opek

no it's not.

An AC system works like the small turbo and intercooler. To extend the AC analogy to this the entire motor would need to a have it's cross sectional surface area increased. The AC unit cools the cabin air while the refrigerant is expanded (post compression and radiation). In this case you are expanding the intake charge, then recompressing it again before you put it into the motor.

patsmx5

iTrader: (16)

In this case we are going to take air and compress it to say 100PSI. That should put the air temp around 700*F give or take. Agreed? Ok, now what happens when we move 700*F air through an air to air intercooler? A shitload of heat will be dumped. The air will become denser. Now, out of the IC we have air that's at a lower temperature then it was, but still under the same pressure. Agreed?

Ok stop. Assume the engine is not getting boost. Let's just dump this air out into the engine bay instead. What's gonna happen when that air is dumped to atmosphere? It's gonna get really really cold.

In this case, we are compressing the charge, radiating a lot of heat from it, then expanding it back. Same as an A/C system except there is no phase change involved as there would be with a refrigerant.

opek

We are together up until the bolded part. This extra cooling offered by an expansion tube makes no sense to me as the intake charge will have to be recompressed by going through a reduction orifice to get into the intake manifold.

patsmx5

iTrader: (16)

Well, I don't understand what your saying either. Uh, I don't think you understand exactly what I want to do. It's literally JUST LIKE an A/C system. Fluid goes into compressor to raise boost to increase the delta T so that heat can be removed more efficiently. Then pump the hot fluid through a heat exchanger and dump some heat. Now, expand it back and it's colder, right? Because we removed heat.

So, what part don't you understand? Why would it have to be recompressed by going through a whatever? I never said I was doing that.

Fireindc

iTrader: (13)

This theory sounds as if it might actually work. I just wonder why it hasn't been done before if it could work so well. Were talking LOW intake temps, which translates into ALOT more power per lb of boost.

Not saying it cant work, you might be on to something.. subscribed to this thread, maybe corky will chime in

patsmx5

iTrader: (16)

Yea, it's basically just exaggerating what everyone already does with the typical turbocharger setup. Seems advantageous to me. I'm so tempted to try it. Probem is I love my power steering and A/C, and don't want to remove them to make room for the two turbos.

opek

How are you going to expand the air? It comes out of the 2.5" intercooler, goes through the 2.5" charge piping, then through the 2.5" (?) TB. Where are you going to insert this 'expansion orifice' and how will it operate.

Fireindc

iTrader: (13)

I imagine it would be inside or right before the throttle body, maybe an extention of the throttle body itself? A malfunction of this device would surely result in engine failure unless it has some kind of fail safe. Overboosting 100+psi doesnt sounds good haha.

Maybe just have an orfice that the compressed air will come out of- but make it small enough that manifold pressure will only be 12 psi max or whatever boost you want to try to run. Have different sized orfices for different levels of boost?

Im not sure how linear it would be or if that would work at all really.

patsmx5

iTrader: (16)

Sorry, read the first page. I already answered all that crap like 4 times in this thread in detail.

opek

I understand, now.

How did you account for the orifice when calculating the pressure ratio?

Fireindc

iTrader: (13)

Any kind of update on this? Are you going to try to do it?

fasteddy

I concede that this may work at WOT. Note that the tractor motors run unthrottled. The orfice tube would reach zero pressure drop, and thus zero charge air cooling, as the air dammed up against the back of the throttle plate.

y8s

iTrader: (8)

you better concede digging up a 9 month old thread is lame. bad newb!