Transmission

[mcoleman5]

Can someone give me all that is required to convert my 5 speed trans to a 350 or 400 automatic. Also with advice on which trans to go with?

89 Supra Turbo

[89Turbo]

the trans(obviously)
custom adaptor so it will bolt up, or somebody sells them
new driveshaft
custom fabrication because i believe TH350's are much larger
much more that i cant think of, Slow66 will chime in....

[dbsupra90]

yeah there are quite a few things involved.

aside what was mentioned you need a shifter, modify the console, adapter for the speedo, and a custom torque converter.

you can keep your 5sp ecu since the 350/400 isnt computer controlled.

the 400 can take more abuse and a little cheaper to build. but it is much heavier and more parasitic loss. a well built 350 should handle most applications but most advise against using a transbrake w/ it.

[Slow66]

Here is what is needed.

-tranny
-adapter (2 types) one that bolts up to thechevy bellhousing, and one where the chevy bellhousing is machined off the tranny, and a toyotya bellhousing is bolted up by way of an adapter on the front pump (also known as oneandgone's method.
-custom converter, PI and ATI make them
-custom driveshaft
-custom tranny mount (i modified the stock one on my previus setup)
-shifter and cable
-custom "bashing" of the firewall if the chevy bellhousing is retained.
-clearancing of the chevy bellhousing for the coolant lines that run behind the block

Thats mostly it....the th350 will take alot of abuse as db said, si i woudl stick with that under 700whp or so.....over that 400 or pg inless using a break.

Remember theres no overdrive, and if you have 3.91s, youll be hitting the limiter at the 1000' mark(by way of converter slippage, uless you get a tight converter...), so i advise the 3.73s.

Thats abotu it i think....

[JCFsupraman]

Bryan, who are PI and ATI?

Also does Shawn C sell the adapters? do I need to buy both? or do you mean that there are 2 ways to actually do this the way Grant was saying and then leaving the GM bell housing too?

Aluminum driveshafts - no one in particular so just shop around? or is there someone that sells them as well.

Sorry if these questions sound basic or simple but I don't know. thanks

[Nick M]

http://www.atiperformanceproducts.com/products/products.htm

http://www.converter.com/

[xXxICExXx]

what is the stock gears anyways in our car? 4.10s?

[JustAnotherVictim]

n/a 4.3
pre 89T 3.91
89T+ 3.73

[xXxICExXx]

well i been reading some false info online then! thanks J-A-V

[JustAnotherVictim]

No problem. No lsd on N/a's without the sport package also.

[Slow66]

Bryan, who are PI and ATI?

Also does Shawn C sell the adapters? do I need to buy both? or do you mean that there are 2 ways to actually do this the way Grant was saying and then leaving the GM bell housing too?

Aluminum driveshafts - no one in particular so just shop around? or is there someone that sells them as well.

Sorry if these questions sound basic or simple but I don't know. thanks

PI - is Precision Industries
ATI - www.atiperformanceproducts.com

Shawn will be sellign the adapters i believe...these use the GM bellhousing and a hybrid converter (ie 1/2chevy 1/2 toyota). And you got it right abotu the 2 ways to do it.

For DS's, i like Dennys www.dennysdriveshaft.com ...they can make pretty much anythign in either steel or aluminum to your specs.

[aye mate]

Also I believe all AT turbo Supras have a 3.73 and 5spd turbos have the 3.91.

[joliroger4]

To add to what slow said, the ATI kit comes with an SFI approved flexplate. Also, TH350s notoriously have a weak 2nd gear sprag which is the biggest problem they have. It is strongly recommended you do your burnouts in 2nd gear and shift into third. If I were building a supra with a GM trans, it would def be a 400 because of how heavy the car is.

Does the PI converter still not match the holes on the 7m flexplate and need to be enlarged?

[Slow66]

To add to what slow said, the ATI kit comes with an SFI approved flexplate.

very good point i forgot to add.


Does the PI converter still not match the holes on the 7m flexplate and need to be enlarged?

Thats exactly what i had to do when i ran the PI. Just slightly though.

[besttrans]

I do sell the adapter plates but out of them right now. My machine shop should have about 5 done soon.

Shawn C

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