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
89 Supra Turbo
Transmission
- Thread starter mcoleman5
- Start date
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.
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.
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....
-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....
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
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
JustAnotherVictim
Supramania Contributor
JustAnotherVictim
Supramania Contributor
JCFsupraman said:
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.
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?
Does the PI converter still not match the holes on the 7m flexplate and need to be enlarged?
joliroger4 said:
very good point i forgot to add.
joliroger4 said:
Thats exactly what i had to do when i ran the PI. Just slightly though.
I do sell the adapter plates but out of them right now. My machine shop should have about 5 done soon.
Shawn C
Best Transmissions
413-736-9496
Shawn C
Best Transmissions
413-736-9496