Gearbox upgrades

[Skym]

Was curious, do you reckon this would fit into a RB20DET gearbox housing, as is supposedly the same FS5W71C gearbox as a S13? -

http://www.nismo.co.jp/en/products/competition/mission/silvia.html

It's interesting the amount of torque a FS5W71C gearbox is designed to handle (30kgm x 9.81 = 294.3nm).

Just wondering if anyone knows someone that's has done this conversion???

I have heard about people fitting aftermarket S13 chassis gearbox parts into RB20DET gearbox housing (3 speed?) and stock S13 chassis gearbox into RB20DET gearbox bellhousing (notch inside of housing to make gears fit).

Also for GTR owners, Getrag gearbox into R32 or R33 GTR -

http://www.nismo.co.jp/en/products/competition/mission/getrag.html

[VAMP787]

are the prices on the site in yen?

[Skym]

In the thousands, so I would say yes.

[M13]

I've wondered if S15 6spd trans mates our KA/SR/RB20 bell housing

[collector240sx]

The 6 spd has a speed sensor in the rear diff. if I remember correctly, and stock isn't even as strong as a regular SR 5spd. From what I have seen and heard the SR and KA trans are pretty equal if the KA isn't a little bit stronger. KA and SR are easily interchangeable. The problem with the 6 spd, is they fitted the 6 spd in the same size trans as the 5 spd. At stock power it shouldn't be a problem but when you start to modify the engine they usually don't last, this kit might be an upgrade but still with a limit of 350hp it's not much of an upgrade when the 5 spd can take it stock and can be had for about $100. lol Unless you really need that 6th gear.

But realisticaly if you have a rb20 and want a better trans. get a RB25 trans. and don't look back, the shear size and weight difference should be enough to convince you. And if I remember correctly the internal parts are the same as a 300zx, so you can get them pretty easy and they shouldn't break the bank.

[Skym]

The RB25DET gearbox takes up too much room inside the R32 tunnel (not enough air around gearbox housing to cool it). Many have had overheating, fluid failure problems with RB25DET gearbox in R32 tunnel on racetrack (need to fit gearbox oilcooler, pump, etc), but RB20DET gearbox supposedly doesn't suffer the same problem (that's behind a 413rwhp RB20DET engine, racetyres) due to more air around gearbox and no gearbox cooler (high km gearbox as well). Some widen R32 tunnel with RB25DET gearbox or fit a 370ZX? gearbox (6 speed?) with adaptor plate for bellhousing.

Some mention SR osGiken gearbox internals fit RB20DET gearbox (I think they are the same size, etc gearbox internals, but different housings), but have to reduce amount of gears for it to fit (I assume to prevent gears fouling the housing).

[Bee-RSkyline]

I went with a RWD modified GTR trans and custom drive shaft.
So far it has held everything I've thrown at it.
Cost w/ all mods was less than a RB25 trans.

[M13]

I went with a RWD modified GTR trans and custom drive shaft.
So far it has held everything I've thrown at it.
Cost w/ all mods was less than a RB25 trans.

Ya, but how heavy is your transmission?...

What power levels and usage did you "throw" at the trans? I've considered BNR trans converted to RWD but need more real-life feedback on this.

[Terrh]

300ZX trans with a skyline bellhousing will work (I haven't tried it, but the reverse works and everything fits so I have no idea why it wouldn't work)

the R32 GTR trans probably works pretty well in RWD cars. Just be careful of 3rd gear. If you gut the tcase properly it won't be that heavy.

I gave up on the R32/33 GTR transmissions and am putting an R34 box in my car. If it breaks, at least supra parts fit. They're not cheap though, $2500 and up.

[Skym]

If do go with R34GTR gearbox, get the race bearing upgrade. Not sure if it's a Nismo option, but check their catalogue (ask Nissan Dealership parts department, as they usually have the Nismo Catalogue).