torque converter replacement

At 171,000 miles, my transmission is indeed starting to show early signs of going. It sometimes slips while cruising. It's not bad at all but I'm going to prepare for a rebuild/replacement. While doing what research I can and talking to a number of people, I've decided that I'm most likely going to get a trans from ZZP as long as 1) they are still doing free installs when I actually get it and 2) I don't come across a much better deal between now and then.

I like the fact that they upgrade several things in their basic rebuild and also automatically give you your choice shift kit and use the dextron 6 fluid. While doing that and installing it, they stay within the same price range as the quotes I've gotten from the bigger transmission chains.

The only thing I haven't come to terms with yet is what I should do with the torque converter. From what I understand, ZZP doesn't replace it unless you are buying one of there higher stall products. It would be foolish of me to reuse my old converter so I'm either going to need to find a refurbished one or buy a "performance" one. I do like the upgrades the performance product gets but I definitely don't want a higher stall. Has anyone seen any options that's built better while maintaining stock stall speed? I do not intend to do anything to my car that will necessitate a higher stall converter.

Aren't going to install a xp cam?


A slighty higher stall would help.

oldsman105 wrote:

Aren't going to install a xp cam?


A slighty higher stall would help.

Technically speaking, sure, but the XP cam is still a pretty low end friendly cam and I don't see how the higher stall would help a car like ours launch better. The higher stall TC would cause the car to go from stop to go with more power pounded to the ground and thats the last of my problems. The gradual torque transfer of the stock stall speed easier to launch with street tires, I think. Plus I don't need my engine revving up to ~2500 every time I leave a stop sign/light going to work, etc.

My belief is that higher stall torque converters should not be used unless needed. The 3800 s/c is characterized very well to work with standard stall. N/A, centrifugal, turbo, aggressive cam, use of slicks, etc is another story.

I have heard zzp will make you a perfomance TC with the stock stall speed.

I am in need of a tranny soon to handle my engine mods. I was told for a heavy car with 400hp or less the stock converter is probably the best option. Stock TC will lock up at 3k. The difference between ZZP is they are a little lighter than stock. The best deal I have found was a rebuilt tranny, hardened 4th shaft, hardened input shaft, 7/8" single chain with 2.93 gears, rebuilt TC, rebuilt diff for less than 3000 installed (they are also replacing my main seal, housing gasket, and oil pan gasket at this price too). I spoke with Dave at Triple Edge Performance in Northern IN and he seems to know his stuff. Turtleman, Dave sis fairly close to you so you might want to give him a call 260-437-8912 or www.tripleedgeperformance.com

IIRC Dave is Trannyman at most forums. From everything I've seen he knows his transmissions inside and out as well as being a respected member of many forums.

If anyone contacts him, please invite him to our board. Would be great to get his opinion.

I just upgraded my trans with 3.29 gears and shift kit. I do mostly city driving and I decided to keep the stock converter. I'm very pleased with my decision.

Unlike many engines that need to rev to make power, the 3800 has a very low torque peak. I think the stock converter takes advantage of that quite nicely. Unless you have ported heads and a big cam and want a 8000 RPM revving beast, I prefer the stock converter but that's just my opinion...

I've never liked driving a car with a high stall converter. Maybe it's just a Buick thing

After driving lots of BMWs ( I know its not the same) I think the 3800 could benefit from a higher stall. I have one ready to go in my new trans.

Your stocker lasted 10+ years and 171k miles.
Don't go crazy on the stall because you wont be able to get traction with street tires.

SLP used to have a nice one that was built by yank. They were liquidating them a short while ago for $150, maybe you should give them a buzz to see if they still have any. The only thing that stopped me from getting one was that they were 3000 rpm stall.

Just a little piece of info I didn't know where to put - the guy at AAMCO transmissions said they will build and warranty transmissions with any shift kit and any PCM settings changed. They will also do upgraded components. The only thing they don't allow is high stall torque converters.

http://www.zzperformance.com/grand_prix/articles1.php?id=58

its an article about stall speeds... i think it pretty much says that its better to have a low stall unless you go turbo or some other high rpm applcation...

I agree
What I don't understand is why high end power is lost with a higher stall. High end power should not be affected one way or another if the converter is doing its job right, was my understanding. HISSSS another reason I don't like automatics.

Higher stall converters slip more , so they have less power higher up. The way it works is the engine revs and the converter goes to a speed and the transmission catches up. or at least thats my vague understanding of it. hence the broad low end curve its an inflated figure , not what your engine makes at that particular rpm , but what it makes at that speed. Our engines make enough low end to where any extra would be a waste unless using slicks.

Ok I have this really silly idea for programmer people. Can you have an input to command torque converter lockup by the press of a switch or a direct bypass switch to the solenoid or something to do it? and what would happen if you did that during WOT while you're not shifting obviously

The '64 Riviera had a ST400 (super turbine). The stall rpm (with a little mod) could be changed from inside the car from a toggle switch. Kind of like a milti-lockup stall. I don't know of any other transmission that has (or could be made to have) a converter that stalls at two different speeds. When I was planning on putting some work into the '64 I had a few years ago, that was one of the things I wanted to do. Wish we could do it for the late model Rivs.