Supra Forums banner
1 - 11 of 11 Posts

·
Registered
Joined
·
208 Posts
Discussion Starter · #1 ·
I just toasted my built auto tranny and wanted to do a six speed swap with exedy clutch but some of the posts about chattering clutches have me concerned. So maybe a TH400 might be a better choice. I have the AEM.


I am looking for drivability. Some of the things I didn't like about the auto with the AEM was how hard the tranny shifted (reverse almost cracks your neck) the 4k stall and going thru my neighborhood at 4000 rpm up hill. Lock up of the converter sucked with AEM ( I know they have a newer version but haven't used it.) I have dynoed 650 RWHP and thats where it will stay.

I don't have any experience with the TH400 and I know the 6 speed will be $$.

any thoughts?

John
 

·
Registered
Joined
·
1,340 Posts
I have a th400 AEM car.
First off i haven't heard of any th400 with a locking torque converter option holding the big power. So your unlocked 24-7 if you go that route.

Best of all worlds in my opinion would be the following:

*Tighter torque converter
*Gear vendors overdrive so your 60mph cruizing speed is not 3200rpms. Move top speed from 143 to 190mph.
*NO lockup option for the th400. All lockups i've heard all fail wiht the big HP
*no transbrake so you can drop gears rapidly and smoke cars on a roll
*Nitrous if your big single won't spool right with your newly tighter torque converter.
*bigger transmission cooler of course

Watch how easy it is to bust out 10 second passes with drag radials at that point. You can beat 6 speed supras often times on a roll due to the fact that the th400 seems to put much more power to the ground without smoking off the tires unlike the 6 speed setup.
 

·
Cheifbootknocka
Joined
·
1,944 Posts
breakemlose said:
*Tighter torque converter

*NO lockup option for the th400. All lockups i've heard all fail wiht the big HP

When you say tighter TC do you mean lower stall ?
and why would a lockup fail vs a non lockup ?
 

·
Registered
Joined
·
208 Posts
Discussion Starter · #4 ·
Whats gear vendors overdrive?. Does the TH400 shift via AEM or manual?


I have BFG DR on now and NOS (50 shot) with T-78.

Thanks
John
 

·
Cheifbootknocka
Joined
·
1,944 Posts
1997SilverTT said:
Whats gear vendors overdrive?. Does the TH400 shift via AEM or manual?


I have BFG DR on now and NOS (50 shot) with T-78.

Thanks
John
GV is a manufacturer that makes a bolt on tailhousing that gives you OD.
Im not sure if Im allowed to post a link but here it goes http://www.gearvendors.com/
 

·
Registered
Joined
·
1,340 Posts
TooJayZee said:
When you say tighter TC do you mean lower stall ?
and why would a lockup fail vs a non lockup ?
Yes a lower stall. Why do they fail? I am not positive why mechanically i just know from others experiences they do fail.
 

·
Getrag Gearhead
Joined
·
1,872 Posts
breakemlose said:
I have a th400 AEM car.
First off i haven't heard of any th400 with a locking torque converter option holding the big power. So your unlocked 24-7 if you go that route.

Best of all worlds in my opinion would be the following:

*Tighter torque converter
*Gear vendors overdrive so your 60mph cruizing speed is not 3200rpms. Move top speed from 143 to 190mph.
*NO lockup option for the th400. All lockups i've heard all fail wiht the big HP
*no transbrake so you can drop gears rapidly and smoke cars on a roll
*Nitrous if your big single won't spool right with your newly tighter torque converter.
*bigger transmission cooler of course

Watch how easy it is to bust out 10 second passes with drag radials at that point. You can beat 6 speed supras often times on a roll due to the fact that the th400 seems to put much more power to the ground without smoking off the tires unlike the 6 speed setup.
Thats the TH400 talk. Lets talk 6-speed next.

It has more gears. A TH400 with a GV O/D is still only 4 speed and I have yet to see anyone here with a TH400 and a GV kit installed simply becuase it adds weight and requires a much shorter drive shaft. IMO, If you really need the brute strength of a TH400 and need 4 gears you should've started with a built 4L80E with a computer controlling the shift solenoids. Do a search on built 4L80E and call around. You'll find a few cars out there that make very good power and can also coast highways with them.

A TH400 w/GV O/D will out weight the 6 speed.

The 6 speed with a clutch that holds power is tricky to drive. Multi-discs rattle but I love the rattle. Everyone else can hate the rattle but I love it. to each his own.

The 6 speed gives you decel control. I'm not so sure you can do so with a built TH400 unless you have someone customize your valve body to have hold control.

The 6 speed is much more efficient. The TH400 has power losses due to slip since thats what autos were essentially designed to do...slip away.

Due to slipping the fluid is subjected to a lot of heat. So a cooler is necessary. A 6 speed gets its cooling from the underside heat fins so a cooler isn't needed but could be very helpful. Only this is that the 6 speed has no pump so you will need to fab an electric pump for the fluid.

The TH400 was never designed to fit a 2JZ. In order to make it fit guys take and mill off the front of the TH400's case right past the oil pump and make an adapter to fit the 2JZ auto bell housing to it with a hybrid converter. That TH400's bell housing was never designed to be supported by the pump cover bolts. A properly done TH400 really needs a whole new case from a company like Dedenbear who makes performance transmission cases for 2-speed powerglides.

The 6 speed is perfect for the road course and can make do on the drag slip with the right clutch and setup. The TH400 is desirable for the drag strip but sucks on the road course.

If you've spent your $$$$ on the Th400 swap and didn't like it. You might find it difficult to find someone who is interested in purchasing your swap. Not to mention that I have yet to see TH400 supras go for any more than most auto supras. I myself wouldn't offer anymore cash for a 6 speed supra with a Th400 in it unless he/she had all the original 6 speed stuff to go with the car.

Just my $0.02

-Joe
 

·
iSketch Master!
Joined
·
9,044 Posts
now while i would like to have a TH400 w/ GV it would just cost too much and be too much of a headache in the end for me. Especially since i drive the car more often than not. So I say 6speed FTW

Alex
 

·
Turbo Pilot Since 1983
Joined
·
1,113 Posts
breakemlose said:
I have a th400 AEM car.
First off i haven't heard of any th400 with a locking torque converter option holding the big power. So your unlocked 24-7 if you go that route.

Best of all worlds in my opinion would be the following:

*Tighter torque converter
*Gear vendors overdrive so your 60mph cruizing speed is not 3200rpms. Move top speed from 143 to 190mph.
*NO lockup option for the th400. All lockups i've heard all fail wiht the big HP
*no transbrake so you can drop gears rapidly and smoke cars on a roll
*Nitrous if your big single won't spool right with your newly tighter torque converter.
*bigger transmission cooler of course

Watch how easy it is to bust out 10 second passes with drag radials at that point. You can beat 6 speed supras often times on a roll due to the fact that the th400 seems to put much more power to the ground without smoking off the tires unlike the 6 speed setup.
I agree with everything being said here except for the lockup statement! The lockup is the way to go for the footbrakers if you don’t abuse it. If you use the Lockup for cruising and occasionally under power it will be fine. It wasn’t intended to be used for all out racing or so many found out shortly after continually pound on it. In my opinion it is the way to go for a street driven Supra. Couple a GV unit to that configuration and you have one hell of a street transmission.

David
 

·
Registered
Joined
·
208 Posts
Discussion Starter · #11 ·
BamaDave said:
I agree with everything being said here except for the lockup statement! The lockup is the way to go for the footbrakers if you don’t abuse it. If you use the Lockup for cruising and occasionally under power it will be fine. It wasn’t intended to be used for all out racing or so many found out shortly after continually pound on it. In my opinion it is the way to go for a street driven Supra. Couple a GV unit to that configuration and you have one hell of a street transmission.

David

I am an auto now. Pricing all the parts to go 6 speed and the cost of a good clutch was wayyyy overkill not to mention the rattle. I don't want used parts that I can't trust. I Know I would hate the rattle. I already know what to expect from the Auto. I would prefer the computer control the shift (I am AEM also) but not necessary. The 4L80E requires too much fab to instal and heard it was an inhouse install? I do like to take the car on the Highway so an OD is desired. I guess I am already moving toward the TH400.

John
 
1 - 11 of 11 Posts
Top