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#1
10th January 2013, 06:44 PM
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CAI .... Cold Air Intake
Needing some advice please Gents ....
With our rather warm ambient temperatures in my parts I have noticed a significant variation in engine performance and driveability when the ambient temperatures are between 15 & 20 deg.C to when they are above 20 deg.C. The car is far more responsive and just feels way happier when temperatures are cooler... Having done some research I have come across a fair amount of talk about CAI's and the benefits thereof .... also talk on the denisity of the air being beneficial etc etc..... Has anybody gone this route ..... are there CAI kits available for the 8's etc etc ?? Any advice would be appreciated.... 
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 " Love the Sound of a V8....... All Day " *still wish it was a V10* 2002 S8 D2 F/L H & R Springs, Koni Coil Overs, Dastek Chip, Sport Exhaust, 19" S5 Rims, Solar Sun Roof (Cause we have Sun) and most of the Bells & Whistles. 
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#2
10th January 2013, 08:31 PM
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We've got rather too much "normal" cool air up in these parts I'm afraid so its not really an issue!!
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Confidence is the feeling you have before you know better . . . .  Audi A8 D2 3.7 Quattro Sport 1999 FL - Melange 2nd Place Winner - A8-Freunde Annual German Meet 2012 at Edersee 20" x 9" Bentley GTC Wheels with 385mm W12 Front Discs & Bentley Caliper Covers, Front Lowered on Coilovers, Xenons, Combined DRLs and LED Foglights to modified OEM front fog lamp position, Alcantara/Leather, Full Black Alcantara headlining + pillars and blind shelf, Bespoke Flat Bottomed Sports Steering Wheel, Dark Myrtle Wood, Autodim Mirrors, Bose, Blinds, Digital TV, Ski Hatch, Modified rear exhaust section for extra V8 Burble  Audi S8 D2 Final Edition 2002, Avus Silver with Red Leather Interior Tiptronic with Sport mode button, Sony rear entertainment package, Bose sound system, Audi Navigation Plus, 20 inch Final Edition alloys, Full Cat Back Stainless Milltek exhaust, giving a great V8 burble Audi A8L D2 4.2 Petrol with LPG - Ebony Black Audi A8L D4 FL 4.0T Petrol twin turbo - Havana Black Audi A2 1.6 FSi Sport - Dolphin Grey with Votex body kit and Red Leather Interior and some other A8's A8L's and Mercs
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#4
11th January 2013, 06:46 AM
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Sorry, I don't understand. What do you mean by "above 20 degrees C"? Have you got your car in an oven?
 It'd be nice to have that oproblem here! 
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2002 Final Edition S8. Ebony black with Silver Grey leather and myrtle wood trim. Current mods: solar sun roof, 20mm rear spacers, 15 mm on front, red brembo callipers, 6k headlights, rear view camera, engine remap, alloy dash dial rings, alloy navi rings, tt/phaeton pedal upgrade, (and custom matching foot rest) dension ipod interface & parrot hands free kit (both fully hidden), av input, tv in motion switched thro' PF switch in blanking plug right of steering column, Audi 'quattro' sill covers, repositioned centre console switches, radio clock, .Planned mods: auto-dimming rear view mirror, dash cam (as steamship's), fit the ski hatch, refit philips drl's (or maybe not - nope, definitely not - horrible botch!).
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#5
11th January 2013, 07:53 AM
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Quote:
In summer our standard daily temps range from 73 deg/F to 102 deg/F.... more ofetn than not at the top end of the scale ... This has a significant effect on the V8 N/A ..... And I am trying to come-up with a solution. I am looking at something more than just a filter on a stick ......
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" Love the Sound of a V8....... All Day " *still wish it was a V10* 2002 S8 D2 F/L H & R Springs, Koni Coil Overs, Dastek Chip, Sport Exhaust, 19" S5 Rims, Solar Sun Roof (Cause we have Sun) and most of the Bells & Whistles.
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#6
11th January 2013, 08:04 AM
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Diesel engines sometimes have a cooler built into the fuel system I wonder if something similar could be rigged up for your car.
I've attached a Range Rover diesel fuel cooling system to give you an idea
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. Nite Blue 3.0L SE Quattro 
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#7
11th January 2013, 09:35 AM
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Quote:
The CAI theory appears to be along the lines of getting MORE air past the MAF. I am looking to get cooler/denser air past the MAF as I understand it ... this has a direct influence on the ECU adjusting fuel/timing etc etc etc..... Or am I heading in the wrong direction here ??
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" Love the Sound of a V8....... All Day " *still wish it was a V10* 2002 S8 D2 F/L H & R Springs, Koni Coil Overs, Dastek Chip, Sport Exhaust, 19" S5 Rims, Solar Sun Roof (Cause we have Sun) and most of the Bells & Whistles.
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#8
11th January 2013, 02:04 PM
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Well you cannot get air cooler than ambient without some type of active cooling(something like extra high power aircon for intake) but that would not be practical and possibly rob more power to operate it that you would gain. Another option would be nitrous injection.
47p2 picture shows fuel cooler which is mounted in intake, that would make intake air even hotter as it cools down fuel. Stock A/S8 already have 'cold air intake' as does all modern cars drawing air from the front of car unlike some old cars that used hot air from under the bonnet. Well known 'tuning' is to put resistor in place of air temperature sensor to fool ECU of thinking it gets colder air and to inject more fuel at WOT and advance ignition.
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Currently 8less 2011 Q7 S Line 3.0TDI, 2016 Tesla Model S 90D 8 history: 2006 A8 Sport 4.2TDI quattro SOLD, 1997 S8, reached end of life with gearbox failure
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#9
11th January 2013, 02:27 PM
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The system is supposed to deal with a normal range of conditions. The lambda sensors detects the amount of oxygen in the exhaust. Too much oxygen indicates a lean condition and so the vehicle computer richens the fuel to correct for this condition. Vice versa -too little oxygen indicates a rich condition and so corrects the fuel input to correct for this condition. So the fuel system automatically compensates for changes in air density. Unless you are driving in Oz (where temperature are touching 50C at the momment and possibly beyond the designed tolerances), i would have though that the system should ensure that little difference is felt.
But what do us in Scotland know about driving in warm climates!!  It would be interesting to know what conditions the system is, in fact designed to cope before performance drop-off. I would have thought that driving at altitude would have a greater effect as air density varies more with height than with temperature - I think?? I am probably wrong about all this as I am no engineer.....
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2002 D2 S8 – Ming Blue, Valcona leather, Vavona wood insert, solar sunroof (to be fitted), Heated rear seats, extended leather pack, 18” Avus, ski hatch, Bose, auto dim rear view mirror, rear blind.
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