Have low air intake temps, need better knock suppression

[mosk]

My question has more to do with WI's ability to suppress knock, and less with it's ability to lower air intake temps.

I have a 2.4L turbocharged Toyota motor (8.0:1 CR, 550 cc/min injectors, T3/T04E turbo, standalone EMS) in a 4x4 pickup truck. It is an older SOHC motor and the combustion chamber design is not ideally suited to high cylinder pressures, although this hasn't stopped me from trying. I am currently able to make 222hp/240 ft. lbs torque at the rear wheels @ 14 psi, pretty good considering the driveline includes a transfer case.

Currently, I have a front mount intercooler that appears to be very efficient, keeping air intake temps to approx. 40*F above ambient at 14 psi/WOT. (I have verified this through extensive datalogging, but this is a street vehicle that isn't spending a great deal of time at WOT). This seems to be the limit of what I can sefely run on the 91 octane fuel they sell here in California. To pull this off and keep EGTs below 1500?F, we have to run an AFR of ~10.0:1, and even with that, I am limited to 9? advance at WOT.

From all my reading, water injection would seem to offer me the possibility to run more advance and perhaps more boost while simultaneously using less fuel and lowering my EGTs. Sounds to good to be true!

Will water injection provide enough fuel stabilization to compensate for what is probably a poor quench area? Ideally, I'd like to run lower my WOT EGTs to ~1450?F while also adding as much performance as possible (from increased timing and boost). Throwing more fuel into the cylinder works, but I am looking for a better solution, as I would like to raise the AFR back to a more performance-oriented level.

Thanks,

Jeff

PS: Looking at the 2d system, as it seems to be the best thing going...

[Warren_from_PINZ]

Water Injection DOES sound too good to be true! But it really works. In addition to the extreme cooling, the presence of water in the combustion mixture lifts the detonation threshold up significantly. As posted elsewhere (by me) I went from 10 psi boost with 96 octane (audible detonation) to 15 psi boost on 91 octane and the detonation was totally gone! Ran it like that for years.

[mosk]

Thanks, Warren. That was exactly the sort of informed reassurance I was looking for

-Jeff