4+3 tranny
Thread Starter
Intermediate
Joined: Aug 2011
Posts: 38
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From: Klamath Falls OR
4+3 tranny
Hello, I'm currently building my L98 to make hopefully in the 600-700 hp range and am looking into tranny issues. I've got just an old stock 4+3, does anyone know how much those can hold before they blow up? It's going to be more of an auto-x car so I don't plan on launching it very often.
I would love to do a swap, but after looking into them, the ZF would be my best option, but it's way out of my price range right now, the T5s can't handle too much power stock right, and building one would cost too much too.
I would love to do a swap, but after looking into them, the ZF would be my best option, but it's way out of my price range right now, the T5s can't handle too much power stock right, and building one would cost too much too.
Team Owner
Joined: Dec 1999
Posts: 34,873
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From: Lacey WA RVN 68-69
NCM Sinkhole Donor
The 4-speed portion is a Borg-Warner Super T-10. It could be built to handle high HP, but the overall design of the trans may not be what you want to use given your HP goals. The OD unit doesn't like abuse. Having said that, I have used my 87 with the 4+3 for autocross and track days for the last 6 years and it's still working fine. I run Hoosier's for events. But the HP of my car is less than half of what you are considering. 
For autocross use, why are you building so much HP? There are lots of very quick cars that are in the 400HP range (think C5 Z06) or 500 HP (C6 Z06's). IMHO, being fast in autocross is 1) driver, 2) tires, and 3) suspension.
A Black Tag ZF-6 would be a good choice as it would be easy to swap in. You will pay less for it compared to a T56 or similar.
For autocross use, why are you building so much HP? There are lots of very quick cars that are in the 400HP range (think C5 Z06) or 500 HP (C6 Z06's). IMHO, being fast in autocross is 1) driver, 2) tires, and 3) suspension.
A Black Tag ZF-6 would be a good choice as it would be easy to swap in. You will pay less for it compared to a T56 or similar.
Thread Starter
Intermediate
Joined: Aug 2011
Posts: 38
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From: Klamath Falls OR
Thanks for the info!
Yeah I'll look into having the 4+3 built, but by the time that would all be done you are probably right, a 6 spd swap would probably be a better choice.
And I'm not really building it just for auto-x, I know that is way more power than I need. I'm just building it for a fun street car, I'm trading one of my cars to a friend and he's going to buy a full forged eagle rotating assembly, head work, and assembly. I just enjoy auto-x as a side hobby, just for fun, not serious haha.
And does anyone know the difficulty of the swap of a ZF compared to a t-56? So far it looks like I can pick up a t-56 a bit easier and cheaper than a ZF-6
Yeah I'll look into having the 4+3 built, but by the time that would all be done you are probably right, a 6 spd swap would probably be a better choice.
And I'm not really building it just for auto-x, I know that is way more power than I need. I'm just building it for a fun street car, I'm trading one of my cars to a friend and he's going to buy a full forged eagle rotating assembly, head work, and assembly. I just enjoy auto-x as a side hobby, just for fun, not serious haha.
And does anyone know the difficulty of the swap of a ZF compared to a t-56? So far it looks like I can pick up a t-56 a bit easier and cheaper than a ZF-6
