RB25 intake manifold on RB20? - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

KlutchKickrr · 03-17-2013, 09:27 PM

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 · 03-17-2013, 09:28 PM

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

feito · 03-17-2013, 09:42 PM

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 · 03-18-2013, 08:10 AM

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 · 03-18-2013, 09:08 PM

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* · 03-20-2013, 05:18 PM

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

ch1873857 · 03-22-2013, 04:22 AM

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..

03-17-2013, 09:27 PM	#1
KlutchKickrr Zilvia Junkie Join Date: Oct 2011 Location: Jersey Age: 35 Posts: 381 Trader Rating: (14) Feedback Score: 14 reviews	RB25 intake manifold on RB20? 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.

03-18-2013, 09:08 PM	#5
Yellow4g63 Zilvia FREAK! Join Date: Jan 2003 Location: Socal Posts: 1,454 Trader Rating: (5) Feedback Score: 5 reviews	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. __________________ 95 240sx RB20 415whp 91 Nx2000 VVL yo

03-20-2013, 05:18 PM	#6
fliprayzin240sx Man w/ CTSV & a Car Seat Join Date: Aug 2002 Location: Tampa Posts: 17,998 Trader Rating: (19) Rides Gallery: fliprayzin240sx Feedback Score: 19 reviews	Or relocate the TB to the front of the manifold... __________________ If you think Zilvia has too many assholes... CLICK HERE!!!

03-17-2013, 09:28 PM	#2
OrangeVirus1 BANNED Join Date: Jan 2013 Location: PyongYang DPRK-N. Korea, Province 2 Posts: 1,236 Trader Rating: (0) Feedback Score: 0 reviews	no you can't. it sucks but you can't.

03-17-2013, 09:42 PM	#3
feito Nissanaholic! Join Date: May 2007 Location: Texas Posts: 1,999 Trader Rating: (1) Feedback Score: 1 reviews	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.

03-18-2013, 08:10 AM	#4
KlutchKickrr Zilvia Junkie Join Date: Oct 2011 Location: Jersey Age: 35 Posts: 381 Trader Rating: (14) Feedback Score: 14 reviews	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.

03-22-2013, 04:22 AM	#7
ch1873857 Nissanaholic! Join Date: Sep 2003 Location: Andrews Air Force Base Posts: 1,906 Trader Rating: (1) Feedback Score: 1 reviews	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..