ram air

[Sleddgracer]

anyone here with experience using a Ram Air set up on gasoline powered motors? - did it make a noticeable difference in performance?

[PNW_Steve]

I have not done it myself but I have read many hot rod build articles that included ram air and dump testing.

It can definitely add a little bit of power. Not a whole lot though.

[Sleddgracer]

Originally Posted by PNW_Steve

I have not done it myself but I have read many hot rod build articles that included ram air and dump testing.

It can definitely add a little bit of power. Not a whole lot though.

thanks - I wonder if the potential benefits and savings on fuel make it worth the cost ?

[PNW_Steve]

If you DIY it can be a pretty inexpensive upgrade.

The dyno results that I have read about show measurable but very modest increases in HP and fuel mileage.

[WARGEAR]

A ram air setup would only be beneficial to you at higher RPMs and higher speeds. You’re not going to feel it really. If anything you could get cleaner, cooler air.

[Ronnie]

In a warm climate I think it works better partly because of the cooler air charge. In a really cold climate it can hurt fuel atomamization, and cause iceing of the carb, or throttle body. Now multi point fuel injection may be fine with it.

On my bus it does better with underhood air. Have tried it both ways. Now I have block filled the heat cross over on the intake manifold, so there is no added heat to the intake charge.

[CHEESE_WAGON]

I think you are thinking of a cold-air intake setup. Basically the same thing. As others have mentioned, you really wouldn't notice much of a difference until about 35-45 mph, even with a hot rod. Not likely it would make much difference on a low-compression bus engine.

Not that it wouldn't help power to a degree, but ultimately I think it would be far more effort to build than could be justified with the gains. Depends on the setup, I suppose. Now, if you're talking about a modern GM-chassis shorty with a 6.0 LS engine, sure, there's quite a bit that could be done with one of those. But a 70s-80s 366 gasser in a C60 chassis? Forget it, you'd get more of a power increase with nitrous, a mod I don't recommend on such a vehicle.

But remember, the more power your engine makes, the more strain it puts on an already-taxed driveline.

[Ronnie]

Ram air is a form of cold air intake, and I have played with both.

I would have to say that if everything else is stock ram air is not likely to gain much. It can be part of a whole system approach. Most buses have rather restrictive intake and exhaust systems. There is a lot to be gained in both areas. Older gas engines do well to have the ignition upgraded as well.

[Booyah45828]

Ram air can work well, if placed right and you're creating a high enough pressure(aka high speed)

Cold air/ambient air is something that is also beneficial. Most stock systems will already have the bus drawing ambient air so there is very little to gain.

Any time I hear people saying they modified their air system I get immediately skeptical because most people don't understand hydrodynamics and they have completely unrealistic result expectations thanks to false advertising.

I cringe when I see someone cutting holes into their factory air filter housing to "allow more air into the filter, more air is more horsepower man". Or they use a k&n open element filter and think they've gained something because of more air flow

And to end it all, here is a video from gale banks showing some interesting data.

https://www.youtube.com/watch?v=E9ixQ3OwzZ4

[brokedown]

This is how we increased air flow when I was young.

I had a WS6 Trans Am which had a ram air setup on it, it was as much a gimmick as the 70s models with cosmetic hood scoops.

[Sleddgracer]

Originally Posted by brokedown

This is how we increased air flow when I was young.

I had a WS6 Trans Am which had a ram air setup on it, it was as much a gimmick as the 70s models with cosmetic hood scoops.

that's what we did too was to turn the air cleaner lid over - lol

[brokedown]

Easy +50 hp right there.

[Ronnie]

I have to agree with what Booyah is saying for modern cutaway buses. However since full size buses with gas engines disappeared by the 80's, cold air intakes from the factory were rare in a bus if they even existed at all. So I think we are really talking about two very different types of bus and engine. The old 366 chevy/GMC or 345 international gas engines were the common ones in the full size bus. These both can benefit from better intakes.

[Sleddgracer]

Originally Posted by Ronnie

I have to agree with what Booyah is saying for modern cutaway buses. However since full size buses with gas engines disappeared by the 80's, cold air intakes from the factory were rare in a bus if they even existed at all. So I think we are really talking about two very different types of bus and engine. The old 366 chevy/GMC or 345 international gas engines were the common ones in the full size bus. These both can benefit from better intakes.

the 450 is coming back and the 8.1 litre gas is available now - also available in propane - it's not uncommon to see them on the Canadian prairies and in the north

[gclarkv]

During the ground roll portion of takeoff in a high performance piston engine airplane the manifold pressure will rise by less the 1" hg. This occurs mostly during the portion of the run where speed is higher than your bus will go. So, ram effect does provide some increase in engine power, but you will likely not be able to discern its effect.

[Mekanic]

Originally Posted by Sleddgracer

anyone here with experience using a Ram Air set up on gasoline powered motors? - did it make a noticeable difference in performance?

Originally Posted by gclarkv

During the ground roll portion of takeoff in a high performance piston engine airplane the manifold pressure will rise by less the 1" hg. This occurs mostly during the portion of the run where speed is higher than your bus will go. So, ram effect does provide some increase in engine power, but you will likely not be able to discern its effect.

/\ /\ /\ /\ This what I found when i worked at crane cams back in the 90s

You could barley tell it was starting to work once you hit 100 MPH.

[magnakansas]

port fuel injection? Carburetor? Two barrel or four barrel? Anyways, I think keeping the air coming in as cool as you can is the biggest help. I saw a thing about datsuns racing on the salt flats, ram air set up... would provide at 150 mph about 1 psi pressure ..... 220 feet per second... only 1 psi.

but 14 degrees temperature change was about 1 percent power.

gale banks says it is all about air density.

william...

I chose a bullet butt bus just because it looked cool, but also trailing side air flow is important to me too.