Well new to me anyhow. I was thinking as I was reading the other thread on this board about the ram air ducting for the camaro style Y box that the guy is selling and others have made. I have never yet seen anybody post evidence that these actually improved their times by anything worthwhile. Did I miss it or does the problem lie herein? By using these are we not lengthening the intake tract another foot or so? Is this not going to tilt the powerband even further into the lower rpm band? Do most of us TPI folk not already have way too much tire blowing away torque and way too little high RPM power? Somebody give me a good technical explanation as to why my thinking here would be flawed if it is?

 

From what I understand it is just a intake that will shove more air down your TPI's throat at speed. I don't think it will affect operation at idle to low speeds much. But the faster you go the more air will be fed into the intake.

Don't ask me on power gains or for proof. This comes from my limited understanding of air flow.

 

Fruity,
Even a well designed Ram air system wont begin to pressurize the intake until speeds are into the triple digits. I just find it hard to believe its useful to us. I do know however that intake tract length has a substantial effect on RPM range. And we already have one longass intake tract. It may not hurt anything, It may actually stifle the high rpms a bit. Just wonderin.........

 

Don't forget that it is drawing in cold air from the outside. And no it doesn't take triple digits for the ram effect to kick in. I saw a very good improvement after adding mine several years back.

 

I agree with DannyT. Just getting the fresh air, not hot air from the engine compartment, makes it worthwhile. And some non 3rd Gen info. On my 82 chevy shortwide 454, i made a ram air setup. Before the ram air, going down road at 75 was half throttle on carb. After i installed it, didnt have to push 3/8" on throttle. No tech info, but a noticeable difference in power at highway speeds.

 

I'm sort of with you on this in some ways.
The two big pipes feeding the camaro Y-duct works okay... starting at around 60mph if it's sealed
and around 90mph if unsealed.
They seem to work a lot better the colder it gets outside..probably due to the air being much heavier when cold.

I don't like the T-style dual pipes made for the pontiacs though. I think if one pipe was lower pressure than the other, then it would flow less and equal out the pressure between the two... that is assuming any pressure at all. All the extra air ducting added over factory just gives more surface area to transfer heat to the air.

 

I agree if you were drawing in fresh outside air instead of hot underhood air it could be a benefit. But....the stock system is not drawing in hot underhood air. The inlets are already in front of the radiator. So the only issue would be if there was insufficient air available without the ducting or the benefits of pressurizing the system with forced air.
Obviously if an entire duct can fit in that space then enough air can easily be drawn thru there by the motor.
Danny T, I dont know where you got your info that it doesnt take triple digits for it to work, it is a proven fact it does. The pressure gain at 80 MPH is approx 1/10 of one PSI. You have to go to 110 MPH to get it to 2/10 of one PSI. Even at 175 MPH the pressure from ram air induction is only about 6 /10 of one PSI and thats about all you can ever expect out of a system. That is good for about an 2 extra MPH at that speed. And that is with a well designed ram air system with the right shape on the inlet, the optimal pickup point and a nice big airbox to pressurize. I am not trying to be argumentative with you, I have just been into sportbikes long enough to be very familiar with ram air systems, how they work, and what the true benefits of them are.
Do I think they are cool? Yea sure do. No issue there, I just cant see how they are going to be beneficial in creating more HP at the speeds we are running.
Hotrod, I can see how that would work on your old P.U. Because now you are breathing cooler outside air instead of the hot underhood air.
Roy

 

1/10 PSI in the intake is significant considering you're probably going from at least 1.5"hg vacuum in the intake!

That would be a 6% power gain at that speed
6% of 250hp = 15hp

so even on a basically stock car, it's a good gain.

Good ram air systems are known for 5%-6% power gains & that's good in my book.
Don't forget that you usually have some vacuum in your intake, so that's even less than atmospheric pressure... any boost at all is a huge improvement.

 

I really didnt start this thread to debate whether or not ram air worked or its effectiveness at speed. I was hoping someone with the technical expertise could offer an explanation of why adding the ram air ducts and lenghtening the intake would or would not reduce the RPM range at which the engine operated prior to reaching any speed significant enough to create a ram air effect. Either that or offer a time sheet up where they did nothing other than change to the ram air and saw either an increase, a decrease or no change. Anyone?

 

Yes that would shut everyone up - some legit timeslips.

 

I have an 89 Iroc L98/auto. At the time of these tests I had the stock 5.7. Consider this my $.02 in the matter:

http://geocities.com/deetree.geo/stock.html

http://geocities.com/deetree.geo/ramair.html

Granted these were on different days and my 60fts improved but you can still get an idea.

Oh, and how is it a proven fact that 1/10 PSI is the magic number?
It all depends on the size and location of the scoop in addition to the dimensions of the intake tract. The intake for a SBC is much bigger than one for a motorcycle.

 

Hmmmmmm...You have given me an idea. I am quite a biut booze up though so bare with me,,,...
wht you are saying makers sense. Longer intake, lower RPM powernband. But, it matters what the diameter of the intake is as well. IE....technically, you could drawn a line 10 ft in front of the car, dependant on air currents, and call that the 'intake'. It doesnt matter how long the intake is if its 15 ft wide heh.....you start measuring it when it starts becoming realistically contsrtictive. It is a insternesting question though....At low end, when ram air isnt givtging a whole lot of boost, does the colder air make up for (what is is possibly) a much longer more restrictive intake path? Anyway......

I am a firebird owner, for us (or me att least) its not as easy to get a ram setup (WITH STOCK HOOD, going undernbeath for air) as say camaros i have allways thought. Cuz they have those bigass grills and stuff. Well you can go through foglites, but, i like to keep my fogs. And those are sorta small too.

I think most people agree with the air dam thing, its the center piece that does maybe 90% of the work. The sides dont matter too much (mine arent even on, just the center, took the sides off so car is easier to jack up) Maybe im stupid but im thinking of fabbing up a curved side air damn piece to push air up to the area where the stock air box is, you could make that pice HELLA freaking big, push alot of air up there, get more pressure and airflow (maybe even help cool engine a small bit, at the sacrifice of almost non-existencent under-car aerodynamics) then put the ram air inlet where the stock one is. Just an idea. Mind you...my head is foggy, and i cant explain the 3d picture in my head very well with type I'll try it out maybe though...And i thnink maybe i have access to a place where i could throw the intake tubing in and run it through a minini air tunnel, and maybe see exactly how much pressure you getting at what speed

 

hmm sorry posted twice

 

The "runner length" that effects the egine power band refers to the distance from the valve to the plenum. Miniram/Lt1 = 3", TPI=17". The length of the intake duct has no effect on powerband unless it is restrictive.