how much power can the rest of the car take

sctwinturbo

New Member
May 14, 2007
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new jersey
i have a 1jz-gte single turbo. (soon 2jz block)
i am just about to buy injectors looking at RC 1000cc. or 1200cc
running a greddy t-78
walbro twin in tank pumps
ems 6860 ecu (soon to buy)
built block and head
89 supra turbo body
from what i heard i can run 25 psi on my 1jz engine
how far can i push this set up not to break my gearbox, diff, and axles
as you can tell my swap is almost finish
1. how much power can the stock w154 gear box take ?

2. how much power can the LSD turbo diff take ?

3. how much power can the axle's take ?
 

IJ.

Grumpy Old Man
Mar 30, 2005
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I come from a land down under
1: Depends a lot on driving style and general condition of the trans

2: Again a bit general and vague of a question, street tires if everything is in good condition LOTS slicks not so much.

3: NEVER heard of a Mk3 breaking an axle I'm sure it happens but it's not common.
 

Poodles

I play with fire
Jul 22, 2006
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Fort Worth, TX
1. rebuild it right ONCE and you won't have issues (ask Duane)

2. Same as 1 especially if you get rid of the crush sleeve that allows the pinion preload to loosen and allow everything to fail

3. With IJ on this one, NEVER seen one fail, only seen where a boot gets torn and they wear out because they get dirt in them. The boots don't seem to fail as easly as they do on a FWD car because they don't do nearly as much twisting...

I'd be more worried about the driveshaft, clutch, and any shockloads that cause damage to components...
 

sctwinturbo

New Member
May 14, 2007
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new jersey
the driveshaft ?? never heard of that as a problem for any supra??


the crush sleeve is in the gearbox ?? (this winter i will remove it)

i guess really i am almost done with the engine and i feel as if it's going to be to strong for the rest of the car.
 

ForcedTorque

Join the 92 Owners Group
Jul 11, 2005
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How much power are you guessing you will make? There are several 800+hp MKIII's with various engines. I'd say if you plan to run that much power or more, you should do it with the assumption that you will break things eventually.
 

Poodles

I play with fire
Jul 22, 2006
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Driveshaft failures from using an old stock driveshaft where the center carrier bearing goes out or the bonded back half twists and goes out of phase causing bad vibration.

Crush sleeve is in the diff and keep the preload on the pinion. As seen here http://www.supraforums.com/forum/showthread.php?t=430339

If I where to rebuild the tranny I'd get the upgraded front bearing cover from marlin crawler (marlincrawler.com).
 

sctwinturbo

New Member
May 14, 2007
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new jersey
i really dont know how much power i will be running
but i talk to some guys at 3 different dyno shop's and they said with my set up i am looking at 900+ hp
should i believe them i dont know ????
but i am asking these questions because when i dyno the car i wanted to know if there was limit i should stop at
meaning lets say i run 1000hp and the gearbox and diff can only hold 750hp i would only set to 750hp
if you guys think i can run full power and say they hell with everything ???
 

Boost Lee

Bee Doo Bee Doo Bee Doo
Staff member
Sep 13, 2006
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sctwinturbo;1123258 said:
i really dont know how much power i will be running
but i talk to some guys at 3 different dyno shop's and they said with my set up i am looking at 900+ hp
should i believe them i dont know ????
but i am asking these questions because when i dyno the car i wanted to know if there was limit i should stop at
meaning lets say i run 1000hp and the gearbox and diff can only hold 750hp i would only set to 750hp
if you guys think i can run full power and say they hell with everything ???

If you're honestly thinking there's a chance to make ANY WHERE near-quadruple digit horsepower numbers, then you may want to reconsider a few things here.

Is the factory driveshaft, trans, etc CAPABLE of maintaining that much power?
Absolutely.

But again, if you're going to be making that much power...
Don't cheat yourself out and then make your way onto the public streets and break something risking both yours and others lives.

If it were me, I would 100% upgrade the driveshaft.
The axles, as mentioned, aren't really a problem-factor with Supra's.

The R154 transmission...
I wouldn't go as far as to say it's bulletproof, but with one in great condition,
They can typically take just about anything you throw at it.

But to reiterate, On a realistic level, if you're setup may take you up to that much power....You may want to reconsider a couple things.

Good luck,

Jeff
 

Turbo Drifter

New Member
Dec 8, 2005
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Surrey, BC Canada
There is no way you are going to make 900-1000whp out of a Greddy T-78, its a fairly small turbo by today’s standards (66mm).

The rest of the questions have been answered.

Jeremy
 

Adjuster

Supramania Contributor
A sprung hub clutch, and smooth engagement is good for the R154 to last as long as possible.
Same goes with a gentle hand on the shifter. :)

The thrust washer has been a problem on the R154. It appears oil is scraped away, and then it galls, and fails. To avoid this, I smoothed the sharp edges on my replacement one, then sand blasted and coated it with molydisulfied. (Friction enhancer that also tends to help keep oil on the part.) This seems to have worked so far. I also thermal coated the cases with a dispersant, to turn the whole trans into a cooler. That made a big difference on how hot the transmission runs. (Based on my highly official right hand on the shifter metal parts testing ability... the shifter metal part would be quite hot when running long distances, now it does not get hot at all, just barely warm.) I also molydisufied coated the rear bushing that the driveshaft yoke can sometimes contact, that seems to make me sleep better at night too. LOL

Never heard of any diff problems etc. That crush tube/collar thread is interesting.

Get a good driveshaft replacement for the stock setup. Aluminum or CF is better than steel for vibration dampening, but I think the steel ones are stronger. (I have a CF one.)
 

honestabe

Happy as hell :D
Jan 15, 2006
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The aluminum driveshafts are only good for about 400 RWHP IIRC. The steel ones are heavier, but stronger. As for CF driveshafts, one knick in them and you have an instant broom. I will eventually be running 600+ RWHP and will run a custom steel driveshaft. The only way I would run a CF driveshaft would be if my Supra were a 1/4 mile queen. But since mine is also driven on the street, no CF DS for me.