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Reverse bonnet scoops.....do they actually work?

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Old 30 July 2013, 07:13 PM
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KJD Mk1
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Default Reverse bonnet scoops.....do they actually work?

I've looked at fitting a reverse bonnet scoop to my Type R for some time as they claim to reduce under bonnet temps but has anyone actually done any back to back tests to prove this.

The traditional bonnet scoop gives the Subaru it's iconic shape and the car is less without it IMO but worth considering if they actually work.
Surely the OEM scoop while is not letting heat out it must drag heat under the car as it passes through the space where a top mount would have sat.

I'd be interested to know if anyone has any theories on it or are we looking at a styling accessory at best.

Thanks
Old 30 July 2013, 08:24 PM
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jaypug
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Who cares about temps kev.... Don't wreck the look of the best type r out there
Old 30 July 2013, 08:45 PM
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alcazar
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Harvey Smith tested this properly. His results showed clearly that fitting a reverse scoop could cause temperatures to rise in normal driving
Old 30 July 2013, 08:53 PM
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scoobynutta555
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Also it looks extremely silly along with rear de-spoilering.
Old 30 July 2013, 08:58 PM
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Originally Posted by scoobynutta555
Also it looks extremely silly along with rear de-spoilering.
+1
Old 30 July 2013, 09:32 PM
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RICHARD J
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Never heard of the RCM cars having any problems with their reverse scoops.
Old 30 July 2013, 09:34 PM
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KJD Mk1
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Originally Posted by jaypug
Who cares about temps kev.... Don't wreck the look of the best type r out there
Cheers Jay, yes I know the scoop in the bonnet is a big part of the overall iconic shape.

Originally Posted by alcazar
Harvey Smith tested this properly. His results showed clearly that fitting a reverse scoop could cause temperatures to rise in normal driving
Well thats worrying, not many in favour so far.

Originally Posted by scoobynutta555
Also it looks extremely silly along with rear de-spoilering.
Yes indeed, the only one I'd of ever considered is an RCM item as some of the others are hideous to say the least.

So far not very popular .
Old 31 July 2013, 09:15 PM
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alcazar
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Originally Posted by RICHARD J
Never heard of the RCM cars having any problems with their reverse scoops.

Hmmmmm.....road cars? I think not.

I did say "normal driving".
Old 31 July 2013, 10:04 PM
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RICHARD J
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Originally Posted by alcazar
Hmmmmm.....road cars? I think not.

I did say "normal driving".
Jeff, just stating that perhaps not all reverse scoops are the same, and there is nothing to stop an RCM one being fitted to a road car. On a high powered car there is also another reason to go reverse scoop & that is bonnet lift due to the scoop acting like a wing & generating lift. On a road car not running excessive power then I'm sure you are right & I know Harvey did a lot of research into this & favoured the standard Scoop for it's ability to pull hot air down past the gear box & away from the engine. However a 6 speed box greatly reduces this cooling ability due to the extra size. As explained to me by the great man himself.
Old 01 August 2013, 11:55 AM
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Had fitted now for 2 years, no problems at all. This is road use only throughout the year. In fact Big-Fud had one fitted and his Syvecs logged lower act temps once the reverse scoop was fitted. IMO there are pluses and minuses to both scoops, and at the end of the day, so long as your front mount ic, either will do the job. Its just down to your personal taste..
Old 01 August 2013, 05:15 PM
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Originally Posted by Hammer man
Had fitted now for 2 years, no problems at all. This is road use only throughout the year. In fact Big-Fud had one fitted and his Syvecs logged lower act temps once the reverse scoop was fitted. IMO there are pluses and minuses to both scoops, and at the end of the day, so long as your front mount ic, either will do the job. Its just down to your personal taste..
+1 mine actually ran cooler with one fitted. Don't know what Harvey researched but it was not what I found from Syvecs logs also.
Old 01 August 2013, 08:41 PM
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I reckon there's a lot that can be done with paneling etc in the bay to improve aerodynamics within the engine bay.

Reading Simon mc beaths recent articles in trackdriver (free subscription) might be a good idea (coupled with his race car aerodynamics book). The reverse scoop probably works to a degree, but things can probably be done much better.
Old 01 August 2013, 11:00 PM
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KJD Mk1
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Some interesting angles here with some good info.
Probably down to your own preference in the end.
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