Some time back I removed the sound baffle and water collector from the intake tube that runs from the front opening (above and to the right of the radiator) to the bottom front of the airbox. I run an Alta CAI.
I think it was Obehave who reported to me that there is measurable airflow in this tube above 50mph. Presumably it supplements the cold air coming from the cowl intake, but is a secondary source of cool air.
What if I remove this tube completely, plug up the hole in the bottom of the airbox, and fabricate a duct that fits the front hole and directs air to the IC outlet horn to produce some surface cooling due to cool air flow?
A reasonable idea, or stoopid?
cheers,

 

I'm not sure you'd see much cooling. As I recall, the airflow was measurable, but not spectacular.

The fact is that there just isn't as much surface area on the intake horn, relatively speaking. Combine that with the amount of airflow you would expect to come from the front opening, and I'm not sure it's worth the effort of fabbing up some kind of diverter...

 

Since you went out on a limb - I might as well.

I always wondered why you could not run a tube from the a/c compress (containing cold freon) into one of the horns and then back out returning to the a/c compressor? Inside the horn, the copper tube would be like a pigs tail increasing surface area thus cooling the air from the supercharger.

If this goes down as the dumbest NAM idea ever - will I have to sell my MCS?

 

The line would be the return out of the condenser back to the compressor. It can and has been done(not on the MINI)but was run through the IC. The drawback is you have to run the A/C for the line to be cold.

 

My logic is this: Although it might not produce much cooling, is the marginal benefit from front air going to the airbox with a CAI greater or smaller than the marginal benefit from directing this airflow onto the IC horn, and into the engine bay in general?
I just got my GTech RR, so maybe I can do some measurements...

cheers,

 

1st idea. I doubt you'd see any improvement. At best you would have to build a cowl or some such around the air horn to make it efficient. Not easy even were it effective.
2nd idea. It would have to have enough thermal gain to offset the parasitic loss of running the AC full time.

 

My A/C is ALWAYS on

Matter of fact any performance comments I have made - has been with the A/C on.

 

I keep forgetting about Fl heat.

I lived in Ft Walton Beach for 3 years. Zero AC in the house

 

My turn to laugh...I recall you making fun of my frozen Mini this past winter

 

Yep, that was me but whats even funnier - is that I just realized I have never driven the car with the A/C off . On a nice day I just put the windows down and open the sun roof but never turn the A/C off.

WHICH means (and this is the funny part) I will turn off the A/C this Friday and drive the car and experience a performance increase that didn't cost a dime.

Bart's new low budget MOD - turn off the A/C. I wounder if SpideyX knows about this MOD?

I will report bacK

 

No kiddn? You're in for a real treat

 

I think you're going to be cutting off the primary source of air to your intake. I hope to log some pressure data this weekend. I just have to rig up the power supply, and we'll be good to go.

 

Glad you said that. I had meant to and forgot

If I had a choice I'd go with this inlet before the cowl inlet if it came to keeping one or the other.

 

Given the shape of this front air intake tube, I wonder if there's enough pressure to actually ram any air into the airbox with it! I removed all the danglees and made the tube round and smooth, to try to make any air that gets into it flow smoothly into the airbox.
I'd like to see some measurements of the flow of air into this tube and how much it actually contributes to the CAI system.

cheers,

 

No idea is a dumb idea.

"I'd like to see some measurements of the flow of air into this tube and how much it actually contributes to the CAI system."
Same here.

 

Funny you should mention that. I had measured it at the same time I did the cowl pressure testing. From memory the readings I got, with the cowl opening blocked off, were slightly higher than the cowl readings.
I think the cowl read .06...psi at 70mph and the inlet tube was in the .07 range. This was before I had done something like you have in smoothing out the inlet tube. It also showed readings at slightly lower speed. Specifics I don't remember but I do recall enough to make the statement I did above that I would choose the inlet over the cowl if I had to decide between the 2.

Apologies that I never entered the data into my computer so the paperwork is long gone

 

Thanks Obe, the paper work may be gone but the info is helpfull.

 

here's why.....

To get good heat transfer, laminar flow is bad. The air has to hit something cooler than it is, and all the air rushing through the IC horn just won't hit the walls enough to do much. That's why radiators have all those fins, and the inside of the IC has all the turbulators (fancy name for fins).

If you put cooler air into the intake track, you get benefits.

If you coil a copper tube into a pig's tail, it will cool the air better, but it will also block airflow, and you'll loose overall density.

If you want to do this (and it's not a bad idea, but it's better for spurts of speed than steady state), it needs more engineering.

Matt

 

OK, I officially withdraw my idea (can you do that? Since ideas are basically public goods once released it's pretty hard to put them back in the box...)
From what Obehave has measured, and from what Dr O says about external cooling of the IC horn, I will keep what I have: a smooth, if serpentine, front air tube to the airbox, and the cowl opening to the airbox.
I just wish we could get a really good opening to the outside world for the CAI like I've seen on other cars.
btw, I was looking at the intake routing for my wife's Audi TT and boy--we think the air takes a long route to get into the cylinders on the MCS? Air must travel twice as far in the TT! Now I don't feel so bad...
cheers,

 

an idea.... You got me thinking about something that would be hard to do, but would probably work.... I've got to noodle some more....

Matt

 

Don't know your new thoughts, but what about putting fins around the elbow, as in a motorcycle engine, to add cooling surface? More surface area = more heat radiated.

 

but I'm just not sure how much benefit is to be had. You're moving tons of air through those horns. How much you can take out of the sides of the horns can be changed a bit with things like this, but look at the relative effects.. Our stock IC is 60%-70% efficient thermally when you going a decent speed. This is a part that is engineered to exchange heat with massive surface area for the task. The motion of the car forces air through it as well.... Adding a thermal dispersant coating to an IC gave about a 1%-2% increase in TE. And this result was very close to the noise floor of the measurements.

Since the IC horn isn't designed as a heat exchanger, and it's cooled passively by air motion under the hood (and even with the cool air directed at it), one would expect 5%-10% as good a result, optimistically, (but probably much, much worse). That's going to be less than an equivalent 0.25% increase in IC TE...., or less than 1 Degree C.

So this is a battle that can be won that won't have any effect on the outcome of the war!

But then, maybe I'm wrong! Do it and test it!

Matt

 

Always comes down to that doesn't it?

 

but the benefits estimations can help with prioritization. cooling the horns won't be high on my list at all.....

Matt