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Joined: 14 Mar 2019
Posts: 8

PostPosted: Tue Mar 26, 2019 9:48 am    Post subject: Cold Air Intakes Reply with quote

Just curious. Do cold air intakes like AFE really improve a vehicle's horsepower and fuel efficiency?
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Joined: 18 Dec 2018
Posts: 440
Location: Scotland

PostPosted: Fri Mar 29, 2019 7:36 am    Post subject: Reply with quote

I am no scientist but as a teenager, I felt my motorcycle was far faster on damp misty nights..... whether it was or not...hmm..?

I was told that cold damp air raised the compression factor of the air/fuel mix a tad and that the fuel burned more efficiently in those conditions..

My fellow m/cyclists determined that I just thought I was going faster as the result of the reduced visibility.. (-:

Many years later, in a sweltering Italy in a bid to get more air flow around the engine I removed the trunking from the carb intakes that extended towards the outside "fresh" air in a bid to get more flow around the engine bay in the hope of aiding cooling, which was the priority as opposed to generating more power and HEAT...!! Jeez even put the heater on in the car to aid water cooling as much as I could...

So if you can find a gadget that creates cold misty air to mix with the fuel in the combustion chamber... you could be onto a winner... but you may need to generate more POWER to run it, kinda like running air con reduces MPG..?

My guess is that a simple matter of volumetric efficiency comes into the equation somewhere Question
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Phil 997
Le Mans
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Joined: 05 Dec 2015
Posts: 15313
Location: Bournemouth,Dorset

2009 Porsche 997 Carrera 4S

PostPosted: Fri Mar 29, 2019 8:55 am    Post subject: Reply with quote

This is one of those subjects that has two groups . when I had my 997.1 I did loads of research into it and TBH came to the conclusion that there really wasn't anything better than the OE true cold air box other than the X51 as it had twin feed like the gen2 and was carbon . but I did think you could improve air flow with a sports filter like BMC so thats what I did . but there are also the arguments that not even the sports filter works .
When I got my gen2 I found there were big holes in the bottom of the airbox covered by mesh this was to allow water to drain out , well how can that be true cold air feed with those holes open in the engine bay I thought , So I looked at a FABSPEED carbon twin cone performance induction , the theory made sense the air travelling more quickly doesn't have time to heat up from the engine temps , after a lengthy discussion on here with a guy who's job was working with induction and airflow even he agreed that probably the only thing that would make a difference was a twin cone feed , but it may not be much extra bang for the bucks it cost.
Currently my car is away being remapped the mapper doesn't rate mods and seems to think that from what he's seen most are snake oil . So we agreed that he would spend some time and set the car up with and without the OE airbox and use the Fabspeed twin cone ,as I was interested as was he to find out if the fabspeed lowered the top end BHP but improved the power curve in the low mid range or whether it had gains or losses across the board. this for me will be the definitive answer as the mapper is the best of the best , everything else on the car will be the same in both trials , the same rolling road and dyno . the car already has a fast flowing exhaust to take full advantage of any improved induction flow the engine bay lid also has forward facing air scoops unlike the Carreras stock lid so should create a ram air effect which could/should improve the speed the cold air moves . I will report finding when I get my car back. Thumb
911 Owners,Some Invest In The Future,
Others Enjoy The Moment Today.
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Joined: 04 Jun 2009
Posts: 2519

PostPosted: Fri Mar 29, 2019 9:01 am    Post subject: Reply with quote

On N/A engines the results are negligible if fitted in isolation. In fact some actually reduce power as they suck in hot air from the engine bay.

I still fit them though as the noise alone is worth it and they make a flat 6 sound fantastic.
I know on 996 GT3s the factory air box is very hard to beat and the likes of Wayne Schofield at Chip Wizards recommends fitting the standard item for mapping as it’s the best.
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Joined: 18 Dec 2018
Posts: 440
Location: Scotland

PostPosted: Fri Mar 29, 2019 11:34 am    Post subject: Reply with quote

Marky911, seems you may prioritise SOUND over actual engine efficiency...?

Have to admit that IF that is the case, then I am with you in that regard... (-:
On a cost benefit analysis, I suspect the sensory payback of increasing induction roar or fitting a straight through exhaust system may work out to be FAR more efficient bang for a buck than spending a few thousand on improving the horse power by a very few percent on an engine primarily designed to provide "sporting" performance...? Types he who used to polish engine internals thought of as an ideal way of passing a LOT of time... Floor
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Joined: 09 Sep 2019
Posts: 1

PostPosted: Mon Sep 09, 2019 6:47 am    Post subject: Reply with quote

Helpful information Smile
Electrical Design Courses In Nagpur
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