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View Full Version : tbi or mpi????



jasonsnova
12-28-2006, 08:43 AM
i'm going to be switching my nova over to fuel injection, i've been looking at holleys comander 950 set ups.... but wich one? they have a tbi, an mpi and a stealth ram mpi?? which one should i go with?? also keep in mind in the future i may be adding a supercharger as well. also years ago i had a holley pro injection 90cfm tbi unit, it was the kind with out the o2 and map sensors.....absolute nitemare! i do know they discontinued them since .

EFI69Cam
12-28-2006, 09:28 AM
Those early holley analog EFI systems scared hundreds of people away from EFI.
I'd go with a MPI system, they are based on carbed manifolds. You are going to get the best fit in your old car, the most flexability and upgradeability that way.

Just my $.02

Rolling_Thunder
12-28-2006, 11:18 AM
Mpi...

jasonsnova
12-28-2006, 11:22 AM
funny thing is i read the sticky thread above this after i posted ...lol!
i'm leaning towards the do it your self holley 950 commander mpi system on top of a performer rpm air gap manifold ( match to my top end and it already has bosses for the injectors!)

64duece
12-29-2006, 07:33 AM
Depends on which supercharger you plan to run. Roots, I would run twin TBI's on top. They're designed for fuel through them. The Commander 950 w/ Auxillery driver will work fine with that setup.

Centrifigual should be used w/ MPFI (either manifold) kit only. The TBI injectors (4) can't support much power on a blown V8 application and their max fuel pressure is also limited as well.

That being said, if it's "out of the box" you after, the StealthRam would be easier to make the supercharger connections and works well.

I prefer a single plane style intake as I feel they offer better airflow distribution but, I like to use an elbow and monoblade throttle body for smoother transition and to make the connections easier. The Holley intake that comes with that kit also could use abit of port work around the injector boss area and port exit. I've made 850hp through it w/ 355 and Procharger. I've also converted one of Holley's standard carb'd intakes (Dorton Strip Dominator) to EFI and ported it a little. On my 380" Turbocharged SBC made 1660hp through it. See pic of coverted manifold
https://static1.pt-content.com/images/pt/2006/12/MVC002S-1.jpg

Here's the Holley MPFI intake w/ elbow and 75mm throttlebody
https://static1.pt-content.com/images/pt/2006/12/inter_a-1.jpg

Comparison of the MPFI vs Strip Dominator
https://static1.pt-content.com/images/pt/2006/12/oldvsnew-1.jpg

What the MPFI intake looks like vs a Felpro 1206
https://static1.pt-content.com/images/pt/2006/12/port-1.jpg

jasonsnova
12-29-2006, 08:31 AM
64duece, nice work! but honestly i'd be super happy with a driveable relieable 550hp! im not looking to go crazy if you know what i mean! lol!

jasonsnova
12-29-2006, 02:01 PM
ok question#2 if you guys had to choose between the holley mpi commander or the commander stealth ram or the accel proram which would you choose and why? they are all in the same price range from what i can tell, keep in mind i may add a supercharger in a year or 2 down the rd