Upgraded 33 Gtr Gearbox

[tk80]

Hi guys

I bought an upgraded gearbox for my car when i smashed 3rd on the std box (last turn at morgan park....should have shifted sooner). The seller of the upgraded gearbox at the time had purchased an unused turnkey race gtr and was told that the gearset was OS giken and was virtually brand new.

I have recently had the box out as i'm in the midst of doing some major upgrades but can't find any markings on the gearset at all. Visually it has larger than standard gears (guessing each gear is around 5mm larger but yet to measure), a standard input shaft and series 3 sychro's. It's handled 320awkw on the street/track/strip without failure where the std box broke when the car had around 260awkw. Gearing felt near enough to std.

Could it be an OS but with a std input shaft? Another guess was route 6 but some argue that even a route 6 has markings on the gearset.

Any thoughts? Trying to work out what it is to determine if it will handle my new mods (400awkw+) and to work out a value for it if i decide to sell.

thanks in advance

Edited August 24, 2011 by tk80

[tricstar]

if it does 95kmph in 1st and 130kmph in 2nd its probly an OS gearset, and I yes I think it could have a standard input shaft, not sure about any markings

[Piggaz]

Ratio's of a OS Box with stock diffs are (8000RPM).

1st=87

2nd=138

3rd= 190

4th= standard (as it is 1:1)

5th depends if you have a stock ratio or not.

I have a few photo's of when I put my box together that I will throw up for you tonight. I'm 99% sure there was a 'OS Giken' engraving on the heavy duty input shaft, none on the gears themselves. This is stretching my memory though.

[tk80]

thanks mate...will take a look at the pics.

didn't think my gears were that long though. only going from memory but i thought 1st was 70-75, 2nd 120-130, 3rd 180ish and i never revved out 4th to know.

Edit:

just looked up what the std gearset is good for @ 8,000 rpm...

1st = 73

2nd = 122

3rd = 181

4th = 236

5th = 313

Looks like whatever i've got is standard ratio or very close to it....so what could it be?

Edited August 25, 2011 by tk80

[Piggaz]

Sounds like a stock box to me.

75,120,180 for a stocker IIRC.

Forgot about the pics, got sidetracked. Tomorrows job

It's pretty hard to mix them up if you know what your looking for.

[Beer Baron]

yeah sounds like a standard box to me too sadly. so many fkers have sold supposed "OS boxes" which turn out to be standard.

the fact that it's holding 320kw is no indication either. plenty of stock boxes running 350kw+ for years and years. most likely your first box braking at 260kw you just got unlucky.

[tk80]

Mr Beer Baron

you're a very knowledgable guy when it comes to this stuff. are there ANY upgraded gearsets that use standard ratios? because everyone that has seen it opened up say it's larger than std (these are people that know gearboxes).

Edited August 26, 2011 by tk80

[Piggaz]

[tk80]

thanks...time to compare.

[Beer Baron]

Mr Beer Baron

you're a very knowledgable guy when it comes to this stuff. are there ANY upgraded gearsets that use standard ratios? because everyone that has seen it opened up say it's larger than std (these are people that know gearboxes).

well there have been a few 'boutique' makers over the years. most aussie and euro stuff use straight cut gears and/or dog engagement. most of the jap stuff are helical gears and still synchro.

generally all the jap boxes have a much shorter 1st gear as back when people were upgrading GTR boxes a lot in the 90s and early 2000s it was for drag racing which was huge in japan. the super tall first gear in 32/33 boxes is pretty useless with decent power so they nearly all shorten it down massively.

route6 make a gearset but to the best of my memory it also had a shorter 1st gear and then close spacing between 1-3 (ratio wise).

AGY made their SS690 boxes with the synchro upgrades and I 'think' they used to make one with standard ratios (but it was a long time ago).

OS obviously don't make standard ratio gearsets.

it's possible they were custom gears.

best bet is measure then and see if they really are 5mm bigger (I assume you mean wider). 5mm (2.5mm each side) is pretty hard to spot unless you have a standard one beside it to compare to so maybe the people who looked at yours just thought it was bigger?

it's quite likely I reckon that it's just a series 3 box.

[T04GTR]

i had a route 6 in mine. i think,, anyway it had a tall first then quite close. sort of in between stock and a ppg.

[Beer Baron]

yeah I remember you had a route 6 dave. it was a bargain that one wasn't it... lol.

[T04GTR]

yes lol. of the best kind...overtime...