lately ive been throwing around the idea of switching to TPI from TBI because i would in the future like to use a centrifugal vortech supercharger on the car and i could do it with TBI but id have to do some major fabrications...anyways is there really a benefit switching to TPI? honestly? there must be a reason that the 305 TPI puts out 50 more hp and more torque than the TBI...

 

not that I'm an expert but I think the reason that the TPI puts out more than the TBI is becuz of our heads and cam. they suck.. to be quite frank about it... hahaha

correct me if I'm wrong, please

 

im pretty sure your right the heads and cam are alittle different...but 50hp from that...

 

Well, the heads and cam are the big part, then you have some smaller stuff that just makes it worse.
Like the fact that the TBI is starving for air, and the TBI isn't exactly the most performance oriented fuel dilivery system ever created, but with some work, a dremel tool, and some blood, sweat, and tears, they can be pretty stout.

Personally, I would never switch to TPI, maybe cuz of some fuhked up loyalty thing to my camaro and where it comes from, but if I was going to go with the blower it might actually be worth your time. I can't say for sure, cuz frankly I don't know..

 

Didn't you know that the heads and cam are the most important parts in a high performance engine? Ok well lets see here, look at my post : Super head comparison. It's got some good pics of the 416 TPI heads vs. the 187 L03 heads. There's a huge hunk of metal that blocks the air/fuel from entering the combustion chamber at a high speed. The camshaft is the old "peanut profile" that was used in the LG4s but its roller instead. If you take these considerations, then you'll realize where the TPI makes up for the horsepower advantage.

Also the L03 exhaust manifolds and y-pipe suck.

Oh and dont forget that horrible intake manifold.

There isnt much of a difference if you compared apples to apples. Maybe 5 horsepower.

 

"the TPI puts out more than the TBI is becuz of our heads and cam. they suck"

Agreed. Plus, at blower levels of airflow, the TBI unit will be far beyond its practial airflow limits and become a definate bottleneck. The way I see it:

TPI: Great torque from a long runner EFI, but has more maximum flow capacity than the TBI does. It lacks top end due to runner tuning, but a centrifugal blower produces most of its boost higher up. So, I'll bet a TPI/Blower setup makes a pretty strong power curve throughout its RPM range. And if you've got the $$ to buy a blower, you must have the $$ to convert to TPI as well. I also like to thing that the TPI's higher pressure fuel injection would be better for a forced induction application. I'd do it, but what do i know.

 

vortech makes a carb box for holley carbs so i was thinking i could get possibly get a carb manifold and a spacer and i might be able to do that but if i was gonna do that id probably just switch to carb

 

I think you should make a decision. One week you want a carb then u want a TPI. Swapping stuff is a pretty big pain so you gotta sit done and decide whats the best route...or you're gonna be sorry.

If you're gonna boost an intake system, I wouldnt use carb or TBI. A good MPFI is the only way to go. A MAF one would be better but a SD system wouldnt be a big setback.

 

im always changing my mind until i actually do it ill be changing my mind constantly if i had the money id probably switch cars (either to a tpi car or mustang) a buddy of mine said he will give me a 600cfm quadrajet and a performer manifold so i wouldnt need much more for the swap to carb...been over on the carb forum and people that switched from TBI to carb seem to be happy...and tbi to tpi seem even happier