Nismo do make a gearset for the S15 box. You can purchase the 6th gear seperately, it's a 0.862 OD, not sure of the cost though.

On another angle........ what about the gearbox in the new 350Z? It's also a 6 speed box, slightly different ratios;

1st - 3.794
2nd - 2.324
3rd - 1.624
4th - 1.271
5th - 1.000
6th - 0.794

Considering the 350Z has 60kw more power, 100Nm more torque and is 220kg heavier than the S15, surey it must be a stronger gearbox? They both seem to have the same model designation though - 6M Does anyone know details on strength of the Z33 box?

Also, how hard would it be to fit to an FJ20? With the S15 box, I was planning on fitting the FJ20 Bellhousing..... could this be done with the Z33 box?

They are good with a lower ratio diff such as a 3.9 or 4.11

1st 3.626
2nd 2.200
3rd 1.541
4th 1.213
5th 1.000
6th 0.767
They would be better with a 0.92 5th

I have been doing some research on the S15 6 speed recently. It seems there is a "fix" to make the gearbox more reliable. It has something to do with the retainer and circlip that holds 4th gear in place. The modification can be done for around $500.

I am looking at using one in the Sunny, but the gearbox guy I spoke to was not sure/confident that it will hold up with the horsepower and application I want to use it for. Cheap close ratio box though, IF we can make it reliable.

yeah mum spelt that way is the way to go. i dunno if id ever spell it mom coz ive grown up spelling mum MUM. umm i duno what im writing!!!!!

Quote:
Mom's,......... MOM"S.
My god, have we sunk so far that we can't spell MUM any more in Australia.

my mate took me for a drive in his mom's the other day....the gear box has weird feel to it...i'm not sure if i like it...

well that answers that question. i think ill give it a go and as you said the transfer into a lighter car may reduce "breakages". If it doesnt work atleast i know ill have the room to stick in the S13 5spd cheers guys

I imagine if it's going into a much lighter car (1200 for example) reliability issues will minimize and it may be a viable alternative. If you've got mountains of cash HKS makes an excellent SR 6-speed

They are longer too, so you'll need to shorten your tailshaft

I've lots of bad things about the owners of S15s... about how they don't know how to drive, and are constantly breaking their 6 speed boxes...

But getting serious, the 6 speed housing is quite a bit bigger in the rear. This means quite a bit more tunnel massaging around the shifter.