im building my 350 right now and i have a TBI intake manifold laying around and 1 1/2 throttle bodies (the 1/2 one has 350 injectors the whole one is off a 4.3) with the right modifications to the throttle body will TBI work well on a moderately high performance engine?

 

What is moderate to you?

 

my motor will have somewhere around 350 HP and 370 ft lb

 

TBI can support 350hp but it will require large injectors, 2" unit (holley or 454 GM TBI) and alot of tuning. The stock sized TBI unit can support a decent amount of power but will not fid your power goals.

 

The stock 305 TBI can support a 400ci engine. The 350 TBI a little more. But a performacne TBI can handle up to 900hp. TBI is defiantly worth using. But if I were you I would get the 454 TBI because of your engine set-up.

 

Umm, I don't know where you got your information, but listen to shifty he knows what he's talking about. There isn't a factory style, 2-barrel TBI that will support 900 hp.

 

I wasn't saying that their was a factory TBI that could handle 900hp. But thier is one made by turbocity.com(4b TBI). I do know my stuff about TBI, and I would of not have posted it if it wasn't true.

 

With 23 post to your name, I doubt you know as much as shifty or some of the others on the boards. The 4-barrel TBI is made by holley and requires a holley specific ecm to use. Some have tried it with our factory ecm, and even with lots of tuning results are marginal. With the cost of the 4-barrel and the ecm you can go multi port, so it pretty much corners a non-existant part of the market. Didn't mean to step on your toes, but your info is a little off.

Also saying a 305 TBI will "feed" a 400 is misleading, sure it will feed a stock 400, but what happens when he gets up in the 300-400 HP range and wants to turn 7000 RPM? No way it will work then, a BB unit would have a hard time with that.

The facts are, a stock TBI with big enough injectors will support around 300 HP without too much restriction. A BB TBI with 2" bores and 80 lb/hr injectors with fuel pressure in the high 20's will support around 400 HP. TBI is fuel limitied, not air limited.

This has been covered a bajillion times before