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      05-28-2019, 01:22 PM   #1
JPuehl
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Does removing actually help keep temps cooler under the hood?

My wife and I plan to take our cars to a drag strip this Friday and was wondering if removing the cowl and cabin filter housing actually helps vent the under hood hot air? I was thinking about trying this just during the race, not for everyday driving since water can get in via the cowl. It only takes something like 5 minutes to remove plus a few minutes to duct tape the cabin air inlets closed so the effort is low but if it's not going to help or makes it worse than there's no point. I know that normally there's a high pressure area where the hood meets the windshield so the pressure under the hood would need to be greater than at the back of the hood.

I know in theory it makes sense but was wondering if anyone has actual experience doing/trying it?

The main reason for even considering this is that I'll be using a BMS open element intake filter and would prefer cooler inlet air.
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      05-28-2019, 01:35 PM   #2
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Originally Posted by JPuehl View Post
My wife and I plan to take our cars to a drag strip this Friday and was wondering if removing the cowl and cabin filter housing actually helps vent the under hood hot air? I was thinking about trying this just during the race, not for everyday driving since water can get in via the cowl. It only takes something like 5 minutes to remove plus a few minutes to duct tape the cabin air inlets closed so the effort is low but if it's not going to help or makes it worse than there's no point. I know that normally there's a high pressure area where the hood meets the windshield so the pressure under the hood would need to be greater than at the back of the hood.

I know in theory it makes sense but was wondering if anyone has actual experience doing/trying it?

The main reason for even considering this is that I'll be using a BMS open element intake filter and would prefer cooler inlet air.
It's likely not worth the trouble. You won't see any significant gains from it.

Just pop the hood in the lot/staging lanes after your passes and you'll be fine, heat wise.
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      05-28-2019, 01:41 PM   #3
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Originally Posted by Soterios View Post
It's likely not worth the trouble. You won't see any significant gains from it.

Just pop the hood in the lot/staging lanes after your passes and you'll be fine, heat wise.
Yeah I usually open the hood, just pop the latch, as soon as I hit the return road, and bring my water spray bottle and spray down the intake piping in between passes. Was wondering about venting the heat while making a pass.
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      05-28-2019, 07:41 PM   #4
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Take out passenger seat, back seat, remove battery once car is started and running and optionally take off your doors (really they weigh a ludicrous amount and your car won't trap high enough for the aero loss to offset the quickness gains). You can also remove hood trunk and fenders cuz they bolt on / off and they are pretty damn heavy! Also, the full exhaust weighs like 50 lbs if you want to go to the trouble of running an open downpipe.

Any one of those things would be quicker to do and give a quicker time on the strip. Do all of them and you might surprise some people here.
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      05-29-2019, 08:38 AM   #5
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Originally Posted by The Wind Breezes View Post
Take out passenger seat, back seat, remove battery once car is started and running and optionally take off your doors (really they weigh a ludicrous amount and your car won't trap high enough for the aero loss to offset the quickness gains). You can also remove hood trunk and fenders cuz they bolt on / off and they are pretty damn heavy! Also, the full exhaust weighs like 50 lbs if you want to go to the trouble of running an open downpipe.

Any one of those things would be quicker to do and give a quicker time on the strip. Do all of them and you might surprise some people here.
Way off subject but a typical nonsensical response from you. Carry on.
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Last edited by JPuehl; 05-29-2019 at 09:56 AM..
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      05-29-2019, 08:58 AM   #6
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Quote:
Originally Posted by JPuehl View Post
Yeah I usually open the hood, just pop the latch, as soon as I hit the return road, and bring my water spray bottle and spray down the intake piping in between passes. Was wondering about venting the heat while making a pass.
Yeah. The temperature delta in fifteen seconds or less is probably hundredths or tenths of degrees. Probably not worth the hassle.

Though the louder noise might be. Haha
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      05-29-2019, 09:42 AM   #7
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Quote:
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Yeah. The temperature delta in fifteen seconds or less is probably hundredths or tenths of degrees. Probably not worth the hassle.

Though the louder noise might be. Haha
This is what i'm thinking as well. I logged another 3rd gear pull yesterday on my way home from work and while the delta between the outside air temp and the IAT temp was a few degrees higher with the BMS intake than the OEM airbox, the IAT temp still dropped about 10* by 7000 rpm, so I would expect a similar temp drop over 1/4 mile. And between the catless dp and the BMS intake, I hear a lot of noise as it is, especially parking in the parking garage, lol.
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