I just recently installed a 97 JDM ITR motor in my 2001 GSR. i noticed on my fuel pressure gauge that it was reading 48 psi with the line on, with the line off it was 58 psi? I know stock ITR fuel pressure with the line off is 47-54 psi. Being that the JDM ITR has 11:1 compression, could it use a higher fuel pressure than the USDM ITR engines? BTW I am using the stock fuel pressure regulator

 

good question. My fuel pressure is right at 60psi with vacuum off. I have a 99 jdm ITR swap in my car. I need to hookup the air/fule ratio gauge to see if it's running rich.

 

anyone with a jdm itr motor know what there fuel pressure is. i know the usdm are between 47-54 psi with the hose off. but mine is at 48 with the line on, thats crazy!!!

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Chubzilla &raquo;</TD></TR><TR><TD CLASS="quote">anyone with a jdm itr motor know what there fuel pressure is. i know the usdm are between 47-54 psi with the hose off. but mine is at 48 with the line on, thats crazy!!!</TD></TR></TABLE>

It should be the same as a USDM, at least my B18C6 has the same fuel pressure, and my engine is basically the same as the JDM but with a crappy header. I have a Sard fpr and a gauge on my car now, and when i bolted this on i adjusted the fpr to 48-50 psi with the hose off. Getting the car to the dyno we had to back it down to 46-47 psi as the car was running rich all over the rpm band.

Maybe your gauge is busted? If not this may be a good time to invest in a adjustable fpr.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Chubzilla &raquo;</TD></TR><TR><TD CLASS="quote">I just recently installed a 97 JDM ITR motor in my 2001 GSR. i noticed on my fuel pressure gauge that it was reading 48 psi with the line on, with the line off it was 58 psi? </TD></TR></TABLE>

Even though stock fuel pressure numbers as given to be 47-54 psi with the hose off, the last time I was at the dyno (after installing the exhaust, intake, AEM FPR and cam gears), we found it was necessary to bump the fuel pressure up to around 60 to keep the mid-range a/f from getting too lean.

Short version, 58 psi is fine.
Though I'd suggest getting some dyno time with a/f readings.

 

thanx for the reply guys. I have a FPR (matter of fact i though the my old fpr was taking a crap on me, so i changed it out for a new one and it read the same. i bumoed it down to about 50psi with the line off and mid range seems to real sluggish so im gonna bump it back up to around 58 or 60. My mods are Comtech Icebox, DC JDM 4-1 header, Skunk2 N-1 exhaust. So maybe the midrange is leaning out a bit. It sucks cause I have no acess to any dynos around me that are within driving distance.