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billson
Joined: 10 Sep 2006
Posts: 41
Location: UK
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 Posted: Thu Mar 29, 2007 8:28 am Post subject: air intake modification |
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Anybody seen/done this modification to the air intake box?
Cooler air would get in instead of air warmed by the engine bay as in the stock set up. But would it really make any difference? Worth cutting your air filter box for?
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ideola
Joined: 01 Oct 2004
Posts: 15550
Location: Spring Lake MI
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| Posted: Thu Mar 29, 2007 9:27 am Post subject: |
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I have seen this and other variations. Hardly seems worth it unless you've installed a big valve head (along with other mods).
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morghen
Joined: 21 Jan 2005
Posts: 9102
Location: Romania
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| Posted: Thu Mar 29, 2007 9:52 am Post subject: |
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i dont think that stock 924 is that sensitive to air temperature.
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pocketscience
Joined: 23 Apr 2006
Posts: 1650
Location: Sydney, Australia... mate!
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| Posted: Thu Mar 29, 2007 11:56 am Post subject: |
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I dunno... the temp here in Sydney has just dipped this week and yesterday it was about 15C when I was driving to work - my toofah definitely felt like the cooler air was helping.
Cheers,
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Dagwood928
Joined: 22 Nov 2003
Posts: 65
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| Posted: Thu Mar 29, 2007 12:04 pm Post subject: |
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cooler air is denser air.  Doubtful that there would be much in the way of seat of the pants, but it is an improvement. I don't think making the duct out of aluminium flex tubing helps as it soaks up engine heat, and transfering it to the cold air coming in, but plastic may help a bit more. Just my two cents!
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Kenodog
Joined: 25 Jun 2003
Posts: 2669
Location: Vancouver,B.C.
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| Posted: Thu Mar 29, 2007 12:15 pm Post subject: |
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On a forced induction vehicle getting 1 hp per 1 deg in temp drop is very doable because you can up the boost. Keep in mind that modern cars have knock sensors in the efi system that will help the computer advance the timing as much as possible thereby making more power. A stock,N/A 924 does not have this luxury so any hp gain is purely due to he physics of denser air as Dagwood said. If you put the car on a dyno with and without i'd say you would be really surprised to see more that 1-2 hp on a stock engine. My $.02
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Min
Joined: 04 Nov 2002
Posts: 2368
Location: Vernon, British Columbia, Canada
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| Posted: Thu Mar 29, 2007 2:05 pm Post subject: |
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| Kenodog wrote: | | On a forced induction vehicle getting 1 hp per 1 deg in temp drop is very doable because you can up the boost. Keep in mind that modern cars have knock sensors in the efi system that will help the computer advance the timing as much as possible thereby making more power. A stock,N/A 924 does not have this luxury so any hp gain is purely due to he physics of denser air as Dagwood said. If you put the car on a dyno with and without i'd say you would be really surprised to see more that 1-2 hp on a stock engine. My $.02 |
and my .02 is that a dyno is not accurate enough to properly measure a 1-2hp increase. But do enough 1-2hp increases and soon you've got 10hp
Min
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Kenodog
Joined: 25 Jun 2003
Posts: 2669
Location: Vancouver,B.C.
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| Posted: Thu Mar 29, 2007 3:16 pm Post subject: |
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Sadly, to get that 10 hp comes at the price.
How many of you are willing to pump hundeds of dollars and countless hours in order to make a relic like the too-fa make an extra 10 hp ?
Not to 'dis the cars but there are better ways to get the same perfomance.
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1979 Euro 931, Olive
1981 931, Sabine
1991 Ford Ranger XLT 4x4, Ricky
1996 Ford E-350 ex-FedEx Van
2014 Mazda CX-5 (Kinderwagon)
2019 KTM 790 Adventure
2024 KLX300
2024 KLX140 |
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Mike924
Joined: 12 Aug 2004
Posts: 2601
Location: IoW UK
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| Posted: Thu Mar 29, 2007 4:58 pm Post subject: |
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We're not talking hundreds of dollars here. An length of tube is under a dollar. If it gains 1 - 2 hp, that's got to be the biggest bang per buck of any mod.
Don't underestimate the benefit of denser air - why do you think intercoolers got invented?
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morghen
Joined: 21 Jan 2005
Posts: 9102
Location: Romania
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| Posted: Thu Mar 29, 2007 8:05 pm Post subject: |
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"why do you think intercoolers got invented?"
because the chargers heat the shit out of the air. boosted cars have much higher intake air temps. But what the hell i'm gonna try it this weekend and see what happens ! i'm gonna try to do some accurate tests. i have a very accurate system measuring time over 400m or whatever distance and i will try to do some tests.
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Vince Ponz
Joined: 02 Nov 2002
Posts: 3581
Location: Florida
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| Posted: Thu Mar 29, 2007 11:31 pm Post subject: |
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Cheap fix.
Spin intake to behind the headlight and put on a K & N filter. Now the heat will not get to the airbox directly over the rad. It cannot hurt at best.
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Mike924
Joined: 12 Aug 2004
Posts: 2601
Location: IoW UK
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| Posted: Fri Mar 30, 2007 12:29 am Post subject: |
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| morghen wrote: | "why do you think intercoolers got invented?"
because the chargers heat the shit out of the air. boosted cars have much higher intake air temps. |
1) it was a rhetorical question
2) beacuse cooler air is denser, which is the point I was making.
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1993 Porsche 968 Coupe, Midnight Blue, 6 spd
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Min
Joined: 04 Nov 2002
Posts: 2368
Location: Vernon, British Columbia, Canada
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| Posted: Fri Mar 30, 2007 1:38 am Post subject: |
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| Kenodog wrote: | Sadly, to get that 10 hp comes at the price.
How many of you are willing to pump hundeds of dollars and countless hours in order to make a relic like the too-fa make an extra 10 hp ?
Not to 'dis the cars but there are better ways to get the same perfomance. |
I think you missed the point of my post entirely. I said that if you do a number of small changes that add 1-2hp they will add up to 10hp. The problem is simply finding easy/cheap things that will increase hp by 1-2 points. Pretty sure that was not a reference to dumping money into our cars to get 10hp.
Min
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morghen
Joined: 21 Jan 2005
Posts: 9102
Location: Romania
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| Posted: Fri Mar 30, 2007 3:47 am Post subject: |
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sorry Mike i was a lil bit.....heavy minded...woke up with a hangover.
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Mike924
Joined: 12 Aug 2004
Posts: 2601
Location: IoW UK
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| Posted: Fri Mar 30, 2007 4:33 pm Post subject: |
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It's cool.  (not your hangover, I mean  )
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1985 Porsche 924 'Lux', Kalahari Beige (my ex)
1993 Porsche 968 Coupe, Midnight Blue, 6 spd
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