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Heat Exchanger - sideways?

Posted: Thu Jul 21, 2011 9:01 pm
by wtdash
I have a radiator off a motorcycle - EX500 - I want use as a the heat exchanger for my custom AWIC:
Image

I want to remove the car's stock sub-fan * on the radiator (pass. side), and put the cycle rad in its place. I'll buy a slim fan to replace the one in the pic as it hits the timing covers.

1. If I turn the rad 90° it fits, but does the radiator still work properly on its side??

2. Will it get enough air flow being on the INside of the stock radiator and AC heat exchanger?

There isn't a rad cap to worry about...just the the 2 hose connections and I'll block of the temp gauge port.

I'm trying to avoid cutting up my bumper to make room behind the front grill, as I'll probably have to remove the bumper to cut it properly.


Thanks,
TD

*I ran the car w/out the sub-fan plugged in for a month (unknowingly)...car never overheated....and I'm running an NA radiator w/my turbo swap.

Re: Heat Exchanger - sideways?

Posted: Thu Jul 21, 2011 10:01 pm
by kimokalihi
Seems pointless to mount it behind the radiator because of all the hot air that will be coming through the radiator. Ditch you AC and you should have room in front. :)

Re: Heat Exchanger - sideways?

Posted: Fri Jul 22, 2011 12:04 am
by Legacy777
As Kimo mentioned, you're going to be getting hot air off the radiator that is going to really make the AWIC exchanger probably act as a heat sink instead. The temp of the fluid in the engine radiator is around 190-200 deg F. The max temp of the fluid (air) in the intercooler is probably 140 deg F or so. So you'll actually heat up your intercooler instead of cool it off.

You want to put whatever exchanger that has the lowest temps in front.

Re: Heat Exchanger - sideways?

Posted: Fri Jul 22, 2011 12:43 am
by wtdash
Ok...fine...I'm cutting the bumper.... :-)

Thanks for the replies!

Re: Heat Exchanger - sideways?

Posted: Fri Jul 22, 2011 1:22 am
by evolutionmovement
How small is it? Could it fit on one of the sides in front of the wheels? You could move the blinkers and use the hole as an intake, ducting for efficiency. Exhausting the air would be a little more difficult. Your best bet for a low pressure zone is probably the side of the front bumper ahead of the wheel well (something like an STI has). Into the wheel well, I'm not sure what's going on as I believe the pressure varies within it.

Re: Heat Exchanger - sideways?

Posted: Fri Jul 22, 2011 1:49 am
by beatersubi
evolutionmovement wrote:How small is it? Could it fit on one of the sides in front of the wheels? You could move the blinkers and use the hole as an intake, ducting for efficiency. Exhausting the air would be a little more difficult. Your best bet for a low pressure zone is probably the side of the front bumper ahead of the wheel well (something like an STI has). Into the wheel well, I'm not sure what's going on as I believe the pressure varies within it.
I've been thinking of doing exactly this but haven't found an appropriately sized exchanger or a good enough aero study to show airflow through the wheel well with the tire moving. From what I understand though, the rolling tire pulls air from around it and 'throws' it out of the wheel well. A louvered sheetmetal guard between the exchanger the tire should help protect it from debris.

wtdash, do you know what bike that came off of, and do you have the approximate dimensions?

Re: Heat Exchanger - sideways?

Posted: Fri Jul 22, 2011 2:44 am
by evolutionmovement
It's not so much debris damage I was concerned with as much as the air pressure in the area you'd dump into. You'd want to be venting to a low(er) pressure area so that the air is pulled through the exchanger. Of course, you'd want it to remain low pressure throughout the speed range, since you wouldn't want the air flow to stall at some point (though, this being for the engine ingestion rather than cooling, losing power isn't as big a deal as possible overheating). I think the safest bet would be the bumper side if you could manage to fit everything and have smooth airflow through, but there is a decent amount of room in there (which shrinks rapidly, of course, once you start to utilize it). The outflow vent design, too, would have to be guessed at, since I don't think any of us have a wind tunnel (dammit!), which is why I'd just mimic the STI vent. It's possible you could experiment by cutting a big hole and making a sliding flush door for it, then getting to a pretty stabilized temp and doing repeat runs as the same as possible with different size openings and logging the temp on the heat exchanger with each to find the best size opening. Not very scientific, but considering the costs of aerodynamic development, ghetto gliding is our only available method if we care to try at all.

Re: Heat Exchanger - sideways?

Posted: Fri Jul 22, 2011 5:13 am
by wtdash
^Thanks for the ideas.....I'll take a look.

wtdash, do you know what bike that came off of, and do you have the approximate dimensions?
It's from a Kawa EX500. Approx. size is 10x12x1.5 inches

Thanks

Re: Heat Exchanger - sideways?

Posted: Sat Jul 23, 2011 2:17 am
by beatersubi
wtdash wrote:^Thanks for the ideas.....I'll take a look.

wtdash, do you know what bike that came off of, and do you have the approximate dimensions?
It's from a Kawa EX500. Approx. size is 10x12x1.5 inches
Thanks.

Here is a good article about measuring pressure differentials with DIY materials. There are some good aero articles in general on that site. It would be interesting to cut a vent in a spare inner fender and test the airflow, or pressure differential, from inside the bumper and outside.