[OzPony]

I'm just finishing the install of my Vortech supercharger and I want to know what size MAF, injectors and fuel pump you guys recommend ??

The kit comes with a T-rex. Should I leave that as well as the new larger fuel pump ??

Do I leave the FMU in once I have the larger fuel pump in ?

[Julian Moore]

I have the vortech on my 95. I have Pro-M 80, 50 pound injectors, 255 in tank pump, and the t-rex. Ditch the fmu and get bigger injectors. Enjoy the new found power..it's awesome.

[OzPony]

Originally Posted by Julian Moore

I have the vortech on my 95. I have Pro-M 80, 50 pound injectors, 255 in tank pump, and the t-rex. Ditch the fmu and get bigger injectors. Enjoy the new found power..it's awesome.

Thanks for the tip.

You have 50 pound injectors ! I was thinking 24..... My motor is stock apart from exhaust and the vortech. Would 30 pound injectors be ok ?

[NoSlow5oh]

OzPony - Here is the breakdown of fuel support for a supercharger. You are substantially increasing the amount of air entering the engine. You must also supply enough fuel to support the incoming air. You must also make sure you are supplying the correct amount of fuel to match how much air is coming in. Your stock fuel system is not up to the task of adding a supercharger, so you have 2 choices based on your current mods.

1. Upgrade your in-tank pump to at least a 190lph fuel pump, or 255lph if you plan on any more mods in the future. Use the t-rex in-line also. You will need 24lb. injectors if you decide to use the fmu (fuel management unit). What the fmu does is hook up to your fuel return line. It senses boost via a vacuum line attached to the intake, and closes off the return line, increasing the fuel pressure to the injectors. Under boost it completely controls the fuel pressure, since once it increases it above the regulator's setting, the regulator is completely open trying to relieve pressure. You will need a maf that is calibrated to match the 24lb. injectors. Take it to the dyno and adjust the base fuel pressure and fmu settings to obtain the correct air/fuel ratio and you should be good to go.

If you are ABLE to get a custom tune, you could get more hp/tq along the whole rpm band. You would need to find a tuner with a dyno that can tune the 94/95 computers. Your fuel requirements would change. You will want a 255lph in-tank pump. You will not need the t-rex. You will need 42lb. injectors (more than enough) and a maf of which the tuner might want to pick out. (The maf is the most important part of the combo, and this is how some work their magic.)

[Julian Moore]

I think you can see by the replies that fuel is VERY important. I went larger injectors, as down the road if I change the pullies I can have enough. I try to never skimp on the fule...less fuel equals boom. As far as I am concerned, if you have invested thismuch in the car..get som eheads and an intake..make that vortech show it's numbers. I run the stock cam, edelbrock heads, and a cobra upper/lower (ported) and make over 450 rwhp. The car hass an sct chip burned and it runs like stock. Just something for you to think about. All the money you are spending and now your gonna bottle nekc th e boost with stock heads and intake. Save and wait..IMO. Goodluck either way.

P.S. You could get away with 30's and the fmu it you needed.

[OzPony]

Thanks so much guys. I understand now. More fuel it is.... I'm ordering the injectors this afternoon.

[go5oh]

So on a naturally aspirated set-up would a t-rex stifle a 255 in-tank? I left my t-rex on after I sold my Vortech t-trim with plans to go turbo. I will be running nitrous however bu tin the mean time it's NA and have always wondered if it was "dead-heading".

[nowhereman]

98mm maf, 39 inj. kb bap. 10psi vortech.