I want an overdrive for my blown car, and I talked to a guy that sponsers my car club and he offered to build me a bulletproof 2004r and custom convertor for a good price with a 3 year no questions asked warranty. I told him the specs on the car and how everything was setup so he could build the converter, but he also asked if I wanted to run a lockup or non lockup converter. He said there is a minimal amount of slippage at highway speeds and using a lockup converter really doesnt help out that much, and it adds complexity to the torque converter and makes it heavier, and not as strong. I asked about a transbrake and he also reccomended against it since he said I would lose the low 1st gear that the 2004r has and said I would be better off without it since i'm going to run it as a street car.

So what do you guys think? I dont really know much about transmissions and have just been taking his word for everything (I trust him completely as he is a great guy) but I also wanted to get a 2nd opinion

I have heard that if you don't get a lock-up converter your transmission will retain more heat. Heat is a bad 4 letter word, when talking about overdrive transmissions.

Unless you are drag racing most of the time a trans brake really isn't needed. FWIW back in the day I had THM400 w/ a full manual reverse pattern valve body built for my Camaro. Yea I know it's not an overdrive but my point is it was a killer trans WITHOUT a trans brake. Since you will be street driving it, I'd go without the brake. I would also ask him about a 4L80E w/ a full manual valve body. A 4L80E is basically a turbo 400 w/ overdrive which is electronically controlled. Lose the "E" and imho you'll be good to go! Nothing wrong with a 200-4R, just make sure with a blower it's built to the hilt!

Read this thread as it will provide plenty of insight on the parts you should use.
http://www.turbobuick.com/forums/transmission-talk/31365-attention-new-version-strengthening-2004r.html There is a ton of 2004R knowledge on that site.

Hunt up Jakeshoe on the Boards.

He's always good to help as is Bruce.

pdq67

From what I know the lock-up convertor would be ideal on the street. It reduces heat which gives you longer life and on the highway i would easily bet a 300 rpm drop when locked up compared to not.

As for transbrake not worth it for alot of street. I would also look into the 4L80 a beefed up 400 with overdrive that built right can handle ungodly power. Its also not to much heavier considering the benefits i think its 75 lbs more than a 400 something like that. You can easily get an electronic controller for it too to change shift points on the go and control line pressures i mean the whole thing, which from my understanding there are electronics involved at all times if you go lock up. So if you go lock up i would just make the whole step to electronically controlled they are definetly worth it.

You said he can build torque convertors so you should be good to go as the are the most expensive part of one of these set ups since they are not as common and harder to find what you want.

Forget the trans brake unless your trying to run sub 10.0's. Also on a street driven car the lock-up is a great advantage if you plan to put miles on, which I'm assuming is why your looking a 4 speed to begin with. Yes the lock-up is about 200-250 rpm drop.

Hunt up Jakeshoe on the Boards.

He's always good to help as is Bruce.

pdq67

x2^.