[Formulajones]

Originally Posted by gtospieg

I didn't see a difference at the track with my 67. I feel like the brick like front of these cars makes the air just go right over the scoop. I think Chevy got it right with cowl induction. I do like the idea of pulling cooler air through the scoop.

Some things you might find interesting. Dad's 69 GTO with scoops facing forward in the center of the hood, which is much like a 67, is right in that area considered a dead zone of air flow.

When he switched over to a sniper stealth I already had the stock appearing fiberglass hood opened and modified to be functional with an L88 air box and drop base sealed to the scoops. Like you I figured it may not be worth much at the track with all the talk of a boundary layer of air, plus those factory scoops just don't stick up much, maybe an inch. But with the Sniper I could now see air intake temps. I was surprised to see the air temp differences with the Sniper. Monitoring IAT's showed that it is indeed pulling in outside air. Stopping for gas and heat soaking for a few minutes saw those temps rise to over 100 degrees, and would keep climbing the longer we sat, but as soon as we started moving down the road they dropped to almost spot on ambient temps. Stop at a red light and I could watch it climb 2-3 degrees, start moving and they come back down.

Whether or not it's an effective RA setup that makes more HP I don't really know, but it does make a difference in the air temps the engine is ingesting.
I will say this, the way I have his hood setup, it's the only way for the engine to ingest any air, through those 2 little scoops. Hasn't seemed to hurt performance. Making over 700 HP and it's gone 10's at 128 mph. Would it run better with a more efficient air intake? Possibly, but the coolness factor of having a one off functional hood setup is why I did it and that's not going to change.

Having a Sniper on my chevelle I can also see IAT's and it acts very similar to dad's car. I have the electronic door wired to stay open all the time. These hoods actually have 2 doors and draw the air in from the very back of the hood at the windshield through the electronic flapper, the vacuum operated door on top is just more of a gimmick.
With that said, I see the same IAT drop that nearly matched the outside ambient temps within a degree or two. It also climbs when the car comes to a stop. This is just part throttle cruising stuff. I do know this hood works at the track because if I take the cowl air cleaner off and run an open element under the hood the car does slow down a tenth give or take. It has always liked being sealed to that hood.

The neat thing about the sniper is that I can add or subtract fuel based on the IAT's the engine is seeing. On the really cold mornings when it's 30 degrees it will actually drive around with 30-32 degree IAT's as long as I'm moving, and I have the tune adding a pinch of fuel for the cooler denser air.