What octane is alky/water injection equivalent to?

[twidge]

With a 50/50 mix of denatured alcohol and water in the tank with an SMC dual nozzle setup on 91 octane, what kind of gas would that be like running without the alky? Understand what I'm saying?

 

[Turbo__Tim]

The answer is 100 octane.

50-50 is not likely with a single stage set-up. Try 90% denatured, and work your way to about 75 %. Ballpark figures. Your results may vary..

Advance timing (if possible) as you increase the percentage of water.

If anybody disagreees with this response I will crush them like a stink beetle...

J/K...

 

[twidge]

What about running a propane kit? What is that roughly equivalent too? For a 5.0 mustang with 9:1 compression and 16 pounds of non-intercooled boost, which kit would you recommend?

 

[blackbuick87]

The octane will vary a lot depending on the alky mixture. Generally there is not quite enough octane to run a full 108 race chip, unless you have a well designed system.

Propane, when mixed with pump gas, comes out about the same octane level, ~ 100, give or take a few points.

Is the 5.0 supercharged or turbocharged? Propane is a little easier to tune and does not cause engine bog as easily, so I would go in that direction, except that it is more expensive initially. As time goes on the propane system gets cheaper and cheaper since propane is cheaper than alcohol.

 

[twidge]

The mustang is going to be running a vortech T-trim blower. With propane do you have the same problem as nitrous where you start losing the intensity of the injection as bottle pressure starts to drop?

 

[blackbuick87]

Yes, but I dont think it is as severe. Propane guys still need bottle heaters to keep pressure up in cold weather. A tank of Propane lasts a LOT longer than nitrous though, possibly months.

 

[blackbuick87]

Originally posted by blown8
and where is your propane kit black buick 87? huh? oh ya, its on order, go back home and keep using your NOS.

WTF are you talking about

Never seen a Troll in the alky section. Maybe your boyfriend can show you how to get to the "kills" section

 

[twidge]

Originally posted by blackbuick87
Yes, but I dont think it is as severe. Propane guys still need bottle heaters to keep pressure up in cold weather. A tank of Propane lasts a LOT longer than nitrous though, possibly months.

Nice! Doesn't hurt that propane is 50 cents a pound and nitrous is 3 bucks a pound either Thanks for your help!!

 

[Schwaeky]

maybe it's because I never heard of it being used before on gas powered engines, but I thought that propane was used for diesels the way we use nitrous oxide in gasoline motors, but that you couldn't run it on gasoline motors, now I hear you can.. i'm confused... also can I do the alky/propane/water tricks on a naturally aspirated carb motor, or is this something limited to the Fuelie/turbo crowd?

 

[YGETV8]

This question has come up before and I have always felt that there are too many variables to have a "set answer." How much alky are you injecting? What mix? What type and how many nozzles (=atomization!)? I ran a 108 Thrasher chip with great results in my GN, but I'm not saying that means it equaled the octane of high octane VP racing fuel! As with everything: your results may vary!