I was just told that when you tune 60 lb. motoron's with efi live you need to set it at 70 lb. injectors because the computer thinks the 60's are smaller than they really are and make them work harder. Is this true and may this be why im loosing so much fuel pressure at wot?

 

I'm ordering my v-2 tomorrow and scanning this tune to see how it looks.

 

60's are rated at a pressure delta of 43.5 (approx) or so, we run a 58 psi fuel system, so the actual injector flow rate will be larger than 60# at the ls1 4bar system.

 

I have the factory returnless fuel system plus walboro/hot wired/msd BAP. I run fuel pressure at 58 but drops to 40-45. Can this be why the fuel pressure drops due to the injector staying open longer than it should?

 

your fuel pressure should not be going that low, something isnt right there. most fuel systems run at 3 bar ratings, 3 bar equals 43.5 psi. our cars run at 4 bar, so therefore we have 58 psi of fuel pressure. so 43.5/60 is to 58/x. The injectors are actually 80 lb injectors if my math is correct.

 

they're not 80's, the flow is calculated by the Bernoulli's principle for pressure change.

Ryan

 

That kind of fade is just nasty, I think you need to
upgrade some plumbing and possibly electrical. At
least verify that the voltage at the pump is hanging
tough, maybe the BAP is sleeping on the job or
something. You can't tune for consistency when
you don't have any, in the fundamentals.

 

First, you set them larger in the tune b/c they are rated at 43.5 psi but you are running them at 58 psi, as stated previously. Using the RC Engineering calculator, that comes to about 69-70 psi.
Second, with your power output, and being boosted (which raises your BSFC) you are right on the borderline for a single Walbro pump. As jimmyblue recommended, check your voltages at the pump at WOT. A boost-a-pump will raise the voltage during boost, to the hotwire kit voltage (usually 13.7-14.5v) plus whatever voltage the BAP is set at. For example, if the hotwire kit raises your pump voltage to 13.7 v and you have the BAP set to 3 v, it will raise the fuel pump voltage to 16.7v. If your voltage is good, you have a restriction. Usually the pump itself, unfortunately.

 

oh ok, i always thought you could use that formula i used. when i come up with 80 i was like dang that seems awful high and did the math again. sorry for the wrong info