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, ideas??

 

Alcohol is a slow burning fuel so it's like using a higher octane gasoline. Adding alcohol to gasoline in a forced induction system just keeps the 92 pump gas from detonating. If pump gas isn't detonating in your NA engine then increasing the octane level won't do anything. Instead of having an alcohol injection system on a boosted car, they could just as easily use C12 race fuel but that gets expensive having to fill up with that every time. The alcohol injection isn't used all the time. It's only on when boost pressure reaches a preset limit.

 

I have done some experimenting with water/alcohol injection on NA motors and it allows the use of low octane (87) when previously at least 91 was needed to avoid spark retard. It will work.

Rich

 

Won't using 87 octane cause detonation at part throttle too, when alcohol isn't present? Did you put the nozzle before or after the maf? Can you possibly give me any more info? Thanks!

 

There are lots of ways to trigger the water, including a switch. I am not using it currently on an NA vehicle, but that's how I had it set up (a switch) on the Taurus SHO I used to have. It was there for WOT use with premium, but I did the octane experiment just out of curiosity. You definitely want to inject after (downstream) of the MAF.

Rich

 

I believe the reason for the use/purpose, and effect of water or water/alcohol injection has become twisted. With the amount of alcohol injected along with the H2O, it does little in the way of raising octane. The purpose of the injection is to cool the intake charge, with combustion process converting the injection to steam, giving the effect of raising (but really not) octane, with the alcohol portion helping the injection to better participate in combstion process.