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How strong are rb25 gearboxes? I am looking to fit one to an sr20 that in its current tune has 270rwkw but after its rebuild hopefully 310-330. I can get a 2nd hand one for 1800-2200 or a brand new one for $3400. I have gone through more many sr20 gearboxes than i'd like to remember and are looking for the best solution without spending a few squillion $$. Thanks

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Fitting one to an SR will cost a lot, the bell housings don't match up and I think you need a Tomei bellhousing?

But in any case, it costs about as much as the gearbox itself

A mate has 588hp on his SR S13 with an SR gearbox, they 'generally' hold up ... so 360 odd hp shouldn't be a hassle for your current gearbox

its not even about kws sproosy

just ask R32-GTS - he broke several boxes in his time. they dont like being leaned on, the size of the box means that the faces arnt big enough to disperse the loading placed on them, and as a result they break.

simply - drive them hard and they will go regardless of how much power your making, even pretty stock power can chew them

This is a little off topic, but how much power can an RB20 Box take on a R32 GTsT?

Cheers peoples!

just to go even a bit more off topic (sorry cool hand luke :Oops:), about how much would an r32 gts4t box handle? laying under the car it seems pretty damn big (havent seen a gtst box to compare though), even the floor inside is rasied either side of the tunnel to make room.

:cheers:

shaun

torque is what kills the poor old RB20 box.

put it behind 25/s and 25/30's and they wont last.

Behind an RB20 they can take a bit more punishemnt as its not pushing as much twist through it all.

nothing lasts forever. Remember RB20 boxes are getting quite old too these days :D

I am actually very happy with the rb20t box, if it went tomorrow I would be happy. :D

It has lasted the longest out of any gearbox I have owned.

Generally they all need a rebuild after 9 months. :D

The mightly VS 5speed included which I was told were almost indestructible.

The old 4speed single rails were fairly tough but always snapped selector forks and chewed out syncro's.

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