When launching my car from a dead stop my car has hung in the gear and not shifted, pegging the rev limiter twice now while in "s". Has this happened to anyone else? Or does anyone know what may cause this? The car makes 609rwhp, it happens around 75mph which I believe is 1st gear? 2006 LS2 A6. I thought maybe the transmission is slipping so it got caught in the gear, but the car has been launched 5 or 6 times now, and it's happened twice now, any ideas?

 

75mph in 1st?

 

Have you put the car in Competition Mode? My 08 A6 does exactly what you said but when using the paddles.

 

The easiest fix is to start your shift earlier...say around 5800 rpm or so.
I've experianced this in the past (with headers only and no tune). Back before there were even tunes for the tranny some of us just learned to drive around it.

My guess is at high rpms the car (especially with mods) accelerates faster than the computer can register the shift, send the message to the transmission, and engage the next gear...which results in it bouncing off the rev limiter and canceling the shift. It's pretty dang embaressing to say the least.

 

I'm assuming that right after you punch it, you're getting wheelspin and wondering why it won't shift out of 1st? If that is the case then it's by design to protect the transmission as it won't shift from one gear into another while undergoing traction issues.

Also, there's no way you can hit 75MPH in 1st gear.

 

My apologies, must be 2nd gear then. I use 's' as I heard it's firmer shifting for racing but don't use the paddles when this has happened. I've pegged first before using it, but that's just because it lags when shifting. This has happened while fully being automatic not using paddles. Maybe it was traction that prevented the shift, but what do I do then? Let off it and get back on it? This was while 'traction control off' was displayed, I don't believe AH was off. I need to figure this out, I can't rely on the car to run right as of right now, I lost money last time on a friendly wager at the track Friday between friends, but I should of been fine had it not happened to me.

 

I have to lower shift points on the higher HP A6's supercharged cars, you might be right on the edge of hitting the limiter so it is intermittent. Or very possibly tire spin like Subfloor stated.

 

Sometimes letting off will allow the shift to happen but if you let off too much and then floor it again, you run the risk of over-revving it on the downshift and toasting your motor. Do a search on threads started by HOXXOH as he had the same thing happen to him last year.

 

Good to know, should I have you re-tune it? Or is that normal so to speak? I'm just trying to figure this out in case money is on the line

 

Hmm, should I just the paddle shifters then to try and avoid this?

 

Unfortunately I don't think the paddles will help in that situation either.

 

Does using 'd' or 's' make any difference? Other than the option to use paddles that is.

 

Possibly, but not likely.

While there are differences between D and S (line pressures, torque settings, shift points etc) the situation you're encountering is more a case of the transmission trying to protect itself rather than not having the right value in your tune.

What probably would help is a stickier tire so you're not having so many traction issues. Although this isn't directly applicable, I used to have the same problem at the track while I was still running Mickey Thompson drag radials.

If I didn't hook properly then I pretty much knew it was a given I'd hit the rev-limiter and the run would be wasted. When I changed over to running Hoosiers however, I was pleasantly surprised the first time I had a bad launch but the car still shifted as they have the ability to rehook. What ends up happening in that situation is the car will short shift a little but to me that's much more desirable than it not shifting at all.

 

Wow, that kind of sucks. Would a different transmission prevent this, or can it be tuned to just keep going? I know it's protecting it, but are there transmissions out there where you don't have to worry about the protection? I know anything is breakable, but realistically I mean.

 

Doug I sent you a PM

 

Yeah, probably a 4L65 or 4L80 but that's an insanely expensive conversion as I priced it out a couple of years back when I couldn't get my transmission to last more than a couple dozen passes at the track.

I'm not overly familiar with how those two transmission work but from my limited knowledge I do believe they'll shift when you tell them to, regardless of what's happening at any given moment.

Before you start chasing what could end up being the wrong problem, I'd suggest trying to find somebody with HP Tuners who can scan your car while it isn't shifting.

If it is in fact wheelspin then it really isn't gonna make much of a difference whether the transmission shifts or not because until you can regain traction you're not going to have much forward motion.

If it's not wheelspin then lowering the shift points (as Doug suggested earlier) might fix the issue.

If it's not wheelspin and lowering the shift points doesn't help then you might be looking at having your transmission rebuilt. When I was having issues like that in the past it wouldn't matter how much I lowered my shift points or how high I bumped up my rev-limiter because it still wouldn't shift no matter what I tried and that included leaving it in Drive as well as trying to shift it manually in Sport.

 

I appreciate the info, next time I'm at ECS I will have Doug take a look at it, maybe the points need to be lowered a tad. I doubt the trans is slipping already at least I certainly hope not, as the car has barely been driven hard, especially from 1st and 2nd gear because I just got a sticky tire, previous it's been 3rd gear playing around (In Mexico)

 

There IS one other factor that you might want to check...and that is when this happens what is your tranny fluid temp? The reason I say this is because I had weird delays, but, the tranny temp was low..below 140 deg. Just a suggestion. When mine warms up it shifts fast, positive and in 1-2 & 2-3 with 50% throttle it'll pop rubber, at least on my 06.

 

I doubt either time it was that low, but I will have to watch it. Thanks!

 

When this happens to me, and it is every time to paddle shift. The car is covering your ***. If the car shifted to the higher gear whatever it is the traction control knows the HP is there to overide the available traction and the car will not shift when you try the make it with the paddles. The rev limiter catches it and says don't do this are the car is going to jump crazy so it holds it in gear and the rev limiter gets it. Had it shifted the tires would breakloose bigtime and around you would go ...big surprise. If its in drive it will choose the best time and shift. My car is much modded and it does this anytime I get a little aggressive on the paddles thinking this is going to be fun. These cars will let you lose them (spin at high speed like a 360) if you press the limits of what the computers say is going to be a big mistake.