400 turbo

Transmission to Rear-end

Moderator: Team

Post Reply
vht
Member
Member
Posts: 82
Joined: Mon Oct 29, 2012 9:05 pm

400 turbo

Post by vht » Sun Apr 08, 2018 9:14 pm

What would you need to update on a 400 to say handle 700 HP, strip use with slicks and no transbrake? I know they recommend the 4L80 type direct drum with a 34 element sprag. I've researched some but seems like there is a whole bunch of opinions. It'll be converted to manual VB.

Coloradoracer
Pro
Pro
Posts: 474
Joined: Sun Mar 21, 2010 9:48 pm
Location: Conifer, Colorado
Contact:

Re: 400 turbo

Post by Coloradoracer » Tue Apr 17, 2018 6:38 am

Just pay attention to clearances and you'll be set. 36 element sprag is the only thing I'd worry about. A stock th400 can handle WAY more hp than you might think. Stock frictions and steels will also be fine. Might want to restrict the converter feed though, and perform the dual feed mod for the high clutch drum as well, but they are easy to do. A quick search on here should find you the information on those, it's been discussed here before.

Still my fav auto trans. Easy to work on and brutally strong!
Mark Goulette
Owner/Driver of the Livin' The Dream rear engine dragster
Speed kills but it's better than going slow!
http://www.livinthedreamracing.com
Authorized Amsoil Retailer

User avatar
af2
Guru
Guru
Posts: 6177
Joined: Sun Jan 28, 2007 4:42 pm
Location: Grass Valley, CA :Northern Foothills

Re: 400 turbo

Post by af2 » Tue Apr 17, 2018 8:25 pm

Ron Sessions book is second to none on the 400. Very good illustration. I wish I had it when I built my first one.

I run a manual Valve body and leave at 6800 on the brake. Stock parts with good clutches and the 32 sprag has been good. Set the clutches to .050" and have fun.
GURU is only a name.
Adam

dwilliams
Expert
Expert
Posts: 957
Joined: Sun Oct 15, 2006 10:00 am

Post by dwilliams » Thu Apr 19, 2018 6:43 pm

Keep the stacks at minimum height. Sessions preferred paper clutches over the molded ones when he wrote the books; I've always followed his recommendation and stayed with paper, and never had any reason to regret it.

Post Reply