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I put this very question to a friend who has a serious speed shop, with a chassis dyno built into the floor. He said it's easier to get good performance from EFI, but for balls-out maximum performance the carburator beats it by maybe 5%. It's just harder to get there. He has the advantage in experience, and of course his dyno makes it possible to operate cars at wide-open throttle while setting adjustments.
Interesting. Is that an apples to apples comparison? In other words, is that pulling off a modern TBI unit and dropping on a carb and picking up 5% or does that include an intake or other changes as well? What kind of engines? What kind of EFI?

I could easily see picking up 5% by going from the stock comb-over EEC IV setup to a single-plane on a 5.0 but that's more to do with intake than fueling but also with the EEC being 20-30 years old. EFI tech is moving pretty quickly now.

What does he think of the Engine Masters segment on EFI vs carb? The carb lost about 3% power (12.5hp peak) consistently under the curve above ~4k. The EFI was easier and quicker to tune than the carb too once they got past some sort of issue running a dual plane intake.

Seems like fuel is fuel. A carb and EFI should be neck to neck in peak power all other things equal. :shrug: EFI would have the edge in precision though, so I would expect it to potentially make more power under the curve and be more drivable. EFI also does baro adjustments for you so you don't have to change tunes due to DA changes.

All I have access to is a butt dyno and it's not very accurate!
 

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$1400 to fix a 2bbl carb problem? I would consider a 4bbl manifold and a NEW 4bbl carb to save money and increase the performance.
 

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How is tuning handled with that setup? it looks to be a standard narrowband O2 sensor so it really should only be able to see and adjust for stoich. Thats something I'd want to really find out about before purchase. It looks as though its just a recycled GM EFI system so making sure it's tuned correctly to run OP's small block would be a concern.
It's a pre set tune, it's not a full learning unit. You can calibrate the PROM chip, it will come calibrated from Howell for the engine you tell them. It is not a unit for a modified engine. It's for stock. They can be calibrated for a small cam but the TBI computer requires a good vacuum signal to the MAP sensor. They are good units, GM put millions of them out there and they were pretty much trouble free. Very simple EFI system compared to the full MPI stuff. I used one on a Jeep 6 and it was miles ahead of the crap carb that Jeep used in the 80's. Another friend did an IHC 345 conversion and liked it, later went to a wide band Edelbrock unit and doesn't like it. To me it's like the Autolite 2bbl of EFI units.
 

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It's a pre set tune, it's not a full learning unit. You can calibrate the PROM chip, it will come calibrated from Howell for the engine you tell them. It is not a unit for a modified engine. It's for stock. They can be calibrated for a small cam but the TBI computer requires a good vacuum signal to the MAP sensor. They are good units, GM put millions of them out there and they were pretty much trouble free. Very simple EFI system compared to the full MPI stuff. I used one on a Jeep 6 and it was miles ahead of the crap carb that Jeep used in the 80's. Another friend did an IHC 345 conversion and liked it, later went to a wide band Edelbrock unit and doesn't like it. To me it's like the Autolite 2bbl of EFI units.
Cool, I was just wondering how it was tuned. I'm sure it works wonderfully once it is tuned for an engine as its an OEM system. I just didn't know how close the open loop fuel table would be just taking a stab at what the tune should be for a SBF.
 

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Interesting. Is that an apples to apples comparison? In other words, is that pulling off a modern TBI unit and dropping on a carb and picking up 5% or does that include an intake or other changes as well? What kind of engines? What kind of EFI?
As I recall it was primarily V8 Mustangs, with the only change being an intake swap to facilitate the change from EFI to carburation.
 
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