Turbo 350 rebuild for track use

Transmission to Rear-end

Moderator: Team

Post Reply
rfoll
Guru
Guru
Posts: 2019
Joined: Mon Jan 11, 2010 12:44 pm
Location: St. Helens, OR

Turbo 350 rebuild for track use

Post by rfoll » Thu Apr 14, 2016 4:52 pm

This is a scratch build from a core for a drag application in a light vehicle that will not likely see more than 500 hp or 400 cubes. This is not for competition. I have been looking at what is out there for kits from the major performance manufacturers, and would like some input to determine what is the best way to go. None of the kits include the hardened intermediate sprag as far as I can tell. Some of them have a shift kit included, but I am not opposed to buying one separate. We may not need steels, but I think the high quality frictions could be a plus. Cost is a factor, we are looking for the best bang for the buck. Thanks, Rick.
So much to do, so little time...

Greenlight
Pro
Pro
Posts: 381
Joined: Wed Feb 16, 2005 10:37 pm

Re: Turbo 350 rebuild for track use

Post by Greenlight » Thu Apr 14, 2016 11:10 pm

See the links below.

Use this rebuild kit:
http://www.ebay.com/itm/GM-TH350-TH350C ... 3641.l6368

Go to the bottom of this page to see where to drill the holes in your valve body spacer plate.
http://www.v8s10.org/forum/viewtopic.php?f=19&t=19791

I would also add the high performance intermediate sprag.

Other than that, you should be good to go.
Project Greenlight

rfoll
Guru
Guru
Posts: 2019
Joined: Mon Jan 11, 2010 12:44 pm
Location: St. Helens, OR

Re: Turbo 350 rebuild for track use

Post by rfoll » Fri Apr 15, 2016 10:59 am

Thanks. Is it your recommendation that the valve body doesn't require any of the different springs that are in a shift improver kit? I will likely leave the spring out of the accumulator. My friend that own a trans shop almost never puts them back in, and most of the rebuilds I have done, the spring was broken anyway.
So much to do, so little time...

Greenlight
Pro
Pro
Posts: 381
Joined: Wed Feb 16, 2005 10:37 pm

Re: Turbo 350 rebuild for track use

Post by Greenlight » Sun Apr 17, 2016 6:49 pm

Most shift kits don't require you to change springs in the valve body.

Drilling the plate, as shown, works great.
Project Greenlight

rfoll
Guru
Guru
Posts: 2019
Joined: Mon Jan 11, 2010 12:44 pm
Location: St. Helens, OR

Re: Turbo 350 rebuild for track use

Post by rfoll » Mon Apr 18, 2016 10:04 am

OK, thanks. The kits I have used have a plate that bolts to the valve body for additional flow or pressure. I don't really know how necessary these are. Distant memory has me thinking it has to do with the direct clutch.
So much to do, so little time...

Rick Finsta
Pro
Pro
Posts: 317
Joined: Sat Sep 13, 2014 10:22 am

Re: Turbo 350 rebuild for track use

Post by Rick Finsta » Wed Apr 20, 2016 9:47 am

Just a PSA I was very close to rolling a sprag with a hardened race at less than 500hp but 1.58-1.59 60' times. I'd personally toss a 36 element drum in there for insurance. TSR sells a quality unit for much less than the other names.

rfoll
Guru
Guru
Posts: 2019
Joined: Mon Jan 11, 2010 12:44 pm
Location: St. Helens, OR

Re: Turbo 350 rebuild for track use

Post by rfoll » Wed Apr 20, 2016 10:49 am

I don't see any expensive hard parts in our future. I have a fairly standard rebuild with the hardened race in my car for about 15 years now, and have no problems. 3500 lbs with driver, and have been in the low 11s for the last 10 years.
So much to do, so little time...

Rick Finsta
Pro
Pro
Posts: 317
Joined: Sat Sep 13, 2014 10:22 am

Re: Turbo 350 rebuild for track use

Post by Rick Finsta » Wed Apr 20, 2016 11:48 am

Maybe I'm just unlucky, then.

rfoll
Guru
Guru
Posts: 2019
Joined: Mon Jan 11, 2010 12:44 pm
Location: St. Helens, OR

Re: Turbo 350 rebuild for track use

Post by rfoll » Wed Apr 20, 2016 5:34 pm

The stock race is supposed to be pretty fragile, yet I have never broken one. Maybe I'm just lucky. For track use, I don't even take the chance.
So much to do, so little time...

77cruiser
Expert
Expert
Posts: 951
Joined: Fri Dec 29, 2006 10:32 pm
Location: I Falls MN
Contact:

Re: Turbo 350 rebuild for track use

Post by 77cruiser » Wed Apr 20, 2016 9:02 pm

Are you going to dual feed the directs? That would be a durability +.
Jim

rfoll
Guru
Guru
Posts: 2019
Joined: Mon Jan 11, 2010 12:44 pm
Location: St. Helens, OR

Re: Turbo 350 rebuild for track use

Post by rfoll » Wed Apr 20, 2016 10:24 pm

Splain please Lucy. Its been a few years.
So much to do, so little time...

tresi
Member
Member
Posts: 168
Joined: Sun Mar 24, 2013 10:10 pm

Re: Turbo 350 rebuild for track use

Post by tresi » Sun Apr 24, 2016 11:09 am

It's not that the stock race is all that bad but if it goes there's nothing left to rebuild. Cheap insurance.

rfoll
Guru
Guru
Posts: 2019
Joined: Mon Jan 11, 2010 12:44 pm
Location: St. Helens, OR

Re: Turbo 350 rebuild for track use

Post by rfoll » Sun Apr 24, 2016 5:38 pm

I was referring to the direct feed.
So much to do, so little time...

Post Reply