. THis last weekend, I spoke with a 2012 GS owner who campaigns an A6 and says he has no shifting issues. He claims to be mid pack, beating Z06's and losing to some, as well. In a prior thread, someone indicated the 2012-13 A6 has been reprogrammed and the issues (when it actually shifts vs. when you hit the paddle) are gone. Is there anyone who autocrosses a GS A6, who can comment, or someone who has familiarity with a GS A6 that's autocrossed? Since this car will be driven on the street, as well, an A6 would be nice, if I'm not going to have shifting issues when racing. Thanks much, Jeff

RaleighSS

My first reply would be the good ole Manual 6 speed it is tough and cheep to repair. Do you know if you can hold a gear in the A6 all the way to redline and even bouncing off of redline or does it force a shift ??

MarkDFW

I don't autocross but it bounces off the redline, unless you have a tune like me. My tuner actually let's it go to about 7k instead of 6,500 rpm.

I do HPDE at road courses and have zero issues with my paddles (knocking on wood). You will likely have to anticipate your shift slightly, and adjust your shift accordingly since the paddles are probably not quite as quick as a manual, but I'm able to adjust on the track and I see to do fine. See video.

Shaka

Autocross good, road courses bad for A6. Over fill the transmission by a quart. No dry sump causes slippage on high g turns with high grip rubber. Keep it in neutral when ever you can or push the car to the start line especially on hot days.

MarkDFW

Don't jinx me! No issues with my A6 yet on road courses. Dry sump would obviously be nice but not having one hasn't caused any issues yet.

RaleighSS

Guess the good thing is it is under warranty if you do not mod the car .... Know the Japanese / Germans / Italians have this technology very well sorted and offer great transmissions without clutches maybe GM is not far away from offering a competitive auto trans.

Shaka

How may laps? What duration is the event/s? Watch tranny temps. enlarge cooler with good airflow. Check oil coloration and change oil 20 hours of hard driving. Check oil. Soft shifts at full throttle indicates slippage(especially in turns). A good tranny shop can offer advice and mods. Expensive.

MarkDFW

True. But I have cam, headers, CAI, tune, aftermarket converter. I also had a big tranny cooler put in since you need one with the new converter. I'm crossing my fingers that keeps me going for a while. My tranny temps normally max out 220 or less at the end of a session, which is a good sign.

MarkDFW

20 to 30 minutes HPDE and also recently started time trials with NASA. I have tranny cooler, Ron Davis radiator with oil cooler. Oil is changed frequently (redline). I shift when the wheel is straight just before any trail braking to be safe. This car is still my daily driver. I know. I'm pushing it. I plan on getting a truck and trailer next year and converting to a full blown track car. Hope she survives that long as I know I risk something breaking the way I drive.

The takeaway for the OP is it can be done in an A6 for autoX. Sessions are short enough they shouldn't be hard on the tranny. Just let the car warm up a bit before your run. More care is needed if you road race.

Shaka

Can be done, ask Jim Hall. Corvette is fixing it maybe for the Z06 also. The GS killed Z06 sales because of the Auto option. Obviously you are aware of the limitations. A stock tranny for road courses is not a good idea. Nice driving and nice lines. What's the stall speed of the verter? Where is the temp taken?

MarkDFW

Thanks. Circle D triple disc 2800 stall. So far, I'm getting away with it! I run through the DIC buttons at the end of a session and I've never been above 220 tranny temps, even in 80 degree weather in Texas. I'm sure they will creep higher in the next month or two. I will take off July and August. Too hot in the Dallas area.

avizandum

I've been autoxing an A6 for 5 years with no issues. The compelling argument for the GS is gearing. You're not quite in that sweet spot with the A6. While you can run up against the rev limiter, you can go ~ 83 in second in stock trim.

(I run SSP with a 3.15 gear and my tune, like MarkDFW, goes to 7k so I run 2nd up to 75 mph.)

Jeff Eikenberry

I've bumped redline many a time and the car will stay in the selected gear. I also checked with "my" engine builder and he assured me that an LS motor can handle the rpm's at the rev limiter. Also told me to count on the motor lasting a good long time. As for the "my" engine builder, he's a friend who is the "shoe" for building great motors where I live. Unfortunately, I've never been able to come up with a justification to have him build a honkin' motor.

Jeff Eikenberry

First, your video is great; felt like I was right there. Since you didn't realize it, we won't dock you for continuing on at the four minute mark when you splatted a Texas bug on your GoPro. One thing I noticed is that you shift yourself in the car quite frequently, which I was doing the same at Buttonwillow and Thunderhill (both in California). When I got to Laguna Seca, I had purchased a devise called Angel Wings and that problem disappeared. Rather than try to describe it, go to ANGELWINGSTECH.COM . A friend told me about it and when I used it at Laguna Seca, I was no longer shifting around. It was the best $190 I've spent. Unless you plan to install a race seat, I'd definitely suggest you consider it. I noticed you are driving a 2012 Corvette. Apparently the shifting algarithms have been improved from my '06. I can anticipate an early shift, but in the '06 I never knew when it would shift.

Jeff Eikenberry

Good points. I believe I'll see where the temperatures go and, if they rise too high, I'll investigate added cooling.

Jeff Eikenberry

I'll be sure to let the transmission warm up. No question an autocross is no where near as demanding on the car. I'd agree that you are not at all passive on the track. What kind of tires are you running?

Jeff Eikenberry

I've know of another autoX'er who runs an '06 A6 and has switched to 3.15 gears, as well. Thanks for the pointer. What are you doing for springs and shocks? Don't tell me you have F55 and it works great. I'll go crawl in a hole, if that's the case.

vettehardt

Using the rev limiter as a shift point is like using a smoke alarm as a kitchen timer. By the time you get there, it's too late. You are past the peak power band where you should be shifting. I've never understood why guys do that. I've seen a guy do it all day long and then loose the motor at the end of the day. Actually had to put out the grass fire under his car from all the hot oil getting on the headers and igniting.

MarkDFW

I am already using angel wings. Helps great on lower body but obviously not upper body. I am having race seat and harness installed soon.

I was on kuhmo v710 scrubs. That was the fifth and last day I got out of them. Take a couple laps to get up to speed, and them they work nice. IMO not a good autox tire. Hoosier A6 is good auto cross or time trial tire.

Toilets

I have a 12 GS centennial that I autox. Mine is a manual and I vote that you should buy a manual. It's only one gear change at the start and that's it. Good choice on a GS. It's fantastic. I have won the SS championship for my region and currently leading SSP this year. A very very capable car. The lotus exige S is truly my only nemisis at this point.