air to water charge cooler question.

[alexideways]

I'm in the early stages of designing a water to air charge cooler for my RB Z and was wondering if this idea I got, concerning the water cooler, was good.

 

Just want to know if there are any drawbacks about it.

 

I wish to use a BMW 335i stock intercooler as the water cooler.

 

(I'm a tech at BMW dealership and can get these for free from the body shop when they replace them on dammaged cars)

 

The idea behind this, is that the front mounted cooler would also use the end tanks as the water reservoir, this way I would'nt have to add an extra tank under the hood.

 

Thanks for your inputs.

[BLOZ UP]

Water-to-air units are great for dragstrips, but not so great for any race that lasts longer than a minute or so. I'd question the effeciency of a air-to-air intercooler being fill with water, but more than that I'd be concerned with the weight it would have with water in it.

[510six]

The main drawbacks to an air/ water cooler are the added complexity of having the added exchange radiator and coolant pump this also adds weight and remember to factor in the coolant/water at 8.36lbs a gallon. That said some years ago I had a liquid/air IC in my 510 due to space contraints with a 5 gallon tank that would be filled with icewater in the trunk, it would turn 20 lbs of ice into warm water in four 1/4 mile runs on hot days .The plus side was that on a 100+ degree day my air temps at idle with 112* track temps were 69*F adding a 200 hp shot of N20 (chemical intercooler) didn't hurt.

 

Most liquid/air IC setups I see are due to space constraints and better results IMO could be obtained from an air/air IC and methanol injection, on a street setup.

[Tony D]

When was the last time anybody here was under full boost for more than a minute, and WHERE so I can go there and do it too!!!

 

Water has a latency effect, you can get better cooling if you know your duty cycle. For a street car with short bursts of the turbo you can get by with considerably smaller components than a air-air deisnged for the same approach temps.

 

There is a reason industrial compressors run water exchangers and not air-air when you get to a given point. The coolers simply get too large and cumbersome. For the time you are on boost, the latentcy of water allows for thermoal loading and then a smaller exchanger to reject the heat between boost excursions will work just fine.

 

For Bonneville, ice tanks rule the day because they get stuff cold. But that's not normal.

 

I'd also put at least a small swirl pot to the high point to add water, deareate the fluid, and act as a suction point for your pump. Ford Lightning pump from Bosch is a nice unit.