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Gtr Gear Box Strenth


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I'd have to say yes, I've blown third due to shockload from my ex os triple plate.

Reason is they don't have a dampened or sprung center, so the driveline gets shockloaded.

I'm replacing mine with an os giken twin which is sprung center to help the gbox live longer.

I'd say they are more suited for a strengthened box, but if you shift carefully you can run em, 3rd gear won't like the shockload though.

Cheers

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hey ive got fairly stock r32 gtr ive broken two boxers both times 3 gear went not sure if my clutch was part of the problem os gykin triple plate?? is a triple plate clutch over kill 4 a standed gearbox??

Yeah I agree it's overkill. I will stick with a single plate as long as I can. For one it's cheaper to replace when you where it out, and I am led to believe that multi-plate clutchs are harder on gear boxs. That said I have never had one so I am only going off what I have been told. Also did you know that Tony Regoli in his wrx back in 2002 when he was the fastest in the world ran a single plate. Just food for thought.

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R33 GT-R running 530awhp (~400awkw).

OS Giken cross set lasted 1 night with the new power. Wheelsping in 1st, hard shift into 2nd (high RPM, low road-speed) equals:

OSBox1.jpg

OSBox2.jpg

Stripped 2nd gear pretty well. Clutch is an OS Giken Triple Plate.

Stupid shift, my fault. Going to get the box rebuilt with all the good gear and sell it, but only if I can get a buyer for it. Will be pretty cheap (~5k including box).

Currently have a stock gearbox in there, has done a Dutton Rally, several track days, and a few runs. Has held up so far, but I know it wont. Will probably end up going with a PPG dog set.

Edited by Brockaz
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Most times its the harsh clutches + hard gearchanges that kill the boxes, esp. third gear. I have blown a Trust dog box (unknown history) shifting into second. Have also blown third gear on a stock box. Car had over 400rwkw and a HKS triple which is what I think killed both boxes as it is very harsh and has little dampening, if any.

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R33 GT-R running 530awhp (~400awkw).

OS Giken cross set lasted 1 night with the new power. Wheelsping in 1st, hard shift into 2nd (high RPM, low road-speed) equals:

Stripped 2nd gear pretty well. Clutch is an OS Giken Triple Plate.

Stupid shift, my fault. Going to get the box rebuilt with all the good gear and sell it, but only if I can get a buyer for it. Will be pretty cheap (~5k including box).

Currently have a stock gearbox in there, has done a Dutton Rally, several track days, and a few runs. Has held up so far, but I know it wont. Will probably end up going with a PPG dog set.

So the gear set was in there before the new power?

Seen a number of OS boxes now run 9's, 10's without a problem, could have been a one off being that many people have them and failures are reportedly low... yours being the first i've seen on this forum thats died so far (others have been running them for 3-4+ years now, over 500rwkw)

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So the gear set was in there before the new power?

Seen a number of OS boxes now run 9's, 10's without a problem, could have been a one off being that many people have them and failures are reportedly low... yours being the first i've seen on this forum thats died so far (others have been running them for 3-4+ years now, over 500rwkw)

Gear set was in there for a while with ~320awkw.

Power went up to 400awkw, and smashed on the first night.

If you read the post, I said it was a stupid shift. I'm sure it'll handle a few 9's and 10's, but if you wheelspin through first and smash 2nd (and it bogs) don't expect it to hold together.

You can break anything with a tough enough shift. I know of a few PPG and HKS dog boxes which have let go on the track/strip due to harsh changes with serious clutches.

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i vote for ppg dogbox anyday of the week if u plan on serious driving :dry: at the drags i slam gears as fast and hard as possible and it shifts like butter and definately engages a shitload faster than any synchro box could. Its currently behind a 420rwkw 2.7l and 1750kg (low 11 second down 1/4 mile) car too so its got some strength with my driving techniques lol :/

pricey but the best mod i have done to the setup by far, the car isnt a daily though so dont expect to drive it on the street everyday unless u like rebuilding them often. Its good to drive one u learn to downshift and upshifts are smooth even when shifting ultra slow, the whine of the straight cuts gets on ya nerves and creates unwanted attention though. I could like with it daily if it wasnt soo noisy and didnt have to replace parts within such short intervals.

I think once u drive a dog box u will never wanna use another synchro box in a powerful car, u will realise how long the shifts take just waiting for the sychros to line up.

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  • 1 month later...
Of all I have read on this site I am yet to see anyone who has used a holinger gear box. Is there any reason for this? Has anyone used one?

yes, the reason is they cost $20K.

but there are a few getting around. and they are a great box. but just like any of the others you can break one if you try hard enough. there is no magic, indestructible box out there sadly.

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i ran an OS 5 speed and raped it hard for a few years...the secret is to keep the maintenance up to them...they are not a set and forget item...strip it down every 12 months, have it inspected and it will last. Lazy synchro hubs will destroy any gearset OS/PPG etc. if shifted hard.

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I am running a stock (as far as I know) box in my 32gtr, 4th gear syncro is foocked, but nothing double-clutching wont solve, but she is running nice.

I push 200.5kw at all 4, but driven with respect, the stock box should be good for a lot more.

B.

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Few months on for me now, and the standard box is still handling 400rwkw.

I've tracked it several times, done Dutton rally on it, hundreds of launches, not a problem.

I'll admit though, I haven't been drag racing it, and that 2nd-3rd shift is very gentle.

Of all I have read on this site I am yet to see anyone who has used a holinger gear box. Is there any reason for this? Has anyone used one?

There's a couple of people using them over here.

Nathan Webb has one in his 34, hasn't had a problem so far.

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  • 4 weeks later...

I broke 3rd in stock R32 GTR box. Had OS giken triple also - (notice how many people seem to break stuff with the OS triple ?) Stripped every tooth clean off on counter shaft and main shaft 3rd gears. I'm currently rebuilding that box with the 1-3 OS Giken set because I want to keep the stock 5th ratio, but it'll only ever go back into my GT-SS powered R33. The R32 box was replaced with a Trust 6 speed dog box. This box has proven awesome so far, with around 8-9 runs per meet over 10 meetings. Learning to shift properly under power (no clutch) has been a little trickly, but awesome when done correctly. It's ok on street also, but I wouldn't put one on a car mainly driven on the street - especially in stop/start traffic. Love the straight gear noise too !

Maybe a better alternative to OS is the Pfitzner 5 speed. PPG wants around $5500 for their 5 speed helical synchro setup. They quote 900hp handling. A little bit dearer than OS, but I think this would be the most reliable helical synchro setup out there.

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It's not just the OS Giken triple...it's any triple (or unsprung) clutch that exacerbates the shockloading on third gear and coupled with the inherent weaknss of 3rd, it is a matter of when, not if the box will let go.

Further to that, how the box is treated will go a long way to maintaining its longevity.

Ben, did you run the 10 using the Trust dog box? Was the car on 560rwkw? Any particular reason for the apparently low trap speed?

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