Pardon my ridiculous drawing, but I'm at work and wanted to throw something together quickly.



Here's my thinkings...

The main airflow over the IC is from the hoodscoop, right? And there are a bunch of mods out there to direct air flow better over the top of the IC... but what about the pressure of the air coming from below the IC?

Would it be a correct assumption to say that the airflow forcing its way through the bottom grills AND through the radiator is both contradicting the airflow of the hoodscoop and is hotter air from below? I would think that it would negate some of the velocity from the hood scoop and thus not cooling the IC as efficiently as it should. Almost seems to me as this is the point of the DFIC, is it not? (on top of not making the air take 2 90 degree turns... but I don't have that kind of money to drop right now.)

If this is a correct assumption, would it be beneficial to create a mod that would block airflow to the IC from anywhere except the hood scoop and maybe direct it out the back of the engine?

 

I think its suffers more from the general heat soak of the giant hulk of metal the releases heat upward. That said I don't think a shield would hurt it; can we make this next weeks project?

 

Ooooh... good point.

So maybe the under-IC diverter could have a two-fold purpose.
1. To allow only hoodscoop air through the IC and divert out the back.
2. Insulate (as much as possible) from the fat hunk of hotness from below.

Yes... next weeks project it is!

 

Rock on dudes!

 

Let me throw my 2 cents in here. I have just put on an M7 extreme scoop. I have a GRS intercooler. The reason for the scoop was at least obvious to me – I wanted to ram as much air into the larger intercooler, because with all of my mods, there is a lot of heat being generated. All I was expecting was that when I was on the track, I would not notice any degradation of horsepower over the 20-30 minutes I am usually out.

What I got was an unexpected result, because in just normal street driving, I was noticing (feeling on the butt dyno), and it wasn't subtle, a lot more HP. The car was definitly quicker(pulled harder) and more responsive. It reminded me of SpiderX's initial comments on the DFIC.

I had another person who knew the car well go for drive without any comment from me. He was also amazed at the difference! (I know, none of this is scientific)

I'm wondering in light of the hypothesis being put forward on this thread, that, if there is competition in airflow from the bottom of the intercooler, is the bigger hoodscoop/intercooler overcoming more of the resistance?

 

and the highest pressure wins.. Kind of. If you're into electronics, think of parrallel resistors.

If you aren't into electronics, sorry for the confusion.

Matt

 

So... remove the competition variable... and there doesn't have to be a fight.

Hm...

 

Here is some data I recorded yesterday at Watkins Glen using a ScanGaugeII (records from the OBDII):

Stock IC, MTH Tuner 93 octane file, Madness CAI, Alta cat back, 15% pulley, BBR bonnet scoop, 80% water/20% antifreeze with WaterWetter, Denso IK22 plugs, Detroit Tuned bypass valve

Ambient air temp was approximately 70 deg F and sunny
94 octane in the tank

Inlet temp was approximately 145 deg F
Timing advance was in the mid to high 20s (not in the mid 30s as on the street)
Boost was 13.2 psi
Water temp 204 deg F

Do any other track cars (not street cars) see numbers like this?

 

in the 190s or so, but I'm running the M7 thermo.... At reast, they sure shoot up!

Matt

 

Bringing a couple ideas from a different thread....

I don't think that insulating the IC to itself is the key, k-huevo is right. However, I think what would be most beneficial is coming up with something that not only prevents non-hood scoop air from reaching the IC, but also optimally directing that air flow over all of the said components.

You can tell by how the IC sits on top that it is meant to work as a system, and not just the IC as a lone part.

Although, what about the DFIC, it doesn't look like that worries too much about the air cooling the other systems...

hm...

 

we want power!

Matt

 

R! - R! - R!!

 

Okay lets get these wheels turning (the mental ones); We helped the intake air through insulating it and getting cooler air into the engine, now to make the IC as efficent as possible.

This means controlling airflow and temperatures while still venting the engine block.

I think this is going to be much more complex than the intake but the dividends are going to be much bigger. So lets get the ideas flowing.

 

I've been sketching out some designs but haven't scanned them yet.

Here have been my considerations.
1. Do not want to restrict airflow from hood scoop.
2. Not block off air from intake manifold (IM), as to keep it cool as well.
3. Prevent air from front grill/radiator from entering under IC
4. Direct all air out the back over the fuel lines/fpr/intake manifold.

I've also been thinking about further cooling to the IM. Here's why... we spend all this time focusing on the IC to cool the air, only to what... shove it into a ridiculously hot chamber? (have you touched the IM after running awhile... I have... and won't do it again)

So my nerdy computer side comes in. What if you attached heat sinks under the IC to the IM just like on a processor and allowed the air, post IC, to cool the fins on the heatsinks and thus draw heat off of the IM? What, if any, would be the benefits of cooling the IM with this method? Goodness know I've got enough of them sitting around my apartment.


I'll try and get my sketches up soon just to see if any of them make sense.

 

bloody brilliant!

 

There are intake manifold thermal spacers for other cars--look like a real thick plastic intake gasket to reduce the heat conducting up from the head. Or even plastic manifolds. Way, way too many BTUs for little heatsinks (airflow issue again), but water sprayers through the intercooler core and onto the intake would help a lot because water's latent heat of vaporization is a very impressive 2260 kJ.kg^-1.

And if pressure was reduced in the engine compartment, air would literally be sucked through the intercooler at speed, with a side benefit being more air would be sucked through the radiator as well. The easiest way to do this is a lower airdam; maybe even a deformable bristle-type one that nearly touches the ground. More pressure in front of it, means less pressure behind it and thus more airflow through any existing openings like the grille and scoop... dead simple, isn't it?

Of course the car must be moving for this to work, but it should be no worse than stock when stopped. A shield blocking the bottom front of the intercooler would mean that, when stopped, hot air from around the exhaust header would rise through the intercooler rather than air from the hot radiator. I don't know which would be hotter, but assume the BMW engineers did their homework.

 

[quote=BFG9000... The easiest way to do this is a lower airdam; maybe even a deformable bristle-type one that nearly touches the ground. More pressure in front of it, means less pressure behind it and thus more airflow through any existing openings like the grille and scoop... dead simple, isn't it?
[/quote]
So, we should keep the little plastic air dam under the lip of the front bumper, and even make it bigger? This will draw air down through the engine bay and out under the rear of the car...mmm, sounds easy.

cheers,

 

Shankrabbit, I'm glad you started this thread.
No mater what you do there are too many heat emmiting things that generate under hood heat, even on a cold day it gets pretty toasty.
The dry ice exp required the removal of the ugly black thing ( it might have a title but it's ugly so who cares ). Without the black thing it seems a bit cooler under the hood, however no way for me to prove it. For sure there is alot more volume being fed under hood. The M7 IC looks real good for flow, cooling area and because the only fab work is a louver for the back & insulation on the bottom ( without the black thing ). The only other piece to fab would be a diverter to seal the hood it the IC. That would not leave any space for the dry ice ( which only lasts for 10 - 15 minutes, tops ).
BMW did do their homework for sure but they also knew there would be an aftermarket that would have a strong following.
Gandini, that might work. Simple is good. A splitter might work also as it is designed to direct air around the car instead of under it.

 

First you have to find out where the heat is coming from. If it's the head, a thermal spacer would be a good place to start, but it will move the manifold away from the head, and it's awful tight in there. A second way to go is to coat the outside with a thermal dispersant, and the inside with a thermal barrier. Some have done the innner coating already. Seach around. I don't remember if they actually saw any benenfit.

I've logged post SC air temps of well over 100 C, so the air coming from the IC may make the problems worse in some conditions, not better.

Don't bother with the CPU heatsinks..... they take up more room needed to get the air out of the IC, and the benenfit to the IM will be small, so they probably will be more harm than help.

Just some thoughts....

Matt

 

"I've logged post SC air temps of well over 100 C, so the air coming from the IC may make the problems worse in some conditions, not better."
For sure. If the IC is hot it's worthless. I like the thermal spacer for the intake, that's got to be worth something, even a couple of degs is good ( it is wicked tight in there ).
There is a heat sourse everywhere in the engine room, only 1 heat shield for the header, even the over flow tank is pretty hot. It's amazing how well the little motor can run with all that heat.
The next time I get a good look at a cup car, I'm going to look very carefully at the components they use to shroud the carb. Those cars realy depend on foward movement for cooling the carb.

 

I looked into the spacer between the IM and the head a long time ago. They are thick; a space must be relieved on the bottom of the supercharger output duct to clear the IM flange, the injectors will be pulled back from the intake port, the intercooler output duct is attached to the IM so the bypass valve will be offset in its relationship with supercharger intake duct as well as the intercooler cold side end tank opening, the mounting points for the intercooler on the driver’s side would have to be adjusted and testing in the Honda community showed the benefits to be most advantageous for NA motors and marginal for FI. When I micro analyze the fitment, I can see potential amplified vibration stress to intake port studs from the weight of components attached to the intake manifold. Not only does the nylon gasket allow some wiggle, the nylon washers required under the nuts also have some give.

 

My approach is going to be to first get the most out of the hood scoop and make it so that air wins the battle in the first place. The next step will be a IC sray for the occasional instant cooling (maybe a resivoir down in front of the A/C radiator to get he water air cooled before putting it on the IC) Then the harder part is going to be controling airflow in the engine bay, and internal heat management. Anything short of relocating or changing the IC is going to be very difficult; on the same token I also don't want to upgrade the IC just yet either. SO that where I''m at.

 

I spent this AM making a template Since I couldn't find any Al sheet stock last evening I made this from posterboard, self adhesive duct insulation and tape.

The original intent was to do something like this to guide the air under the IC.:

Unfortunately it's too thick but once I get my hands on the sheet stock it'll work well.

My on the fly mod ended up being this:

This butts up against the intake and allows the air to flow under it.

The additional piece I am faking right now is the hood seal gasket. Once I buy a new one I will section the gasket to allow just this gap. For now the gasket is just tucked down behind the radiator support dam.
I do also plan to make end guides in the Al version.

Yes it's ugly and yes the knock sensor is crooked again

The total unknown for me here is whether or not this has a significant impact on flow through the radiator.
The nice advantage to having this made out fo flexible material for now is that I can do temps with it in place then fold it out of the way, put the gasket back in place an check temps again.
Another is that the engine rocks forward. Less now that I have the urethane inserts but still there's motion.

This is my route.

I'm starting to feel like the TonyB of temps


EDIT:

Just did one trip down the road and back. At a steady 35mph in 4th I jotted down some temps. Just did the math. 55.6 % thermal effivciency!! Pi$$ poor.

I have a function to go to, maybe(it's up to the wife) so I can't do any more for now but definitely need to do more soon.

 

I took my sketches and cut out some paper.

It made me all giggly cause I felt like I was in kindergarten again... playing with paper and tape.

My thoughts were more along the complete blocking of frontal air going under the IC completely. ((edit: I also just got a job at the Department of Redundancy Department...))

Here are some images of the goofy little paper temp I made. (not to scale... not really measured... not accurate... pretty much a 3d sketch.)

Oh... and thanks obehave... i used a very transparent image of your IC just so you can imaging where this would go. (it's humid and 90+ here in WI and I don't feel like being outside much)










Here are my thoughts with this design.
-Maximize the airflow from the scoop and, with the curved ramp on the front side, smoothly direct everything towards the back while making sure that the fuel rail, IM, and everything else under there still gets enough air.

-Make sure the air coming from through the radiator doesn't get stopped dead, but has somewhere to easily flow, which is why I have the front triangle.

-Attach to current IC bolts.


Those are my thoughts and ideas currently. I'm going to keep sketching and maybe come up with a few other ideas.

Thoughts on this design?

 

I think we need a clod front ot hit the Chicago Milwaukee area soon!!

I'm going to play witht he scoop first, but I'd love to hear how your prototype turns out, w/o surface data this is going to be a little harder to get just right, anyone know where we can get some custom modling done quick and cheap, I can do test models in cardboard and basic fabrication with metal but if I make something that works real well I want it to look like it has a chance of being stock and be able to out last the elements.