Ram Air?

How to make it go fast

Moderators: Greenleaf, KTA, BC847, Richie O

Ram Air?

Postby JimmieD » Sun Jan 07, 2007 8:02 am

Just scratching my head here but I was thinkin'...

Cold air intake and large filter/box helps because of the denser mixture causing more available oxygen for the burn. Though these engines are all turbo'd I was thinking it still might help to use a Ram Air intake to the filter box. Seems like it would take some strain off the compressor and exhaust wheel if the air charge is already getting rammed down the intake pipe, sort of like a sub-booster? That way the turbo doesn't have to work as hard as it does getting dead air into motion. Instead the air is already getting slammed home and the turbo can the reach a higher efficiency level?

I can do this easily on my particular truck and just wondering if it's worthwhile or not....

JimmieD
JimmieD
fuel screw!!!!
 
Posts: 126
Joined: Sat Jan 06, 2007 12:02 pm
Location: Mid-Cal

Postby TugboatPhil » Sun Jan 07, 2007 9:10 am

JimmieD

I just looked on my 93. There is a hole below the park light on the passenger side. If I remember correctly, my 90 had a plastic tube that drew air towards the filter housing. The 93 hasn't got it, and I long ago got rid of the housing.

If you didn't want to go through the hood, you could possibly incorporate this hole into an airbox. Just my $.02 (has anyone else noticed that computers don't have the symbol for cents?)
93 D350, Modifed by Smokehouse Diesel, Ashland, Ohio.
Truck renamed by wife as "The Global Warmer."
User avatar
TugboatPhil
fuel screw!!!!
 
Posts: 56
Joined: Sun Jan 07, 2007 7:20 am
Location: Floyd, Virginia

Postby TWorline » Sun Jan 07, 2007 9:58 am

JimmieD:

Our trucks really do not go fast enough to benefit from Ram Air. It would take a great deal of speed to cause a positive pressure reading on a 4" hose after going through over 450 Sq. in. of filter element. The only real benefit is in drawing in cooler air for a denser air charge.
Tim Worline
1992 W250 Club Cab LE, S300 62/71, 5" stainless intake, 4" into 5" exhaust, ATS exhaust manifold, SDX 5X18 Injectors, AirDog 150, Borgeson shaft, Coolingmist Vari-cool, Con OFEK, 3" Stainless CoolerTubz, 354/749.

http://www.CoolerTubz.com/
User avatar
TWorline
14mm rotor
 
Posts: 2480
Joined: Thu Jan 04, 2007 6:32 pm
Location: Continental, Oh.
Top

Postby JimmieD » Sun Jan 07, 2007 1:26 pm

TWorline wrote:JimmieD:

Our trucks really do not go fast enough to benefit from Ram Air. It would take a great deal of speed to cause a positive pressure reading on a 4" hose after going through over 450 Sq. in. of filter element. The only real benefit is in drawing in cooler air for a denser air charge.


What you're saying makes good sense. There's 450 sq. in. of filter but the turbo has to overcome all that resistance to the air's motion. I'm thinking that a large surface area hi-pressure inlet would make it just that much easier for the turbo to get large quantities of air up to speed. One way or another the job is to ram in more than normal atmospheric pressure of about 14 psi. Seems like a well positioned ram inlet of a large size would help the turbo's effect and for virtually free horsepower gains.

On my truck there's two areas available, one about 3" X 8" or another about 3" X 18". The second area of 3" X 18" or 54 sq. in. under positive pressure seems to me like it could force a lot of air into a 3" pipe? That's roughly 7 1/2 times the square inches of the 3" inlet pipe. At speeds over 40 mph that could be a lot of air, or am I missing something? I'm not real bright on numbers....
JimmieD
fuel screw!!!!
 
Posts: 126
Joined: Sat Jan 06, 2007 12:02 pm
Location: Mid-Cal
Top

Postby TWorline » Sun Jan 07, 2007 2:14 pm

JimmieD:

This is a Quote from Answers.com for ram air.
"Technically, there are two types of Ram-Air:

Systems compress air and force it into the throttle body, and thus the combustion chambers
Positive pressure systems, which increase pressure only in the airbox and improve intake efficiency
Ram-air systems are used on high performance vehicles, most often on motorcycles and race cars. Ram-air has been a feature on some cars since the late sixties, but fell out of favor in the seventies, and has only recently made a comeback. Modern parachutes use a ram-air system to pressurise a series of cells to provide the aerofoil shape.

However, Fluid Dynamics can support claims that only 3 % higher volume of intake air is accomplished at speeds attainable by high performance and race cars (and an intake on the side reduce the volume by 3 %). Forcing a large volume of air into a cone by motion alone is only possible at supersonic speeds (below that it reduces the volume)"

I have saw better explanations of this in the past but cannot remember where I saw it.
Tim Worline
1992 W250 Club Cab LE, S300 62/71, 5" stainless intake, 4" into 5" exhaust, ATS exhaust manifold, SDX 5X18 Injectors, AirDog 150, Borgeson shaft, Coolingmist Vari-cool, Con OFEK, 3" Stainless CoolerTubz, 354/749.

http://www.CoolerTubz.com/
User avatar
TWorline
14mm rotor
 
Posts: 2480
Joined: Thu Jan 04, 2007 6:32 pm
Location: Continental, Oh.
Top

Postby JimmieD » Sun Jan 07, 2007 7:50 pm

Hmmm, so what are ya saying, TW, use higher rear end gears and go for it? :lol: :lol:

That's interesting to read. Not sure if it's correct to make such a blanket statement covering all applications of ram air, as ALL only giving a 3% max velocity change?

This isn't aimed at you but at the writer of that article: Somebody needs to tell NASCAR, NHRA, AHRA, SCCA and all the Euro racers and Weber, Edelbrock, Holley, DeLorto, Mikuni, K&N and many others that they're wasting their time and money if that's true. Seems like you'd need a dyno set up in a wind tunnel to know for sure, but many company's research and development has resulted in various ram air systems to improve performance. As a matter of fact it's the basic principle that makes the venturi and/or velocity stack work in a carburetor, as playing with pressure differentials to speed up air's motions.

So no offense to you at all, but I can't see why it wouldn't work without some experimental data to support the claim to the contrary. Again, NOT getting in your face about this!
JimmieD
fuel screw!!!!
 
Posts: 126
Joined: Sat Jan 06, 2007 12:02 pm
Location: Mid-Cal
Top

Postby TWorline » Sun Jan 07, 2007 8:51 pm

I understand completely :D I have noticed that the dragsters are running bigger supercharger scoops now days. I`d say go for it & report back, that is what these forums are for R&D. :D
Tim Worline
1992 W250 Club Cab LE, S300 62/71, 5" stainless intake, 4" into 5" exhaust, ATS exhaust manifold, SDX 5X18 Injectors, AirDog 150, Borgeson shaft, Coolingmist Vari-cool, Con OFEK, 3" Stainless CoolerTubz, 354/749.

http://www.CoolerTubz.com/
User avatar
TWorline
14mm rotor
 
Posts: 2480
Joined: Thu Jan 04, 2007 6:32 pm
Location: Continental, Oh.
Top

Postby JimmieD » Sun Jan 07, 2007 9:36 pm

Ha ha, a man after my own heart! Something about torpedoes and full speed ahead..... :lol:
JimmieD
fuel screw!!!!
 
Posts: 126
Joined: Sat Jan 06, 2007 12:02 pm
Location: Mid-Cal
Top

Postby TWorline » Sun Jan 07, 2007 9:47 pm

There you go, I can't leave anything alone. My last toy or I mean car was a 92 Daytona with a v6 5 speed that turned a 15.3 @ the strip. Embarassed a few v8s with that one!
Tim Worline
1992 W250 Club Cab LE, S300 62/71, 5" stainless intake, 4" into 5" exhaust, ATS exhaust manifold, SDX 5X18 Injectors, AirDog 150, Borgeson shaft, Coolingmist Vari-cool, Con OFEK, 3" Stainless CoolerTubz, 354/749.

http://www.CoolerTubz.com/
User avatar
TWorline
14mm rotor
 
Posts: 2480
Joined: Thu Jan 04, 2007 6:32 pm
Location: Continental, Oh.
Top

Postby JimmieD » Mon Jan 08, 2007 7:35 am

Ha ha, yea, my viewpoint is that ANYTHING can go just a little faster..... :lol:
JimmieD
fuel screw!!!!
 
Posts: 126
Joined: Sat Jan 06, 2007 12:02 pm
Location: Mid-Cal
Top

Postby MMiller » Mon Jan 08, 2007 7:58 am

TWorline wrote:I understand completely :D I have noticed that the dragsters are running bigger supercharger scoops now days. I`d say go for it & report back, that is what these forums are for R&D. :D


I'm not so sure its for "ram air" effect, as the mulitengine pullers use the same scoops, and they don't move fast enough down the track to get any ramming effect. I think its just the best way to eliminate turbulance, point the air intake in the direction of travel. I've been told that the new "birdcatchers" on the forced induction engines help HP a bunch, just by getting the air in smoother and with less turbulance.

FWIW I'm no engineer, and have done no testing on the subject. I know that the old scoops on 60's and 70's mopar muscle cars were more for decoration then funcunality. Especially the Shaker scoops. Sure you were getting cool/denser air, but no ram air effect.

Michael
MMiller
fuel screw!!!!
 
Posts: 391
Joined: Mon Jan 08, 2007 6:26 am
Location: Lenox Ia
Top

Postby Begle1 » Sat Jan 13, 2007 8:56 am

Guys I know who have installed scoops (Jim Lane has the best one I've seen) all report seeing "free boost" at high speeds; even while coasting on the freeway, they see 5-8 PSI of boost pressure from the scoop.

Which makes sense; if I'm going 60 miles per hour and you were to reach out the window with a pot, you're not going to be strong enough to hold onto that pot.

I do not know if it is really "free boost", however. First of all, I don't know how that air flow affects the air filter; I wonder if it doesn't damage the filter along the same lines that blowing them out with air compressors would. Secondly I don't know how rammed air cooperates with the turbocharger; it seems to me that if there is pressure on the inlet side of the turbocharger, there has to be a matching load on the exhaust side, so you're not really gaining anything. Or not gaining much.

Nonetheless, I still think that a scoop like Jim Lane's is the best way to do it. That way you can tuck an air filter under the hood so than won't get wet and you will still get the coldest air avaliable.
User avatar
Begle1
14mm rotor
 
Posts: 1964
Joined: Sat Jan 06, 2007 5:31 pm
Location: Kihei, Maui, Hawaii
Top

Postby BC847 » Sat Jan 13, 2007 10:52 am

Here's my take on it for what it's worth . . . .

Unless you have the scoop placed in an air flow that would in fact have the thing take advantage of the air velocity (as that's what drives the air in) such as a top fuel dragster with the scoop up high, then you're not really getting a ram effect (compression).

What we can do is take advantage of high pressure air zones. That being in front of the radiator area, and the base of the windshield.

We've all had the experience of passing a big-rig at highway speeds where we get blown to the side as we pass the front of the rig. That's all the air that the rig has to push to the side and over the vehicle as it moves down the road. You could almost view it as a bubble of compressed air.
Perhaps you've noticed that on really humid days, as you come up side of the front of the rig, water drops mysteriously get blown around on your windshield. It's broad daylight out with no rain! . . ? The rig pushing through the air, compresses it enough that some of the humidity condenses into a liquid (water).

While our trucks don't move that much air, the effect is still the same.

The taking advantage of such is nothing new. Consider the '70's muscle cars that have the hoods that allow the intake at the base of the windshield.


With that, it really doesn't matter how you grab the air be it a scoop under the front bumper, or behind the headlights, or the base of the windshield.

In those settings, you're gonna flow much more air as compared to the typical hood scoop simply because it's subtly compressed (at highway speeds). Image
David

1993 12mm VE Fueled W250 CC, Green
12.67 @ 103.35
Your basic farm truck ;)
BC847
Administrator
 
Posts: 2203
Joined: Wed Jan 03, 2007 5:22 pm
Top

Postby JimmieD » Sun Jan 14, 2007 9:40 am

Begle1 and BC847: YES! Simple physics says YES! Looking at 'air' as a substance have particulate mass, we know then that properties such as inertia apply to it. Thinking of the steam launching machinery on an aircraft carrier: The aircraft has its own propulsion system, like the turbo does. But it gets a huge boost on take off from the steam launch blasting it off the deck, like the ram air to the turbo.

My truck has another advantage to this ram air, in that the whole top of the hood is louvered. Whatever air pressure slams against my frontal area can pass right on through entire engine compartment. If I place my intake in the front grill area, not precisely but close, I can get a serious ram effect to the turbo.

In my case I don't actually need a scoop, as I can take hi-pressure air from front of truck. I do need a properly shaped ducting with smooth bends and transitions to maintain air velocity to compressor intake.

I even wonder if this ram air would not lower EGT's just a little bit, with turbo exhaust housing able to spin more freely and easily by getting a slight boost from compressor intake side.
JimmieD
fuel screw!!!!
 
Posts: 126
Joined: Sat Jan 06, 2007 12:02 pm
Location: Mid-Cal
Top

Postby JimmieD » Sun Jan 14, 2007 9:41 am

Begle1 and BC847: YES! Simple physics says YES! Looking at 'air' as a substance have particulate mass, we know then that properties such as inertia apply to it. Thinking of the steam launching machinery on an aircraft carrier: The aircraft has its own propulsion system, like the turbo does. But it gets a huge boost on take off from the steam launch blasting it off the deck, like the ram air to the turbo.

My truck has another advantage to this ram air, in that the whole top of the hood is louvered. Whatever air pressure slams against my frontal area can pass right on through entire engine compartment. If I place my intake in the front grill area, not precisely but close, I can get a serious ram effect to the turbo.

In my case I don't actually need a scoop, as I can take hi-pressure air from front of truck. I do need a properly shaped ducting with smooth bends and transitions to maintain air velocity to compressor intake.

I even wonder if this ram air would not lower EGT's just a little bit, with turbo exhaust housing able to spin more freely and easily by getting a slight boost from compressor intake side.
JimmieD
fuel screw!!!!
 
Posts: 126
Joined: Sat Jan 06, 2007 12:02 pm
Location: Mid-Cal
Top

Next

Return to The good stuff

Who is online

Users browsing this forum: No registered users and 9 guests