I have a '02 Denali 6L with a Magnacharger Radix I installed in Aug. '03. Most daily driving is a kick in the pants. However, occassionally I tow a boat in hot weather and pulling uphill with boost will naturally generate an enormous amount of heat. When ambient temps are in the low 100's, heat becomes a limiting factor for the Vortec which powers down to protect itself (I'm told). 1) Can a Radix system be overridden manually when it becomes a deterrent to performance, or 2) would a water injection system be appropriate in this situation? And, if useful, how complicated would it be to install a water system to engage only when conditions dictate?

 

Maybe a water spray setup on the intercooler to get those coolant temps back down.
Set it up on a toggle switch, so that the water sprays on the intercooler when you need it.

 

The water would be a good deterent if detonation were to occur due to the higher IAT's. A scan tool would be able to tell you if there were a lot of KR or funny O2 readings.
Not sure if you could just spray the IC with it being in the valley pan area. A larger IC radiator and use of some of the special heat extracting fluids in the system could really help you out.
A separate controller, like a Megaquirt, could allow you to modulate the water injection as needed.

 

If your going to spray the IC with water ala STi/EVO style.. You want to use a misting nozzle and not something like your windshield nozzle. That way the water does not puddle and you get maximum benefit by dispersing the water over a larger area. Try Arizona brand nozzels found at Home Depot and the like..

 

Look into these kits:

http://www.smcenterprises.com/
http://www.alkycontrol.com/
http://www.snowperformance.net/

I'm leaning towards the smc or alkycontrol kit, for use with about 10-11psi. I believe these would work better than just misting the heat exchanger.

 

All good suggestions. Thanks. I don't have a detonation problem unless rpms exceed 4,500. I'm running about 8psi boost above bypass (2,500 rpm) and the engine has never overheated (though I've tried). The computer (with Magnacharger factory tuning) apparently backs the timing off as temps go up. Nice feature to prevent damage, but after a half-mile of uphill I'm using 2nd gear at 3,500 rpm to hold near 45mph, feels like a 40% reduction in HP. I've been told water injected after the SC would reduce intake temp and threat of detonation, allowing the computer to advance timing a little and tune the fuel ratio for more HP. And that spraying the IC will work, but may not be as efficient as a direct injection. Thanks again.

 

Theres no easy way to spray after the Radix, but spraying before it (in the intake tube) works fine, and probably atomizes the liquid better as well.

 

So this is safe? I wouldnt spray water though. It isnt as good at preventing detonation through my experience and I think it would be the most corrosive to the impellers. If you are using it irregularly I would go with meth without question.

 

Magnacharger does not recommend the use of Alky or meth for warranty reasons. Can't blame them for that. "You break it, you bought it" is how I've always played anyway.

 

I actually wasn't thinking about water, even though thats what the thread was pertaining to. I'm going to be using meth, for the cooling and octane.