bryan767

iTrader: (6)

Okay, so i recently acquired a 1jzgte single turbo sc300 with a fresh A340LE. it has a factory stall at 2000 rpm. my problem is i want to launch this at the track. and for the life of me i cant unlock the stall.

methods i know of:
-some other cars you can reverse and unlock it..
-you could do 100% brake 100% throttle, then 0% brake and 100% really fast and itll rev up.
-even neutral drop it.
-power brake (again it wont rev past 2k rpm since thats the stall)

i just cant get a good launch.. hell it wont even spin! yet once i spool ill lay two tire marks at 40mph going into 2nd on 275/45's

i need some advice, because iv asked everyone. it seems like a easy question but, "***** wont burn".


-edit. i think i might be giving it to much brake when i power brake. i just remember my old sc300, i had to be all the way on the brakes

turbodremz

iTrader: (18)

umm...get a 5-speed? Pre-loading an auto trans for launch isnt hard. And I dont see how you cant launch with a 1JZ and get spin off the line. I could spin 275's on a stock GE with the auto from the line no problem..problem I had was finding the right spot to not spin..

Get a different tc with a stall more suitable for what your wanting...but dont expect that trans to last long. You would be better off with a w58 atleast...ideally an R154

MMCtuner

I have a good launch by making the powerbrake method but mine starts to spin the tires even at hard braking. If I lift the brake after the first seconds of spinning (when starts to rev up) the launch it´s really nice; if I lift earlier, then the launch is damn slow, if I lift too late, wheels keep spining and loose some seconds again.
The drawback at the drags is if the other car aligns first, then you´ll have no chance to do it.
By slamming from neutral...I don´t think that would be any good for the trans.

xspsi6

iTrader: (31)

It's never going to launch right on a stock converter.

bryan767

iTrader: (6)

this is my third sc, iv done the r154 swap before. im not doing it again. im not asking which is better, i just dont get why it wont spin. but it makes since why i could spin with my twins and not my single. the twins made boost way lower, and i could get the wheels to peel. but now i have to let it sit alot longer and try to load the tranny more. maybe itll work better when i go to the track, tire warm up area. idk

blueboost6

iTrader: (4)

With a single you move the power to the right of the power band to get a good lauch you need a stall. what size single do you have?

stockhatch

iTrader: (12)

Get a decent converter and that thing will launch. End of story.

TechGreek

iTrader: (4)

Number one, you've got a torque converter that has to "spool up" to engage - hence the stall. So if your max boost on a single turbo is at 3800 RPM then you're going to be all N/A power until you reach that rpm off a 2000 RPM stall. You'll need to go up to at least a 3000 RPM stall so you can be in your power range off the line.

You can't spin a stock auto because the ECU retards the timing based on the smoothness of the launch.

Spinning is not winning...and good god don't neutral drop your poor transmission.

If you're really wanting to take it to the next level, a line lock would be your answer but you need to upgrade your stall rpm first.

whiteSc3

iTrader: (1)

**ding ding** And your stall is unlocked that's why it revs up to 2k, it is too tight to get into your power range though. Buy a looser stall, through a 50 shot of n20 and you'd be fine. You may also try the line lock, but it may not be enough..

TechGreek

iTrader: (4)

I didn't mean to say a line lock, I meant a transmission trans-brake. A line lock would help in keeping it in place.

whiteSc3

iTrader: (1)

Going to need a built american tranny to run a TB. Running a line lock may take enough rear brake off to allow it to build boost. But I would try n20 or higher stall..

TechGreek

iTrader: (4)

Any particular reason we can't do a trans-brake? I was under the assumption thats what the higher built A340E's had in them ready to go.

whiteSc3

iTrader: (1)

Don't know trannies well, but from my understanding a TB locks 1st and reverse gear together to hold the car in place.When the solinoid releases the fluid in the valve releases from the reverse gear and allows the car to move forward. This puts a lot of shock on the drivetrain. I am only aware of them really being used with Th350/400's and the Ford equivalents. I believe the built toyo auto guys are either using a TB or foot brake but I may be wrong..

whiteSc3

iTrader: (1)

Plus a TB will only allow the convertor 'flash' up to the stall speed. So a tight stall will still be too tight. That's why I use N20

xspsi6

iTrader: (31)

I wish there was a way to get a trans brake in to the toyota trans but it is not at all possible unless you convert to a gm trans and as stated above the trans brake engages 1st and reverse however driveline shock is much more "soft" as you are pre loaded where as in a manual trans the shock loading kills driveline parts much like a neutral drop would and not to mention blow the seal out of the forward pistion in the trans.