96-98 cobra fuel rails question

[mgt351]

What kind of power can the factory fuel rails support?
Interested in blown applications primarily

 

[96dreamer]

I'm interested to see answers to this. I'm currently making about 11lbs of boost and should be about 550whp and it looks im running into fuel pressure issues on e85 around 5500rpm. I don't have any dyno time this is all street tuning.

 

[mgt351]

I'm interested to see answers to this. I'm currently making about 11lbs of boost and should be about 550whp and it looks im running into fuel pressure issues on e85 around 5500rpm. I don't have any dyno time this is all street tuning.

What are the issues you’re having?

 

[96dreamer]

it's losing fuel pressure..

 

[9397SVTs]

it's losing fuel pressure..

What does your fuel system consist of and how is it wired?

 

[96dreamer]

What does your fuel system consist of and how is it wired?

Intank walboro 450lph pump wired through a relay to an auxiliary fuse box that's ran direct to the battery on stock lines and rails and 80lb injectors. Calculated pump flow according to logs is only about 360lph. Pressure peaks around 47psi and drops to under 40 around 5500rpms.

Currently need to diagnose non working blinkers before doing any more logging.

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[9397SVTs]

What size wire are you using throughout and where is the battery located?

I found this interesting:

Walbro 450LPH Fuel Pump High Pressure TIA485-2 F90000267 (Universal E85 Ethanol) TI Automotive

Do you have a genuine Walbro?

Do you have an adj. FPR? What happens when you crank up the pressure at idle? Does it fall off?

What is the voltage at the pump?

 

[96dreamer]

Battery is in the factory location. 4 ga ran from battery to aux fuse box, 10ga from fuse box to pump. Voltage drop should not be an issue. Computer is seeing ~14v running off the same fuse box so voltage at the pump should be similar.

I got the pump off amazon a few years ago but everything pointed to it being a genuine walboro at the time.

Factory fpr, I was pretty much trying to max out the stock fuel system setup on e before dropping the money for a full fuel system. So I've avoided putting any money towards trying to limp the factory stuff along.

 

[9397SVTs]

I would at least replace the stock FPR with an adj. rising rate FPR.

Do you have a relay for the pump in the back of the car?

 

[96dreamer]

Relay is in the trunk next to what I believe is the pats box. Triggered off the factory wiring. Found a used adjustable fpr for $50. That's cheap enough that I don't mind essentially throwing the money away just to test with.

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[PACIFICGREENSVT]

600 hp