IAT tenps

What are you seeing for IAT on e85 or e90 boosted?

Running E90 and spraying 36GPH 25/50 water meth 18psi single turbo no Intercooler. During 1/8th mile pass seeing IAT hit 250 f. 1000 wheel EFI small block ford.

Plan to up go 50 50 water meth and up the gph to maybe 50. Also looking to get an Intercooler but I'm curiouse what you guys are hitting for IAT with similar setups

Jim,

Since the IAT measurement is taken before fuel injection, the fuel comes into play when you get into combustion temps, intake valve temp (especially if port injected), exhaust temps. You can get away with higher IAT on E85-90 than on pump gas since once that charge makes it to the point of mixing with fuel, more cooling work is done.

That said, 250 F is hot enough that aside from the concern of detonation or pre-ignition, you're losing a lot of power due to inefficiency.

I've run non intercooled many years ago and you can make it "work", but you'll make more power, more efficiently, and with more margin for safety with a proper intercooler, so I suggest adding one. Since this is a drag car, my preference is water to air with an ice box. At that point you could have 50 degree IAT instead of 250 degree, and you'll have a great deal more power to work with at a given boost level, more consistency in your tune since IATs are stable, and none of the issues that come with the inaccuracy of meth injection.

Or like you said you could spray more water, which will cool the charge more, but that's not as effective, and since the fluid delivery isn't very well controlled, it's not as consistent either.

With air to air my 1300 HP street car picks up about 10 degrees from ambient during a 1/4 mile, and drag cars are on water to air with ice box so they're below ambient temp.