did some searchin didnt find anything. im currently buildin a new motor. i got a d1 pro charger. ive had a couple of people to tell me that alc. injected is the best way to go if you want more power. i was told i could run high compression and still have the same to more boost. there for lots more power?. ive never seen, read or seen kits for this on an lt1. just lookin for imput on this subject. can you run partial alc and full?

 

You really need to do a search. Your post has a number of seemingly simple questions that are actually not at all simple. I will give an oversimplified answer to one of your questions. You state that "i was told i could run high compression and still have the same to more boost". To answer, you need to understand what WATER (not alcohol) injection does. There are two reasons blower cars tend to detonate. One is high inlet air temps, the other is higher cylinder pressure (which in turn further heats the charge). There are a couple of ways to deal with this. One is higher octane fuel, which is not practical for day to day use given what is available at the pump. Another is making the AF ratio very rich, which is used by all blower tuners. The extra fuel acts as to cool the intake charge. This costs power, but not to a great degree. Another way is to retard timing under boost. This is also used by nearly all tuners. Timing retard costs hp and has somewhat limited effectiveness at preventing detonation. Lowering engine temp by better cooling helps, to a small degree. Lowering CR is quite effective. Based on both theory and practice, if you have the choice between lower CR and more boost, or a higher CR and less boost the former will unequivocally produce more hp. The explanation is somewhat long winded and I don't have time to go into it now. The only downside is decreased fuel efficiency under light load (where a street auto engine spends 95% of its' time).

Lowering intake air temps can markedly decrease detonation. This is done by the use of intercooling. The resistance to flow through the intercooler will decrease apparent VE and hence cost power, but this is more than compensated for by the denser intake charge (due to cooler IAT) and the ability to run more boost without detonation. As noted above, extra fuel also cools charge temperatures. Methanol is a fuel. It has a much higher heat of vaporization than gasoline. So, using methanol instead of gasoline as the "extra" fuel is more effective than using gasoline. Methanol also has an octane rating of ~99, so it will raise the octane of the charge in amount proportional to the quantity compared to gas. Just like mixing a little race fuel with the pump gas.

This brings us to water. Water has an even higher heat of vaporization than methanol. It is not a fuel and has no "octane" at all. It cools better than methanol due to the higher heat of vaporization. It also slows the combustion process after ignition, this dramatically reduces detonation and is primarily why the most effective injection fluid is at least 50% water. Why not all water? Well, that does work. So does straight methanol, but not as effectively. What practice has shown is that a 1:1-2:1 water:methanol mix works best. I don't know the theoretical explanation for this. I suspect it has to do with water displacing air. Of course, methanol does too but it allows less gas to be used which will partially compensate. Water increases the need for a strong spark because it is so effective at slowing combustion. That's one limiting factor in it's effectiveness and maybe why some people report better results with methanol. BTW, the combustion slowing effect will require some of timing we already took out to be added back in.

So, max hp for a given octane fuel is obtained by lower CR, higher boost, water/methanol injection, intercooling, careful tuning, and a strong spark.

Cliff's Notes: If I hear "alky injection" one more time I am going to scream. Call it WATER injection or go home.

Rich

 

Alky Injection rules

You dont put water in good bourbon rite.. You dont put water in your beer.. You dont put water in your gas tank... why would you put it in your motor

Would the words "Methanol Injection" be better