So I did the injector swap this weekend along with a Holley adjustable fuel pressure regulator. My motor is a stock l98 with SLP 1 3/4" headers and free flowing exhaust. Also I run the 9 psi Procharger kit. My old injectors had 185,000 on them and were pretty tired. Anyway I am curious as to what are some of the fuel pressure numbers others are running with a simular combo. Also I am using the ATI FMU. As of now I set the pressure pretty low at 39 psi. When I get into boost I notice that my my boost fuel pressure is lower as well(in the 40's) with this set up. That I am not liking. I was use to seeing higher numbers with the stock set up.T rying to figure out a good compromise so that the car doesn't run to rich at idle or part throttle.

 

Tune the chip.

I'm running 24# SVOs at 40# with the line removed, no blower.

 

I have the 24# SVO injectors in my TT IROC-Z, running 6psi of boost on a stock L98. I use a Vortech SFMU and a T-Rex booster pump. Idle FP is set to around 38psi, with fuel pressure around 85psi at 6psi of boost. Fuel pressure goes to over 100psi with 9psi of boost in the intake manifold. Stock ECM/PROM and blowing through the MAF sensor. Been working good for me for three years/10k miles. I want to do custom ECM tuning to go over 10psi of boost once I have a stornger bottom end...

 

You shouldn't blow through the maf sensor. the MAF should be on the air filter side.


-- Joe

 

Why? Didn't Paxton S/C systems blow through the MAF? My MAF is after the intercoolers. Like I said, it has been working well for nearly 10k miles now.

 

The Procharger is the same setup as well.

 

Temperature differences between inlet side of blower, and outlet.

Vortech puts it on the air filter side. Paxton puts it on the outlet? You sure?


-- Joe

 

Page 195 in 'Maximum Boost' Shows a Paxton SC blowing through the MAF in a TPI Vette. I'm not real familiar with the SC systems, so I don't know how the F-body set-up was.

 

I don’t get it… what exactly is supposed to be the problem with putting it on the outlet side?

The MAF measures air mass based on how much power needs to be applied to a heated coil in the air stream to keep it heated. By definition, you have to know the temperature of the air stream for this to be anything resembling useful data, by definition it HAS to be temperature compensated. Second, it’s a _Mass_ air meter, meaning that it can detect density (more dense air cools the coil faster).

So what exactly is the problem??? I suppose that you could exceed the limits of the MAF, but that is going to happen in front or behind. You could have airflow differentiation across

Personally, I’d much rather be forcing pressurized air through a 2.75” maf then trying to suck air in through it, especially since most superchargers do not deal with suction side restrictions well at all.