chevy TBI'S

[NewEnglandRaceFan]

how much bigger is the big block one compaired to the 350sbc ones.?

think I'll start my efi learning with a tbi that bolt on, with an adapter first then move to mpefi on the high hp 355 for the monte SS

thanks..

[STINEY]

Answer = Lots.

I went with a 454 TBI on the Cadillac Megasquirt conversion. (No its not running on megasquirt yet)

The 454 TBI flows far more than the 350 versions. Larger venturies (or whatever they are on a TBI) and larger injectors.

Details are on my megasquirt mustang cadillac thread. http://www.bangshift.com/forum/showt...caveman+gained

[NewEnglandRaceFan]

900 cfm compaired to 390..
2" blades """"""""""""" ??
the reason I'm asking, is If I run the 454 tbi the throttle would be cracked less than the 350tbi at same engines speed/load correct..
and that would phuck up the t.v. cable settings I'd think.. as the throttle wouldn't be opened as much as it would be with the smaller tbi..
what am I missing?

[Beagle]

longer arm on the tv cable mount or progressive TBI pulley. You're overthinking it likely, GM has probably already done your math for you.

[TheSilverBuick]

900 cfm is only the aftermarket 4-bbl TBI's. The 454 ones might flow 640'ish cfm versus 390-400'ish cfm.

[Bamfster]

And the later ones should have the correct TV arm on them so the geometry will be correct.

[TheSilverBuick]

Being a chevy, I'd go right to multiport injection and skip the TBI altogether. It really isn't any more complex since fuel rails and intake manifolds are readily available.

[STINEY]

I stand corrected. Went back and edited for clarity.

I swear I got that # out of a manual somewhere.....

[NewEnglandRaceFan]

Being a chevy, I'd go right to multiport injection and skip the TBI altogether. It really isn't any more complex since fuel rails and intake manifolds are readily available.

may just do that.. but the tbi can be used as the t/b and give me the tv cable brackets/etc.
shouldn't be that hard to saw off the injector pods

[Bamfster]

I've actually been thinking about running 2 of those on a tunnel ram as the TBs ....

[Matt Cramer]

I've actually been thinking about running 2 of those on a tunnel ram as the TBs ....

I've seen that done before. Was thinking about trying it on my truck before I found the cracked block.

[dieselgeek]

2 TBIs are way worse than 2 carbs on a tunnel ram. Just go MPFI unless you want to practice with EFI on a budget.

[Bamfster]

2 TBIs are way worse than 2 carbs on a tunnel ram. Just go MPFI unless you want to practice with EFI on a budget.

Can you expand on that? Are you just talking about running TBI's .... injectors and all, atop a tunnel ram? I was just thinking about the throttle bodies to control air .... not fuel

[TheSilverBuick]

He's talking fuel and all at the top. Simple air throttlebodies are needed of course. Gutting TBI's would probably be fine as well.

[dieselgeek]

why not just use cheap carbs as TBs instead of the pricey TBI units?