RobWilson

My brother-in-law has a '99 A4 convertible and is looking for some performance improvements. The car currently has 3.15 gears and LT headers. I recommended gears and a higher stall torque converter. I put a 2800 stall Vigilante in my '97 Z28 and was very impressed with the performance gains.

It has been a while since I modified an automatic transmission car. What is the general opinion on the best stall and best converter to go with? He is already planning on going with a DTE differential with 3.73 gears. Would a 2800 stall Vigilante (lock up) be the way to go? The car is a street car and will rarely, if ever, see the track. Would a 3200 stall be better?

Another question is how much should labor cost to install the differential and torque converter? I know how much the differential install costs (I've had my DTE differential installed twice), but wondered if there would be a labor savings by doing both at the same time.

Another question is what transmission cooler options are available? I know that the higher stall generates more heat and that it is a good idea to do a transmission cooler at the same time.

Thanks!

Patches

I installed AR headers, 3.42's, a Yank 3200 stall and an Elite tunnel plate in the wife's '02 A4 coupe last summer and was very pleased with the gains I got. Had it been mine, I probably would have gone with the 3.73's but the rest would have been the same. I put in the 3.42's because I already had them sitting in the basement from my other M6 C5 I had put 4.10's in - plus, it was going in the wife's car and I didn't want to overwhelm her with wheelspin problems. It had 2.73's from the factory. I also added a tranny cooler at the same time - highly recommended - and I did my own tranny and code-delete tuning with EFILive as well.

Drivability of this combo is excellent - even I like driving it and mine is a heads/cam/header/4.10 M6 with lots more power.

Here's a post of the install I did so you can see the work involved.

http://forums.corvetteforum.com/show....php?t=1753571

verano29

Holy crap!! There is no way on God's green earth am I attempting to do that myself armed with only jacks and jack stands! Why did GM ever put that worthless 1200 stall mated to a 2.73 differential!!?!!

Can anybody give me an idea of how much the labor is going to cost me?

verano29

How much can expect to pay to have someone install this for me?

RobWilson

Patches,

Thanks for the feedback and the link! Can you provide any more information on the tranny cooler you used?

RobWilson

You should be able to get the differential replacement done for $400 or less.

verano29

Do you know if this is something that my friendly neighborhood GM dealer would do? I can, of course, call them...just not sure if they are into the "custom" type of mechanicing.

RobWilson

The GM dealership can definitely do it. It is no different than installing the oem parts. However, I'm guessing they will charge you a little more.

Patches

Definitely labor savings doing both. I'd say, at most, a couple hundred more to do the stall although it's not much more work. You can pull the tranny and diff without pulling the whole tt like I did so it's just a bit more work.

I used a Hayden tranny cooler because I couldn't get a B & M in time for my install. The Hayden, though, worked great - even through the 100+ degree summer we had here this year. I may swap in a B & M or Hitek this spring when I swap the lines with a set of ss braided hoses.

navy99vert

I have a Vigilante 2800 and 3:73. I think they work great together. I have read that the Vig 2800 and the Yank 3200 work about the same.

2000BSME

No offense meant to Patches, but he didn't use a very good cooler. You would do much better to get a stacked plate cooler rather than a tube and fin design.

I can send you some links to some very cost effective and efficient coolers if you are interested.

RobWilson

I'm interested. Post the links or PM me. Thanks!!

Patches

Understood - and as I mentioned a couple of posts up, I will probably swap in a stacked plate and possibly fan-cooled version this spring. Couldn't get one in the short time frame I had to do this (last minute change in the stall) so I went with the tube and fin temporarily. The tranny temps never got over 185 in 100+ deg. driving so I opted to wait until I could source the correct fittings and hoses as nothing is available off the shelf for later models - at least, nothing I could find and the forum was no help there.

The B&M or Hitek are the two brands I'm currently looking at.

2000BSME

http://www.bulkpart.com/Merchant2/me...roduct_Count=1

Great cooler, if you want to deal with a company that has a phone number, buy this from Summit for $20 more. I bought mine from Makco though, for $180. Very nice cooler. Has JIC fittings, so you can buy pushlock fittings and hoses from Summit and connections are very nice.

If you get serious about road racing, you may need one of these:

http://www.fluidyne.com/pl_hpaccessories.html

Bunch of nice products there. I used this:


But you have to have extra room in your trunk to make it work.

Patches

Nice stuff at Fluidyne. Any options for later-model C5 fittings?

2000BSME

My '99 has #6 inverted flare fittings. I don't know if yours is the same, but I don't think it would be difficult to have a hose made to go #6 flare to #6JIC. My local hose shop can do it.

In my particular case, I removed the fitting at the transmission, which is #4NPT (1/4"). I put a #4npt to #6JIC, and made everything else JIC down the line. Much more prevalent than 'inverted flare' fittings.

I know that sounds like a lot of work, but if anyone needs fitting info/advice, I know a little bit about it.

--in all honesty though, a simple $50 stacked plate 24-30gvwr cooler in front of the radiator will suffice for all but the most rigorous road tracking. I got by like that for years, drag racing and mountain climbing. Road racing will really heat the tranny up though.

RobWilson

Thanks for all the feedback guys. I think 2000BSME's solution is a little overkill for my brother-in-law. He uses his trunk and does not road race his car.

I think he is going to go with a DTE stage 1 differential with 3.73 gears, a 3000 stall Yank, and a B&M supercooler.