What's a healthy fuel pressure?

[born2drv]

Stock fuel pressure is aprox 35psi correct? Is it better to be able to run on less fuel pressure and achieve the correct A/F ratios or should I just keep it at 35psi no matter how rich my mixture is?

Also what's the maximum fuel pressure you're able to get?

I just installed a walbro 255 with stainless braided hose, bypassed the J-tube and I can only get a max of around 42-45psi at idle.

I'll be upgrading to 550 injectors + MAFTPRO next week, will the 550's allow the fuel pressure regulator to pull more fuel past what I can get it now, or is that restriction based on the fuel pump or something else?

Thanks.

 

[CPT Furious]

Set the pressure via the TSRM. 23-30 with the hose connected and 33-40 with it disconnected. I had mine set at 38 with the hose connected & 550s and had to pull 20% of fuel on pretty much the whole curve on the dyno with my S-AFC II. I turned the fuel pressure down to 28 at idle with the hose connected and now I'm happier with the tune of the 550's.

 

[suprahero]

Hey guys, I just stumbled onto this thread. I have the walbro 255, 550's, and lexus afm as well. I just installed my aeromotive fpr and I set the fp to 38 with the hose on. I've been running rich ever since then. I hope to get it dynod and tuned this saturday so he can adjust the fp their, but I was wondering if maybe I should lower my fp and pull fuel. I also have the safcii. Any help would be appreciated.................lol

 

[BosoMKII]

Stock fuel pressure or above to correct for slight lean condition is best. If you lower the base pressure you effectively lower the flow rate of your injectors. Plus you can hurt atomization if you go too low. The injectors need a certan ammount of pressure to get the right spray pattern.