2G AFPR Actually Needed With E85?

[idkiliketurbos]

Hey all - I am planning out some power upgrades for my car and am wanting to go with as OEM of a look as I can in the engine bay. I am doing a basic 16g setup on E85 and would like to avoid running an AFPR if possible for a more OEM+ appearance. Is an AFPR needed to resolve the overrun that you'd typically experience when installing something like a Walbro 255 on pump gas? Knowing that running E85 will consume about 30% more fuel volume compared to pump gas had me hopeful.

I look forward to responses with legitimate experience on this topic. Thanks!

 

[habitatguy187]

E85 at idle will not flow enough to provide an adequate pressure drop to prevent overrun…..PROBABLY.

Some guys claim no issues with overrun, others do. With and without e85

 

[bastarddsm]

I don't know on a 2g, but on a 1g, I've never had an issue using a stock fpr with E85 and a walbro 255 high pressure. Yeah it overruns a few psi, but it's really not an issue. The injector flow goes as the sqrt of the pressure. so sqrt of 45/37 isn't much.

 

[jdxnc]

Can you get away without it? Probably. Doesn't mean its the correct way to do it. Usually by the time you're thinking of E85, you're looking for more power and it snowballs from there. Eventually the 255 won't be enough and so forth. I usually stick with the buy once, cry once motto.

 

[TuskeeTuner]

You're going to have corrosion inside the OEM fuel rail running e85 - don't ask how I know. You'll also dissolve the glue inside the OEM fuel filter, clog your injectors, and possibly degrade your OEM seals.

I bought a car last year destined for partout and have been making repairs as time allows. I've done the clutch pedal, installed some new fuel pump wiring, new seals, LED conversion, sent the trans off for rebuild, and installing a Fuelab filter+AFPR+feed line setup, ETC... The Napa Gold fuel filter looked immaculate, the OEM fuel rail had exfoliation inside, and all the seals left behind a black residue when removed/disassembled. The last owner bragged about how E85 gave him an extra 100 HP; meanwhile he had FIC 1200CC injectors, an Aeromotive pump, oem fuel rail, and oem fpr. The spark plugs were BLACK after running on gasoline.