A6 HP Limits
 

Anybody have a "valid" opinion on just how much HP an A6 can handle, without grenading it?

I just bought an '11 GS LT3 A6 Vert, and was hoping to TT it, but am afraid of blowing up the trans. JUST looking for a dramatic HP gain and NOT interested in tracking, or racing (well...), responsible on-ramping you know. I'm hoping I didn't make a mistake by not buying a manual.

I did have an '06 Z51 A6 Vert with an Lingenfelter S/C, but sold it after about a year. The purchaser called me and told me he had to replace the tranny after he put @ 1500 miles on it.

I did do a search for this very topic but only found a thread from about 2 1/2 years ago. Any factory changes in the trans. since then?

Appreciate the knowledge and experience on this forum.

600 will last for a little while with a good tune. But it is just a matter of time

My A6 held fine with about 615 whp and 546 wtq. We added a smaller blower pulley and were pushing around 680 whp but didn't dyno it. The A6 was running fine, but just for safety I bought a spare A6 from a forum member (thanks, XcessiveX) that was in great shape. I sent it to Century Transmission near Houston for their upgrades. I got it back and my tuner was tweaking it today during Test n Tune at Dallas Raceway...best of 9.75 at 139 mph.

Agreed-

Killer run.:thumbs:
what upgrades do they do to the A6?

everything is just a matter of time :lol:

From Century:

Complete rebuild with all new gaskets, seals, rings & filter. New pistons & retainers where needed.

Alto 6L80 PowerPacks® in the 4/5/6 & 3/5/Rev clutch packs, this transmission's weakest links. Alto's state of the art Red Eagle® friction material incorporated with additional plates added to the clutch packs for a major increase in capacity!
* Raybestos Stg 1 performance frictions in the 2-6 clutch pack. PowerPack® for the 2-6 coming soon.
* Raybestos or B&W h/d frictions in the low/rev clutch pack & 1/2/3/4 pack.
* Century Billet Intermediate Shaft (output carrier shaft-4/5/6 hub). Now that we've got the clutch packs holding better, the OEM powedered-metal shaft is twisting & breaking with increased H.P., the next weak link.
* Century reinforced clutch hubs for increased reliability.
* Century's proprietary valve body ugrades.
* Heat dissapating case coating.
* Consultation on your transmission "tune". A proper performance tranny is tune is very important for optimum transmission performance & longevity!
* 1 year warranty.

I skipped the intermediate shaft upgrade. It was less $$ than I thought it would be and great service...you can thank "The Subfloor" for the pioneering of this upgrade.:thumbs:

I have almost 11,000 miles on My A6 Vette with 580rwhp with zero tranny problems!{guess I got a good one}

Any racing/track use and/or ultra aggressive street driving on these two transmissions as well?

Yes, I probably put about 20 1/8 mile passes and 10-15 1/4 mile passes on the totally stock A6, and I drove it hard on the streets as well. The tune is very important and keeping temps cooled is important, so add an external cooler if you don't have one yet. The trans cooler is not an expensive mod...even in a Texas summer my temps only rise to about 175-180.

I believe I will enjoy the peace of mind of the Century upgrades to my A6. I will PM you the price I paid for the A6 upgrade....it was much less than it lists for on their web site. :cheers:

DUDE, 9.70s, thats awesome. congrats. i think we should get a 6l80e trasn best et list going this summer. I cant wait.

I've done a little track,but have done alot of aggressive street driving{hey,,I live in L.A.:thumbs:}

I just picked up the car from RMS-MAN and got to looking at the time slips. There were two 9.7 passes (9.75 and 9.77), then 9.80, 9.83, 9.93, 9.95, 9.96. The other 3 passes were low 10s because the tune started off rich or the tires got blown away at the start. 7 out of 10 were 9 second passes. I just drove the car home and it is smooth, nice shifting. I like this A6 upgrade :cheers:
http://i904.photobucket.com/albums/a...027/97runs.jpg

Thank you kindly for the detailed info. I'll keep this in mind for the future.:cheers:

You definitely won't regret it if you're looking for something bulletproof as I put another 11 passes on it today bringing the total to 110 so far.

:willy:
lol, the average person does not measure longevity of there cars by numbers of passes. just sayin. I would say everytime i get in my car, on the street, it goes wide open through at least 2 gears 5-6 times. how many passes is that?:rofl:

Ever heard of stress testing Bill? You know that little ol' thing where a company will push a product far beyond the limits of normal everyday use as an overall measure of longevity?

Since one of your so-called "bulletproof" rebuilds let go in less than 150 miles (while driving it home from the shop) and then another one blew up on the dyno, you should be the last person to question anything to do with longevity.

Given that the clutches are the weak link in the 6L80E, what I'm doing is the absolute best kind of stress testing available. Granted, not everybody races their car but for someone looking to be reassured that the rebuild would last in their high HP daily driver, any reasonable person can conclude that if I can't break it at the track then they probably won't be able to either while only just driving it on the street.

both of those happened because I had a incompatant tuner, as soon as Roadrebel went back through it, trans was fine, but regardless. This is why i always tell people, spend all you want on the trans, but regardless, a stock trans will outlast a built trans if the tuner is not capable.

I disagree 100% on your track threory. I have NEVER had a trans break while at the track. not one. I freshened the trans that is in the car right before the shootout (i dont just race at local events) and it has been running solid ever since.

I am of firm belief you cant go wrong with a few of the builders out there, as the actual hardparts people are using are all the same. I have seen one of these trans come apart and go back together, in minutes. if you put one together wrong, it will simpley NOT work when installed. If you use good clutches, replace the 4-5-6 shaft, and put a big cooler on, I am of the firm belief that the trans will live or die based on the tune. there are no special tricks out there one shop does another cannot do.


silverbullets car is proof that a good tuner can change a car. That is a amazing car.

Was that a jab at RPM ? I need to know Chris.

I doubt it. I'm pretty sure Chris knows the tune has more to do with longevity than anything. I know who originally did Bill's car. I redid another car originally by the same guy and after only doing the engine tune, the trans began to shift properly.