DeepSeaSnake

you had a badass water/alcohol injection system? Bigmike said he can get intake temps in the neighborhood of 40 degrees with 40 bucks of home depot parts pumping window washer fluid. So is it feasible to cool the ping out of 87 octane?

mastacox

Why bother? I doubt you'd save money when you consider the cost of the distilled water and methanol you're using...

Are you running a FTC to retard your timing and control fuel delivery?

DeepSeaSnake

I'm not running anything just asking hypothetically

okie81

Hypothetically, it would work. The alcohol in the mixture burns, contributing to combustion and fuel requirements, but is also much more resistant to detonation than gasoline. So I guess the result would be a cooler, higher octane charge.

X-AWDriver

It would work but your now relying on a separate system to prevent catastrophe instead of keeping it simple and running premium. It's a risk.

mt_goat

I'm going to vote no. Apparently the water/meth injection can actually make the low rpm ping worse. Something to do with the ECU only using the feedback from the knock sensors during higher rpms (over 3000) to make timing adjustments. That is also when the w/m injection is flowing the most. So as I understand it the ECU "thinks" the ping is under control because the w/m injection is helping during high rpms, then the low rpms come along and the w/m isn't there but the ECU doesn't "see" that because it doesn't use feedback from the knock sensors at low rpms. At least that's the way I understood it from Gadget. This would probably apply mainly to a w/m injection system set-up to mist at 5 lbs of boost or more. I don't have a clue how you would control the injection with parts from Home Depot.

Another note, I know one guy that ruined a new engine (still under factory warranty) by running too much w/m injection. It seems it is one of those "a little is good", but too much isn't.

vr6freak

i ran a devil's own water/meth kit on my supercharged vr6 in my gti. logging intake temps in real time we watched the IAT's drop to below ambient temp's on a summer day of 70 degrees F. One of the main advantages of running w/m is to run lower octane than your chip tune calls for, lots of guys have run this with no ill effects.
more beneficial to turbo guys as you can ramp up the boost more easily with the turn of a knob as opposed to swappin out pulleys and watching your A/F's until they are tits.