S15 6 speed gearbox in R32

[funkymonkey]

I've been told that CA18DET gearboxes and RB20DET gearboxes are similar and match up with no probs, and apparently SR20DET gearboxes do too with minimal modification.

Which got me curious... can one take a 6 speed gearbox off an S15 Turbo (Type R whatever you wanna call it) and chuck it in an R32?

Also how well does it mate up with an RB25DET (sicne I'm doin an engine swap anyways).

Also how's the reliability of an S15 6 speed gearbox? I've been led to believe that at over 400hp it shits itself... I'm looking at around the 375 to 430hp range once my pet project is done, so this is important.

[T0nyGTSt]

The six speed boxes are apparently very WRX-like if ya know what I mean.

Who makes them? Not Getrag I believe.

T.

[predator]

yeah, the 6 speeds are meant to be dodgier.. Some of the S15 guys actually go for the older s14 5speed boxes when the new ones die.

also: I seem to remember reading that the 6speed wasn't fantastic as the ratios weren't that suited either. Some of the gear changes were especially too short (hmm rex there too..lol)

[neil_se]

s15 boxes are crap! It's not uncommon with s15's around 200rwkw to have gone through 2 or 3 boxes and now most just use an s13 gearbox.

[MattR]

yeah the s15 boxes are the weakest in the S series where as the 34 boxes are the strongest in the R series. go figure. Ive recantly put a s13 box in my s14 instead of the usuall s14 box

go the 33box

[T0nyGTSt]

The strongest Skyline boxes are apparently the final R33 GT-R boxes and by association, the 33/34 GT turbo boxes.

The Skyline Getrag six speeds? Do a search

T.

[funkymonkey]

nah can't afford a getrag but maybe an r34 gtt one... bah i'll just run my RB20DE one till it dies

[Maxx]

i think the box is very good, but yes it is weak compare to other nissan gearbox.

ratios is nice, when u drive up the hill it's a lot better than my R33

go for nismo S15 6 speed then

around $5000

not hell lot more than a R34 Gear box but u got 6 speed

[sewid]

The strongest Skyline boxes are apparently the final R33 GT-R boxes and by association, the 33/34 GT turbo boxes.

The Skyline Getrag six speeds? Do a search

T.

Are you saying the R34 GTR gearbox wouldnt fit or it's weak?

[2fardown]

If you are planning on fitting a 6 speed from an S15 don't put in a massive twin plate clutch or anything stupid like that. This is the major contributor to failed gearboxes in S15's.

There are many 12 second S15's still running the factory box with no problems and with 250rwkw over at www.nissansilvia.com.

The 3rd gear ratio is fantastic. This is the gear I beat my 2 friends who own R33's.

[CerealKiller]

$5000 for a S15 box?

[2fardown]

You missed the key word "Nismo"

[funkymonkey]

$5000 for a nismo box when a supra 6 speed box made by getrag is around the same price... i'm thinking budget 6 speed here...

also when building up the car I'm aiming for more than 250rwkw. which will be a lot more at the fly and hence the stress on the gearbox as well. So using appropriate clutches etc, what's the max you guys reckon a 6 speed S15 box can handle?

Any other budget alternatives?

[Fitzpatrick Speed Works]

i know its not what you are after but i have to correct earlier info that might mislead!!! the pull type r33 gtr boxes are the weakest in the gtr rb series by a long shot as nissan tried to correct problems that where in the r32 boxes but overcompensated and made themselves a whole set of new problems, the series 3 box is better but still no where near as good as the six speeds in japan are holding up to 10 second gtrs and they are getting reliabilty!!!

[Maxx]

once over 200rwkw with hard driving style, the S15 box will possibly break.

normal around 250rwkw it starting fragile.

nissan say 400hp.

budget? go 5 speed

nothing came cheap while can handle big hp and got nice 6 speed.

[predator]

Any other budget alternatives?

rb25det gearbox.. that *is* your budget alternative..

if it will work for me it will work for you

[CerealKiller]

I recall there was a thread about this a while ago (I was thinking the same thing because I was doing a fair amount of highway driving). The main issue was that the S15 box wouldn't be able to cope with the torque of the RB20...but I've been reading a lot recently that the SR20 makes more torque than the RB20...now I'm confused.

[funkymonkey]

hmm but I'm doing an RB25DET engine swap don't think the box could handle it from what you guys are saying... oh well... back to the drawing board.

[T0nyGTSt]

I think it goes like this...

R32 - both GTS and GTR are good strong designs. The RB20 box has a weakness at very high power but you have to get the RB20 to produce 250kW+ first.

R33 - not much problem at all. The RB25 is a just a RB26 box with the front output cut off. "Weaknesses" are that it's a big fat bastard (you'll see if you have a RB25 next to an RB20 box). The Series III R33 GT-R is supposed to have the strongest internals.

R34 - same as the R33 except the Getrag six speed has some problems very well documented on this forum.

S13 - ok box, good design.

S14 - got a bit better, bit stronger.

S15 - six speed is weak compared to the relatively strong Nissan reputation. It's also another big fat bastard.

You must admit that for drivelines strength, Nissan have a good rep. and we've all been lucky. That's why we drive them. Not as a good as Toyota boxes IMO but close enough.

T.