new here and a few questions about rb20 upgrades

Discuss the RB20, RB25 and RB26 series engines.
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littlenicky24
Posts: 3
Joined: Tue Jan 26, 2010 8:36 pm
Car: 240sx

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basically i bought an s13 240sx for 750 bucks canadian, and i bought an rb20det with transmisssion, ecu, blah blah blah for 600 bucks. i will be rebuilding the engine while its out with a full gasket set, and a new clutch (thinking clutchmasters fx200 kevlar clutch, lemme know what you think). now ive got a 3 inch turboback exhaust including test pipe, and HKS filter. heres my question. if i get tomei poncams with 256 duration 8.5mm, 255lph walbro pump (only because the stock ka pump will not be suffice for rb20det), up the boost on stock turbo to 10psi via hopefully EBC, will it be super wise of me to have the power gains proven on a dyno? dyno-tune it? or can i expect everything to work fairly well right off the get-go?

reason im asking is because i dont live anywhere close to a dyno shop, and the cars not meant to be a complete money pit. im just trying to verify if im going to have to spend more money than i have to to get a little extra boost and poncams to work efficiently and not lean my engine to hell. sorry, im a n00b when it comes to car computers and tuning.


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DriftingisLame
Posts: 974
Joined: Wed Feb 02, 2005 1:41 pm
Car: '91 240sx coupe, rb20det

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I've put poncams on a close to stock setup with more boost, and a very slightly larger turbo, likely the equiv to an rb25.

In my opinion the cams were not worth the money. Yes good idle quality, good midrange, not much more power at all. Now I believe they were good for more power than I made, but I didnt have the opportunity to tune my cam timing on the dyno to optimize my setup. Since you are in the same situation, I suggest trying a cheaper or just different power increase option. Maybe a used RB25 turbo and a Solenoid type boost controller.

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RustspecS13
Posts: 928
Joined: Sat Sep 08, 2007 5:30 pm
Car: '74 260z and '88 300zx turbo

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Stock boost is 10psi, and I wouldn't go over 13psi on the stock turbo because it will blow the ceramic exhaust wheel up.

Get a RB25 turbo (same 13psi problem it'll just make more hp at that boost though) or similar sized turbo.

Id probably skip the cams and spend it else where on the car, at under 300whp there isn't much benefit since your on what looks like a budget build. Id get water and oil pumps in addition to a tstat and all that.

~Alex

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littlenicky24
Posts: 3
Joined: Tue Jan 26, 2010 8:36 pm
Car: 240sx

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i know the guy who im buying the engine from, and his rb20det is running at 7 or 8 pounds of boost. i hear different things from everyone. but yea, that does sound like a better idea for me. rb25 turbo is what im thinking.

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RustspecS13
Posts: 928
Joined: Sat Sep 08, 2007 5:30 pm
Car: '74 260z and '88 300zx turbo

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Well then it has a 7 or 8psi actuator on it or it has a boost leak or something because stock rb20 r32 boost is 10psi.

~Alex

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littlenicky24
Posts: 3
Joined: Tue Jan 26, 2010 8:36 pm
Car: 240sx

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huh....maybe its his old style hks ssqv bov leaking boost? ive heard that happening with those things. hes running it vented to atmosphere if that has something to do with it, but i dont think thats what it is. on that note, how much boost is a stock rb25 NEO bov good to? im using the crosspipe off his neo 6 because the bov is mounted on the side rather than top, and might use the stock bov too.


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