i know the engine has 2 dif trannies it can come with. for the swap into a 240 does it have to be the 5spd or can it be the 6 spd also??

 

i beleive the 6 speed was in the GTR, which is all wheel drive, so you wouldnt be able to use that, the RB25 tranny is smaller then th e RB25 and it is ussually the one people go with with that swap.

 

i second the rb25 tranny. frankenstein is what i normally hear about.

 

i heard of someone that used the 6 speed tranny but because it is an all wheel drive tranny he had to block off the hole where it the driveshaft would goto the front diff. i saw it once but i dont know how well it worked cause he wasn't done with it yet. ill look and see if i can find it cause id like to know if it worked.

 

the RB26 tranny is twice the size of a RB25 tranny.

 

i didnt know that but there was a guy that said he was using the 26 tranny really wish i could find it.

 

To be very honest with you, the 26 tranny will not work in this swap. The very reason is this:

1.) the chassis is RWD (2wd)

2.) the tranny housing is not big enough to fit the 26, as others have noted, its HUGE. Major modification to the firewall and tranny housing is required (not worth the $).

3.) even if you do find a way to install the tranny, you cant use it since its AWD, Henry at Motorsport Dynamics said that if you run the 26 tranny, the motor spins the front (which are not connected) and you go no where.

Best thing to do is run the 25 tranny, make a metal cover plate for the exposed area you will have in the bell housing area and drop in with a special mount kit or take it to a custom shop and have them mod the firewall and make a custom mount kit so that the RB sits right next to the firewall.

 

^Word

 

Also forgot to include, you will need the 25 oil pan as well for this swap.

 

I also read somewhere that you can trick the computer into transferring power to the rear wheels only. Not sure if this would be a torque split controller, but I think HKS and Blitz both make one that allows you to control the percentage of power to the fronts and rears. If it was me, and I was already going to be in $10k to swap the motor in, I'd go for the 6-speed.

 

Sorry to say, those torque splitters are designed to be used in STi's and Evo's. In the GTR, there never was a need for a torque splitter because of the ATEZZA ETS AWD program.

That is where you get in trouble with the 6 speed. Hands down it cannot be used in the S14. Not only will you have the front axel problem, but you will also have to modify the tranny housing of the chassis in order for it to fit (front torque converter box is built within the 26 oil pan, not to mention the 2 huge mounting spots for the front axels on the sides of the 26 oil pan).

Unless you own your own custom metal fabrication shop, AND know all about a cars structure design, then stick with the easy and use the 5 speed plus upgrade to an Apexi Power FC w/ FC Commander to run your game (26 ecu will not work for this set up).

***Any other way is virtually impossible, if there was, Motorsport Dynamics would have been one of the first, if not the first, to create an AWD 240 with RB26. Look at our Gold S13, thats the closest you'll get to an RB swap in a 240.***

 

So Nismo, or anyone that knows..
You would have to use an RB25DET ECU with the RB26DETT with RB25 Tranny?

 

25 ecu from my recollection cant be used since 25 and 26 motors are 2 different worlds.

Best thing to do is Apexi Power FC w/ FC Commander, hands down one of the best aftermarket engine management systems you can get that is a complete set. HKS has the Fcon Pro, but you have to buy the entire setup individually which means more $... way more $. Plus if your gonna do a swap like this, why stay with a stock ecu? Defeats the whole purpose.