Best track hood for cooling (coil overheating issue)

[GrandSport]

Is there a "best" hood to get? Mine has louvers in it already (but they are from eons ago before there were better options). So my options now are a new OEM hood + verus or just getting a whole new hood. By the time I get the hood and jack cut it and etc, I'd rather just get a carbon hood. It will match my carbon fenders, lol.

Just tired of overheating coils and killing track days. It doesn't happen OFTEN, but even twice a season is annoying.

[Pat]

Look into Marsh Composites.

[whataboutbob]

http://www.marshcomposites.com/produ...86-gtspec-hood

[GrandSport]

I like the idea of positive pressure to let air in and negative pressure to suck it out... but it looks like the air coming out of the front will just go into the naca duct lol






And that's assuming you can even do that. I have a few intuitive (though far from substantiated) concerns about having positive and negative pressure zones so close to each other under the hood.

IDK. I assume there is a reason positive and negative pressure hoods aren't super popular/common.

Anyone have any experience with them in hot climates on dedicated track cars?

[KillerBMotorsport]

^ yeah that's not an ideal spot for naca ducts. That front exit duct should pull a ton of radiator heat out though. When I made that plunge on a shop STi there was a noticeable improvement in cooling, lower under hood temps, and even high-speed stability improved.

[Code Monkey]

This is good enough for GR cup cars... They have a resonator deleted with a block off plate so all the hot air can vent straight out...

[NoHaveMSG]

My understanding(as a guy on the internet who eats pizza for breakfast) has always been that without a leading gurney flap on a hood vent, it is not going to extract efficiently. The air pressure under hood has to be greater than the air pressure on top(kinda sorta). If you look at the verus hood vents or the driveway labs, they have a gurney on the front to trip up the airflow and create a little low pressure zone. I have the driveway labs vent, and in the rain it actually causes the water to swirl inward on the windshield.

https://drivewaylabs.com/collections...ood-duct-large

https://www.verus-engineering.com/sh...ory=41#attr=64

[kask2_6.0]

Working on some vents for those looking to increase the size of existing vents to something more geared towards a track day car. I was in this boat as well. I don’t have CFD data or wind tunnel test results to back up any claims of increased cooling at this point. Would like to do some A to B track comparisons though.

[Ohio Enthusiast]

Originally Posted by kask2_6.0

I don’t have CFD data or wind tunnel test results to back up any claims of increased cooling at this point

Yarn threads and a camera (or even just looking at them at speed) can serve you well.

[kask2_6.0]

Originally Posted by Ohio Enthusiast

Yarn threads and a camera (or even just looking at them at speed) can serve you well.

That is first on the to do list! But at the moment I’m waiting on some other parts to get my car back up and running.

[Breadman]

Originally Posted by kask2_6.0

Working on some vents for those looking to increase the size of existing vents to something more geared towards a track day car. I was in this boat as well. I don’t have CFD data or wind tunnel test results to back up any claims of increased cooling at this point. Would like to do some A to B track comparisons though.
Attachment 218843

THis is what i should have done when cutting and installing my trackspec vents. Im are slightly off but you cant notice it from the outside. They get so much heat out especially when running my fans

[GrandSport]

Originally Posted by Code Monkey

This is good enough for GR cup cars... They have a resonator deleted with a block off plate so all the hot air can vent straight out...

They don’t have the same coil packs I do. They also get new coils after every session or two.

I don’t have a “heat” problem. I have a TON of cooling and if anything it’s over cooled because my oil doesn’t get above 205, even in texas.

My problem is the coil packs popping.

[GrandSport]

Originally Posted by NoHaveMSG

My understanding(as a guy on the internet who eats pizza for breakfast) has always been that without a leading gurney flap on a hood vent, it is not going to extract efficiently. The air pressure under hood has to be greater than the air pressure on top(kinda sorta). If you look at the verus hood vents or the driveway labs, they have a gurney on the front to trip up the airflow and create a little low pressure zone. I have the driveway labs vent, and in the rain it actually causes the water to swirl inward on the windshield.

https://drivewaylabs.com/collections...ood-duct-large

https://www.verus-engineering.com/sh...ory=41#attr=64

My grand sport didn’t have one and it was definitely pulling a lot of hot air out. On cold days , the center of my windshield would fog up right behind it. I think the idea is that the air rushing in will build up pressure in the engine bay and the high speed air over the hood creates negative pressure. In the grill, out the top vent.

That’s why naca ducts there concern me. You’re not only feeding the hot air into them, you’re reducing/disrupting the low pressure air. Honestly, and this intuitively from someone who hasn’t been in a wind tunnel or even scientific field for two decades, that hood raises a lot of eyebrows.

Obviously, a flip will create more negative pressure, but it comes at the cost of drag.

I think I need air rushing to the coils, not removing more hot air.

[RedReplicant]

Originally Posted by NoHaveMSG

My understanding(as a guy on the internet who eats pizza for breakfast) has always been that without a leading gurney flap on a hood vent, it is not going to extract efficiently. The air pressure under hood has to be greater than the air pressure on top(kinda sorta). If you look at the verus hood vents or the driveway labs, they have a gurney on the front to trip up the airflow and create a little low pressure zone. I have the driveway labs vent, and in the rain it actually causes the water to swirl inward on the windshield.

https://drivewaylabs.com/collections...ood-duct-large

https://www.verus-engineering.com/sh...ory=41#attr=64

I've got four of the Verus ones in my hood, I can see them pouring heat out on grid and they leave dust trails on the hood behind the vents after events

Originally Posted by kask2_6.0

Working on some vents for those looking to increase the size of existing vents to something more geared towards a track day car. I was in this boat as well. I don’t have CFD data or wind tunnel test results to back up any claims of increased cooling at this point. Would like to do some A to B track comparisons though.

How far do these extend from the hood surface? Greater than 3/8"?