BrianG

A source of ambient temp air IS a significant issue to the huffer crowd. Pre-heated under-hood air subsequently compressed is a recipe for detonation........

pappy92651

Adam,

Thanks for sharing your experience. More detail if you don't mind me asking. Which modifications do you have on your 928? Performance intake manifold, big exhaust, more fuel, new computer map, cams?

I don't believe that conventional hood scoops by themselves will produce a noticeable increase in horsepower (see my previous post). Instead an entire series of changes would have to be made. So if your car is nearly stock I would agree with your findings.

The issue concerning induction of cooler ambient air is actually what I'm after. I need to make a few measurements in order to profile this.

wicked944

I have a few mods on my 928s, most obvious is the s4 wing, and Fikse wheels. I had a guy in Phoenix make me a custom cat back exhaust, and I'm getting msds headers, with a cat bypass for Christmas (Santa couldn't stand not telling me). I've got a K&N Air Filter, custom made are intake, tornado air spinner. For fuel, a raising rate fuel pressure regulator with a set of performance chips. I've got Bosch Platinum 4 plugs, and am dreaming of Nology plug wires but $350.00, ouch... So yeah thats it as far as performance goes. I've had this whole set up for about 5,000 miles and it's going good so far, it uses alot more gas now but it might be because I'm getting on it alot more now, I can't help it. I think it needs the extra spark from the wires.

What about you guys what kind of mods are you doing.

pappy92651

Hello wicked944,

What year and model is your 928?

My 89 S4 is a custom mule. It has GT cams indexed +3 degrees advanced. The intake valves are 968 valves. I'm running custom Autothority chips, no mufflers, a 2400 RPM stall torque converter, a custom built transmission, Enkei RC5 18" racing wheels, etc. The exhaust is being upgraded, headers, Ott X pipe, Random Tech CATs, and 2.5" pipe to a DynoMax muffler. The computer will be augmented by an SMT-6 from Perfect Power. The intake system is in the works, ceramic coated GT with 3/8" side spacers. The final engine configuration is in process (stroked).

I built the surrounding systems to accommodate the power that will eventually be generated.

Adam C

Pappy,

I no longer own that car. It was a stock S4 with the exception of a chip, free flow exhaust - 3" straight back, no cats, flowmaster. Real fast car.

Hood scoops came about as "spark of genius" and a couple days later there they were. This was about four years ago.

Again, no noticeable difference, ecept they look cool. I made them look just like the ones on the hood of an old Ferrari 250GTO.

heinrich

Pappy that beast looks baaaad just sitting there.

Fastest928

Bring in the air at the highest pressure point...the nose of the 928, followed by the front axle line, then at the base of thw windscreen.

copy the Ferrari 550/575M or the viper or the vette cold air intake. Watch the latter as it also sucks "water" very nicely!

If anyone comes up with a 550 "look-a-like" hood scoop/system, you might sawe me a $100K someday

tomboyea123

I have recently completed my supercharged 89 gt with 517 rwhp.I am using a fast fit whish has an open element k&n right behind the radiator which is the worst place to put the air intake.Because the fast kit deleats the factory fan and air intake tube holes,I had a 2 3/4 inch opening right above above the radiator.I just made a cold air box with no top just like what a k&n kit looks like and I then put the rubber that surounds the rear of a hood on top of it so that no hot air could around the box from the rear or the sides.then I put a 1/16 inch pressboard(wood is the best insulater) on top of the radiator and opened up a factory heat sheld (on the drivers side between the radiator and the fender.I put a an indoor outdoor themometor that I got at walmart and found that The air intake is only 2-3 degrees f above ambient temp at slow speeds and am about 2-3 degrees below ambient at highway speeds.

tomboyea123

Just spend some time and look at how a c-5 corvette gets its cold air which is a flat intake tube just above the radiator.something like that could be used for supercharged applications.

Gretch

You should post a picture of your install, I am sure many of us here would like to get a look at it............

heinrich

I was just thinking that too.

heinrich

I invented this also (in my head) and was impressed to see Blown Beast had already DONE what I had been planning ... very nice job too.

Jim_H

Pics? Your decription is how I envision mine.

pappy92651

Guys,

Thanks for the input. You confirmed many of the things that I now need to evaluate. Also many good ideas about how to get cooler air from high pressure zones. I may buy a scrap hood and do some testing. A trip to Home Depot for modeling materials. Ferrari 550, hmmm?

mark kibort

No real gains in a hoodscoop over a cowl induction, or just a vent to the base of the windshield with or without the stock tubes open to the front. keep in mind, and Ive posted this many times, the max HP gain from a ram scoop, (but it would have to be like a dragster, not a street car mustang type raised hood inlet) would be .36psi at 160mph and .08psi at 80mph. so, take these numbers and divide them by 2 since the hood is not a good zone for a ram scoop and it is still in the boundary layer flow area. in the nose, like the stock tubes is one of the best places. heat soaked plastic tubes, hardly transfer any heat in to the air flow, at full throttle anyway. Id be (and am ) more concerned with removing pressure drops in the air box, by better filters, and venting the air box.
this can FAR exceed any gains from a hood type scoop that is primarily for looks anyway.

Mk