Speedtoys

Whatever it is, you dont get energy for free from the engine driven systems.

hacker-pschorr

You should be removing those anyway. Nice idea on the bar napkin, not the best idea in the real world.

Once those are gone, lots of room.

One of the GM sensors we tested was just a tick slower than the VW unit, so that's good to go..

You don't get "free power" from any system except maybe NOS, which has its own limitations.

For anyone that believes a turbo is "free power", measure the back-pressure between the exhaust port and the turbo at boost. On average it's at least 1.5 - 2 times the intake pressure (on a good system). Now take a normally aspirated car with the same engine and plug up the exhaust to simulate the same back-pressure and tell me how much power loss there is.

Hint - I've seen this test performed, it's a substantial power loss.

Speedtoys

Valiant effort, but I knew it would come to this. Cooling a charged intake takes VOLUMES and VOLUMES of air, or a _fair_ amount of water and a huge heat exchanger.

Air cools more with more volume and more pressure (mass flow).

That pump isnt moving much..and you have pretty much zero surface area to transact it across when you compare the mass flow of the intake, and the air pump cooling it.

Its like saying we no longer need large radiators...because air cooling math all these years has been so so wrong.

Sorry..its not working.


Of course, the dyno runs will tell all.

gruffalo

I like creative thinking!

...as mentioned earlier in this thread, how about plumbing the fuel through the intercooler? It is circulating anyways, and wouldn't take that much extra effort to try and compare to your current setup.

Another idea wuld be to use the upstream side of the air pump. Same volume, lower temperature.

dprantl

Using fuel as a medium to remove heat from the intake charge of a forced induced motor was mentioned as a joke. It probably won't cool the air too much anyway, and will heat up the fuel to the point where it will boil in the lines and the car will stop running.

Dan
'91 928GT S/C 475hp/460lb.ft

Cosmo Kramer

Victor, how big is the surface area of the core on that intercooler? From the pic it looks a bit small, but could be just the pic.

Something like that would fit in my car if I decided to up the boost.

victor25

Ted... I designed the intercooler for the S4, but if the MAF is in the same spot your we are golden. The output is 4inch OD and slides snugly over the maf. They are not cheap, but if you want one PM me.

MM... yeah fuel wont work, and too risky. But the thought of drawing cool fresh air instead of pushing it is interesting. I may have to try that one and see what it does

Speedtoys

Fuel..hell, would be nice in a way...but to pressurize it, meter it for expansion, and then recover and condense it...hell, just like your A/C system.

It'd have to be huge.

But it'd work..but..you wouldnt wanna just because of the scale of the energy required.

AO

It's been in the 50's the past week here in Michigan. Wait until you test it on a 70 or 80 degree day. My prediction is your charge temps will skyrocket up to 200+ again. It's just not going to work as is in my opinion.

As for heat soak... the best you can ever hope for is your cooling medium (air or water) to be at ambient unless you spray with NOS, water, etc and use evaporation cooling to provide a denser charge, but that kind of trickery is usually left for the 1/4 milers. So it's a function of your heat exchanger. The benefit of Air to Air, is that you have an endless supply of ambient air. But the problem with air-air is you need a HUGE intercooler core to provide enough surface area to be effective.

With air-water, you can use a smaller sized IC, but then you need a heat exchanger to bring the coolant down to ambient. My car uses two Ford Aerostar heater cores, I think. I have a Kenne Bell H.E. from a Blowzilla kit that I plan on putting in this Spring (along with the super charger = more power!). It should clean things up a bit and provide better cooling overall.

Speedtoys

Which again, comes back to using a low density cooling medium (air) with a high density cooling medium (liquid) intercooler.

Aint gunna work...its cool, but isnt doing anything. Its orders of magnitude small.

Cosmo Kramer

Ya it's about time you did something with that slug of a car!

The R8's are going to be hiding forever now!

A good option for a small radiator to cool the water for a air/water IC is getting one off of a motorcycle. Most of them have a small 12v fan already attached which can be used to help the cooling.

AO

I know... it's pathetic.

The Aerostar heater cores have worked ok-ish. The problem has been that they block too much of the AC condensor and radiator. The one from KB is only about 4" tall but spans the entire width.

I know some people have used the motor cycle trick in the front wheel wells. It's an option... I'll leave it at that.

ptuomov

Am I missing something here, but isn't this intercooler 99% just a heat sink in a hot engine compartment? If you dyno a cool car shortly after starting it, the aluminum heat sink is going to cool the charge meaningfully. Not so much when the engine compartment is hot and the car has been driven for a while.

That engine at 420 crank hp or so will move about 1000 kg of air per hour and will use 30 hp or so for the compressor to do that. I don't know about the 928 smog pump specifically, but a quick look at the CARB docs makes me believe a typical smog air pump moves about 10 kg/h of air. Furthermore, smog air pump heats the air that it moves.

Here's a quick physics question for the home gamers.

Question: Perfect temperature equalization is the _best case scenario_ in terms of the charge cooling. If you have 10 kg/h stream of 80F air and 1000 kg/h stream of 250F air interact in a heat exchanger to perfect temperature equalization, what is the outlet temperature of both the 10 kg/h and the 1000 kg/h air streams?

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Answer: 248.31F

DKWalser

They told me there wouldn't be any math....

Mongo

I like the idea. If the supercharger kit is for a street application, I see no problem with using the air pump to cool the IC. Some of us use our cars as weekend cruisers, which I think would be a great application for.

Something that did cross my mind though is that if the unit uses the air tube from the recicrulation valve to cycle air through the IC (originally this hose is used to redirect air back to the airbox once the cats warm up), wouldn't that mean the air feed to the IC would be disabled until the cats warm up and the recirculation valve closes?