RB25 intake manifold on RB20?

[KlutchKickrr]

Now, I am sure that this topic has been beaten to death already, but I really want to make sure for myself about this.

Is it possible to use a forward facing intake manifold from an RB25 on an RB20? I have heard that you can, and you can't. Whats the verdict?

Also, if it does fit, but with some modifications, what exactly are these modifications?

Cheers.

[OrangeVirus1]

no you can't. it sucks but you can't.

[feito]

have u upgraded you turbo? gone over 400 horses? If not you'd be just wasting your time, your stocker's better that that ffim, as ugly as it looks. Believe me, i looked for an excuse to do the conversion on my rb25 but i just couldnt do it, i cant sacrifice performance for looks. Now if u just want it for the looks, then yeah, whatever.

[KlutchKickrr]

Thanks for your input!!! You are apparently correct on that performance issue. The manifold can be fitted, but the head would need some machining, otherwise you lose airfolw into the engine, according to a friend. My guess is that the intake ports on the head would need some port work.

Thanks for all of the help again!! Much appreciated.

[Yellow4g63]

Only way you can is to chop the RB25 flange off the manifold and weld on a RB20 Flange. Buy a Thailand manifold from ebay or spend some coin and get a ripps intake manifold.

[fliprayzin240sx]

Or relocate the TB to the front of the manifold...

http://i236.photobucket.com/albums/ff219/fraz1/jb3fx2.jpg

[ch1873857]

hey Ray, has there been any solid intel on the equal dispersion of air pressure amongst all cylinders by doing that. I was thinking about making some upper plenums for 20s and 25s that would essentially do the same thing but with a tapered plenum to mitigate those issues. would like to get some affordable alternatives to knock off greddys out there to these guys..