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Discussion Starter · #1 ·
me and my dad decided to put a th400 in the supra since the stock auto will take a dump soon now that im over the 650whp mark..

so we chose to run the pi converter with a 3800 stall and a rev pattern manual valve body with a lockup switch on the dash. it also has no engine braking since it feels like it goes into "n" anytime i let off the gas and have no throttle.
so far im liking the fact that i can just "slap " down on the shifter for each gear as i go down the track. there is no chance of missing a shift and is idiot proof.

but, how much abuse can it handle on the street? down shifting and nailing it at any given moment? highway pulls? any tips? i guess since it doesnt have engine braking i cant jerk myself around if i would go to first like others ive seen? and for cooling of the th400 i eliminated the stock lines that went to the radiator and ran some large direct lines under pass headlight to a derale double stacked cooler with a fan also. will this keep things cool enough under mild abuse/use? any help would be nice to cut some good 60's and take advantage of the th400. im new to the th400 so any tips/help would be nice to maximize its potential.. :sadance:
 

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Bad Karma Supra
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Welcome to the th400 world.

Abuse wise, the trans should handle you HP all day, every day, 650 is not alot for a 400 to take :) Granted, I have no personal experience, however, based on some stuff here on the forums - those PI TC's can be hit or miss :/ And DEF do not lock it up under WOT - keep that for highway cruising only.

If you don't have a trans temp gauge, put one in and see how your cooler is doing. I ended up with two coolers, each with a fan - one where yours is and another under the driver side headlight.

Cutting 60's will take some practice and IMO - nitrous is much better than standing on your stall at the line :D

Jay
 

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Might be a dumb question but can you get a Th400 in a six speed? If not what swaps are available for manuals? Sorry to jump in your thread!
 

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blazinsi said:
Might be a dumb question but can you get a Th400 in a six speed? If not what swaps are available for manuals? Sorry to jump in your thread!
The Gear Vendors overdrive unit makes it like a 6 speed by giving you an overdrive for each gear. For manual swaps you're looking at going with something custom like a sequential manual gearbox but then you're talking big big bucks and customization. No real reason to switch out the getrag 6 spd. unless you're looking for straight line performance.
 

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1chic2nv said:
but, how much abuse can it handle on the street? down shifting and nailing it at any given moment? highway pulls? any tips? i guess since it doesnt have engine braking i cant jerk myself around if i would go to first like others ive seen? and for cooling of the th400 i eliminated the stock lines that went to the radiator and ran some large direct lines under pass headlight to a derale double stacked cooler with a fan also. will this keep things cool enough under mild abuse/use? any help would be nice to cut some good 60's and take advantage of the th400. im new to the th400 so any tips/help would be nice to maximize its potential.. :sadance:
first off, like was said before, the precision converters are really hit or miss... some guys love them and have no problems, other guys have blown them up like they were stock.... luck of the draw i guess

do not under any circumstances downshift and nail it right away! that is a guaranteed shattered forward drum... you have to downshift and slowly bring it up to speed, then you can floor it (only true for reverse pattern w/o engine braking)

itll be fine on highway pulls as long as you watch ur temps

the derale cooler will do a good job, but most guys still go with a second (no fan) cooler

man, i just got done with my th400 swap a couple days ago and i love it! except i went with a forward pattern w/engine braking because mine sees alot of street miles... i can honestly say that the 400 is better on the street then the toyo trans
 

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lightxx said:
are you sure about this? i thought this was for a specific gear (like 2nd or 3rd gear) only.
no, its for every gear... the OD unit is separate within itself added onto the transmission (replaces the tailshaft actually)

so lets say you are in first gear... and you engage the OD, then you are in 1.5
then you disengage od, and go into second... you are in 2

and so forth for a total of 6 gears

edit: i just looked over the gear vendors website to make sure im right... and i am
but did you konw that the damn gearvendors units cost like 3k? its ridiculous
 

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What? Me Save Gas?
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ic ... despite the fact that i'm 100% positive that there is zero space in my bellhousing to add anything i would suppose that having to press the O/D button so often to gain full advantage of 6 gears will quickly become annoying...

after all, i hope SP finishes its SP4L80E soon ...

swearitsstock said:
no, its for every gear... the OD unit is separate within itself added onto the transmission

so lets say you are in first gear... and you engage the OD, then you are in 1.5
then you disengage od, and go into second... you are in 2

and so forth for a total of 6 gears
 

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lightxx said:
ic ... despite the fact that i'm 100% positive that there is zero space in my bellhousing to add anything i would suppose that having to press the O/D button so often to gain full advantage of 6 gears will quickly become annoying...

after all, i hope SP finishes its SP4L80E soon ...
no no no.. its not in the bellhousing... its on the tailshaft (the tailshaft meets the driveshaft)

let me just set this straight...
bell housing is where the torque converter is
case is where the gears are held
tailshaft is where the driveshaft enters

Well, in a racing application it would be a hassle... but im sure there would be a way for AEM to take care of it
CO2 Shifter + AEM + Gear Vendors unit = glory
 

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Discussion Starter · #12 ·
swearitsstock said:
first off, like was said before, the precision converters are really hit or miss... some guys love them and have no problems, other guys have blown them up like they were stock.... luck of the draw i guess

do not under any circumstances downshift and nail it right away! that is a guaranteed shattered forward drum... you have to downshift and slowly bring it up to speed, then you can floor it (only true for reverse pattern w/o engine braking)

itll be fine on highway pulls as long as you watch ur temps

the derale cooler will do a good job, but most guys still go with a second (no fan) cooler

man, i just got done with my th400 swap a couple days ago and i love it! except i went with a forward pattern w/engine braking because mine sees alot of street miles... i can honestly say that the 400 is better on the street then the toyo trans
ok, if the p.i. converter fails, what is my next choice thatll fit inthere like the pi and bolt right up that is reliable?

and is it really needed to get another cooler on top of my derale w/fan?or is it a added insurance only? i bypassed the stock cooler in the radiator and went directly to the derale cooler, is this good? the no engine braking is very weird to drive. its like going into neutral 2 second after no throttle is applyied. with stock wheels on driving on street it screems w/out hitting the lockup switch on the highway.? my drag wheels its ok.
 

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Bad Karma Supra
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Some of you guys need to: 1) Look around some domestic sites to understand GV units and 2) Look at summitracing.com to find desired parts :)

1chic2nv said:
ok, if the p.i. converter fails, what is my next choice thatll fit inthere like the pi and bolt right up that is reliable?

and is it really needed to get another cooler on top of my derale w/fan?or is it a added insurance only? i bypassed the stock cooler in the radiator and went directly to the derale cooler, is this good? the no engine braking is very weird to drive. its like going into neutral 2 second after no throttle is applyied. with stock wheels on driving on street it screems w/out hitting the lockup switch on the highway.? my drag wheels its ok.
If you have the hybrid setup (?) - I'm not sure, perhaps Larry @ SP or Kean @ BL can help there with suggestions. If it's straight Chevy...there are alot of options. I love my ProTorque - kicks ass :) And they're local to the NE.

Extra coolers are added insurance for alot of street driving in the summer - a 2nd certainly won't hurt anything. Get a trans temp gauge.

What do you mean the street tires scream? Like you're spinning the street tires and the drag setup doesn't spin?

All in all - seriously, I can't even think of how you'd break even a decently built TH400 :D
 

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Hybrid conveter options are:
Midwest Converter (i dont like them... my converter wasnt welded properly and caused my trans to blow)
Protorqe (this is what i use)
Precision (some people love em, some people just have bad luck)

Hurst shifter:
sure you can use one... go on summit and find one that is for the th400 trans... i dont know if it will fit where the stock shifter goes though, so it might require a bit of hacking away at your dash

coolers:
One with a fan is good...
Two (one with fan, one without) is better
-reasoning- at higher speeds the fan acts as an obstruction to airflow and causes the trans temps to raise a little bit. Two coolers ensures the most stable temperatures at all times, but i dont suggest stacking them because that acts like one thicker cooler (not as efficiently)
 

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Black Widow Supra
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Also off topic, but what can leak on a TH400? I recently bought a TH400 Supra and in my garage there is some reddish-brown fluid on the ground, probably directly under the drivers seat, i havent had the car up in the air to see exactly. More seriously, i did a few highway pulls and noticed some fluid on the sides of the car and coming from inside the wheels. Are there any other hydraulic lines that go to the tranny? AAP (in Atlanta, where i bought the car from) said there is a 3 bolt flange on the side of the tranny that can get gummed up and i should take it out, clean it, and reseal with silicone. Any TH400 experts out there? Thanks.
 

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mandrelbent said:
Also off topic, but what can leak on a TH400? AAP (in Atlanta, where i bought the car from) said there is a 3 bolt flange on the side of the tranny that can get gummed up and i should take it out, clean it, and reseal with silicone. /QUOTE]


Havent heard of any issues with that.. but not counting it out..


What sensor/setup are you guys using to get your speedo to work and are you guys using the stock auto shift linkage (just bent to fit) or aftermarket. Looking to build a TH400 setup and finally change out to a 71GTQ (Currently on a T61) but still weighing the options/disadvantages.

Any advice or sugestions from anyone now that you have done it? (Stall sugestions, what works what doesnt, did you use the 6 spd center plastic piece, Did you use the stock shifter, ETC...
 

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Black Widow Supra
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roliks said:
Any advice or sugestions from anyone now that you have done it? (Stall sugestions, what works what doesnt, did you use the 6 spd center plastic piece, Did you use the stock shifter, ETC...
I have the 6 speed center piece, because it has the 6spd shifter boot at the base, makes it look like a 6spd except for the actual shifter, its the chrome topped one with 'B&M' engraved in it.
 
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