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Condor232
09-04-2009, 01:07 PM
Did a search for this and didn't find everything I needed. I am building up a 94 SC motor, specs I have put below. Planning on getting a 255lph fuel pump, but am unsure of the Injector size I need as well as if I can use a stock rail or no.

-1994 TBird SC Motor
-4.3L Stroker kit
-.050 overbore
-224/230 cam
- 1.7 stud mount rockers
- Stage 3 Superheads from Tom at Supersix
- Ported lower intake
- Ported/polished MPII with enlarged inlets and raised top
- Ported inlet tube
- 85mm TB
- Double Intercooler
- 5% overdrive pulley

I was thinking to be safe going with 60#, but 50# seem to be a cheaper and just as effective application. I also was hoping to reuse the fuel rail from my 98 Mustang since it is going back into that car. Also, any good brands to check out for the injectors?

Help would be much appreciated.

fastsc92
09-04-2009, 01:20 PM
i would go with 60's. contact dave dalke (mdkracing@windstream.net) and i'm sure he could hook you up with them at a good price.

David Neibert
09-04-2009, 02:41 PM
Stock rail will be fine. I would also suggest going with 60# injectors. Make sure you get the high pressure version 255 lph pump and consider upgrading the fuel pump wiring....the MPII will be your limiting factor.

David

Condor232
09-08-2009, 01:56 PM
Stock rail will be fine. I would also suggest going with 60# injectors. Make sure you get the high pressure version 255 lph pump and consider upgrading the fuel pump wiring....the MPII will be your limiting factor.

David

Not to start a war, but the MPII I am getting is ported/polished to hell and has seen some pretty high numbers in the past. Is it really limiting, or is this just because it isn't an MPx? Not starting anything, but seriously interested why that may be the case.

David Neibert
09-08-2009, 03:23 PM
Not to start a war, but the MPII I am getting is ported/polished to hell and has seen some pretty high numbers in the past. Is it really limiting, or is this just because it isn't an MPx? Not starting anything, but seriously interested why that may be the case.


I know what the MPII is capable of...I had one for several years and was producing as much or more power than anyone else. It's your limiting factor because, the heads, cam, 60# injectors and 4.3 liter displacement will handle more air/fuel flow than the M90 based MPII can efficently supply. To get max power from the motor you will need a bigger/better blower.

I'm not really an MPX fan, but it is designed to flow more air than the MPII because it can be overdriven considerably more without going off the chart for HP consumption and heat generation, but even the MPX will be a limiting factor with the mods you have listed.

To get the most power from the mods you listed (and still stay with a positive displacment supercharger), you will need to step up to a 2.0 or larger twin screw.

David

Condor232
09-08-2009, 03:26 PM
I know what the MPII is capable of...I had one for several years and was producing as much or more power than anyone else. It's your limiting factor because, the heads, cam, 60# injectors and 4.3 liter displacement will handle more air/fuel flow than the M90 based MPII can efficently supply. To get max power from the motor you will need a bigger/better blower.

I'm not really an MPX fan, but it is designed to flow more air than the MPII because it can be overdriven considerably more without going off the chart for HP consumption and heat generation, but even the MPX will be a limiting factor with the mods you have listed.

To get the most power from the mods you listed (and still stay with a positive displacment supercharger), you will need to step up to a 2.0 or larger twin screw.

David


Ah, I see. Thank you very much for the clarification. Out of curiosity, how much was your AR setup and where did you get it from?

David Neibert
09-08-2009, 03:38 PM
Ah, I see. Thank you very much for the clarification. Out of curiosity, how much was your AR setup and where did you get it from?

I got the 1.7 AR kit from Dave Dalke back in 2006. I don't recall the exact price but it was in the area of $3,500 with the 8 rib pulleys and fuel system upgrades. Even though I'm currently using the same blower with more overdrive on my new 4.3 motor, it's not really big enough to make the boost I want (20 pounds) without spinning it faster than it was designed for. That's why I suggested a 2.0 or larger.

David