Can new bolt on TBI's support big power N/A?

[-SS454-]

I'm getting really interested in converting from a carb to EFI. Right now I have a 425-440 hp 454 BBC but would like to upgrade to a near 700 bhp 509 BBC, and Id like the EFI to be able to handle both setups.



I talked with FiTech and they said their EFI throttle body is 835 cfm, which seems quite small. Quite a bit smaller than the FAST 2.0 or Holley's 950 cfm. Is that enough air flow to support a big inch engine at around 6600-6700 rpm?

I know the EFI-8 is said to support 1200 hp, but thats simply in terms of fuel injector capability. Talking with the tech support, apparently on an N/A engine FiTech doesn't even recommend using the EFI-8 on 1000+hp applications, that an MPFI is a much better choice.

So simply put, can the EFI-8's 835 cfm support a future 700 hp 509?

Thanks

[Bonehead]

CFM means nothing with a TBI EFI. They are rated by the injectors. That being said, if you're looking for hp numbers that robust, you're better off going with a direct port injection set up. Much easier to tune (not a self learning unit) and something you can grow past your HP number.

[HandOverFist]

Talk with Bob about it...he has been running one on his BB for a spell now. http://www.chevelles.com/forums/89-e...ll-w-pics.html

[-SS454-]

CFM means nothing with a TBI EFI. They are rated by the injectors. That being said, if you're looking for hp numbers that robust, you're better off going with a direct port injection set up. Much easier to tune (not a self learning unit) and something you can grow past your HP number.

That is something I have been debating. I know for sure right now a direct port (MPFI) is not something I'd like to do on my current engine. There is no all inclusive kit that I really like on the market at this time. I'd most likely want to get a Edelbrock Victor 454 EFI and have it ported for the AFR heads. I am unsure if I want to do AFR 300 Rovals, or 305/315 rects. A future decision.

I like the Holley Dominator ECU, maybe even the HP ECU (the one that comes with the Terminator EFI kit), as it has a ton of features that will work great with a TBI or MPFI system. But at the cost of a terminator kit, plus regulator and whatnot, the FiTech simply is a far better value right now.

I have a few options.

1) Get the FiTech EFI 8, run it on any engine I build assuming it can sufficiently support enough air to the engine.

2) Get the FiTech EFI 4 600 hp, run it on my 454. Sell it for half the price in several years when I go 509 BBC, and build a direct port setup.

3) Get a Holley Terminator EFI 600 hp system, run it on my 454. Buy a different intake/TB/fuel rail for direct port and keep the ECU from the existing Terminator kit.

One thing about a Direct port setup, will it still do a -6 Feed and -6 Return that I would run with a TBI setup?

[-SS454-]

Talk with Bob about it...he has been running one on his BB for a spell now. http://www.chevelles.com/forums/89-e...ll-w-pics.html

I have been. He's running about 550-600 hp on a 439 bbc which makes the EFI 4 a good choice there. I haven't found anyone so far running the EFI-8 on a 650+ hp N/A engine.

[HandOverFist]

Yeah, it's tough getting info from users on new things. I took the plunge with FiTech before anyone else and have yet to install it lol. In my case it will be a warmed over 327 tho.

[Bonehead]

I think perhaps it might be a good idea to set a baseline number. Have you been on an engine or chassis dyno yet?

[-SS454-]

I think perhaps it might be a good idea to set a baseline number. Have you been on an engine or chassis dyno yet?

Yeah with the current 454 it made 363 rwhp.