An intercooler is a heat exchanger. That means there are two or more fluids that don't physically touch each other but a transfer heat or energy takes place between them.At wide open throttle and full boost the hot air coming from a compressor is probably between 250 and 350 deg F depending on the particular turbo/SC, boost pressure, outside air temperature, etc.. We want to cool it down, which reduces its volume so we can pack more air molecules into the cylinders and reduce the engine's likelihood of detonation.

How does an intercooler work? Hot air from the compressor flows through tubes inside the intercooler. The forced air transfers heat to the tubes, warming the tubes and cooling the forced air. Outside air (or water) passes over the tubes and between fins that are attached to the tubes. Heat is transferred from the hot tubes and fins to the cool outside air. This heats the outside air while cooling the tubes. This is how the forced air is cooled down. Heat goes from the SC air to the tubes to the outside air.

Wondering if your intercooler is up to snuff? The big test: measure your intercooler outlet temperature! When I did this I got a K type thermocouple, the thin wire kind, slid it under the throttle body/up pipe hose and down into the center of the up pipe, and went for a drive. On an 80 to 85 deg day I got a WOT temperature of 140 deg, for a 55 to 60 deg approach. That tells me that I need more intercooler. If I can get the temperature down to 100 deg, the air density in the intake manifold goes up by 7%, so I should flow 7% more air and presumably make 7% more hp. On a 350 hp engine that is 25 hp increase. On a 450 hp engine that's a 30 hp increase. Damn, where's my check book…

 

FWIW I have been experimenting with a popular large top mount vs the DFIC and I have to say that so far the DFIC is doing a better job of cooling and I have inperceptible pressure drop..... there is some more work that I need to do and that will take place in the next few weeks.... I still have my stock unit so I am adding that to the mix. soon.... we'll see....

I want the rear vent that Randy has.... I will post my findings when it is all said and done


where is Dr O these days?

 

Just today, I posted a very positive follow-up on the m7 coilovers.

So my intent is not to bash m7, but simply to see if there's a way to get the IATs down on a long auto-x course or on the track.

When on the highway, the approach is at about 14 degrees on average. Sometimes as low as 10, but that's usually after sustained speed on a level highway with constant light throttle.

But if more throttle is applied, producing more boost than simply what's required to maintain speed on a level road, you can see the IATs creeping up, as I would expect.

If I pull away at the starting line (at an auto-x) with high IATs, they'll still be high at the end of the course, for three reasons:

(1) Not much time for it to cool - typically from 40 seconds (short course) to sometimes as much as 1:40 (long course).

(2) Not a lot of speed for the air velocity to cool the IC faster

(3) Heavy throttle does NOT produce level or lowering IATs on the DFIC. They always go up, and I suspect that other ICs would exhibit similar behavior.

The water/methanol injection is interesting, but I'd be afraid it wouldn't be there after about 12-15 minutes of 20 on a track session.

As a point of reference re quantity of water/methanol, on the track my car gets about 8-9 miles to the gallon.

 

well guys i have the MM WTA I/C with heat shielding on the intake and over the entire intercooler. i have the scangaugeII. ant a 17% pulley. it was 105 here in tucson today. i was thrashing my mini for about 45 min on and off.the highest iat i saw was 119 degrees. even sitting at a light for awhile the hottest it got to was 122 degrees but whent back down to 113 while cruising. so this 212 degree temps sound insane too me.

 

That is amazing..... even the mfgs say that under track conditions the W2A will soak... explain so I can learn

 

well a few things. i'm running an HKS fan controller set at 182 degrees. so my water temps stay between 177degrees and about 181 degrees. the heat exchanger is in front of the radiator so it greatly benefits having the fan on more often and longer. i am also running a 180 degree t-stat. i have the palo uber hood scoop(lots of air directed into the engine bay). the heat shielding made a big improvement. look at my posts and you can see pics of the install. i am not pulling any timing from the cooler iat's that's the trick. after hammering the mini and then turning it off to go into a store after 5min and then coming back i turned the key and the scan gaugeII said 136 degrees. then after 30 sec of driving it's back to 114 degrees. then more light throttle and down to 111 degrees. by then outside temps were 103 degrees. so that's what i am seeing with my own MCS.

 

No bashing was noted , we are all just trying to assist with your particular situation. I am actually starting a little methanol project project myself and will report my findings when I can . One thing to note is that most good injection systems allow you to set when you want the injection to start . You can set it to 8lbs boost for example and it will only come on when you think you need it . This would allow you to finish any track event short of a 6 hr enduro. I have a close friend with a 700 RWHP blown vette that he daily drives and he owes it all to his Meth injection setup. He also has to refill his gallon tank bi weekly at most . Now back to your specific needs . As Tuls mentioned above the key to a IC is air movement . As you noted there isn't a lot of that in a autocross. Maybe 50 to 60 mph tops is the most I've ever seen . These are facts we can not avoid so we need to deal with them in the best possible way.Perhaps in addition to some sort of on board intercooler sprayer could you have a friend /team mate spray it down with chilled water during those brief moments between runs ? If you want to do it in a hurry a bottle of C02 or NOS sprayed into the IC opening would ice it down in a big way and fast. None of these ideas would have a detrimental effect on your engine and could only help the situation . I've used dry ice in the past but it is really a pain in the butt. Hopefully you will get additional help with this thread but these are my ideas for now .

Randy
M7 Tuning

 

Jim, if you get a minute tomorrow afternoon give me a call. 800-753-0063 After 1:30 EST is better for me.

 

i'm running meth inj in my wrx drag car and it does the trick at 850awhp and street driven too! i need to get this in my mini asap! i agree with randy.

 

Thanks!

There are some times as I mentioned when there's no chance to stop and spray down the IC. I carry a large sprayer for that application when possible (as well as for misting the tires).

So it sounds like I should employ an external, relay controlled cool spray system and maybe internal water/meth injection to cover both requirements.

The downside is that's a lot of extra weight (maybe a couple of gallons of water) and complexity for the events.

At this point it sounds as if there may be no better choice.

Is there a time delay when using water/meth injection?

 

I am just exploring the Meth injection process so I am sure there are more experienced people on here that can give more detail. The system I am going to be putting together will work off boost. As soon as I hit the preset boost level it is running and is progressive as well. As the boost builds so does the amount of meth. If I were you , I think an external water sprayer for the front of the DFIC would be helpful for your stationary moments and the meth system would take over once under way.

Randy
M7 Tuning

 

Your idea for the onset of the meth injection (before boost, then progressive with boost) sounds interesting.

I'd like to hear how that works out.

Guess I have to explore an external sprayer for the DFIC, but I don't want to use the wiper reservoir.

What's happening with the vents?

 

this has no bearing on weather or not the IC is working or making more power... the biggest TOP MOUNT pressure drop I ahve seen is 1 lb... that is only 5 HP... but the gain from the efficiency was well over 5 hp....

I have seen some misunderstandings regarding intercooler pressure drop and how it relates to heat transfer. For example, one vendor's catalog implies that if you had little or no pressure drop then you would have no heat transfer. This is incorrect. Pressure drop and heat transfer are relatively independent, you can have good heat transfer in an intercooler that has a small pressure drop if it is designed correctly. It is easier to have good heat transfer when there is a larger pressure drop because the fluid's turbulence helps the heat transfer coefficient, but I have seen industrial coolers that are designed to have less than 0.2 psi of drop while flowing a heck of a lot more air, so it is certainly feasible.

Pressure drop is important because the higher the SC discharge pressure is the higher the temperature of the SC air. When we drop the SC discharge pressure we also drop the temperature of the air coming out of the SC. When we do that we also drop the intercooler outlet temperature, although not as much, but hey, every little bit helps. This lower pressure drop is part of the benefit offered by new, bigger front mount intercoolers; by the Duttweiler neck modification to stock location intercoolers; by bigger up pipes; and by bigger throttle bodies. You can also make the SC work less hard by improving the inlet side to it. Air filters, free flowing intake pipes, removing a filter itself when switching to an aftermarket system, ( I run to filter for instance jsut a velocity stack on the intake tube) these all reduce the pressure drop in the inlet system which makes the compressor work less to produce the same boost which will reduce the discharge temperature (among other, and probably greater, benefits).


not to confuse the issue... just trying to give some of the stuff I went through in my process to achive the rediculous HP with a relatively stock set up

 

Who is saying that? Randy has one on his race mini and loves it! no heat soaking at all...

 

Specifically.... GRS

 

I see some fuzzy niomenclature going on here about heat soak.

Every IC will heat soak to some specific temp depending on all the variables in effect during operation.
To say a W 2 A will heat soak is just as misleading as saying a A 2 A will heat soak. Of course they will.

What matters is avg. temp under desired operating conditions.

For exaggerated effect...

Let's goof and say a W2A never gets hotter than 90º. At that point it is "heat soaked" or saturated. What's so bad about that?
To never heat soak means you'd always be at ambient. If you can find one of those...let me get in line.

So to just say something "heat soaks" is goofy talk.


BTW... Has there been a rule change in auto-x? I thought that spraying on circuit was illegal most particularly with non OEM products.
I could easily be wrong here.

 

You know what they say about assume?

I run in the most modified auto-x class at BMW CCA events and SM at SCCA events.

I assumed that I could do this in those modified classes. To be clear, I'm talking about external spraying to cool down the DFIC between runs, not out on course.

I already use a big garden sprayer between runs when possible.

The water methanol is actually the one I'd question at an auto-x.

I know we can't run nitrous, and now that you mention it, I'd think we probably couldn't do water/meth either.

On the other hand, using water/meth at track days would probably be ok.

Unless you had tuned your car to expect it and you ran out...