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[ratcityrex]

So I have what I believe is a stock th400 transmission. It shifts pretty smooth. I believe it has a pretty low stall on it. Sub 2k. I'm looking to use this behind my lq4 that im turboing. I'm shooting for 500-600whp. I don't really think this thing is going to hook the tires to the ground, and if it does I'm sure it's gonna blow up the 10 bolt rear end first. But that being said it's all in my nova which weighs less than 2900lbs. Going for a smaller turbo for lightning fast spool. Think rhb5/d16 on a much larger scale. So im going with a 72mm with a .96 ar hot side. Also this car will probably never see that track. It's 100% street car on street tires. Might get some M&H's to drive around on. Going for low budget on this. Just like all my builds.

[jdmhatchracer94]

should be fine at that level I would throw a shift kit in possible diff stall and call it a day

[Minor Threat]

Shift kit and good converter.

[ratcityrex]

I also asked over on ls1tech. Jake from Jake's Performance told me on street tires it would live at that power level for a while. But down the road the only thing needed would be a good converter, a valve body, and 34 sprag. He said adding tome roller goods would help too.  I also read this today. http://www.jakesperformance.com/TH400_Rebuild_Tech.html?no_redirect=true

[Ntrain2k]

I also asked over on ls1tech. Jake from Jake's Performance told me on street tires it would live at that power level for a while. But down the road the only thing needed would be a good converter, a valve body, and 34 sprag. He said adding tome roller goods would help too.  I also read this today. http://www.jakesperformance.com/TH400_Rebuild_Tech.html?no_redirect=true

Wish they has a set of instructions like that for the 4l60e.

[highroller54]

T56 magnum/

[dvst8r]

Line pressure is what is needed. Typical ways to get that are: Through a shift kit, up the line pressure and firm up the shifts, or if you are going super ghetto budget, just pick up a tighter line pressure spring, and put some JD Hyguard instead of atf.

I would say a converter is a must otherwise it will feel doggy as shit unless you are doing highway pulls.

[Ntrain2k]

Line pressure is what is needed. Typical ways to get that are: Through a shift kit, up the line pressure and firm up the shifts, or if you are going super ghetto budget, just pick up a tighter line pressure spring, and put some JD Hyguard instead of atf.

I would say a converter is a must otherwise it will feel doggy as shit unless you are doing highway pulls.

If he's going small turbo/instaspool I would think he'd be fine with a low stall convertor?

[ratcityrex]

No t56. To much money, and I don't want a 3rd pedal with this car.

 Ok I'm trying to take all the info in that can right now.

[ratcityrex]

Automatics are new to me. It's all witchcraft inside them....lol

[dvst8r]

Line pressure is what is needed. Typical ways to get that are: Through a shift kit, up the line pressure and firm up the shifts, or if you are going super ghetto budget, just pick up a tighter line pressure spring, and put some JD Hyguard instead of atf.

I would say a converter is a must otherwise it will feel doggy as shit unless you are doing highway pulls.

If he's going small turbo/instaspool I would think he'd be fine with a low stall convertor?

Still won't make the torque at the 1500-1700rpm the stock th400's stall at. A 2200-2400 will really wake it up.

[ratcityrex]

Good to know. On the compressor map it looks like I'll be at 10lbs of boost by 2200.

[dvst8r]

Good to know. On the compressor map it looks like I'll be at 10lbs of boost by 2200.

Ouch that will put you well over 600ft lbs of torque at that point as well then. Torque is what you need to hold / what is breaks things. With an air to air intercooler you won't need much more than about 10psi to get your 600hp.

[crxvtec91]

I also asked over on ls1tech. Jake from Jake's Performance told me on street tires it would live at that power level for a while. But down the road the only thing needed would be a good converter, a valve body, and 34 sprag. He said adding tome roller goods would help too.  I also read this today. http://www.jakesperformance.com/TH400_Rebuild_Tech.html?no_redirect=true

Wish they has a set of instructions like that for the 4l60e.

Nope but there is a great write up to convert to a 4l80e!

[ratcityrex]

Yeah really want that rhb5/d16 feeling. Like a car that has nitrous but I never have to fill a bottle. I know it tq that breaks shit but when you tell half the people out there that you want to hold 600 ft lbs of tq they look at you funny. I know I'll never get traction on street tires. And once I do I know my 10 bolt is gonna kill it's self b4 anything else. I'm gonna end up with a 9" just not right now. Maybe next year.

The ebay 72mm turbos compressor map along with there turbine size makes for a perfect fit for what I want. At 10 - 15lbs it's showing that it plots out on the map from 2k-6k. Should make for a real fun ride.

[dvst8r]

I agree, just don't get tempted to put it on drag radials. LOL

2200-2400 stall, and a good shift kit, and it should be an absolute riot on the street. Donuts and rolling burnouts at will.

[ratcityrex]

I agree, just don't get tempted to put it on drag radials. LOL

2200-2400 stall, and a good shift kit, and it should be an absolute riot on the street. Donuts and rolling burnouts at will.

This is purely gonna be a street car that is FUN to drive. I know as soon as it gets traction shit is gonna break. What do u believe would need to be done to keep it alive once drag radials are put on?

[turbohf]

I agree, just don't get tempted to put it on drag radials. LOL

2200-2400 stall, and a good shift kit, and it should be an absolute riot on the street. Donuts and rolling burnouts at will.

sign me up to, I'll take one... 

[ratcityrex]

And I'm also going to using the stock truck I take manifold too. So that should be good for some more low end tq. The only thing that's gonna work in the negative is I'm going to be using the stock lq4 cam.........for now.

[dvst8r]

I agree, just don't get tempted to put it on drag radials. LOL

2200-2400 stall, and a good shift kit, and it should be an absolute riot on the street. Donuts and rolling burnouts at will.

This is purely gonna be a street car that is FUN to drive. I know as soon as it gets traction shit is gonna break. What do u believe would need to be done to keep it alive once drag radials are put on?

Typical hard parts:
-Forward Steel Clutch hub (or a 4l80e hub)
-34 Element sprag
-Direct fed drum
-8 bolt pump
-Aluminum pistons (not engine, trans accumulator pistons)
-I would probably get a a full valve body at this point vs just a shift kit. (big line pressure and the best shifts this way)
-Rear case to output shaft bearing
-Proper sprag retainer snap ring or spiral loc
-Deep pan

I am sure there are more, but that is what I can think of off the top of my head.

[ratcityrex]

Thanks man. I appreciate the help. So from what I gathered. This transmission came from a 1973 gmc motor home. It has the deep pan on it already and a pretty good sized cooler up front that im gonna try to keep there but if it doesn't fit with my air to air intercooler and my 4 core radiator I'm gonna move it to the rear with a fan and a temp sensor controlled my by ms2.

[ratcityrex]

I posted this over on ls1tech too. Here's what I got from them so far. http://ls1tech.com/forums/automatic-transmission/1746115-what-needed-make-th400-hold-power.html

[Ntrain2k]

Line pressure is what is needed. Typical ways to get that are: Through a shift kit, up the line pressure and firm up the shifts, or if you are going super ghetto budget, just pick up a tighter line pressure spring, and put some JD Hyguard instead of atf.

I would say a converter is a must otherwise it will feel doggy as shit unless you are doing highway pulls.

If he's going small turbo/instaspool I would think he'd be fine with a low stall convertor?

Still won't make the torque at the 1500-1700rpm the stock th400's stall at. A 2200-2400 will really wake it up.

Good to know. On the compressor map it looks like I'll be at 10lbs of boost by 2200.

Good to know. On the compressor map it looks like I'll be at 10lbs of boost by 2200.

Ouch that will put you well over 600ft lbs of torque at that point as well then. Torque is what you need to hold / what is breaks things. With an air to air intercooler you won't need much more than about 10psi to get your 600hp.

Hence my suggestion of staying with a low stall. He'll have a hard time hooking as it is.

[dvst8r]

Line pressure is what is needed. Typical ways to get that are: Through a shift kit, up the line pressure and firm up the shifts, or if you are going super ghetto budget, just pick up a tighter line pressure spring, and put some JD Hyguard instead of atf.

I would say a converter is a must otherwise it will feel doggy as shit unless you are doing highway pulls.

If he's going small turbo/instaspool I would think he'd be fine with a low stall convertor?

Still won't make the torque at the 1500-1700rpm the stock th400's stall at. A 2200-2400 will really wake it up.

Good to know. On the compressor map it looks like I'll be at 10lbs of boost by 2200.

Good to know. On the compressor map it looks like I'll be at 10lbs of boost by 2200.

Ouch that will put you well over 600ft lbs of torque at that point as well then. Torque is what you need to hold / what is breaks things. With an air to air intercooler you won't need much more than about 10psi to get your 600hp.

Hence my suggestion of staying with a low stall. He'll have a hard time hooking as it is.

Then it will be doggy doggy, tire smoke.

At least with some stall it will be relatively driveable off boost. If it were an NA 6L I would be saying stall it 3k+.

[turbohf]

so this seems expensive. found a built TCI trans that was about 1500bucks. but seemed to imply in the description it was for NA apps (but good for 875hp). and doesnt seem like it has a converter (no lockup listed).

only did some quick looking, but doesnt seem like they list above is very Jewish either... 

[Ntrain2k]

so this seems expensive. found a built TCI trans that was about 1500bucks. but seemed to imply in the description it was for NA apps (but good for 875hp). and doesnt seem like it has a converter (no lockup listed).

only did some quick looking, but doesnt seem like they list above is very Jewish either... 

Might be my lack of TH400 knowledge, but I didn't think they came with lockup converters?

[turbohf]

sorry. I meant stall speed.