Is this correct??


New Member
Jan 13, 2004
I'am a newbie when it comes to alky injection but from what I read and from what I heard...alky injection doesn't really help that much IF you're running good fuel in the tank (110 and higher)

How true is this??

(I know the concept behind the alky system is to keep FROM HAVING to run the good fuel..but I'm wondering with the combination of the two....are the results worth it?)
When I first started playing with alky injection not having to run higher octane fuel was not what I was thinking (although I have never used higher than 93 to this day). My primary objective was to cool the air charge entering the intake and subsequently the cylinder temps. Cooler air = more power and that is something you can benefit from no matter what fuel you are putting in the tank.
The guy(s) @ Snow Performance were telling me that they based their HP gains on pump gas alone......they added if I were running good fuel (110 and higher) that alky would not "help" that much......when I asked, "What do you mean, 'help that much' ? " He just said, "You won't gain as much power with it (Alky injection) as you would IF you were on pump gas"

When I asked, "What difference does it make if I'm on good fuel or pump gas" The best I can gather of what he was trying to explain :confused: was......"race fuel burns cooler, but makes a hotter explosion in the CC's, since it is a naturally "cold" fuel (he added if I ever spilled any on the ground or on me just how quick I observed it evaporate) when it 'hits' the cylinders it is already acting like an anti-detonation agent due to it's low temp, but explodes violiently, thus gives you more power...and allows more boost/timing/etc.....adding alky on top of this already 'cold' mixture just doesn't yeild the same results as it would if you were blown and on pump gas"

So I threw this at him.....

"Why then does my car run about 5-10 degrees HOTTER with race fuel (110)?"

He said, "Remember the race fuel, even though considered a 'cold' fuel explodes violently, thus putting a little more heat in the cylinders than normal fuel would, if your running an alky system as part of your application, all it would do is basically lower the cylinder that extra degrees that you run hotter with on race fuel"

........and I added,
"So basically an alky system removes the extra heat, added by race fuel, thus taking full advanage of the fuels potential?"

"Basically" he said.

So, I think I'm MORE confused now than ever :D .....

Seriously, I do understand where they're coming think.

Its like the case of someone running a huge liquid/air IC packed with ice water. See theyre outlet temps may be 32 degrees. So if your running race gas and have intake air temps of 32 degrees.. alky would be of little benefit. Just like water.. yes there are always benefits in the way it helps the combustion process, but the primary of reducing temps.. I hope it clears things a bit.

Also cars that are EFI have the issue where they cannot use the fuel for cooling as a carb'd engine can. See the gasoline on a carb'd motor helps cool the air some. This is one area where carbs are better than EFI.

I guess the easiest way I look at it, if your intake air temps are high becuase of inadequate turbo/intercooling/conditions/etc.. then there comes a point when the air going into the motor gets so hot that no amount of "octane" can handle the temps. In that type of scenario, alcohol would reduce those temps and allow you to increase your potential.

I look at alcohol as an inexpensive way to reduce intake air temps, and yield a mucher higher octane to burn. In laymans terms. For a race car that has a cold IC, you can see where this is going :)

Street cars typically cant run huge IC due to space constraints, this is why injection is so popular. A lot depends on your combo..

I'll toss in this bone, water has infinite octane :D