Weber Look A Like Fuel Injection!

[D-CEL]

In theory, a carb or an EFI system that have equal flow and are properly tuned will make the same power. Flow is flow at WOT (wide open throttle). What we are really talking about is low and mid range power and drive-ability.
The main advantages of an EFI system over a carb, comes from its ability to precisely control the mixture. The result is better drive-ability, enhanced fuel economy and usually a flatter, wider torque curve under the WOT threshold.
But with these "PROS" come with some big "CONS" (no pun intended to the EFI mfgs) primarily system complexity and much higher costs. On top of that, you have to re-learn how to tune. The good part is that tuning becomes more scientific in practice, taking away some of the Juju associated with adjusting a carb.
Conversely, carbs are cheap(er) and simple(er) and for the most part can be made to produce sufficient power and acceptable drive-ability. While cabs work, to me they are a “compromise” system. I run them, but I don’t like them!! LOL

We all search for BIG HP in our mostly STREET DRIVEN toys.
But we must all remember that carbs need Vacuum to function. The wilder the engine combination becomes, the less happy most will be with the street manners of a carburetor.
EFI doesn’t need or care about vacuum and because the fuel is forced into the engine and the high level of control, it can be used to tame an otherwise….grumpy motor, another advantage.

While it is interesting to see head to head comparisons of the power, I think the true measure is how they start and drive on a cold morning in the mountains. How crisply it accelerates after idling for half an hour on the freeway when it’s 110 Deg. How controllable is the power delivery when you’re rolling into the throttle while exiting a hard right hand turn.

All things I don’t like about my very expensive, well tuned, super trick carb.

I’m putting EFI on my new motor, because it has flow potential that no carb can match thereby making the most possible HP and torque and with the right ECM (BIG STUFF or ACCEL DFI) will offer the best possible drive-ability. No compromises.
To me that is worth the additional cost and extra effort.

As I have said many times, there is no right way or wrong way, just opinion.


Jason

[rokndad]

Originally Posted by D-CEL

I’m putting EFI on my new motor, because it has flow potential that no carb can match thereby making the most possible HP and torque and with the right ECM (BIG STUFF or ACCEL DFI) will offer the best possible drive-ability. No compromises.
To me that is worth the additional cost and extra effort.

As I have said many times, there is no right way or wrong way, just opinion.


Jason

Wowzers!! Jason, what is that system? Very nice. We all want to hear how it runs when you get it going.

[D-CEL]

Rokndad,

That is the Kinsler Super Cobra Jet EFI manifold. It is the first SCJ specific “Stack” injection manifold. They did their homework when they designed it. it has a bunch of great features and options.

http://www.kinsler.com/NewProducts/PDF/SCJweb.pdf

LOL, yea it should be a hell of a thing….


Jason

[rokndad]

Originally Posted by D-CEL

Rokndad,

That is the Kinsler Super Cobra Jet EFI manifold. It is the first SCJ specific “Stack” injection manifold. They did their homework when they designed it. it has a bunch of great features and options.

http://www.kinsler.com/NewProducts/PDF/SCJweb.pdf

LOL, yea it should be a hell of a thing….


Jason

Thanks for the link. They sort of look like updated versions of the old Hilborns....the workhorse of the drag strip from the 60's. Very nice. We want details when you get them going.

[Anthony]

Originally Posted by D-CEL

In theory, a carb or an EFI system that have equal flow and are properly tuned will make the same power. Flow is flow at WOT (wide open throttle). What we are really talking about is low and mid range power and drive-ability.
The main advantages of an EFI system over a carb, comes from its ability to precisely control the mixture. The result is better drive-ability, enhanced fuel economy and usually a flatter, wider torque curve under the WOT threshold.
But with these "PROS" come with some big "CONS" (no pun intended to the EFI mfgs) primarily system complexity and much higher costs. On top of that, you have to re-learn how to tune. The good part is that tuning becomes more scientific in practice, taking away some of the Juju associated with adjusting a carb.
Conversely, carbs are cheap(er) and simple(er) and for the most part can be made to produce sufficient power and acceptable drive-ability. While cabs work, to me they are a “compromise” system. I run them, but I don’t like them!! LOL

We all search for BIG HP in our mostly STREET DRIVEN toys.
But we must all remember that carbs need Vacuum to function. The wilder the engine combination becomes, the less happy most will be with the street manners of a carburetor.
EFI doesn’t need or care about vacuum and because the fuel is forced into the engine and the high level of control, it can be used to tame an otherwise….grumpy motor, another advantage.

While it is interesting to see head to head comparisons of the power, I think the true measure is how they start and drive on a cold morning in the mountains. How crisply it accelerates after idling for half an hour on the freeway when it’s 110 Deg. How controllable is the power delivery when you’re rolling into the throttle while exiting a hard right hand turn.

All things I don’t like about my very expensive, well tuned, super trick carb.

I’m putting EFI on my new motor, because it has flow potential that no carb can match thereby making the most possible HP and torque and with the right ECM (BIG STUFF or ACCEL DFI) will offer the best possible drive-ability. No compromises.
To me that is worth the additional cost and extra effort.

As I have said many times, there is no right way or wrong way, just opinion.


Jason

Well that's kind of true, from what I have learned. I remember reading an article in Hot Boat years ago, testing Merc's then relatively new 454 packages, One a 454 HO and the other, a 454 EFI. Reportedly, both had the same short block and heads, the differnece being only the induction unit, a holley carb on a dual plane intake, and the other a tuned port, 8 runner FI intake. The testing revealed the Carbed motor out ran, made more power than the EFI version of the same engine, by like 2-3 mph in the same boat, by radar gun. What was explained is that a carburetor can be taylored to optimize fuel droplet size, whreas the EFI system sprays a mist like fuel, which vaporizes more easily, taking the place (space) of would have been additional air (O2) with the carbed engine, enabling the carbed engine to make slightly more power. Interesting.