What NOT to do..............

Unit 5302 · 03-17-2002, 02:52 PM

EFI is more susceptable to the turbulence than a carb because EFI's intake charge doesn't carry any fuel.

On a racetrack torque isn't the prime need, it's horsepower. The turbulence isn't an issue at higher rpms, pure volume is the issue. Long runner intakes have more flow capacity on a carbed car. Short runner, large diameter intakes have more flow on an EFI car.

The upper intake on an EFI car is very messy. It's complex and it's since the intake charge has very little mass, it serves to reason the flow would be restricted and imperfect. Getting rid of the long runners in favor of big short runners and connecting them closely to the external air supply makes for more flow. It also makes the air charge more likely to be disrupted by turbulence (including the turbulence that would be created by the fuel injector itself), and it's large volume makes for poor velocity.

A carbed car doesn't have an upper. It's intake flow is more stable because of the additional mass of the fuel. Large, long intake runners hold a generous amount of air/fuel mixture, and at higher rpms, that's what you want.

Velocity must be obtained two different ways because of the place the fuel is added to the intake charge, and how it's added to the intake charge.

For a load of BS that I'm just thinking through my head it sounds pretty convincing doesn't it? LOL.

03-17-2002, 02:52 PM	#21
Unit 5302 Registered Member Join Date: May 1999 Posts: 5,246	EFI is more susceptable to the turbulence than a carb because EFI's intake charge doesn't carry any fuel. On a racetrack torque isn't the prime need, it's horsepower. The turbulence isn't an issue at higher rpms, pure volume is the issue. Long runner intakes have more flow capacity on a carbed car. Short runner, large diameter intakes have more flow on an EFI car. The upper intake on an EFI car is very messy. It's complex and it's since the intake charge has very little mass, it serves to reason the flow would be restricted and imperfect. Getting rid of the long runners in favor of big short runners and connecting them closely to the external air supply makes for more flow. It also makes the air charge more likely to be disrupted by turbulence (including the turbulence that would be created by the fuel injector itself), and it's large volume makes for poor velocity. A carbed car doesn't have an upper. It's intake flow is more stable because of the additional mass of the fuel. Large, long intake runners hold a generous amount of air/fuel mixture, and at higher rpms, that's what you want. Velocity must be obtained two different ways because of the place the fuel is added to the intake charge, and how it's added to the intake charge. For a load of BS that I'm just thinking through my head it sounds pretty convincing doesn't it? LOL.