Well I'm getting pretty good pressure drop on two Walbro 450's. I'm running a base of 58psi and with 21-22psi boost i'm down to around 50-55 up top and duty cycle goes with it. I'm currently running one all time, other on 3psi Hobbs switch.

Any one got 3 in a stock basket? options? I still have a stock tank, uncut basket.

 

What size lines you running? And gas or e85?

 

-8, e85

 

There are others that know more but I question if your fuel line is large enough to support your setup on e85. I have -8 also but mine is based on gas.

 

wow, I would imagine mid 50's while approaching 22PSI manifold pressure would certainly make IDC jump.

How big are your injectors?

 

Bosch 127s.. Yeah I'm going to first change my fueling at the rail setup as it not optimal. I currently feed driver side rear first with a -8, -6 cross over to passenger front, then out passenger rear to regulator. Regulator to factory return line.

I want to y it at the feed to both rears -8an in, and -6 returns on front of rails to a Y, the n a single to the regulator. factory return.

 

That was my plan when I was on E85. I was going to run a -10 feed and then wye it right before the rear of the rails to two -8's then both out to the regulator. I bet that would help a lot for your situation.

 

Dont waste your time changing the line sizes, -8 is not a restriction, nor is how you have it configured at the rail.

2 450s should have enough juice to hold the injectors to 95% IDC up to 84psi fuel pressure, it sounds like you about there though. Basically there is nothing wrong with your fuel system, you just need more. If you really think something is wrong, I would replace the fuel filter and/or get a bigger one.

Even if you bump your base pressure up to 70psi and your pumps can hold that pressure (they cant), that would only buy you about 80hp more. Adding a 3rd 450 will not increase your capacity that much (since you are injector limited), but it will hold pressure up to about 50psi of boost

That setup of 127s and 2x450s will max out with e85 around 1000rwhp around 25psi or so, so it sounds like you are there.

What is your injector duty cycle at a given boost and given fuel pressure just so I can do a point check with the model I made.

Your next best bet is dual A1000s and 160s, should be good for 1650ish at 30psi.

 

I updated my spreadsheet in the stickied thread to prove it using some math. I added in a section that takes into account pressure drop from line sizes. Feel free to play with it.

 

Good to hear -8 isn't the bottleneck as that's what I have also.