TPITuned Port Injection discussion and questions. LB9 and L98 tech, porting, tuning, and bolt-on aftermarket products.
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You could have a MPFI induction system with tuned runners so a better comparison would be batch-fire injection vs. MPFI, in which case MPFI would be better because the injectors are firing right when their respective intake valve opens, not all at the same time.
MPFI IS batch fired....SFI is the one Red Firebird is talking about.
That is the difference between "MPFI" and "SFI." SFI fires sequentially, when the valve opens, not all the time. Thats what MPFI does.
I have SFI on my '95 Grand Am and my '97 Z28, and had MPI on my '89 Camaro 2.8. I've already researched all this stuff
To answer the first question, TPI is a type of MPFI! TPI got the "T" due to its tuned-length intake runners. Now, I've been a TPI owner for about 2 weeks, so I'll let someone else get into the true details. But TPI IS a type of MPFI. Both are batch fire.
Hope I didn't confuse anyone
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Yea those four barrel ones that Edelbrock sells. You can get them from Jeg's. Are those better than TPI? My friend swears that they are but I didn't think so.
Originally posted by Jason E That is the difference between "MPFI" and "SFI." SFI fires sequentially, when the valve opens, not all the time. Thats what MPFI does.
Yes, but unless the "Sequential" has VERY LARGE injectors, they all work batch in WOT (surprised?). SFI only works during idle and part throttle.
To have SFI work in WOT you'd need fuel injectors 3-4 times larger than an equivalent batch fire injector.
The TPI is better.
I contacted Edelbrock about thier mpfi setup, the only reply I got was that it would not work on a firebird, it was designed primarily for trucks.
Spend your money on some headers and better gears, maybe a cam.
Like John, that is designed mainly for trucks that had TBI. There was an episode of HorsePowerTV where they put it on a chevy truck... I think it was a 454SS or some kinda special edition truck... I don't remember that well.... I just remember it was a TBI and they used the MPFI that looks like a 4 barrel, and they gained like 30-50hp or something.
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