Fuel pressure clarification/$70 fpr

[AWDfrank]

I don't understand very well how the base fuel pressure should be set when tuning.

I have a 255 lph fuel pump, 560 cc evo 8 injectors, and a safc-2 to tune as well as a datalogger, boost gauge and fuel pressure gauge.

Anyways, I want to use this fpr of sorts ( go down the page a little) http://www.roadraceengineering.com/eclfuel.htm and I want to know if this will work since it only allows you to raise base fuel pressure but not lower it.

My question is when using a fuel pressure regulator do you want to raise fuel pressure from stock or lower it? I want to know because I will only be able to raise fuel pressure.

Will this be a good alternative to using an Aeromotive adjustable fpr? Keep in mind this is for a very moderatly modded car.

 

[romeen]

No, that won't work for you. With the larger fuel pump your base fuel pressure is going to be too high on the stock fpr. You need a fpr that will allow you to decrease the base fuel pressure back down to the factory setting of 37 psi. This value is a constant that does not change regardless of injector size, boost levels, etc.

 

[AWDfrank]

I see, that was my question, so I will need to decrease not increase. Thanks a lot! I'm such a cheapskate, I really don't want to spend the $180 but oh well.

 

[oldman]

No, that won't work for you. With the larger fuel pump your base fuel pressure is going to be too high on the stock fpr. You need a fpr that will allow you to decrease the base fuel pressure back down to the factory setting of 37 psi. This value is a constant that does not change regardless of injector size, boost levels, etc.

Agreed, B&M Commend Flo is not an adjustable fuel pressure regulator, it is a stock FPR modifier, unfortunitely it retains the part on the stock fpr that causes FPR overrun, the return orifice. It hurts me to see a reputable shop like RRE still selling that piece.

http://www.dsmtuners.com/forums/showthread.php?t=186834

 

[duck95]

You definetly want to lower, not raise your fuel pressure. Do your research on the different FPR's. There is quite a few. Full Throttle Speed has a good one that I use, some people swear by the Aeromotive ones. Choose what you're comfortable with.

 

[Dream On]

I also was going to recommend the FTS AFPR. I use it also and it holds base pressure just fine. The only problem I had with it is the amount of modification that you have to do to the thing to get it to bolt on. And the screws and nuts that go through the holes on the fuel rail instead of threading into it...Other than that, works great.

 

[Calan]

I went with the Import Evolution Aeromotive kit a few months ago:

http://www.importevolution.com/product_info.php?cPath=24_45&products_id=1620

Fair price, shipped quickly, installs easily, works perfectly

 

[steve]

So you have two choices, get a real AFPR or get a smaller fuel pump. If you used the 190 it's unlikely you would need the AFPR. Downside is you'll have to replace the file pump again and get the AFPR is you go much bigger than the EVI VIII injectors.

Steve

 

[DSMunknown]

I also was going to recommend the FTS AFPR. I use it also and it holds base pressure just fine. The only problem I had with it is the amount of modification that you have to do to the thing to get it to bolt on. And the screws and nuts that go through the holes on the fuel rail instead of threading into it...Other than that, works great.

Is this the AFPR from FTS you are currently using? I only ask because there are a couple universal AFPRs this company offers.

I went with the Import Evolution Aeromotive kit a few months ago:

http://www.importevolution.com/product_info.php?cPath=24_45&products_id=1620

Fair price, shipped quickly, installs easily, works perfectly

An upgraded version of that product can be found here for about 20 bucks more.

So you have two choices, get a real AFPR or get a smaller fuel pump. If you used the 190 it's unlikely you would need the AFPR. Downside is you'll have to replace the file pump again and get the AFPR is you go much bigger than the EVI VIII injectors.

Steve

The only reservation I have with that is this and this statement by Jim.