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Sunoco hood & high IAT's

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Old 05-11-2010, 09:57 AM
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Default Sunoco hood & high IAT's

My hood sits pretty tight against my windshield so hardly any air escapes from the engine compartment. I am running an accufab TB and my IAT's are getting 120+. Would spacing the hood off the windshield help get the hot air out? Anyone else have the same problem?
Old 05-11-2010, 10:49 AM
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Originally Posted by minytrker
My hood sits pretty tight against my windshield so hardly any air escapes from the engine compartment. I am running an accufab TB and my IAT's are getting 120+. Would spacing the hood off the windshield help get the hot air out? Anyone else have the same problem?
First, air will actually come into the engine compartment at the windshield when drive at speed. Where is your TB drawing air from? If it is just open to draw air in from under the hood, that IAT makes sense.

Cooler air makes more HP and cooler pressurized (no matter how small) air makes even more HP.
Bob
Old 05-11-2010, 11:09 AM
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My old hood was just a normal sunoco vs the extended one, when I was sitting in the staging lanes you could see heat coming out the back of the hood, you could also feel the heat on the windshield. Now with the extended hood I dont see any any heat and the engine compartment gets much hotter. I realize going down the track the spacing the hood wont help but the problem I have is the engine is getting heat soaked after one pass and then I cant keep the IAT's down.
Old 05-11-2010, 11:55 AM
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Where exactly is your TB drawing air in from? Do you have a lid or just an open cone filter or something?

I would imagine putting a little space at the windshield would help, but there are plenty of other things you could do to keep underhood temps down. Header wrap, etc.
Old 05-11-2010, 01:35 PM
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Currently the TB has nothing on it, no filter or anything.
Old 05-11-2010, 01:48 PM
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Carb hat and a home made CAI will help a ton.
Old 05-11-2010, 06:03 PM
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That's what I was thinking but I'm worried the carb hat may mess with how the air goes in the tb, being a nitrous car it needs to be smooth air.
Old 05-11-2010, 09:02 PM
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Did you happen to take the small black air deflector off your car? I have seen some guys that do that and have big problems with IAT's and the car running warmer than normal.
Old 05-12-2010, 08:50 AM
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I've seen a couple people trim the corners of the hood, where the rise is that meets the windshield out so that there's a way for some air to get in/out.

What do you have for a fan on the radiator too.. any chance you can put a 2nd on it? reason being it will force alot more air to move around in the engine bay and should help the under hood temps some.
Old 05-12-2010, 09:14 AM
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Still have stock fans and radiator. I do have an override switch on the fans to cut both on high, I usually do that and run the water pump after a pass to help cool the car down.

Im really thinking about trimming the hood like you describe, I was looking at it yesterday thinking the same thing.
Old 05-12-2010, 09:29 AM
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Yeah, almost a little teardrop in the corners, should do the trick. Just make sure you have the dzus fastners across the middle, if not the thing could get air under it and lift it up off the car.
Old 05-12-2010, 09:40 AM
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Maybe build a Tray to seal the air between the TB and hood then duck it to the rear of the hood to the opening of the windshield to hood. This will also take advantage of the high pressure area there to add a little ram effect at high speed.
Bob
Old 05-12-2010, 09:43 AM
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Yup if you can build a pan that will seal to the hood, then put the small openings in the corners would be perfect. Just have to fab the hood sealing pan... pita to deal with when working on the motor but some benefits are definietly possible.
Old 05-16-2010, 07:13 PM
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I shimmed the back of the hood the other day with the car idling and hot air was pouring out the back of the hood. So I am going to first just trim 1/2-3/4 inch off the back sides to see if that helps and go from there.
Old 05-16-2010, 08:54 PM
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the best bet would be a carb hat with an EV carb hat, and some 4" tubing. have it run down into the front bumper. much better. your air temps will be in the 60* range and you'll probably pick up at least a tenth.
Old 05-17-2010, 06:37 AM
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I'm not sure that will work, the air flow will then be limited to the flow of the elbow and the piping, whereas the actual TB will be able to suck as much air as it can...

I'd try the corner vents on the hood first and se what that gets you, unlesss you can get a carb hat that's meant to take a 5 inch pipe or something big enough so that it will outflow the TB by a good bit, so that a restriction isn't being created.

Best bet would be to leave the hood off and leave the fan/water pump running as much as possible, and don't leave the car idling if you can avoid it.. with a nitrous car you're gonna load the plugs up letting it idle anyway.
Old 05-17-2010, 01:43 PM
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http://www.superiorairflow.com/dyno-sheets.html

you can get em in a dominator size too, i dont think it'd be a restriction.
Old 05-17-2010, 01:47 PM
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again, its proven that ram air works. a 4" pipe would be pleanty.
Old 05-17-2010, 03:33 PM
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I looked at the 90's all seem to flow less cfm than my tb. Also this is a on a nitrous car, not to thrilled about a 90 right at tb dont know what that would be doing to the air going in.



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