RB25 gearbox strength.

[Cool Hand Luke]

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

[2BNVS]

if the box is in good condition, they are extremeley strong, handle 330 for sure

ben...

[RB30-POWER]

As has been mentioned before.

Internally they are basically the same strengthwise as the GTR boxes, just without the 4wd transfer case.

They are a big box, do you have room in your transmission tunnel for it?

[R31Nismoid]

you could say they are stonger than a GTR box as they dont get the stress a GTR box does due to the 4WD.

they'll take well over 270rwkw, thats nothing for em

[50FFT]

hey, if you look around you should be able to get a bit cheaper than that, i just paid 1000 with a tailshaft to go into a r32, just have to find the right person, i thought that was pretty cheap

[R31Nismoid]

$1000 is a steal.

Usually they are around $1500

[PSIKO]

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

[Lepperfish]

SK told me that one if good condition will uphold 700hp easliy..

Sk is da man. !

[sproosy]

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

Cheers peoples!

[R32-GTS]

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

Cheers peoples!

Not much at all if driven hard. Save your pennies now for a 25 box.

[sproosy]

Cheers R32-GTS. Anyone got an idea of how many KW's?

[teejay]

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

[Cubes]

Up over 200.

Mine was fine with just under 170rwkw for quite some time.

Bolted the rb30 up and making almost no boost and it has now started to make strange whinning noises.

[teejay]

most likely has more to do with the new found buckets of torque loading the box up

[sproosy]

Cool. Well as i start to mod my car and get more power ill see how things go....... I see a new R33 box is usually around 2g's. Couldnt you rebuild the box with stronger internals for the same price?

[krush]

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.

shaun

[R32-GTS]

GTS4 box same as GTR box.

[teejay]

2k for a new 33 gtst box?

doubtful mate.

[R31Nismoid]

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

[Cubes]

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

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

Generally they all need a rebuild after 9 months.

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.