More fuel pressure means more fuel flow with the same pulsewidth. The only disadvantage is you will also increase idle fuel flow, and it'd be possible to get way too rich at idle with no way to correct. In my experience that won't happen with flow force injectors, not even a 1.6 on gasoline.

You have 42.5psi base pressure at atmospheric, run it up to 72psi or 4 bar and you get free 800cc injectors. You just have to make sure your fuel pump can flow enough at that higher pressure. Remember the rail is manifold referenced, so if you are running 20psi of boost you need a pump that can flow enough volume at 92psi, otherwise your pressure will drop and your injectors will shrink where you actually need em.

Edit: Maths for volume to horsepower...

Numbers..

.91BSFC for e85, 350hp for 80%dc at crank= ~318lbs/hr

318lbs/hr / 6.59lbs/gal = ~49gal/hr

72psi + 10-14 pounds of boost = ~90psi at WOT

You'd need a pump that does ~45 gal/hr@92psi to run 72psi, the warb is really the only single pump solution I know of at the moment.

 

Walbro450 is beast. Check my build thread, I'm about to drop one in next week probably. I'm controlling it with PWM so I don't have to run it at full tilt all the time.

 

If it runs at full tilt all the time and you don't need it most of the time I take it your FPR is running g overtime to bleed of pressure right?

 

Not really, the fuel just circles around over and over again. The walbro runs more amps with more restriction from the FPR from increased rail pressure. At 43.5psi it's around 180W, up to 240W at 90 psi. Since the FPR is manifold referenced actual current draw will vary.

For a comparison a walbro 190 would be turning around 70W at 43 psi.

 

If you get a proper fpr, its fine.
Stock fpr is on borrowed time with a 450.

plenty of people here have splooged their stock fpr with even a wally 255hp.
even if it doesn't get overwhelmed I'd imagine it would be unstable pretty often trying to bleed off all that fuel. just a thought

 

^^the reason PWM fuel pump control needs to become the norm.

 

Yeah lot's of newer OEM's use that now too

 

FYI, this is the only accurate map for E85 stations around me: Alternative Fuels Data Center: Ethanol Fueling Station Locations

Maybe it's accurate for you as well. Every other one I've tried is either outdated, or just plain wrong.

 

This site also provides a "last confirmed" date if you look at the details for a station. Helps provide a little more confidence. I've been thinking hard about E85 of late. I've got a station very close to my house, I think I'm going to try it on my next tank of fuel.

 

I have mine all wired outside the car. Track day tomorrow then I'll get to installing it.