V8 Supra MK3 1UZ Twin Turbo from Germany - Part II

FoPar

New Member
good to see alot of work being done by owner, instead of paying someone.

how much plenum volume did the custom one have? also shorter runners the custom would have more up top, unsure why it didn't work must have had some serious issues. usually you can throw anything on and it will work.

we use the factory lower with custom plenum, might be costing us 50-80hp, but, it works fine engine is showing 1200hp with a couple old 62mm cast wheel turbo's, and was under $1000 to do. we will be doing a full custom intake manifold later, will be a good lil design with much smaller plenum volume, currently has 8-9L. new one 3.6-4L should be plenty.
 

Speeedy

Member
good to see alot of work being done by owner, instead of paying someone.

how much plenum volume did the custom one have? also shorter runners the custom would have more up top, unsure why it didn't work must have had some serious issues. usually you can throw anything on and it will work.

we use the factory lower with custom plenum, might be costing us 50-80hp, but, it works fine engine is showing 1200hp with a couple old 62mm cast wheel turbo's, and was under $1000 to do. we will be doing a full custom intake manifold later, will be a good lil design with much smaller plenum volume, currently has 8-9L. new one 3.6-4L should be plenty.
Yes, thanks a lot. I'm very interested in doing a lot of parts myself.

Plenum volume is about 10L, like yours. I have no idea why it does not work. :confused::confused: But I will build another one. ;)
Why do you think a smaller plenum would work better? I've heard, plenum volume should be around 2xdisplacment. So your 8-9L should be perfect.
 

FoPar

New Member
2x was the go 7-8 years ago, now it's more like 100% now, you keep the speed up fills everything nice and quick.
 

CHB

New Member
Ok thanks. But why you want to made in into larger size? Isn't that you have to recut the teeth on all discs as well?
 

Speeedy

Member
Ok thanks. But why you want to made in into larger size? Isn't that you have to recut the teeth on all discs as well?
Yes, you're right. But the machine shop who did machine the hub hadn't the right tools to do the same teeth like the HKS hub/disc. That's the reason for the custom solution.

Best Alex
 

Speeedy

Member
Hey guys!
A few weeks ago, I rebuild my R154 transmission with the marlin crawer parts including the billet shift forks from Driftmotion.
But yesterday I destroyed the tranny when fine tuning the AEM boost control. It happened at only 1,35 bar in fifth gear where the transmission must handle about 9xxNm. It looks like that the R154 can not handle that much torque for a long time.
Now I'm thinking about buying a Tremec transmission. I'm not sure which I should looking for?
TKO600 or the T56 Magnum six speed? Could the TKO600 handle torque over 1000Nm? Anyone have experience or informations?
 

cribbj

"Supra" Moderator
Staff member
Alex, sorry for your R154......RIP :)))

Over the years, we've had a lot of discussion about the Tremecs on 1UZ's in Supras, SC's, etc. but I don't know that anyone has actually done one.

The general conclusion was that it "should" be a great alternative to the overpriced V160 on the 6spd MKIV Supra.

Hope you go forward with this and document it here. You're probably one of a few who have the knowledge AND equipment to do this.
 

Speeedy

Member
Thanks John!

Of course, I will let you know what I will do and which parts of the R154 are broken.
I give you an update in the next few days.
Alex
 

JustenGT8

New Member
Mine has run a TKO600 for years now. The only issue I've had was the pressed steel front cover not bring strong enough to support the sky's haft bearing. There is a fix for that now which makes it a pretty bullet proof choice up to 1000hp.

As they are rated at 600ftlbs constant load, they should handle spikes to a 1000ftlbs ok I'd suggest......that's crazy torque though, not many 4 litres will ever mske that?
 

cribbj

"Supra" Moderator
Staff member
Mine has run a TKO600 for years now. The only issue I've had was the pressed steel front cover not bring strong enough to support the sky's haft bearing. There is a fix for that now which makes it a pretty bullet proof choice up to 1000hp.

As they are rated at 600ftlbs constant load, they should handle spikes to a 1000ftlbs ok I'd suggest......that's crazy torque though, not many 4 litres will ever mske that?
Dayum, why didn't I remember you had a Tremec, Justen? Wait....don't answer that :)
 

Speeedy

Member
Haha John.... I forgot it too, that Justen has a TKO.
I'm happy to hear, that there is a way to make the TKO bullet proof. But I think I will go the T56 Magnum way. It can handle a bit more torque, it's a six speed, and nobody did it yet. And it isn't much more expensive. "only" a few hundred dollars more..... I let you know....
 

Speeedy

Member
Today I checked the R154 tranny... Holy...
Pictures tell the stotry... :eek:




Fifth Gear is gone...I found it like this in the rear housing.







Input Shaft




 

cribbj

"Supra" Moderator
Staff member
I'd say you were running a bit of boost there Alex....

Now the R154 crowd will want to know how much you think you can safely put through that box?

BTW, were you running really grippy tires, or were they spinning when you inflicted all that carnage on your poor box?
 

Speeedy

Member
It happened @ 1.35bar of boost, about 4500-5000rpm, WOT and in fifth gear. The engine should make about low 9xxNm at this boost level.

I have Toyo R888 semi slicks, and yes they are very grippy.:D

I already tested 1.5 to 1.7bar peak boost, but in 2nd and 3rd gear. I think the time is too short in the lower gears to kill the tranny directly. But in fifth gear the peak torque hold on for longer time because of the higher vehicle speed and more drag. That kills the transmission, in my opinion...

I have some 2jz buddies with R154 transmission driving in the 700-850Nm range without any issues. Another friend has a 720Nm 7M-GTE and he does a lot of hard starts, fast shifting, road racing etc withot any issues, too. So I would say about 750Nm is ok for the R154. Maybe more...about 850Nm. But it could be critical, like when drag racing etc...
Important too, you shoud change the pressed steel bearing cover (like Justen's TKO600) to the billet one from Marlin crawler...;)
 

JustenGT8

New Member
Yeah the thrust washer is a known r154 weakness, but you have destroyed that box from pure torque overload of the gearset i reckon :) good job ;) 5th is obviously the weakest gear too, so a prolonged full throttle run wouldn't have helped.

the Magnum should work well....they are double OD still though aren't they? Which i have always found a bit daft? If they were a true close ratio 6 speed i'd probably upgrade to one....although with the torque we have a close ratio box isn't really needed.

BTW my rear diff ratio is 2.92:1 (still manages a 1.5 60ft) and theoretical geared top speed is 413kph LOL with the twin OD 6 speed it would be up around 450+kph. I'd need a very long test track, in a vaccum to reach that :)
 

Speeedy

Member
:pYes Justen, the fifth gear of the R154 is weak... Obviously... ;)

If I'm right, the Magnum has approximately the same ratio, than the R154 with an extra six gear. So it would be perfect with the stock Supra diff (3.72:1)

Your diff ratio is interesting, Justen. What diff is it? Stock?
A buddy bought a BMW E46 3.0d five speed tranny for his 2jz Ford Sierra. But the Supra MK3 Diff don't work. It's too short. Need a diff with a ratio about 3.00:1. So yours would be an option.

400kph+++ is horrible... :eek:
 

JustenGT8

New Member
It's a Team Toyota diff, used in their MA70 supra race cars on the tracks with higher top speeds. I had two but I sold one sorry. A slight chance you could find one thru TRD? I'd hate to think of the price.

I do have a 3.4:1 G series crown and pinion if that would help?
 

Speeedy

Member
That's cool, Justen!
My buddy Jürgen has some racing parts from a race team too. I just tested a LSD Diff from him with stronger output shafts. Maybe he has another ring and pinion. Do you know the number of teeth of your ring and pinion?

Alex
 
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