Hermosa

I need a tranny but can't decide.

gadgetSC

Hermosa...Did you loose your tranny as a result of too much power from your turbo? If so, what power levels were you at and how long did it last?
Is it completly gone or just slipping badly?
My vote is for the SP400 w/TT LSD. I didnt know the OD was available. Sorry for all the questions.



gadgetSC-t

Fred Smith

You're NA-T right? What power level?

If you originally had a 5 speed SC300:
Don't get any of those options. Get yourself a R154 out of a MA70 Supra Turbo. Look on Supraforums (if it ever comes back to life that is). If you are willing to blow 400-500, you can get one real quick. I held out and got mine for a lot less.

Now go down to your Toyota dealer and order yourself a R154-1JZGTE bellhousing (and possibly a crossmember if you aren't creative) out of a JZZ30 Soarer. Over here they run about 350 US Dollars. Check that it bolts right up, but I dang near guarantee it will. I believe your SC3 shifter will work in the R154 as well. Now you just need a clutch, and maybe a trip to the driveshaft shop for an adjustment. I hope you already have a LSD. If not, shame on you! Just a little fooling around with the wires to hook up the speed sensors and stuff, and you're done. The MA70 service manual is online and frrrrreeeee!

This should be a heck of a lot cheaper that getting a V160, and the ratios will be better for a ~3.9 rear end like you have, instead of having to get a 6sp LSD, axle and driveshaft.

Hermosa

Mines an automatic so it is hard to go manual. I would need a manual SC300, 6spd Getrag, Supra TT driveshaft,LSD, and left half shaft as well as a couple months at least. Maybe in the future but I like using this as my daily driver.

The Sp400 or equivalent seems pretty nice.

I have plenty of diffs by the way.

Stock 4.27
Supra NA LSD 4.27
2 x Supra Turbo Auto LSD 3.79
Supra Turbo Manual LSD 3.13


Oops the power question...360RWHP for two months.

Ebanks

You will not be disappointed with the SP400. It shifts quick, and firm. If you have a tall rear end in the car like a 6 speed LSD you will not need OD. Did you see the video I posted where you can hear how quick and positive the shift is? No slippage whatsoever.

-Ethan

TurboB6

I dunno if its just me but 360rwhp doesn't seem to justify a SP400 conversion. I'd just do a built NA tranny for those power levels. This is just my opinion though.

Fred Smith

Hermosa

I have a R154 in my garage next to my V8 auto Soarer. I am planning on installing it soon. As you are aware, there is no manual ecu for the V8.

I am an electronic engineer. I will work out the ECU issues without a doubt. It is definitely possible to use the auto ECU with a manual tranny. I have the service manual for the SC300 as well, so I can help you get a manual working with your car. What would I ask? A deal on one of those Supra auto TT LSDs. I have been looking for one of those for ages.

I would stay away from the 6 speed. Not worth the hassles, and there are a lot of them. If you want to go manual, I would definitely go the R154. It can and will hold your power level. I am planning on 500+ through mine. If you want to go this route, I would suggest that you look for a cheap auto to stick back in your car now, stop abusing it , and start collecting parts for the manual swap. I will help you (as well as others on lextreme.com) with the ECU issues. With the parts you have, I bet you could get this whole thing done inside 1500$ no problems at all. R154s go all the time for 300 US Dollars. Give me a month on the electronics and I should be in good shape. Just got the gearbox about 3 days ago.

Don't waste the money on a SP400. What happened to your auto? Gears exploded?

BTW, I have heard the TT Supra autos are quite strong, but youre gonna pay.

Hermosa

If I get the SP400 then I will go to 450RWHP immediately and then later change turbos to go 600RWHP.

Yes the auto fluid now has all kinds of junk floating in the charred fluid.

808SC300

Do you have a trans cooler? How often did you change the fluid? Having the auto crap out really puts a damper on turbo plans. Having to spend an additional 5-6k *just* so the car can handle the power. Did you look into sending your trans off to SP and having them do a rebuild? Dave H did that and he's running in the ~600 Hp range with it.

Fred Smith

yeah, but that's a big price, and seriously... who wants an auto with 600rwhp on tap?

gadgetSC

I'd take it



gadgetSC-t

Hermosa

I have a huge trans cooler. The fluid was changed about 6000 miles before it crapped out. I can't find a web site for Sound Performance anymore. It is gone. How much does a good rebuild cost? Does it shift well?

- Mike

And nothing wrong with a 600rwhp auto. Once I find something I would really enjoy driving as a daily driver I will keep the auto. Having a manual as a daily driver is a waste around here. Too much stop and go. I might buy a nice truck to haul the dirt bike though

Hermosa

To add to that, my SC300 is a project car that I plan to tinker with for years to come. I try to keep most of the aspects of the car intact. Eventually though I plan to try, and I stress try, to do the following:

built tranny (sooner than expected)
methanol injection (coming soon)
stand-alone computer for engine
larger turbo and injectors
custom leather seats and wheel
custom taillights
custom front bumper
custom hood
computer in console to handle A/V
auto-retractable hard top (pie in the sky)
repaint

Ebanks

I had a built SP NA trans before the SP400, and if you want to make 600 RWHP eventually save yourself the hassle of having to try and unload your $4000 NA trans and converter build later when you could have spent the extra couple grand up front and never had to replace it.

Get the trans you know you will eventually need now, because when you make big power you will eat even a built NA trans... Mine lasted about 1 month when I was making 600-650 RWHP.

-Ethan

DaveH

Surprisingly enough, my SP built NA trans has held up fine for 3 years now. I don't drive it a whole lot of miles tho, but it has held up to numerous 11 sec passes, and a handful of 10 sec passes just fine. I have a fairly large cooler, and change the trans fluid every time I change the engine oil. I will eventually get a SP400, just because I plan on more HP than I'm currently making.