RamAir II

**Sarge** · 01-20-2007, 06:12 AM

The old RamAir debate thread took the course of every other RamAir debate thread I have ever seen. http://www.ls1.com/forums/showthread.php?t=35363 Garage physics and math take over and you end up with a 50-50 split of "experts" debating pressure and RWHP gains. During that thread I remembered a really good article about RamAir and it's continued ( for the ages) debate on if it "works" or not. Some old gear heads took a car with a hood scoop and took it to the wind tunnel...they had thought of a new angle to the debate and that was the wind resistance and drag created by the hood scoops and what measurable RWHP effect the hood scoops had on the car. I looked everywhere for that article and could not find it so I didn't mention it as I had no data or defensible reference to refer the members to. Well guess what. It was in my private bathroom in the magazine rack at the office. So here we go.
Hot Rod magazine April 2006. Page 113. Taping the hood scoop closed returned a measurable gain of 8 horsepower. Removing the scoop altogether returned an additional 8 horsepower. So now we are realizing a measurable 16 horsepower gain by removing the hood scoop. Front lift was reduced by 50lbs!!! By removing the hood scoop. Now guys no RamAir effect ( real or imagined) can outweigh the losses of the scoops drag on the car. So lets throw the aerodynamics of the scoops into the discussion and once again ask ourself if RamAir generates horsepower when the air drag effects are entered into our formulas.

**9t8z28** · 01-20-2007, 11:03 AM

What make and model car was it? And would that have anything to do with it?

**Jon7I2** · 01-20-2007, 11:20 AM

It is settled, ram air has LITTLE to absolutely no advantages. (except a cool looking hood)

**BlackLT1Z28** · 01-20-2007, 11:39 AM

That's good shit.

**Sarge** · 01-20-2007, 01:08 PM

Originally Posted by 9t8z28

What make and model car was it? And would that have anything to do with it?

Oh it was an old....like a 40 Bonneville roadster or something....but no....the issue was any car with a hood scoop. Doesnt matter....because you have a baseline run...then you take off the hoodscoop and you reduce drag and that equals horsepower....so the aerodynamics of the hoodscoop apply to any car and any hoodscoop....your gonna have drag.

**AKIRA** · 01-20-2007, 02:18 PM

Originally Posted by Sarge

Oh it was an old....like a 40 Bonneville roadster or something....but no....the issue was any car with a hood scoop. Doesnt matter....because you have a baseline run...then you take off the hoodscoop and you reduce drag and that equals horsepower....so the aerodynamics of the hoodscoop apply to any car and any hoodscoop....your gonna have drag.

What a drag.

**9t8z28** · 01-20-2007, 02:20 PM

If its gonna rob horsepower it might as well look cool.

**WS.SICK** · 01-20-2007, 03:19 PM

drag schmag- ram air looks nasty- i don't care if it "slows me down".. thats what mods are for.. if your faster without it, good for you, at least i look good going fast-- no offense to non ram air cars, i drove a 98 formy for several years.. fast as f***

**9T8W66** · 01-21-2007, 06:24 AM

I guess I'll be putting my stock Flat hood back on.
NOT !

**twozs** · 01-21-2007, 09:12 AM

i dont think that its the "raming" of the air down the intake that makes the hp unless its realy ramed in there like some form of forced induction (turbo or blower) its more the introducion of cooler outside air that will make a small difference. any static pressure developed by the scoop is lost by the time it hits the filter . take the ss hood, the air coming in makes 2 90 degree turns before it even hits the filter. in the industry any 90 is worth 25 feet of ducting so do the math, that a long way to the filter

**Sarge** · 01-21-2007, 09:20 AM

I'm all for a hood scoop or two. I just dropped around a 1000 bucks for the fully functional Banshee on Oprah. But I dont believe for one second I gained diddly squat from "RamAir"

**GatorSS** · 01-22-2007, 09:26 PM

Then maybe you need to add a Tornado or two.

**Hot Black Trans-Am** · 01-22-2007, 09:33 PM

Ram air adds power to go slower. That's what I get out of it. Atleast it looks good!

**z28punk** · 01-24-2007, 02:29 PM

the air can be RAMMED in there as fast as it wants, but your gonna need some heads to get that air into the engine.

**JohnnyBs98WS6Rag** · 01-25-2007, 06:05 AM

Originally Posted by Sarge

So here we go.
Hot Rod magazine April 2006. Page 113. Taping the hood scoop closed returned a measurable gain of 8 horsepower. Removing the scoop altogether returned an additional 8 horsepower. So now we are realizing a measurable 16 horsepower gain by removing the hood scoop. Front lift was reduced by 50lbs!!! By removing the hood scoop. Now guys no RamAir effect ( real or imagined) can outweigh the losses of the scoops drag on the car. So lets throw the aerodynamics of the scoops into the discussion and once again ask ourself if RamAir generates horsepower when the air drag effects are entered into our formulas.

This is a bit misleading WRT the WS6 hood.

1) The HR test was done on the car in the attached photo, which had a HUGE hood scoop. No doubt the WS6 hood adds drag compared to a "sleek beak", but it's misleading to imply that the WS6 hood had drag comparable to the scoop used in the HR test.

2) The estimate of a 16HP penalty for the drag from the hood scoop was based on a speed of 200MPH. Since wind resistance increases with the square of the velocity, at 150MPH would only cost you ~9HP, only ~4.41HP at 105 MPH (approx 1/4 mi trap speeds on stock LS1 f-bods). And that is with the HUGE scoop in the photo. The only way to know for sure how much drag-HP a WS6 hood costs you is to perform a test on a WS6 and non-WS6 car in a wind tunnel. I suspect that the WS6 hood doesn't cost nearly as much drag-HP as that, probably alot less than 2HP at 105MPH.

3) They made no attempt to measure how much HP gain is provided by the scoop blasting air into the engine. The test was done in a wind tunnel without the engine even running. Of course, there are many factors that affect how much HP gain a given engine will produce w/ different scoops.

I'll post up the C&D article I mentioned in the other thread, which is a much better assessment of the effectivity of "Ram Air" than that Hot Rod article.

**440 rwhp trans am** · 01-25-2007, 06:13 AM

Originally Posted by Sarge

I'm all for a hood scoop or two. I just dropped around a 1000 bucks for the fully functional Banshee on Oprah. But I dont believe for one second I gained diddly squat from "RamAir"

can we get a pic of Oprah

with her new hood?

**9t8z28** · 01-25-2007, 06:14 AM

Originally Posted by JohnnyBs98WS6Rag

This is a bit misleading WRT the WS6 hood.

1) The HR test was done on the car in the attached photo, which had a HUGE hood scoop. No doubt the WS6 hood adds drag compared to a "sleek beak", but it's misleading to imply that the WS6 hood had drag comparable to the scoop used in the HR test.

2) The estimate of a 16HP penalty for the drag from the hood scoop was based on a speed of 200MPH. Since wind resistance increases with the square of the velocity, at 150MPH would only cost you ~9HP, only ~4.41HP at 105 MPH (approx 1/4 mi trap speeds on stock LS1 f-bods). And that is with the HUGE scoop in the photo. The only way to know for sure how much drag-HP a WS6 hood costs you is to perform a test on a WS6 and non-WS6 car in a wind tunnel. I suspect that the WS6 hood doesn't cost nearly as much drag-HP as that, probably alot less than 2HP at 105MPH.

3) They made no attempt to measure how much HP gain is provided by the scoop blasting air into the engine. The test was done in a wind tunnel without the engine even running. Of course, there are many factors that affect how much HP gain a given engine will produce w/ different scoops.

I'll post up the C&D article I mentioned in the other thread, which is a much better assessment of the effectivity of "Ram Air" than that Hot Rod article.

Good point but I didn't understand that whole: Since wind resistance increases with the square of the velocity, at 150MPH would only cost you ~9HP, only ~4.41HP at 105 MPH (approx 1/4 mi trap speeds on stock LS1 f-bods). Please explain?

**JohnnyBs98WS6Rag** · 01-25-2007, 06:20 AM

Here's the pertinent poop from the C&D article from 8/99.

Note that the SS has a weight advantage on the WS6. And they both ran identical 1/4 ETs, but the WS6 was a tad faster through the traps. That indicates the SS got a jump on the WS6 (due to the weight advantage), but the WS6 was producing more effective HP once it got moving. Also, once past the 1/4 mi point, the WS6 really began to run away from the SS. Granted, a better test would be a WS6 vs a non-WS6 car, providing they had equal exhaust systems to level that playing field. Or better yet, swap the hood on the same car, providing it can still be done and tested at the track on the same day under the same conditions. ALSO, the WS6 hit the limiter at 163 vs the SS hitting the proverbial wall at 160 (I was slightly off on these number in my prior post in that other thread). Who knows what the ultimate drag-limited speed of the WS6 would be, but it is obviously producing much more effective (engine-drag) HP than the SS.

Like I stated before, at street speeds, "Ram Air" is mostly marketing hype. But at 10/10ths, it does in fact produce HP.

**JohnnyBs98WS6Rag** · 01-25-2007, 06:25 AM

Originally Posted by 9t8z28

Good point but I didn't understand that whole: Since wind resistance increases with the square of the velocity, at 150MPH would only cost you ~9HP, only ~4.41HP at 105 MPH (approx 1/4 mi trap speeds on stock LS1 f-bods). Please explain?

Every time you double the velocity, the force of drag goes up approximately 4 times (2 squared, or 2^2 = 4).

HP@150 = 16HP * (150^2/200^2)

HP@105 = 16HP * (105^2/200^2)

**Sarge** · 01-25-2007, 02:45 PM

Guys guys guys.....who gives a shit about how big the scoop is or what kind of car it was on for the test. The point is....you must inject the drag of the scoop into any RamAir benefit formula. My point is one will wipe out the other pretty much. If a WS6 hood scoop is teeny tiny then any "RamAir" benefit would be teeny tiny and the drag would be a negative teeny tiny but the end result would be the freakin same!