ssbowtie1

So I see alot of forced induction guys running alcohol injection to increase octane at WOT to prevent detonation. Well living in the great state of CA, the land of watered down 91 octane with all kinds of additives, I was wondering why people don't run alky injection on NA cars.

I remember on my old 94z, I ran a few logged runs. Part throttle was always fine, but I'd always pull a few degrees of knock at WOT. I contributed that to crappy gas, since my car was absolutely bone stock. Unfortunately I never got a chance to run it again with better gas, since I sold the car.

Anyways, any ideas???

mike85gn

The boost pressure helps atomize the alcohol when it is injected to the incoming air stream. That removes some of the heat generated by forced induction systems and gives a big power boost. The rest of the gain comes from detonation resistance, which is where naturally aspirated engines could potentially benefit from alcohol injection, but I was always led to believe that you need more air velocity than volume to properly inject alcohol into an engine. I really can't see it being any different than injecting nitrous, though. My best guesstimate is that it would probably work fine, but the results wouldn't be as impressive as they are on a forced induction vehicle.

mike85gn

FWIW, we installed alky on a friends Buick T-Type which is mostly stock, with downpipe, chip, 3K stall, and some big injectors/hi-flo fuel pump. He was running 18psi before the alky and made 290hp/380ft.lbs. After the alky kit was installed and set for a 12psi turn-on, he was running 23psi and made 330hp and a freakish 440ft.lbs. Ran 11.8's all day on slicks.

96capricemgr

Alcohol has fewer BTUs than gas, that is why oxygenated fuels suck for power and milage, given that fact I don't think you would see any gain in an NA motor. Forced induction yeah it helps cool the intake charge always a plus.