Do 8 Stack EFI or Weber Carbs Run Good On The Street?

[PaulProe]

Originally Posted by FUNFER2

Very nice Paul !

What's the engine specs, including the cam ?
Do you have screens down in the stacks ?
What filters are those, manufacture and do they filter well without obstructing air flow ?
Please add any other details and photo's.

Engine is a bored/stroked 390 FE to 432". Cam is a mild Crane Hydraulic Roller, Edelbrock heads. Built for drivability/longevity, not HP. IMO, Some in this hobby get themselves in trouble by chasing the highest horsepower numbers - that last 10% is very expensive, very problematic.

The filters are "Bill's B Racing" filters, a double screen and rubber lip to mount to the extension tubes. Tried the typical Weber screens and noticed some elevation in silicon in the oil samples. These are not as effective as an air filter but better than screens.

Manifold is Blue Thunder from Pierce Manifolds. Plenum is included under center for vacuum chamber. Linkage started as components from them and I then reworked it extensively to get it to perform as it should. The key to proper performance is a linkage system that will open and close the venturis equally and with minimal effort. Was a lot of work to get everything aligned.

Much of the key to an effective system is the ECU. Not all are equal and not all will properly manage an individual runner setup. I chose Performance Electronics and have been very pleased with its capabilities. They have experience with the EightStack system (it is slightly different - the injectors are above the throttle plates and it makes a difference in tuning and start compensation settings). It has self-learn capabilities, but I've learned you really need a good tune to start. Self-learn will help but it won't do it on its own.

Injector sizing is important (bigger isn't always better), Idle Air Control is critical to making it idle smoothly as is "blue-printing the throttle plates. The PE ECU allows cylinder trim without sequential operation so you can tweak cylinder balance.

The Webers I had were fun, a challenge and I really learned alot. But they really prefer "full open" over "idle". The EFI system was a learning curve, but you can't imagine the difference it makes in drivability, fuel mileage and still have performance. It's not a cheap ride but highly recommended.

Paul

[fordracing65]

Just think of how much fuel you can buy staying carb instead of switching to efi for the price of the system. A 2 mpg gain efi over carb is not that great.

[fordracing65]

How much hp do the screens rob from your engine. With the Roush 8 stack k and n filters it's about 25hp and up.

[FUNFER2]

What are the cam specs ?

[PaulProe]

Originally Posted by FUNFER2

What are the cam specs ?

It's a Crane Cams 349521. Looks like they've dropped the grind but Jegs and Summit still have it. Link to specs

222Intake/228 Exhaust Not real wild but great for cruising and track performance

[PaulProe]

Originally Posted by fordracing65

Just think of how much fuel you can buy staying carb instead of switching to efi for the price of the system. A 2 mpg gain efi over carb is not that great.

You miss the point - it's not about economy, its about how easy it starts and how I can now cruise with the small block guys and make it to the next station.

At 10 mpg and a 15 gal tank, your cruise range is really limited. More than once, I was crossing my fingers, hoping I'd make it to the next station.

[fordracing65]

I have a 40 gallon tank. I understand efi. Just on my car I don't drive it enough to justify the cost. And a well tuned carb is fine in az. I wanted efi and had the funds to do it but I choose carb for ease, mechanical fuel pump for ease. Etc. keeping it simple. Your intake looks great.