The Ram Air Effect......are hoodscoops noticibly benificial

[Chevrolet4x4s]

I am wondering if a hood scoop would be beneficial to a 6.5 N/A Diesel.Would the effects be noticable with an open element air filter?Would this help economy?If so, by what 1-2mpg?Is anyone running a hoodscoop?
Here are the scoops that I am thinking of using if(eer when)I build the truck



Thanks
Shane

[Robyn]

Keep in mind that the forward facing scoops look reeeeeeeeeeeeeely kewl and suck up all the bugs for miles around.
However the rear facing scoops take good advantage of the high pressure area at the base of the windshield and will most likely offer more results.
As far as tangible results only testing will show for sure, and this would need some careful work to examine the results. This is not going to be a mega gain in HP or MPG.

Hope this helps you decide
Robyn

[CleviteKid]

I have a 4" hose poking through the radiator support taking "Ram Air" from the grille on my '84 with the NA 6.5L engine. By my calculations, at about 50 mph and above, the air going in will exceed the air consumption of the engine, so there will be a minor ram air effect.

My SOTP opinion is that there is something to this - my truck will climb a hill at 85 mph better than at 80 mph, and at 90 mph seems to show even more spunk.

Confirming what Robyn stated, the NASCAR types take combustion air from the grille at the base of the windshield and stuff it into their huge 4-bbl carburetors for a nice ram-air boost at 180 mph or so . . .

Dr. Lee

[Chevrolet4x4s]

So I would be better off with a cowl induction scoop?Or would I be better off with a ram air setup?......Im not looking for huge effects just trying to squeeze out another mpg If(when) I build it....And I alsolike the sound of an open element filter for somereason lol.
Thanks
Shane

[Tatraplan]

I've done a mod similar to Dr Lee's. A 4" plastic cone is
placed beside passenger side headlights and the air runs
trough a 4" hose to the air cleaner. The cleaner is also
raised 2" to hold a 50% larger air filter.

The massive improvement in power combined with the
standard look, makes it a real sleeper! A bit wishful thinkin'
perhaps, but i do think the milage is slightly improved. The
highest before my mod was 21.2, but i recently got 24.2.

/Robert

[grape]

Ok heres the deal with the giant scoop facing forward, have you ever held a glass under the faucet..............it finally gets full and water runs over the side and water inside the glass becomes stagnant. Replace the word water with air in the previous sentence and you will soon see the problem. Very few people in the world know what the formula is for the proper amount of scoop area vs. hp and engine size, unfortunately i'm not one of them and the people i know at G-force and Dallara, along with the honda IRL engine program won't tell me. But it is a fact that you will never see pressures of more than about .3 Lbs of inlet pressure in this kind of system due to the air spilling out the front.

[grape]

huge 4-bbl carburetors for a nice ram-air boost at 180 mph or so . . .

Dr. Lee

busch and truck run a huge 390 CFM holley four barrel........lol

[moondoggie]

Good Day!

Many moons ago, someone (can't remember who, might have been Banks) used to sell a kit for the 6.2's. It consisted of (I think) a non-restrictive air intake from the radiator support area, a thingy that attached inside the top if the IM to smooth the airflow, & exhaust manifold adapters. IMHO the good Dr. has got it right. "Swanger Air" the intake & toss the unbelievably restrictive factory exhaust-manifold-to-pipe adapters & you might actually be able to measure the improvement. The problem is: where do you get the exhaust adapters? Maybe the good Dr. will give you drawings of his & maybe he won't (or can't).

I trust grape on this one for sure, unless someone has the magic formula(s).

Blessings!

[JeepSJ]

Ok heres the deal with the giant scoop facing forward, have you ever held a glass under the faucet..............it finally gets full and water runs over the side and water inside the glass becomes stagnant. Replace the word water with air in the previous sentence and you will soon see the problem. Very few people in the world know what the formula is for the proper amount of scoop area vs. hp and engine size, unfortunately i'm not one of them and the people i know at G-force and Dallara, along with the honda IRL engine program won't tell me. But it is a fact that you will never see pressures of more than about .3 Lbs of inlet pressure in this kind of system due to the air spilling out the front.

Real world experience with our Bonneville car - we got higher pressures in the air box with a cowl style scoop than we did with any of our front facing designs. IIRC, we never were able to get anything front facing to generate any pressure at all, and we got about .5psi with the cowl system.

[DmaxMaverick]

Another thing to consider is the overall aerodynamics. Disrupting the airflow over the hood may give you a detectable amount of intake pressure, but the tradeoff may cost in the big picture. These trucks are designed to be aerodynamic for economy (efficiency), so anything you do that effects the airflow can decrease any gains you get on the power end. If you were going 180 MPH, you could probably overcome that issue, but when was the last time your truck was traveling at more than 100 MPH (if you have an answer for that, better keep it to yourself)?

[CleviteKid]

Good Day!

Many moons ago, someone (can't remember who, might have been Banks) used to sell a kit for the 6.2's. It consisted of (I think) a non-restrictive air intake from the radiator support area, a thingy that attached inside the top if the IM to smooth the airflow, & exhaust manifold adapters. IMHO the good Dr. has got it right. "Swanger Air" the intake & toss the unbelievably restrictive factory exhaust-manifold-to-pipe adapters & you might actually be able to measure the improvement. The problem is: where do you get the exhaust adapters? Maybe the good Dr. will give you drawings of his & maybe he won't (or can't).

I trust grape on this one for sure, unless someone has the magic formula(s).

Blessings!

I saw the same advertising years ago (not Banks, someone else), and that was my inspiration for "Swanger Air" and my exhaust adapters. Anyone who wants a drawing for the adapters, just email me at clevitekid at yahoo dot com and the drawing will be coming your way.