I am looking to buy an LS1. I have read that A4's are not reliable for stock or modified f-bodies. I plan on adding more HP to the car and am looking for low 12sec times. Will an A4 handle 400+ HP regularly?

I had a stock A4 LT1 and it never gave me problems.

I will like to drag race and take it to the road race track also occassionally.

 

Who told you that an A4 LS1 is not reliable?

 

Well they break extremely easy.....My friend when he was stock floored it from 50-60 then pulled over turned his car on and his 1-4 was gone but had reverse.

Anyway to make a long story short he's been through 5 trannies......

3 when he was light modified or stock

He now has a 3500 built up tranny and has been fine

Not for long though He's pushing probably close to 500 if not over 500 all motor lol

 

He was doing something wrong. He should never of had a problem when he was lightly modified/stock.

 

I've also gone through one here just a month ago. I do rag on it a bit though. All stock tranny's are gonna have their pros and cons. An A4 will last a while without needing any work then you'll have to eventually do a rebuild. A M6 will last you longer as a whole but you'll be constantly having to take it out for clutches, synchronizers, throwout bearings, etc. I'd rather pay to have an A4 rebuilt than to have to remove the tranny over and over for one problem after another. There are also some here that have over 100k on their stock A4 and no problems. Just do a search.

 

It's every bit as reliable as any other mass produced automatic. There will be some that fail early, some that last forever... too many variables in production tolerances, mods, maint, driving habits to give a firm mileage.

If you are going to be in the low 12's though, there are some basic things you need to take care of. Cooling, suspension (avoid hop/tramp), tuning, and so forth. Read up, lots of information here.

Remember for every 1 person you hear complaining about their A4's, there are 10 more running along happily. You don't see posts like "Hey, I've got 80k hard miles on my A4 and it's still trucking".

Having said that the LS1 is a lot of motor. If you are planning on heavy mods to the low 12's, then that plan should include attention to the transmission and drivetrain as a whole.

Bad planning to get into the 12's spending your whole budget on power. Read up, enjoy.

 

If you can drive you won't need new clutches, syncrhos, etc often...I just got my tranny rebuilt after 100k miles. Needed 3-4 synchro assymbly and blocker rings. I also put a new clutch in it. A4 clutch packs will burn up just like m6's need new clutches. I'd say a4's are less reliable than an m6. M6 problems come from people powershifting and missing gears. You can't do that in an automatic

 

Well, I have an A4 and I agree they are UNreliable. On my 3rd one in the past year. Both times I lost 3rd and 4th. Got one built right this time, and I haven't had problems.
Things are going to happen when you mod your car, such as the transmission and rear end...
If you want the A4 ls1, get it. Just build it right when it goes out the first time and you should be fine.

 

With an A4 there is probably more of a chance the tranny will break, but if you plan to add a lot of power with an M6 there is more of a chance the rear will break (if you keep that stock). It's a tradeoff really. In general I think they're about as reliable as you can expect when you jack up the power.

 

I agree, the more power you add to your car, the more you have to build your car to hold the power. That's just part of the game.

 

Very well said.

 

A4s are reliable beyond belief, they will also take a massive beating. 3000-4000 stalls can be found on completely stock A4s. A4s are controled and talk to the computer. they have torque managment that basicly cuts back the motors spark if it is going to harm the transmission. the only people that ive heard about screwing up their transmissions have been in the computer to mess with torque managment or the computer is doing something wrong. it basicly WONT let it harm itself... intelligent cars are great..

 

Mine didn't even last a week after the stall went in.
Could have just been a fluke, but the same thing happened to me with 2 different A4 transmissions.
I am not flaming on the A4, but they need to be built to hold power. And personally I believe you should invest in a good build. If you have the money to spend on mods, why not back them up with a well built tranny? I learned my lesson.

 

Thanks for all the advice.
After actually reading alot of the forums it seems as if A4 vs. M6 is a matter of choice and how one wants to drive his car.
I had an LT1 A4 and had no problems but that was a stock 220WHP.
Now I am looking for a used LS1 knowing they put out closer to 280-300WHP stock and I want to mod it for 400-500WHP.
My commuter car is a little Tracker 4x4 5-sp. It has 83,000 miles on it and the only service I do is add oil when the lifters get to loud. The tranny has been severely abused by off-roading, creek fording, and occassional gear grind.
I would like to go back to automatics because the hills are a pain here in No California.
Seems like an A4 is the best choice for me.
My primary goal is quick 0-60 times and then 1/4 mile times. Before I add HP I would rather build a platform that can transfer the stock HP to the ground most efficiently. Any advice on a well planned step by step process for getting the most out of a stock LS1 (+free mods) and A4?

 

TORQUE CONVERTER!
And good, light suspension.

 

I put 89,000 miles on my factory transpushing 437 NA HP to the wheels. It had a Yank ss 4000, shift kit 32,000 cooler, computer tune for stall. then it was pushing H/C and a dual stage 175 shot.
Then one day it split the reaction shell and burnt all clutches and 1-2 servo. $5600 later I have a nasty TH400 trans.
Its really a crack shot as to how long they hold up. Another guy here has a camaro with 273 gears running 10's on juice with stock trans.

 

Stock A4 is very reliable... the problems generally gets into once you break it (if you're pushing alot of power thorugh it will eventually break) not all transmission builders are made the same.. some just don't know what they're doing

A stock A4 can handle 400rwhp but it's a matter of how long... if you beat on the car all the time it won't handle it for years...

 

I'll go ahead and add to what everyone else has already said. My old car (`99 SS) was an A4. I added a B&M 24000 cooler, Yank ST3500, tuned out torque management, and fixed shift points and pressure with a Predator programer. The car ran 12's on a otherwise stock tranny. Of course it was my daily driver too, and I didn't really beat on it off the track... much. It had 68K miles on it when I sold it and it was still going strong.

It's all in the details. You can't add a stall without a cooler and aleast some reprograming. It's also wise to get a shift kit if you're serious. If you add serious power be prepared to rebuild and added stronger clutch packs. If you beat on it, it WILL die sooner.

PS: my current car (`02 SS) has a M6 but I've never really tested it yet and it only has 18K miles total. My buddies car (`98 SS) with a M6 needed two rebuilds in just the time I had my `99 A4 (never rebuilt). I was much faster than him but his is the one that broke. Just FYI its not always the A4 with tranny problems.

 

stall (minimum 3500), 3.73 gears,good tune,intake and exhaust, et streets will put u right there easily also get the biggest tranny cooler u can and a trans temp guage. oh and to get 11s a nice 100 shot is a great final touch

 

Mine took a **** with only 15,000 Miles on it ! They SUCK in my opinion. And let's not even start on our 10 bolts ! lol. But you gotta love the Mighty LS1 !