Kaido

Hey there, I have an RB25 in an S14. It's becoming a more and more popular swap here in the States, I actually just used a premade kit. Came with motor mounts, downpipe, and driveshaft. All I needed was the motor/tranny/ecu/harness and R33 crossmember. http://dfreaq.com/shop/index.php?cPath=21&...2376ce3fbb8bc46 My KA24 was crapping out on me at the time, and though I love the RB, if I had to do it all over I'd probably just get a new KA (~$300) and build up the internals. The whole project ended up being alot more expensive than I had anticipated. Plus, the RB motor threw off the car's balance with 200 extra lbs. up front.

Ok so...is it better to almost max out a GT3076r and make 300rwkw, or is it better to run less boost on a GT3040r and have some headroom (despite the often mentioned "inefficiencies")? Can we assume that the 3040r is ~200rpm behind on spool with less transient response?

This has probably been said many times, but i'll still mention it. At that power level goal, you should just go with a GCG hi flow, and save money by keeping all the stock lines and piping. Plus I believe it would easily out-spool a GT3071. I hear the spool is almost like stock.

Thanks for the advice, I might just have to get by on the 3"...

Haha my car is already a huge cop magnet, so as cool as a side pipe would be I couldn't afford the legal problems.

Well, it's a 1998 240sx with a Series 1 RB25. My plans are a 6boost manifold and a 600hp GT3040r .82ar turbo (I believe it's the one you had) topping out around 450-480rwhp ideally, with of course supporting internals/fuel and all that good stuff. The whole "backpressure" myth is still going strong here in the US, mostly because of Honda kids, but no one here has the experience with RB's that you folks have. I don't know how much a Skyline GTS-t weighs, but my car without me in it is around 3100lbs now compared to the ~2900 it used to be with stock motor. Needless to say I've really felt the difference in the front weight and have been working on ways to lighten the car and improve balance (remove sunroof, CF hood, battery relocation, etc). My eventual goal is road racing and the dragstip. Another thing I considered, is that with the 3.5"+ exhaust I would have to find a 3.5" downpipe and cat or test pipe, so that there won't be any restrictions.

Hi all, I have an S14 with RB25DET swap. While I love the motor, it really has added alot of weight to my car. Exhaust wise, I was considering getting the Greddy 80mm full titanium exhaust (save about 25-30 pounds), or try to find a bigger diameter exhaust. The biggest one I could find so far was the Apex-i GT-Spec which has piping that goes from 75mm to 95mm and a 115mm tip. So what's more important, size or weight?

Er, nevermind. I searched and found the answer. Disregard this noob post.

GT35R would be more suitable for 500's, but I hope you're going to add a full engine rebuild to that list for those power levels. Try not to get so hung up on a particular hp number, but rather go with what feels best when driving in real world situations. Alot of times, less power can be faster if that makes any sense.

Hi everybody, I have a Series 1 RB25DET in an S14, but I don't have a working tach so I really don't know how far I can push each gear. Redline is stock, does anyone know at what speed each gear tops out at? Thanks.

He could still get valve float with Tomei valve springs? Also, one more question, what kind of fuel were you using for the 24psi run?

Nice numbers! Is the 3040 pretty much maxed out at 24psi, or do you think you can squeeze a bit more out? Also, where did you get the manifold from?

Whoa, 20rwkw from cam gears on an RB25? Please elaborate further, are we talking even w/ stock turbo and stock cams? I thought it was generally accepted that stock cam gear position was optimal, even with poncams... As it is, I was under the impression we could only adjust the exhaust side due to the intake-side VTC.

First of all, nice numbers! Few questions though: 1. How does it spool so quickly? I thought it was commonly accepted that you wouldn't have 20+ psi until 4700ish on a RB25 w/ stock head. Is it all because of the manifold? Or the tune? 2. Shouldn't the .82 AR GT3540 make around 500whp at 26 psi? Not saying that 425 is low by any means but still. 3. At what rpm does boost really start building? Not calling BS or anything, just tryin to figure things out for my turbo setup. Thanks!