Sr20 boost - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

DMC · 08-15-2003, 08:59 PM

Ok i know you all may think this a stupid question but to me it seems like something we should have in faqs. what on the redtop sr20 is limiting the boost( ex: injectors only allow for 12 lbs without rrfpr)thats not rite just an example. my goal for my sr is to put down as much boost as possible without upgrading the turbo and i would like to see what needs to be done to get the turbo to peak level( i believe 13 lbs) thanks alot guys

NZO · 08-15-2003, 09:20 PM

You answered your own quesiton. The turbo looses efficiency past ~13psi.

DMC · 08-15-2003, 09:29 PM

so the injectors can take it? and the maf can take it? and the cams(i guess if thats ever a problem) can take it? and the stock ecu can take it? and the 300zx fuel pump can take it? thats all im askin but i guess your sayin my engine now is fine to run 13 lbs on thanks for replying

kazuo · 08-15-2003, 09:42 PM

This has been discusssed numoerous times. Please use the search!!!

Stock SR20DET Turbines are good up to 12psi. Anything more and you are pushing your luck. You probably want to run wuth a aftermarket FPR and a bigger fuel pump, and 70mm or larger exhaust, but you should be fine with stock items, but be aware that performance will suffer.

Good luck

DMC · 08-15-2003, 09:46 PM

hey man if u look i did search
but what would does a fpr do? givin it allows u to adjust the fuel pressure but how would that help???

Jsquared · 08-16-2003, 02:19 PM

more fuel pressure = more fuel injected by the injector at the same duty cycle.

injectors, ECU, MAFS, etc should all be able to handle about 12-13 psi (need an upgraded intercooler!!). i'm running 11.5 with an S-AFC (dyno tuned with a wideband O2 for correct A/F ratio) and everything works fine (although boost falls from 6000rpm to 9si at redline... just a characteristic of that tiny-*** turbo

). if in doubt, get on a dyno with a wideband and see what your A/F ratio is.

P.S. I'm assuming you're talking S13 SR (T25, 370cc/min injectors). on an S14 SR you have a better turbo (T28) that can run more boost safely and bigger injectors (440cc/min), dunno about the MAFS...

DMC · 08-16-2003, 05:17 PM

yea redtop thanks man i will need to upgrade ic since i have none

08-15-2003, 08:59 PM	#1
DMC Zilvia Addict Join Date: Jan 2003 Location: Chesapeake, Va Posts: 609 Trader Rating: (0) Feedback Score: 0 reviews	Sr20 boost Ok i know you all may think this a stupid question but to me it seems like something we should have in faqs. what on the redtop sr20 is limiting the boost( ex: injectors only allow for 12 lbs without rrfpr)thats not rite just an example. my goal for my sr is to put down as much boost as possible without upgrading the turbo and i would like to see what needs to be done to get the turbo to peak level( i believe 13 lbs) thanks alot guys Last edited by DMC; 08-15-2003 at 09:01 PM..

08-16-2003, 02:19 PM	#6
Jsquared Zilvia Junkie Join Date: Feb 2003 Location: Raleigh, NC//Charlotte, NC Age: 42 Posts: 503 Trader Rating: (0) Feedback Score: 0 reviews	more fuel pressure = more fuel injected by the injector at the same duty cycle. injectors, ECU, MAFS, etc should all be able to handle about 12-13 psi (need an upgraded intercooler!!). i'm running 11.5 with an S-AFC (dyno tuned with a wideband O2 for correct A/F ratio) and everything works fine (although boost falls from 6000rpm to 9si at redline... just a characteristic of that tiny-*** turbo ). if in doubt, get on a dyno with a wideband and see what your A/F ratio is. P.S. I'm assuming you're talking S13 SR (T25, 370cc/min injectors). on an S14 SR you have a better turbo (T28) that can run more boost safely and bigger injectors (440cc/min), dunno about the MAFS... __________________ 1992 SR coupe, ~11psi a.k.a. "Zip-Tie" www.carolinanissans.com

08-15-2003, 09:20 PM	#2
NZO Zilvia FREAK! Join Date: Mar 2002 Location: Reno, NV Age: 42 Posts: 1,424 Trader Rating: (0) Rides Gallery: NZO Feedback Score: 0 reviews	You answered your own quesiton. The turbo looses efficiency past ~13psi.

08-15-2003, 09:29 PM	#3
DMC Zilvia Addict Join Date: Jan 2003 Location: Chesapeake, Va Posts: 609 Trader Rating: (0) Feedback Score: 0 reviews	so the injectors can take it? and the maf can take it? and the cams(i guess if thats ever a problem) can take it? and the stock ecu can take it? and the 300zx fuel pump can take it? thats all im askin but i guess your sayin my engine now is fine to run 13 lbs on thanks for replying

08-15-2003, 09:42 PM	#4
kazuo Post Whore! Join Date: Aug 2002 Location: Posts: 2,762 Trader Rating: (3) Feedback Score: 3 reviews	This has been discusssed numoerous times. Please use the search!!! Stock SR20DET Turbines are good up to 12psi. Anything more and you are pushing your luck. You probably want to run wuth a aftermarket FPR and a bigger fuel pump, and 70mm or larger exhaust, but you should be fine with stock items, but be aware that performance will suffer. Good luck

08-15-2003, 09:46 PM	#5
DMC Zilvia Addict Join Date: Jan 2003 Location: Chesapeake, Va Posts: 609 Trader Rating: (0) Feedback Score: 0 reviews	hey man if u look i did search but what would does a fpr do? givin it allows u to adjust the fuel pressure but how would that help???

08-16-2003, 05:17 PM	#7
DMC Zilvia Addict Join Date: Jan 2003 Location: Chesapeake, Va Posts: 609 Trader Rating: (0) Feedback Score: 0 reviews	yea redtop thanks man i will need to upgrade ic since i have none