Do I need to rescale the MAF, stage 2 cam, ported tb LS1

[kenand1988]

I have two assumptions about this, first it only needs to be done if you change the placement of the MAF or the diameter of the housing and two, if you make so much power you outflow the stock maf scaling.

My friends trans am that im tuning just has a LS6 intake, ported TB, sloppy stage 2, ls3 injectors, and E30. I have not rescaled the MAF because I did not think it would be necessary but now I'm seeing ridiculous MAF lb/min #s like 60lb/min on a NA LS1. The car drives great, idles great, and pulls hard, he and I really have no concerns with the tune but that could be because I'm not seeing something some of you might.

I'm sure everyone has an opinion on MAF lb/min translating to HP and I have my own thats based off half a dozen cars. When the MAF is scaled correctly it can inform your HP assumption pretty accurately. Thats just been my experience so when I saw a MAF lb i really did not expect to see it got me thinking if I have done something wrong here.

[Alvin]

You are also pretty damn high on the injector duty cycle. I've made over 600 rwhp NA on LS3 injectors. This setup isn't going to make anywhere near this.

All of this indicates to me that the fuel pump is weak. You are compensating with the airflow models. Check fuel pressure at WOT>

[Fast4.7]

You are also pretty damn high on the injector duty cycle. I've made over 600 rwhp NA on LS3 injectors. This setup isn't going to make anywhere near this.

All of this indicates to me that the fuel pump is weak. You are compensating with the airflow models. Check fuel pressure at WOT>

Fuel pump is weak or the injector data is wrong.

[kenand1988]

I believe injector data is correct and the pump is a dw200 which should be more than enough. There's no way to check fuel rail pressure, there is no sensor.

[gtstorey]

No Schrader valve on the fuel rail?

[bk2life]

There's no way to check fuel rail pressure, there is no sensor.

autozone has a free rental fuel pressure testing kit thats really nice, i use it monthly to do fuel psi tests on my customer cars from idle to WOT

[kenand1988]

autozone has a free rental fuel pressure testing kit thats really nice, i use it monthly to do fuel psi tests on my customer cars from idle to WOT

So my friend checked voltage at the pump and it's 13.5+ while idling. He also attached a fuel pressure gauge to the Schrader valve on the rail and it was 55psi at idle but would drop to 40 just revving it standing still so looks like the pump is bad.

[Alvin]

bam... that's the issue.

[kenand1988]

We switched to an aeromotive 340lph pump. Whoever had the car before put a cheap kemso pump in there, thank god we found this before spraying nitrous. After the new pump the inj dc went from 95 to 55 and maf is a more reasonable 40 lb min.