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Discussion Starter · #1 ·
hi guy, i have a 1991 r32gtr and now im saving money for an engine rebuilt ( rb30 t51r kai 800-1000hp) and i dont think that the standar gearbox could take it. the car will be a streetcar and will see sometime drag and track day. i want to know what is the best cost/effective/reliability between these 2 option.

1st option is a r34 getrag with all the mod to fit in a r32gtr (push pull converter i think? front and rear diff but how it going if you don't change it? drive shaft front and rear? transmission crossmember mod?anything else?)

or

2nd option do a complete rebuilt of my r32gtr gearbox with a os giken gear kit ( 1,2,3, and input shaft, want to keep the stock 5 for top speed because osgiken is shorter. im right? if not the case i will take the 5gear set.os giken center plate,r33 syncro i think i need?? hd bearing and new seal.)anything else i need if i dont want any used part in the tranny?

it dont make any difference to me to have a 5 or 6 speed transmission. my choice will be really on cost/reliable option

i want comment from people who know the cost of one or both of these option or people that have 800-1000hp and know wich tranny option is reliable at this level

thanks a lot!!

christ
 

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Dont know about the 34 box but, i got approx 800bhp with os conversion box, never missed a beat, well happy:thumbsup:
 

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I've been thinking about this myself after seeing videos of the Mines R34 running r32 diffs.

I've got a r32 gtr, sure it'll be expensive and lotsa work but wonder how quick a r32 goes - with r34 6MT box and same r32 diffs?
 

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Discussion Starter · #4 ·
im considering the getrag gearbox in my choice because theres a lot of drag supra with 1000hp+ with the stock same getrag transmission but rwd
 

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im considering the getrag gearbox in my choice because theres a lot of drag supra with 1000hp+ with the stock same getrag transmission but rwd
i actualy heard that the r34 getrag box is different from supra... different model no....can any1 confirm?

apparently the r34 getrag is weaker and breaks much more
 

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The supra and r34 box's are simular and use alot of the same parts. I used the supra manual when rebuilding my r34 getrag and the fact that my parts come from toyota tells you something else. hahahahaha.

They do break but then i have seen more broken os giken kits then getrag's :)

Its the v160
 

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I had my R33gtr gearbox rebuilt with OS gear kit 1-3, hollinger input shaft, OS centre plate and new oem 5th,like you said it is taller for higher top speed.

I have to say it is very impressive, feels very strong and smooth,like stock only better.
 

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you get a better spread of gears with the os gear set!
first on the getrag is a bit short with 4.11 diffs (r32/33)!
 

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The supra and r34 box's are simular and use alot of the same parts. I used the supra manual when rebuilding my r34 getrag and the fact that my parts come from toyota tells you something else. hahahahaha.

They do break but then i have seen more broken os giken kits then getrag's :)

Its the v160
thanks! was it expensive or not too bad? hows the response on ur car?
 

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Discussion Starter · #10 ·
The supra and r34 box's are simular and use alot of the same parts. I used the supra manual when rebuilding my r34 getrag and the fact that my parts come from toyota tells you something else. hahahahaha.

They do break but then i have seen more broken os giken kits then getrag's :)

Its the v160

wich front diff and rear diff are you running? r32 r33 or r34?? how much power do you have??
 

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Discussion Starter · #11 ·
I had my R33gtr gearbox rebuilt with OS gear kit 1-3, hollinger input shaft, OS centre plate and new oem 5th,like you said it is taller for higher top speed.

I have to say it is very impressive, feels very strong and smooth,like stock only better.
how much its cost consedering that im not rebuilding the gearbox my self and i want the os giken 1,2,3, kit with the input shaft that is the 4th gear at the same time i think? with the os center plate and all new everything to goes with that?
 

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Discussion Starter · #12 ·
you get a better spread of gears with the os gear set!
first on the getrag is a bit short with 4.11 diffs (r32/33)!


thanks! it's good to know that and at the same time, i want to know at this hp level (800-1000 at the flywheel) does the other part in the drvietrain will be able to work properly or they will fail instantly (transfer case, front diff, rear diff, driveshaft, and dont know how to say cardan in english?(driveshaft from the diff to the wheel))


thanks for your answer!

christ
 

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Transfer case is fine unless old and worn.
Front diff - risky if launching hard at the strip often. Aftermarket LSD is the solution.
Rear diff - only issue is how worn out it is - aftermarket LSD and new bearings/seals cures any issues.
Rear driveshafts - fairly bombproof - but known to break on occasion.
Front driveshafts - not so bombproof.
There are a few companies offering uprated driveshafts.
Propshafts - no issues if in good order - check the centre bearing rubber isn't shot.
 

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2nd option do a complete rebuilt of my r32gtr gearbox with a os giken gear kit ( 1,2,3, and input shaft,
want to keep the stock 5 for top speed because osgiken is shorter. im right? YES
if not the case i will take the 5gear set.os
giken center plate,
r33 syncro i think i need?? YES
hd bearing and new seal YES .)
anything else i need if i dont want any used part in the tranny?

I run the 123 5 os set / 5th is slightly less tall than the factory one (so it wont go off the 300k speedo now (shrug)

Theres already a lot of threads about th 6 speed into the R32 / search / advanced search / 6speed / R32 / enter....
 

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Do you want 800hp or 1000hp?

The T51R KAI is only rated to 800hp, for 1000hp you'll need the T51R SPL.

To be honest, launching on a strip with 1000hp isn't going to be very friendly to either transmission. I think the Getrag and the OSG kit will prefer 800hp over 1000hp though, but as Madden has mentioned, they both break. And that's with less power.
 

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Discussion Starter · #16 ·
Do you want 800hp or 1000hp?

The T51R KAI is only rated to 800hp, for 1000hp you'll need the T51R SPL.

To be honest, launching on a strip with 1000hp isn't going to be very friendly to either transmission. I think the Getrag and the OSG kit will prefer 800hp over 1000hp though, but as Madden has mentioned, they both break. And that's with less power.
i agree with you but what will be your choice of drivetrain at this power level(800hp)
i cannot afford a sequential transmission and like i've said the car will be street driven first and may be 15 launch at the drag strip per year

nobody can tell me the whole cost of one of the option??
 

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Getrags have been ok with 800hp and so have the OSG gear kits. It's the drag racing that kills them, but on the street you should be fine if you don't launch it from every set of lights, lol.

A new Getrag will cost around 5,600.00 US Dollars. As for the gear kits, I have no idea.
 

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thanks! was it expensive or not too bad? hows the response on ur car?
Yea the response with a big single is great. Still on stock r32 diffs and lobe it :). Running at 531 hubs.

Don't get me wrong the os giken kit is good but I know I will smash a gear and then it would cost a fortune in parts alone to put right. :(. I have seen quite a few loose a tooth where on the stock gearboxs I was smashing all the teeth off both gears :) so they are abit stronger :chuckle:
 

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Discussion Starter · #19 ·
Yea the response with a big single is great. Still on stock r32 diffs and lobe it :). Running at 531 hubs.

Don't get me wrong the os giken kit is good but I know I will smash a gear and then it would cost a fortune in parts alone to put right. :(. I have seen quite a few loose a tooth where on the stock gearboxs I was smashing all the teeth off both gears :) so they are abit stronger :chuckle:
tranny killer! loooll

running the 6 speed with r32 diff is better for drag than topspeed because of the gearing?
 

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Yea it just make's the gearing really short but does make my car come to life as it keeps the revs in the sweet spot all the time for my turbo :)

Basically it like being in 4th when I'm in 5th using the getrag;)

1st gear is pretty shit for drag racing as you just run of of get as soon as you have lifted the clutch. I'm going to try and launch the car in 2nd now to see how that works :chuckle:

Cost wise. I would say a good box will cost you £2.5-3k maybe more. Coversion kit is not much at all say £500 max.

Now go price up a os giken 1-4 kit :) hahahaha. Once you have the kit you need to buy all the later spec r33 syncros and bearing's and everything you need to make it work :(
 
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