max fuel rail pressure using stock msp pump?

[jeffmsp]

just wondering if anyone here has experience bumping fuel pressure in the rail with the stock msp fuel pump in place (not a walbro) and how they are calculating the max "safe" pressure for the pump to handle, or what data they have suggesting what the max safe pressure for the pump to operate may be.

trying to get away with orange top rx7 460s instead of 550s. wrong way to go about it I know but I have the regulator sitting here on a shelf from another project from years ago so I am thinking of jumping up the rail pressure to try and get the most I can out of the rx7 injectors..

according to rc fuel injection calculator I could pull 300 flywheel with 460cc and 72psi pressure running at 80% duty cycle..

270HP at 60psi..

I have a few friends running pressure in the 70-80 psi range but I have never seen a post about anyone bumping pressure on the stock msp pump so I figure I should see if anyone else has had good results with the stock pump and higher pressure.


thanks, jeff

 

[jeffmsp]

dont think this is gonna work, at 60psi rail pressure over IM pressure I am going to be around 76psi total pressure once the car is at max boost and I am not sure if the fuel pump with 200,000kms on it will be able to keep up in the high end. rather than take a risk and ruin the motor over $100 set of injectors i think i am just gonna send rrfpr to ebay and start looking for bigger injectors for 300 flywheel.

 

[HighSpeed]

Glad to see you come to that conclusion, if only other people on here had your sense of backwards planning

I prefer an upgraded fuel pump anyday to cranking the fuel pressure, IMO its just covering up for a lack of volume coming from the pump........kinda like a cross dresser.....may look like a good idea and is sexy, but the end result is definitely disappointing....

 

[shane02pro5]

Nice metaphore

I'm swapping back in my 565cc's and selling the RC750's if you like to idle around 10.5afrs at min flow

Didn't realize this was the problem with my 565's causing me to run lean in spots. Until figuring out closed loop once the 750's were in and my 02 correction proved at light throttle 750cc's pretty much don't flow under 1.300ms

Or there is always using a secondary injector set-up at the onset of boost