Originally Posted by crutt

I'm running an LSA blower on my 5.3 with ID850s, a 212/218 cam and long tubes. When I go wot my AFR goes to a minimum of 12.1ish instead of the commanded 11.2ish, if I increase the PE to just see if I can fool it I still get a minimum of 12.1 and a bit of bucking, and my fuel pressure drops from 58 psi to 50ish. Am I running out of pump? From everything I read the flex fuel pump should be plenty enough for 93 pump gas at 7 psi. Do I have to buy a walbro at this point? I really dont want to drop my tank but I'd rather do that then run around at 12.5 wot everywhere and burn a hole in a piston.

Originally Posted by jtphelps289

I just put down these numbers with stock flex fuel on my pt88 404stroker 1000cc injectors tes did a hell of a job tuning the flex fuel supported a lot more than I expected

Originally Posted by smokinlmm

Nice! Those are impressive, I was told they are good for a solid 600 so the OP should be good. I think adding a 450 is a bandaid, I'd figure out why my flex fuel supply system isn't performing properly before I added anything.

Originally Posted by jtphelps289

Yea I've always been told 550-600 too and seeing it push nearly 7 I'd definitely think the op should be alright without changing pumps yet also

Originally Posted by B00sted2007

kinda off topic, but I wonder why on your dyno sheet the ho and tq peaked early in the rpm range then steadily declined throughout the rpm range? Just curious, because usually all the dyno graphs I see, on boosted trucks, are basically the opposite.... they all usually gradually climb throughout the rpm range.

Originally Posted by smokinlmm

Bingo! I'd just swap in the new flex fuel pump.

Originally Posted by smokinlmm

Run an evap test? How big are your injectors? Your only at 41% duty cycle?