turning up boost rb20det

[cademfjohnson]

hi this is my first post on what i hope is a great forum. i've been reading for hours and it seems to be great. I've aquired a 91 240 with a r32 rb20det swap and have since been busy rewiring and cleaning up the install, as the previous owner was retarded. I'm well versed with cars, but don't know tons about nissans (hoping to change that now) though i know a small amount as all import guys lust over skylines. i'm a honda lover and own/built a big 16g turbo'd b16 swap civic hatch, so im not new to boost either.

now my simple simple question. the car has an FMIC, and a 2.5" exhaust/ s***ty cold air intake. otherwise looks untouched other than the swap. stock turbo and everything. im wondering if the stock ecu will see and correct tuning for boost increases up to about 10psi without a problem or tuning modification. i want to install a MBC and just bump it a few psi for now. i assume its probably good for 13psi max, especially with the s***ty ceramic turbine on these t28's

thanks and i hope we all get along great and i look forward to knowing you all. lovin the nissan scene so far!

[Lozer]

13 or 14 psi on the stock rb20 turbo. if your running the rb25 turbo you might get away with 15 or so but your maf will hit a wall at 15 (ask me how i know) so then you need an n62 maf off of a z32 and a tune or a safc (cheap alternative to a tune)

[Kalypso]

congratulations!

^ This guy sound like he's got it down.

Im not sure what the stock MAF and ECU can handle, im an sr20 person.

but as a bonus, you should browse the FAQ thread, for the RB motors. ( top of the RB forum ) a lot of basic and useful info that will answer questions you haven't even thought of yet.

[cademfjohnson]

ok thanks guys. sounds good. yea i'll definately just retune after i change maf, i never skimp on tuning.

[ST240]

13 or 14 psi on the stock rb20 turbo. if your running the rb25 turbo you might get away with 15 or so but your maf will hit a wall at 15 (ask me how i know) so then you need an n62 maf off of a z32 and a tune or a safc (cheap alternative to a tune)

If I'm not mistaken, you've forgotten an even more important element. The stock 270cc injectors will be maxed out with the rb25 turbo at 14 psi.

[cademfjohnson]

yes i've read the same. those injectors are tiny.

already lookin at some 550cc's and a garrett gt25 turbo to replace the stock, and of course a new MAF. not shootin for but 300-350whp on this car. think these injectors and turbo will reach into that range? i know the turbo is cuttin it close probably but its cool, don't have to hit exactly 350

[Yellow4g63]

why not get another 16G and make a adapter to bolt it to the T3 flange on the stock manifold?

[bades]

hell ive been thinkin bout doin the same thing... lol rigging up my old big 16g off my suby's old turbo setup and slappin it on my drifter and seein how she does lol

[cademfjohnson]

not a bad idea, not too expensive either. i can just get a mani and cut/weld a different flange.

[93coupe]

13 or 14 psi on the stock rb20 turbo. if your running the rb25 turbo you might get away with 15 or so but your maf will hit a wall at 15 (ask me how i know) so then you need an n62 maf off of a z32 and a tune or a safc (cheap alternative to a tune)

I just traded my coupe for an s14 with rb20. Stock motor with a modified intake manifold and rb25 turbo. Once I grab a boost controller I would like to turn it up to about 13lbs. which looks close to the max without z32 maf and bigger injectors. Am I really risking it on 13lbs before injectors and maf?

[Yellow4g63]

I just traded my coupe for an s14 with rb20. Stock motor with a modified intake manifold and rb25 turbo. Once I grab a boost controller I would like to turn it up to about 13lbs. which looks close to the max without z32 maf and bigger injectors. Am I really risking it on 13lbs before injectors and maf?

Your going to need bigger injectors. The RB20 stocks are 270cc and around that boost I'm sure you will be maxing them out with the RB25 turbo.

[93coupe]

I don't plan on upgrading to a larger turbo, can I get away with 440's?

[Yellow4g63]

that will more than do the job.