pappy92651

Can anyone tell me what they think this does? There are multiple correct answers. Air is forced to turn upward against the uninsulated and now shielded portion of the hood.

The radiator and oil cooler are covered with polycarbonate and foam. The protoype diverter is made of construction foam sheeting 1/4" thick. It extends from the top of the oil cooler to within 3" of the head light actuator shaft. The final version will be made with thick polycarbonate and foam.

SharkSkin

Looks like you'll be pulling air that is relatively fresh, less of the hot air that is blown out around the edge of the fan when it's running and less radiant heat absorbed by the intake air when the fans aren't running. The portion of hood panel just above it will tend to be relatively cool, being in a high pressure zone on the outside(faster heat conduction to outside air) while moving. The net result ought to be an improved ability to idle for an extended length of time and still be able to nail it off the line without detonation, because it should take longer to heatsoak to the point it degrades performance.

I seem to recall you collected a lot of baseline data on another thread... Are you going to be comparing data from all of the points, maybe even comparing g-tech runs?

Adam C

Can I get a bigger pic?

pappy92651

Adam, I will send you one. I am also going to post a sketch that shows how the air flows with the diverter in place.

pappy92651

Attached is a better top shot.

pappy92651

Attached is a better front shot.

pappy92651

Modified air flow sketch attached. Can this be made even better? Yes. Stage II in process. BTW this panel fits snugly without any physical attachments.

Adam C

Hi Steve, Thanks for the photo - it makes sense.

Have you tested it, and if so, has it proven effective? Maybe even by seat of the pants?

Adam

pappy92651

Hello Adam,

Yes I have tested it. I shaved another 0.1s off my 0 to 60 time. I am accumulating data. Stage II will have hoses routed from the diverter to the nose vents. I'm after cooler air since pressure at the nose is already given.

FlyingDog

Have you measured a change in temp in the tubes or intake with the diverter? Have you experimented with different sizes of diverter?

Adam C

I like the idea - I like the air ducts ducted to the nose even better. How do you think that would work pressure wise?

Sierra Shark

Your idea has merit, however, the leading edge of the white diverter should be curved to divert the airflow over the top leading edge. Think of an upside down airplane wing or an airbrake on a large jet aircraft (the ones that drop down off the trailing edge of the wing when your landing) in reverse. Airflow has a difficult time making a 90 degree reverse turn under pressure as your drawing would indicate. A better idea would be extend tubing from the fronts of the air intake tubes down to the vent openings using a rigid tube the same shape as the openings. That would keep the vortex of air the same as it is when it enters the stock tubes. Should be easy to fabricate from fiber glass and foam. Aside from the obvious change to the looks of your car, why not cut in 2 Nacal ducts for a ram air effect without any surface drag? Connect the air intake tubes directly to them.

Anyway, enough. No wonder my wife gives me the same look as my dog. She married an aerospace engineer.

pappy92651

Matt, I measured a significant temperature drop which improved with speed (-15F at 100 MPH). I do not think that air flow was altered in a detrimental way. I also don't think it was improved. This is experiment stage I. On to stage II.

Adam, Stage II is in process. Highest pressure is under the nose. Top of the nose scoops or the base of the windshield scoops are in marginal pressure zones (see attached).

Sierra Shark, I understand that look. My friends are always trying to find the right girl friend for me. Will not happen.

Stage II will be something like what you mentioned. The key is to bring in cold air in from a point which has significant positive pressure. The other goal is to retain the aerodynamics of the body. Ducts can be installed at the base of the original integrated grill or NACAL ducts could be installed close by. Pressures measured under the nose are highest (area 3) with the base of the windshield being second best (area 11) but marginal. Nose = 1.2 PSI and base of windshield = 0.2 PSI. Higher up on the glass is better but still only half the pressure of the nose. With insulated ducting from the nose temperatures and pressures should be improved at all speeds.

pappy92651

Two other issues,

Not all of that 1.2 PSI is going to the air box as others pointed out. Some of it leaks from the air box. In the stock configuration most of it goes through the radiator and into the engine bay. That's also why the diverter picks up cold air without additonal pressure (also no flaps on my car to direct the air upwards).

Now to connect points A and points B to obtain some of the available positive pressure.

SharkSkin

Steve, what is the source of that pressure diagram? Was there any accompanying text? We seem to be reading it differently; It looks to me like area 3 is the very tip of the bumper, meaning that you'd be better off replacing your fog lights with air inlets. Maybe 5 times better off in terms of psi. As I see it, that diagram shows .2 or at best .3 psi at point 2, which seems to be the top of the grill opening.