Efi Vs Carb

[BenHonda400ex]

Well I was just wondering today if carb operated atvs are faster than efi operated atvs. Like say you had a ltr 450 with a carb and the other one efi. Would there be any difference in power?

[finsteratv]

im guessing EFI why else would they do it? also i think the efi would allow you to run more consistently going from low elevationn to high without ever having to mess with jetting. PLUS theres tuners and such to unlock power even easier.

[BenHonda400ex]

Yeah I think efi might be I was just thinking because I might want a 450 and I was wondering if a ltr 450 was nice. Did you ever get that 450 or keep the 400ex?

[wilkin250r]

There are a lot of different aspects to creating power, one of them being the shape and turbulence in the intake tract.

But let's assume all that is equal, the EFI and the carb would have equal top-end power and equal top-end speed. If you're racing your buddy up the street, you'll be dead-even.

However, carburetors work by the air SPEED through the carb, not total volume of air. So when you stab that throttle from low throttle to wide open, your engine hasn't picked up speed yet, so you have the same volume of air, but drastically larger opening to pull it through. This drops the air speed, which drops the fuel amount, which drops the power and causes a stumble. You can get an accelerator pump to compensate for this, but it's not perfect.

With EFI, you get the exact amount of fuel you need, regardless of throttle position and changes, no stumble when you stab the throttle. This gives you much better throttle response and acceleration out of corners.

Plus, with EFI, you can map the ignition for different rpms, throttle positions and fuel delivery much better than a carb (even with a throttle position sensor). The ability to tailor the ignition will give you more power during acceleration.

Fuel delivery for almost any engine is really easy for a consistent RPM, and carbs work great for that stuff. But EFI gives you much more control during the transient times when things are changing.

[Stiles86]

i like efi beter but i switched back to carb for simplicity... i dnf'd 2 races last year becasue of efi issues... its what you want, ill stick with the carb for now