Got car on dyno. She made 438 RWHP and I think 450 TQ We shut her down after a couple of runs due to lack of fuel. Tech said 60's instead of my 42lb injectors due to A/F going up. He dosen't want me to shift above 5,200 due to a/f going into 12's. Car is only pushing 5- 6lbs on procharger. She pulls great right now shifting at a measly 5,200. Can't wait to see what she will do with right fuel.

Now he recommends 60lb inj. I would think my 42's should do just fine right?? He also had mentioned the boost referanced fuel regulator. Wouldn't that be a better option than buying a new set of 60's. He has the car at 11.9 A/F and thats where he wants to keep it. Will I still be safe going above that?? Car has stock PCM with a tune, stock fuel pump with the supplied procharger fuel pump booster.

Whats a GOOD A/F ratio to stick with??? Thanks guys!!!!!!!

 

You need to give a little more info like engine size, heads, fuel pump, which blower. but most likely you'll need the bigger injectors. Are you still runing FMU? also I belive the stock fuel pressure reg is 1:1 ratio.

 

42# injectors will get you to a little over 500 Hp. Are you running out of fuel (pressure dropping) or injector (maxing pulsewidth at 100%). If your running your stock regulator it does boost reference. 60# injectors won't solve your problem if your loosing fuel pressure. What kind of power are you wanting to make?

Bill

 

Hey, this is a stock block, stock everything except some headwork and hotcam. Im not running an fmu, stock fuel pump with just the procharger fuel pump booster, stock regulator. Not sure if its running out of fuel but on the dyno the tech said once we go above 5,200 rpm's the a/f ratio goes way up. He said he added more fuel, got it a little better but he says he wants bigger inj so he can add more.

not running out of fuel. At wot press is about 52-54 psi. I would like to make as much power as the car is setup for. I think it did real well for what it has.

 

Go with 60's and a better pump or pumps if you plan on much more. The stock fpr is boost sensitive like others have said.

 

As mentioned, a set of 42lb. injectors are going to start to reach their limit when you are near the 500hp mark. You didn't mention what the injector pulse width was at when the a/f ratio started to climb. If it was near 90%, then you definately need to consider upgrading the 42lb. injectors for something larger.

Unfortunately, the 500hp level is when you start to push the limits of some of the components you are currently using. It's been said many times before here that boost is very addictive, so it is always advisable to choose the proper parts so you will have some room to grow. Nice dyno numbers for your first session, especially for a relatively stock motor.

 

I know I should have bought 60's right off the bat, Oh well anybody need a practically brand new set of Lucas 42's LOL. Ya I was happy with those numbers, we should be able to do a little better once I get the fuel issue straighten out. Thanks!!

 

You can make way more than 438Hp with that kind of fuel pressure. I don't believe that you are out of injector either, did your tuner stop at 85% duty cycle? I made 540Hp with 42's at 100% Duty Cycle.

Bill

 

Agree with what everyone else is saying on the injectors. You also need an adjustable FPR.

11.5 AFR is safe and ideal. If you are getting 11.9-12.0 you are lean IMO (borderline dangerously lean), ESPECIALLY for the stock internals that I hope you know are not going to last on even 6#'s of boost.

 

Yes once motor goes KABOOM We will make a nice boost motor, Im well aware. How about a aftermarket fuel pump. Good Idea??

 

atleast a 255 with a hotwire kit good start.

 

how much do you want for you 42s???

have you thought about meth injection? i think im gonna do that next.

blownbird, what is a hotwire kit?

Jeremy

 

Yes what Is a "hotwire kit"

 

Its a marketing ploy to get you to spend a massive amount of $$ on a plug and play kit to run heavier wire to your fuel pumps. Its a relay and some wire. Idea is that the pumps perform better on more voltage, heavier wire means less resistance and more voltage.

We really need to know what your pulse widths were, but every car is going to be different. I would say you are working the whole fuel system pretty well. I do not like boost a pumps though.

 

get a good intank pump.