minnyminh

iTrader: (3)

does anyone know if a toyota soarer transmission fits onto a 99 gs300? i have one and wanting to put into mine but i do not know if it fits. the tranny now shifts hard with 8 lbs. of boost. right now im scared to go more... dont want to be laying on the side of the road for tranny failure.

DaveGS4

iTrader: (2)

You might want to start out with valve body upgrade. What kind of HP are you pushing at the rear wheels?

minnyminh

iTrader: (3)

i got in dialed in at 278hp at the wheels. how much is the valve upgrade?

DaveGS4

iTrader: (2)

Hmmmm... most of the tuners I've talked to say you should be good to about 400 rwhp on the stock tranny. After that there are problems. I'm at 360+ rwhp on mine and the only real problem I have is hitting the rev limiter.

I got my valve body upgrade used from another member. Shifting is much faster and more precise, but it is definitely rougher (no more lexus smooth shifts you don't feel). SRT sells one (link below), and I think RMM and a couple other places do as well.


http://www.swiftracing.com/engine/tranny.htm

minnyminh

iTrader: (3)

isnt the gs4 tranny better built and stronger than the gs3? the gs4 has lsd also.

SeattleGS400

iTrader: (1)

The stock GS4 doesn't have a LSD (unless you swapped it out for a Supra LSD). Anyways, you may have a good point about the build quality between the GS3 and GS4 (as they have different gearing, and maybe different durability of the gears used). . .

Try doing a search on CL and see what others with forced-induction GS3s did to their trannies to beef it up. Good luck.