This is just a theory, I have not tried this but maybe someone else has.

Has anyone removed the intercooler and replace it with a pipe to see the difference. Our intercooler is small and restrictive. Just by looking at it I would think that there would be an increase in power and drivability by doing so.

The less restriction would increase the flow and thus making power. I think that the amount of cooling is really negligable. As for those of you have measured it and know what the delta, I commend your efforts. Just like the cold air intake debate of the power coming from more less flow, not from the actual cold air coming in.

Or scrap the factory intercooler all together and get a larger one from a turbo car and put it in the front lower grill. There you would get some real cooling and much more less restritive flow. This would take some work but I think it would be big power gain.

Again just a theory and I think worth testing if someone has the ability to fab a small connector pipe. In my past ecperiences a hungry motor cant get enough air so flow is more important than air temp.

 

No. The stock IC is more effective than you think. If you just let the heater air from the blower run straight into the engine, you would loose ALOT of power.

A FMIC is not realistic on the MINI, as the additional piping causes air to be restricted. The factory path is simple and effective in its design. That is why people have reported Air leaving the m7 DFIC at close to ambient temperature. You don;t need a FMIC in you get that kind of result from an intercooler in a factory location.

 

Maybe so on a normally aspirated car that relies on sucking air in, But with a Supercharger/ Turbo engine, you are FORCING compressed air into the engine. Compressing air causes the temp to rise, thus the need for an intercooler. If they would run better without an intercooler, i doubt the factory would waste the money putting them on, would they?

 

Motoman, you need to do some homework on supercharging. As the previous poster noted, the s/c compresses the intake charge, which raises the temp of the air dramatically. Read some of the threads about improving the i/c diverter and the M7 ram air scoop to see how much improvement can be wrought by improving the cooling of the intake charge. Once you've read that info, I think you'll see the 'pipe replacement' thought in a different light.

 

Here's one of my favorite sites

Intercooler theory

 

Leave it to Obe. Good link!

The next question would be; How much boost can you loose before the IC becomes a negitave?

 

Where's Matt?

 

Obe, I think this is a question you could realy get your teeth into

A good mass, surface density, air flow problem? I think so.......

 

take the absolute pressure (boost + 15 psi gets you pretty close) and devide it by the absolute temp (IAT in degrees C + 273). This is air density. If this number is higher, you MAY make more power. I say may because there's no guarantee that you won't hit timing retard....

So the stock IC drops about 1 PSI ( I think) at redline. My car developes 14 PSI with a 15% pulley.... So the stock IC drops my boost from 30 to 29 PSIA. Or about 3%.... (This is a decrease in density...). The temps drop from about 100 C to about 40 C (to use round numbers)... That's a drop of 60 K from an absolute temp of 373. Or over 15% improvement. So a straight pipe will do worse than the stock IC. But for any IC, just look at the T-MAP outputs, convert to absolute units, and the devide. Works every time....

I'm going to play with a water to air. It's got some interesting possibilites..... The heat resivouir of the system means that you can cool the water all the time that you're going fast, and use this "stored heat resivoir" (actuall stored cold resivoir) to cool the charge down at high loads independant of car speed. Should give some benefit in tight corner exits.....

Matt

 

One might think that but your gonna have to do a search on IC and read up for there is tons of info, viewpoints and testing. DrO (Matt) has done alot of testing and published his findings.

I can't speak the techno explanations but I can share my experience -
1) I went from stock IC to a GTT (perhaps the largest on the market) and there was a difference.
2) then I swapped out the GTT and went to the DFIC with scoop and there was a more notable difference. Bear in mind that I lost about 1lb of boost yet the car ran stronger.

 

something off to the side.. im starting to look into Smokey's Turbo Fero that used a Heated intake system. Since it was on Speed channel some days back. It never made it to market.. but it improved power and gas milage.

 

Replace your stock one with the bigger one Alta offers. I can't even begin to tell you what a difference it made in my husband's MCS!

 

might make sense for carb'ed or TBI where you have to make sure you carry the gas through the intake without it dropping out, but for port fuel injection, it just doesn't make any sense at all. But I've been wrong before.....

FWIW, my 75 Fiat has a hot water resivoir fed by the cooling system that is integrated with the intake. It's for emissions mostly...

Matt

 

I'm glad Dr. O raises the water-to-air (W2A) issue, as I think it's the poor relative to air-to-air (A2A) here on NAM. Of course, there's reason for this.
A friend installed the Ultrik W2A system and didn't find much improvement other than faster recovery in daily stop go traffic. I have read nearly all the arguments for, and against, W2A and remain interested. Dr. O raises the issue of a "cold reservior" which I presume depends on the volume of water in the system that is not cooling (absorbing heat energy) from the IC at any point in time. The Ultrik's tank seemed small, perhaps a problem or limitation causing the relative lack of improvement over the stock IC.
Anyway, let's keep discussing this.
cheers, as always.

 

Which tank? The jacketed core or the reservoir?

Did he run Water Wetter or coolant or pure water? All make a difference in efficiency.

 

might be so .. heres a link to the system i found .. just thought it was interesting reading.

http://schou.dk/hvce/

 

Another thing to consider when evaluating intercooler efficiency - the pressure drop across the intercooler doesn't mean much by itself, and a pressure drop is not necessarily a bad thing. In fact, since the whole purpose of the intercooler is to cool the pressurized air, there **should be** a pressure drop across the intercooler, and the bigger the drop, the better! (Think of putting a balloon in the freezer. As it cools, the pressure inside drops, and the balloon shrinks.)

The reason we don't see bigger pressure drops across the intercoolers on our cars is that the outlet is a smaller diameter than the inlet, which offsets some of the pressure drop.

I feel that the temperature difference across the intercooler is more important than the pressure difference.

Scott

 

The GRS made more power by having a higher IC exit temp, but higher pressure (less drop across the IC). Really, it's just math....

density is proportional to absolute pressure divided by absolute temp.

And both numbers matter, you can't get the whole story with just one....

Matt

 

Has anyone tried just straight up refrigerating the intake charge?

 

Yes. The Cryo Sprayer.
Worked well but the CO got ingested and choked the motor on occasions.

 

Well, it's not exactly the same as the classic "refrigeration cycle", because it's not a closed system and there's no change in state from gas to liquid, but if you think of the supercharger as the compressor and the intercooler as the condensor, that's kind of what we're doing already.

The intercooler's biggest limiting factor is that the "heat sink" is the ambient air, so it's hard to get huge efficiency numbers because you don't get a big temperature difference between the compressed intake air and the heat sink. If the sink temperature approaches the compressed intake air temperature, then there's almost no temperature difference, so there's no heat exchanged in the intercooler. This is what they're talking about when you hear about a heat exchanger being "heat-soaked".

I know some people have used air-to-water intercoolers with ice water as the heat sink, and others have sprayed water, water/alcohol, or compressed gases across an air-to-air intercooler to increase the temperature delta or take advantage of the latent heat of evaporation of water and/or alcohol. These methods are a little more complicated because you have to keep renewing the coolant (the ice water, spray water, alcohol, or compressed gas).

Scott

 

Pressure drop (on the internal flow) should be measured without any external cooling air flowing across the IC. Otherwise, as you note, the outlet pressure will be confounded by contraction of the air as it cools. Tested this way, a smaller pressure drop is preferable. The IC pressure drop data posted on various threads here doesn't state, as far as I remember, whether it is done using a bench flow test, or on the car.

Also, the smaller IC outlet will increase pressure drop, rather than decrease it. Air velocity will go up with the smaller outlet, but then there's always a trade-off between air pressure and velocity.

 

were with the car at rest, so no cooling air. But really, this is getting way overthought. PV=nRT does it all.

For the larger vs smaller side of the IC. With cooling, the charge shrinks in volume, and doesn't need as big a path as before the IC. But in case the effects at the IC end tanks are non-trivial, measurements were made (at least mine) in the rubber IC boots.

Matt

 

Actually, the Ideal Gas Law is for static gases in enclosed containers, not for gases flowing through a heat exchanger. That's why there's nothing in PV=nRT that will account for pressure/velocity changes due to changes in cross-sectional area at the inlet or outlet.

Also, if you try to use the Ideal Gas Law for this purpose, don't forget that as T decreases, n will increase as the density of the air goes up. That makes it impossible to use the IGL to determine what will happen to pressure as temperature changes, without knowing whether n increased more than T decreased.

Scott

 

Good stuff, Doc Ob and Scott!