fuel pressure regulators hepl alot?
Im thinking of getting one. But i am debating because i am running a little rich on the dyno with the wideband o2 sensor. So im think a vafc. WHat u guys think? what are the advanages of the fuel Pres reguator? Is only around 100 without tuning. Should i bump up the fuel?

 

If you're already rich, a FPR is not going to help much. The VAFC will let you lean out the motor a bit.

 

agreed

 

any gains if i lean it out??

 

you don't want it running lean or rich, but if you're rich now then lean it. fpr's are a constant pressure and can't be tuned like the vafc.

 

Do fuel pressure regulators help alot?

Yes and no. They help, but I only got 1.3 peak horsepower from 36 psi to 40 psi. I would never be able to have 500cc injectors without dialing down the pressure at idle. Dont know who said you cant lean out with a fpr, but its incorrect info.

If you're on a dyno you should be tuning for POWER not a/f ratio. If you add more fuel and it gives more power keep adding fuel. Dont shoot for 14.5 a/f 'cause every motors different.

If the debate is between the regulator and the VAFC, I would do the VAFC hands down. Much more control over a/f and gains would be throughout the rpm band.

BTW, you can add and subtract fuel with both the fpr and VAFC.

 

thanks for the info niedjb. I figure the VAFC was the way to go. I dont have that much mods in order to get a FPR.

 

can you get the fpr and vafc together?

 

I'm using both.

 

if u get both will you get more power or is it useless to get the fpr?

 

If you do not need to go to bigger injectors or if you have a VAFC, you dont "need" it.