Fuel Pumps and Tuning... 2.80 Pulley

[ArizonaSnake]

Greetings,

In the middle of tuning my 04 Cobra.

Bassani X w/cats
Bassani Catback
K&N Intake
NGK TR6s
2.80 Pulley

A/F is fine at WOT but creeps to 11.5 at red line.

Fuel Pressure runs 39lbs until 5k or so and then starts to trail off finishing about 30lbs at red line.

Pumps are maxing out at 4500 RPM despite tuned voltage increase.

Was considering a BAP but with these MODs is it normal for the pumps to max out at 4500?

Is 30lbs too low on the top end?

Do I have a pump issue or is this all normal news?

Car has 19k miles on it but the original pumps failed and PO put in some 20k mile used Cobra Pumps.

Note: Tuner is keeping the timing seriously retarded on the top end (13 degrees max) while we are working with this.

 

[supraman1990]

My car ran out of fuel with similar mods, listed in my signature. As you see I put a BAP and some 80's in it, all is good now.

 

[ArizonaSnake]

Do you happen to know when the fuel pumps maxed?

The shop is comparing to "another car" and they say it didn't max out the fuel pumps til 5900.

I am going to change the fuel filter and see what it looks like. But other than that I don't know how to confirm if the pumps are weak or not. I don't want to BAP poor pumps.... but I don't want to "throw money" at the problem as well.

Decision Decisions.

 

[Bdubbs]

Look at my mods in sig, my fpdc was maxed out so I added a bap with lethals wiring upgrade. Your fuel 30-39psi doesn't seem right, especially at wot. I thought I seen mine jump up into the 60's during wot pull.

 

[ArizonaSnake]

Yeah... quite confusing but I don't have any hard specs on what I should be seeing.
Thanks for the input tho.

This shop has tuned a bunch of Cobras and say I should be fine (if pumps were strong) with the 2.8 pulley, but they aren't getting what they want from these pumps.

 

[ArizonaSnake]

Look at my mods in sig, my fpdc was maxed out so I added a bap with lethals wiring upgrade. Your fuel 30-39psi doesn't seem right, especially at wot. I thought I seen mine jump up into the 60's during wot pull.

What model number BAP did you go with?

 

[supraman1990]

If the pumps are maxing out you may be seeing the FPDM go into thermal shut down. I know when I logged mine a few weeks ago with the 2.76, intake, x, catback, and lund tune it was maxxed out. I would strongly suggest you log your pump duty cycle as well as your injector duty cycle and see where your at. I have my money on a maxxed out FPDM. Get yourself a 40A BAP along with the wire upgrade and I bet your issues go away. A lot of people say you can make a little over 500 on stock everything, but my car didn't do it. If I had to guess I may be at 485 currently, and mine were done for.

 

[ArizonaSnake]

I will have to ask the tuner about exactly what he is logging... I assume he is logging the duty cycle of the pumps because he told me the pumps were at 100% at 4500 RPM.
The only place he saw any issue right now was he didn't like the pumps maxing out so soon and the dropping fuel pressure at the top end.

 

[Bdubbs]

What model number BAP did you go with?

Not sure on the number, but it's the 40A unit. My fpdc was maxed at only 455rwhp, and there's been plenty others on here whom have maxed there's also with just an upper pulley swap. It wouldn't hurt to install a bap even if it isn't needed. Also your tuner may want to datalog volts just to make sure there's enough voltage running back to the pumps.

 

[ArizonaSnake]

Thanks lads....

 

[supraman1990]

If he is logging it and saying its maxxed out at that rpm their is no wonder its losing pressure. You are for sure running into some kind of shutdown.