Roush 98 S351 Fuel Delivery ???

[Apollo 13]

Guys, my 98 Cobra runs out of fuel at about 400rwhp. The 1st tune it peaked at 370hp @ 5200rpm. I removed the Vortech FMU and added a Walboro 255 pump, 42lb injectors and 90mm Lightning MAF. Also someone had a boost a pump installed so it was removed also. 2nd tune, 400 rwhp @ 5600 then out of fuel again. Replaced the fuel regulator. Removed the Walboro pump, replaced the basket, after butchering it for the Walboro install, and installed an Aviator fuel pump. 3rd tune, 426rwhp @ 6000, then out of gas.
I'm told the 98 fuel systems suck. What am I missing. Is the basket getting sucked dry? Test were made at 1/2 tank. I'm told the pump is controlled by a relay for above and below 3500rpm operation for quieter operation at low rpm. Anyone heard of this? If so , maybe a constant 12 to the pump will help.
Lastly, what did the S351's use? Dual pumps? BAPs? Any help is appreciated. Car should go 460-470rwhp @ 6800 without too much trouble. Thanks, Ron

 

[98 Saleen Cobra]

Apollo 13,
I had the same problem with my Cobra when I was getting tuned. I couldn't get over 420rwhp. I'm sure there are other ways around it but for me I just rebuilt the entire fuel system. I installed a Aeromotive fuel pump and regulator, and 1/2 fuel steel braded fuel lines. With the setup that I have I can run up to 1000hp. As far as the 351 question. I have read alot on this board that there fuel setup was ok but the tune is what mattered most. I'm not quite sure what pumps they used but is Marcus reads this thread I'm sure he will know. I hope this helps

 

[Apollo 13]

98, thanks for the response. Is your Aeromotive pump in the fuel tank? Is it still a return system?
I refuse to start the supercharger project on the 99 until the 98 runs properly.

 

[98 Saleen Cobra]

The fuel pump is not in the fuel tank. I did keep the return system. I don't blame you for not starting the other project. Have 2 projects going at once can be quite the hassel. Also can you post some pics of your rides?? I would love to see them!!