TH400 build for 1000hp

[matt69olds]

I'm getting ready to freshen a TH400 for a friends 73 Camaro, it was a mid 11 second 406 street car. He is jumping on the LS1 bandwagon, going to a 6.0L with a turbo. The trans was build by me with a 34 element sprag, dual feed direct drum, roller bearing output, homemade manual valve body (looped governor oil) and a aftermarket pressure regulator spring. What would the experts in readerland recommend as far as internal upgrades? How much power will the stock 400 internal hard parts handle? If I remember correctly, this trans was built with the Blue clutch plates that come with premium TransStar rebuild kit. Any suggestions? Thanks!

 

[Reggie West]

A 400 will work but a 4L80 will take the power and he can control it with whatever ECM he uses for the LS motor. Line pressure, shift points all controlled by the ECM is a nice feature to have. You cant go wrong with either one.

 

[SSedan64]

4L80E is a good idea.
400 Info >> http://www.turbobuick.com/forums/threads/th400-build-pictures.255286/

 

[bison]

4L80E is a good idea.
400 Info >> http://www.turbobuick.com/forums/threads/th400-build-pictures.255286/

Converter availability makes the 4l80 a no go for most

 

[turbobitt]

Converter availability makes the 4l80 a no go for most

Plus with a 1000 HP build, you will most likley have a very streetable gear anyway.

Allan G.

 

[turbobitt]

I'm getting ready to freshen a TH400 for a friends 73 Camaro, it was a mid 11 second 406 street car. He is jumping on the LS1 bandwagon, going to a 6.0L with a turbo. The trans was build by me with a 34 element sprag, dual feed direct drum, roller bearing output, homemade manual valve body (looped governor oil) and a aftermarket pressure regulator spring. What would the experts in readerland recommend as far as internal upgrades? How much power will the stock 400 internal hard parts handle? If I remember correctly, this trans was built with the Blue clutch plates that come with premium TransStar rebuild kit. Any suggestions? Thanks!

At least the following,
Steel clutch hub
Billet intermediate shaft
super sprag direct drum
200 PSI line pressure with converter feed restriction
Get rid of the blue plates
Chris (CK performance) manufactures all these parts and is a supporting board member and could give you a more detailed parts list.

Allan G.

 

[matt69olds]

At least the following,
Steel clutch hub
Billet intermediate shaft
super sprag direct drum
200 PSI line pressure with converter feed restriction
Get rid of the blue plates
Chris (CK performance) manufactures all these parts and is a supporting board member and could give you a more detailed parts list.

Allan G.

Maybe this has been discussed before, but whats the issue with the blue clutches? Any other suggestions?

 

[turbobitt]

Maybe this has been discussed before, but whats the issue with the blue clutches? Any other suggestions?

The Blue plates are very tough and can take a lot of slipping and heat but they don't grab very well on a shifting clutch application. You could probably get away with using them in the forward drum if you already have them or want to reuse what you have.

I've used the Alto Reds but havn't inspected them yet after running this year to give an opinion but the shifting seems to have held up fine. I know some people like the High energy clutches. On my next inspection I'll switch to the Raybestos Stage 2 frictions in direct.
Allan G.

Allan G.

 

[matt69olds]

The Blue plates are very tough and can take a lot of slipping and heat but they don't grab very well on a shifting clutch application. You could probably get away with using them in the forward drum if you already have them or want to reuse what you have.

I've used the Alto Reds but haven't inspected them yet after running this year to give an opinion but the shifting seems to have held up fine. I know some people like the High energy clutches. On my next inspection I'll switch to the Raybestos Stage 2 frictions in direct.
Allan G.

What would be a good application for the blue clutches? The only application I could think that might benefit from a hard clutch that takes heat from slipping might be a 4X4 truck that bounces around alot, possibly uncovering the pick-up? I have always used the waffle style clutches, maybe thats what I will reassemble it with.

Allan G.

 

[Mike E]

You might be suprised that some of the big name trans builders use stock borg warner tan paper clutches. Of course, the setup has to be right for them to work. Clearance, apply speed, pressure, etc. But if the setup is wrong a high dollar clutch won't work either.

I'm far from a trans expert, but here is what I was reccomended. http://www.turbobuick.com/forums/threads/1000hp-th400-build.386794/

For 1000hp I'm going to run 5 grooved borg warner stock clutches in direct w/ .070 clearance, 3 smooth borg warner clutches in the intermediate w/ .040 clearance and anything will do in forward. 195 psi of pressure. Griner brake. Smooth clutches in the intermediate will cushion the hit on the sprag.

I put a 300m input shaft/drum and intermediate shaft in for insurance. I'm also going to use a 34 element sprag, but it's on a drum with a freshly ground special sized inner race and with some extra support for the drum. A few extra bushings and bearings here and there also.

 

[coach]

I never tell anyone to not use a vendor, but your not building a Buick, so alls fair.
Carl Rossler transmissions in Girard, Ohio builds the worlds strongest 400's. He was handing 2000+HP in the mid 90's for the fastest street car guys like Mark Tate and Annette Summer. He machines all the items on-sight and his Ros-Loc trans brakes are second to none.
He is a family friend and has built all my trannies except my 200.

 

[Alky V6]

1000 hp, you're on the edge of needing the super sprag. I flipped 3 complete HD sprag setups in the course of 4 or 5 runs. Switched to the super sprag and have not been able to put a dent in it.

 

[SSedan64]

Converter availability makes the 4l80 a no go for most

Yep, didn't think about that. The Lockups are Heavy too.
Anyone making Non-Locks for the 80E?

 

[Dusty Bradford]

I'm sure i can get the parts to build a 9.5 non lock for the 80e. I personally would just use a t400 with a 3.23 gear and 28" tires.

 

[bison]

I'm sure i can get the parts to build a 9.5 non lock for the 80e. I personally would just use a t400 with a 3.23 gear and 28" tires.

If the general consumer knew about this there us probably a good market for them. They're spending $3000 on a trans. Another $1050 shouldn't matter much

 

[Dusty Bradford]

I've tried pushing the non lock on several 80e customers but they are usually of the same mind set that you must have lock up for a street car. The latest was a 540CI twin turbo pro touring car....he just had to have a lock up. Most going with the 80e stick with a lock up so the trans doesn't have to be modified. I'm not sure if making them non lock is complicated or the builders just never offer them as a non lock.

 

[bison]

Lol. They dont know what their missing.

 

[matt69olds]

Thanks for the suggestions, something that hasn't been address is hydraulic changes. I'm going to replace the modulator with a plug, replace the steel sealing rings with Teflon and do the required modification to prevent the line pressure from getting out of hand with the reverse boost valve. I have always brazed closed the reverse boost signal in the spacer plate to the boost valve, then drill a vent hole in the valve body Can anybody in readerland suggest any other changes or modification that need to be done?

 

[turbobitt]

Thanks for the suggestions, something that hasn't been address is hydraulic changes. I'm going to replace the modulator with a plug, replace the steel sealing rings with Teflon and do the required modification to prevent the line pressure from getting out of hand with the reverse boost valve. I have always brazed closed the reverse boost signal in the spacer plate to the boost valve, then drill a vent hole in the valve body Can anybody in readerland suggest any other changes or modification that need to be done?

Hydraulic changes would depend on VB used. I would have thought with a 1000 HP build you would have used a fixed line pressure T-brake VB.
Allan G.

 

[matt69olds]

The valve body he is using now has worked fine for the 406 that was in the car, I'm asking for suggestions as to what I should do for the LS1 engine. The valve body in the trans now is a stock one with the typical shift kit modifications and looped governor passages for a cheap forward pattern manual vb. The modulator was still in the car and functional, I'm thinking if the engine really is going to have the Wheaties he thinks it will I should set it up with fixed line pressure. Opinions? Suggestions? Thanks!