355 Challenge Grill from Exotic Auto Recycling?

Yes I do all international next day also, only way to go

Good deal

 

I just ordered mine today. Great guys there.

 

Dave,

Are you going to (or did you already) install yourself?

If so, I'm really hoping for one of your superbly detailed DIY write ups.

 

Looks nice Dave.

 

Looks sharp!

Enjoy.

 

Dave, did you take any engine bay temps before the grill installation?

Just curious to see how much of difference it makes.

 

I question the reality of any heat dissipation through a perforated panel, that at best is 75% steel/25% air, oriented horizontally behind the heat source with no air flow directed at it from in front of the engine or behind it.

Now if you're driving hard in reverse maybe it might do something.

 

Mount a couple thermocouples in the engine bay and see

Seat of the pants analysis, muffler heat shield and the air boxes are in the way of any horizontal air flow out the rear of the engine bay, the "grill" is mostly solid steel with as I said maybe 25% perforation. Heat rises so it won't do anything when the car is standing still.

If it was truly and effective location for a "grill", on the challenge cars they could have made that panel removable so that there was nothing there or made it as on open slat design like the front grill with a lot more penetrable area.

I bet it is marginally effective at best if analyzed with sensors.

 

NO fans....very simple yet effective design based on fundamental laws of aerodynamics and thermodynamics.

If I have a great enough pressure differential I can get a full grown cow to pass thru a hole the size of a softball or better yet I can drive upside down in a tunnel.

 

Calculation of open area - RMIG

Go get three measurements and feed it into that formula. Round holes, triangular or rectangular pitch.

Size of hole and the other two criteria for spacing and tell me what you get.

My bet is it is less than 20%

 

Anyone with a challenge grill, can you supply those measurements. Diameter of hole and spacing between holes and if oriented rectangularly or triangularly.

Thank you

Pulled this image of a CS grill. I think it is the same. My guess here here without a ruler is 3mm hole with 8mm between holes, triangular pattern. Using that calculator the open area is 12.8%.
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So we have 1 small panel that has the possibility to flow appx 30% under optimal conditions if blocking panels and heat shields are optimized. This one small panel is part several so at best a single % improvement in heat reduction.

Trust Italian engineers? Maybe so but not after the bean counters and styling team add their 10 cents to the outcome.

Why do I feel like a glass of milk?

 

FFS, 20% of that panel is a huge amount of area for air to low through, especially compared to 0% with the stock panel. The % is inconsequential, but the area is, which that would equate to a pretty large single hole in the back of the car to let heat out (about 2x the size of a license plate). However, the small holes are better than a single large one as there's no need to funnel the air through a single hole, it can just go straight out without having to make any turns or have any ducting adding weight.

You guys have obviously never opened your oven just a crack, have you? Maybe it's 3% of the area of the whole door but it sure lets a lot of heat out. Open it 20-30% and you'll let almost all of the heat in the oven out. You could open the door all the way and it wouldn't make much difference.

 

Looks great, Dave. When mine is sitting at idle, I can literally feel the hot air coming out of my challenge grill if I'm standing back there.

 

As the name of the part implies, it was designed for the F355 Challenge to increase ventilation of the engine bay.

This is from the 1995 F355 Challenge Manual (Table 4: Body External Elements)...
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Yes Pete and you open the oven with the crack at the top and the heat escapes up and out, not out and up. Very similar to opening the engine bay. If your oven had a panel on the front door and you opened it like a fireplace where the challenge grill is you would feel the radiant heat but not the release that occurs upward.

Using the fireplace analogy, with no door or screen you enjoy the radiant heat. If you put a panel in front of the fire made up of challenge grill material you would not feel the radiant heat anything like with no material there. The heat from the fireplace mostly goes up the chimney.

Its just conjecture without absolute testing of two vehicles under identical conditions. If you like the way the challenge grill looks then its your car and thats all that matters. I think that thinking the challenge grill is reducing engine bay temps is a fallacy.