As most of you know, when you compress air, it gets hot. As air temp increases, density decreases. As density decreases, less oxygen gets in the cylinder.

Intercooling lowers the temp, so does meth/water injection. The problem with water, as far as power is concerned, is that it displaces air and negates the denser air. Spraying pure methanol can be used as a fuel source, but isn't a good idea with a carb if you want to maintain a max power air fuel ratio.

My boost tops out at 8 psi at 4500 rpms and stays at 8 all way to 6500+. Obviously this has to do with the impeller spinning past its highest efficiency point and just creating hotter air cancelling the cfm output.

One option would be to upgrade the blower but then I have to deal with belt slip. Upgrading to a cogged belt is expensive and I'm worried about the crank snout twisting off.

Another option would be to find a chemical that cools more but has a lower mass.

Here's a link of liquids
http://www.engineeringtoolbox.com/fl...eat-d_147.html

It says water is the highest, but when I get alcohol on my hand, it sure feels colder than water. Now this means water takes more energy to vaporize right? So it would pull the most heat?

This is over my head a little, and I'm hoping some smart guys can teach me something here. Is there anything better I could use than water thats reasonable? I'm looking for something that will cool down the air, but not displace as much air.

Another option would be to spray a dry nitrous shot into the impeller, which comes out at -127*. But I haven't found much data on this, and I've heard that the nitrous is pretty localized and isn't very effective at cooling the impeller. Keeping it cool at the source is the ticket.

I'll be upgrading to E85 with my carb which will cool the air substantially before it enters the cylinders which will restore some lost energy, but there is a lot more to be had if I can keep the air cool at the source, and the blower's output will increase.

 

The pre-blower N2O and the carb running E85 will do what you want. You will make more power at the same boost level you had before, but I wouldn't try to get any more boost pressure out of the blower. I would consider running a little less boost -> slightly less RPM than before. The E85 & N2O combination will increase your lower RPM power output enough that you can shift a little sooner.
Keep in mind that your exhaust volume will increase at all RPM.

 

It still removes less heat from your hand than water would, but it does it faster than your body can warm up your hand.