2MCHPWR

iTrader: (10)

We baselined my car and got 375 hp and 355.5 TQ. TQ curve made over 300 lbs/ft between 2600 and 6000 rpm's. HP peaked at 6300.

after LS1edit, car made 385.6 hp and 364.9 TQ. nice smooth graph.

but alas, all is not rosey....the wideband was showing a lean condition starting at 6000. they hooked up the fuel pressure gauge and made more pulls. the pressure was 60 lbs, but dropped to mid 40's at around 5700 rpm and up. atap showed the injector pulse static (wide open) at 20. they quickly changed out the fuel filter just to make sure.....no dice. julio says the pump isn't keeping up; must be bad. time to go to the dealer to get a new fuel pump. i hope that cures it.
Julio says the injectors are good for up to 400 hp, so that shouldn't be an issue.

i can't find the power cord for my scanner so i'll try to get the graph's on the net as soon as possible.

hoping for low 12's this saturday (drag radials, 17's in front)....even with the low fuel pressure...juilio said i can run it, but not to normal rev limit.

CHRISPY

Yep sounds like the pump.
Throw in a new one and your laughing <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />
Cheers,
Chris
ps- Good numbers BTW <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

Pro Stock John

iTrader: (34)

My stock fuel pump was going below 40psi at WOT... I replaced it.

I would not bother racing with a dying fuel pump personally, you can just go lean and heck it might even conk out on ya.

2MCHPWR

iTrader: (10)

thanx guys!
john, what do you mean it may konk out on me? are you referring to the pump or to the motor? i don't really care is the pump konks out on me, but i don't even want to risk losing the motor? can a bad pump hurt the motor?

Taco

iTrader: (1)

I would say yeah, a bad pump will more than likely do some damage, considering your A/F ratio will more than likely go Good, rich, REAL rich, then no fuel, and motors don't usually run good on air alone! Not being a smart ***, just demonstrating what will more than likely happen.

But, what I actually wanted to know is what heads are you running? Stock, ported? Running an LS6 intake? The reason I ask is because so far you've listed two of the mods I'm planning on doing (B1, Hookers, Ported Heads, Holley intake) and you're making real good power, so I was just curious about what to expect.

Thanks man,
Taco

Pro Stock John

iTrader: (34)

Fuel pump might conk out.

My car ran really lean with the bad pump in higher rpms, so I was afraid to get on it.

2MCHPWR

iTrader: (10)

taco, i can't believe i forgot to include my sig. all mods are in there. stock heads by the way. let me know if you want more info...

FYI...the tuning made sure that my car won't go real RICH.

thanx!!

LS1LT1

iTrader: (16)

Nice numbers. <img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" /> <img border="0" alt="[Burnout]" title="" src="graemlins/burnout.gif" />

Amarillo3

Call Mustangs Unlimited to get a walboro 255 fuel pump - it is around $130. This will solve all of your problems.

2MCHPWR

iTrader: (10)

thanx amarillo! will that pump be a drop in replacement? no mods required?

Trevor @ Texas Speed & Perf.

iTrader: (3)

You can also get a 255 lph pump direct from Summit Racing. Mine for my '98 T/A was labeled as a BBK for a 5.0 Mustang. <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" /> I used a large screw clamp to hold the 255 pump in place since it won't fit perfectly in the stock pump location. It's much easier to see what I mean once the pump is out of the tank. Just be sure that the float can move freely away from the sock filter before it goes back in the tank. Mine got stuck after we had it all back together, and we had to pull it back out. <img border="0" title="" alt="[Mad]" src="gr_images/icons/mad.gif" /> You'll also need a small piece (buy 6" to be safe and then trim as necessary) of fuel injection hose to connect the pump. I used two screw clamps to hold the hose in place, one on each end.
My FP was dropping to 47-48 at WOT prior to the swap. With the 255 lph pump in place, my pressure never dropped below 56 psi at WOT.

2MCHPWR

iTrader: (10)

thanx trevor. what hp level were you at when you had the low fuel pressure? i am going to put a stock pump back in (warranty), but i want to make sure that a new stock pump will be able to handle my power level.

by the way, here are my dyno graphs.
this shows the fuel pressure falling:
http://www.ponycars.net/images/dyno11.jpg

this shows before vs. after LS1edit:
http://www.ponycars.net/images/dyno12.jpg