Which Fuel Pressure Regulator with Bosch 040

**BrianV8** · 02-06-2012, 02:05 PM

Hey, needing a bit of info I'm having trouble finding via google.

I'm planning on building my rb25 plans of 500-550whp. Which leads to my question

I have a walbro 255 fuel pump now and upgrading to a bosch 040. I'll be running 750cc injectors and currently have the small body Sard FPR.

Now is the small body Sard fuel pressure regulator good enough or do i need to look at upgrading to the sard RJ or an aeromotive regulator?

Thanks Brian

**craftz** · 02-06-2012, 04:33 PM

I use the Aeromotive, works great and no leaks.

Originally Posted by BrianV8

Hey, needing a bit of info I'm having trouble finding via google.

I'm planning on building my rb25 plans of 500-550whp. Which leads to my question

I have a walbro 255 fuel pump now and upgrading to a bosch 040. I'll be running 750cc injectors and currently have the small body Sard FPR.

Now is the small body Sard fuel pressure regulator good enough or do i need to look at upgrading to the sard RJ or an aeromotive regulator?

Thanks Brian

**BrianV8** · 02-06-2012, 04:43 PM

haha i know i could just buy one. I already have a sard small body. I need to know fact wise does it need to be upgrade or not. Rather not have to buy the same part again if its not necessary

**GTR-Dad** · 02-06-2012, 05:42 PM

I realize it doesn't answer your question directly, but I have had good success with the Nismo adjustable unit. Not sure how body size compares to the Sard you have, but it fits the OEM fuel rail.
Dan

**BrianV8** · 02-06-2012, 05:53 PM

ya basically i have everything custom on my car, 6-an line on a top feed conversion rail. I can literally use any one just a matter of bolting it up.

My reasoning for this question is i keep finding theads saying that it may not flow enough over 450hp. I don't know where that number comes from because i would assume its by fuel flow. Like will it handle an 040 pump or will i have surge issues and such. I was hoping someone with more experience or with a similar combo could chime in.

**bignate** · 02-07-2012, 10:10 PM

I see no reason to change the FPR unless you can't get the pressure at idle to be low enough with that pump. Remember all its doing is bleeding off excess pressure to the tank, so saying its flow capability will limit you to a certain HP is wrong. The higher the HP, the more fuel is required, therefore less fuel needs to be returned to the tank.

**BrianV8** · 02-07-2012, 10:48 PM

ya thats the way i saw it too. I really didn't understand what point people were making. Made no sense. Well i'll go with that haha thanks for the input!!

**evilgtr** · 02-08-2012, 12:50 AM

Brian the oem Nissan units have been proven to handle the amount of power you are after so probably safe to say the unit you have will be up to the task. You can buy the big aero motive FPR's for less then $200 and that will eliminate any doubt you may have.. Remember when you're on the Dyno paying $200/hour it's always nice to be confident in your set up and not questioning any parts you chose.