yeah those are pretty expensive, but would also are made for a turbo unlike the air ram. i was looking at some DSM turbo IMs and they arent super bad in pricing, but are really nice..

thats the thing, what would put this ALL to rest would be before/after dynos, flow tests, professionally modded stocker tested, etc. but theres no one to front the research, time, money to do it. and of course Rside didn't give design specs on the AIR RAM.

i know weapon R is usually crap, but they make an IM for the eclipses 540$ shipped. its a turbo intake manifold. straight runners.
only weighs 6 lbs as opposed to the heavy air ram.

 

I still think it's one of the best mods for the price. BUT, I may be picking up one of the SC when they are done, so I can make my money back off of the AIRRAM to help fund the SC smile.gif

 

actually socks.. you got something backwards.. long runners are best for low and mid range power. The longer runners allows the air to build up velocity as it enters the head, promoting swirl and a nice even burn.

Short runners are what you want for top end. This is why the BMW M3, the Nissan Skyline GTR, and all F1 cars use ITBs on short intakes.. With the speed of the engine, the air is being sucked in as fast as it can and longer runners will actually slow it down.

 

really, i was always told that the longer runners would help the high end power. i also thought that was the reason that the shorter straight runners would be better for F/I. hmmm

 

As for lowest pricing ive seen, there was on on hp i think that i pointed out on here. I believe it was 350 or 400. Yamaha bought it, then sold it to daniel for 500 i think (maybe 550) and then daniel sold it for like over 800. I should have just bought the damn thing in the first place and doubled my money. I will never own an Airram. I will build or modify my own before I buy one. Or just get a supercharger and be done with it.

 

longer runners don't mean much when it comes to turbo applications. The only thing the turbo cares about is VOLUME, pure and simple. the length and design of the runners matters more when it comes to N/A tuning. allow me to copy something for you guys, me and my buddy worked together to type this up

"Intake Manifold Tuning/Design

I'm not sure if a supercharger will use the same rules as a turbo, but I would assume it would. Not like with camshafts, where turbo and supercharger cams are different, I just don’t see the manifold design changing too much.
To alter performance on a motor you are going to change two things, the runner length and runner area. If you properly tune your intake manifold you can achieve greater than 100% volumetric efficiency.

In a naturally aspirated engine, the piston drops creating an area of low pressure in the combustion chamber that is less than atmospheric pressure. When the intake valve opens, the air from the outside is sucked down into IM runner. Now, when the valve closes, where does all of that air being sucked toward the valve go? It does not just stop and wait. Rather, it backfires. It strikes the closed valve and travel back toward the plenum (this is called a rarefaction wave, by the way). This is no simple wave, it determines a lot.

Like every wave, this wave has amplitude, frequency and negative pressure. It turns your plenum into a resonance chamber. It bounces around and builds energy (called spring effect, as the pulsation looks like a spring being pushed in). So it now has positive pressure. But wait, isn't that a "turbo term". Nope!

Now, the intake valve opens and air is sucked down into the combustion chamber. But it's being assisted by those wave lengths, it's traveling with much more energy behind it. This is what is known as resonance tuning. The trick to resonance (or sound) tuning of the IM is to have these maximally amplified waves arrive at the intake valve just as it opens . What you want is to have it so that when the intake valve opens the CFM into the cylinder higher at a given engine speed or rpm.

Now, to select the proper sized plenum for you naturally aspirated motor. General rule of thumb is that if you make peak torque at 5000 RPM on an efficient motor, you will want your plenum volume to be about 50% of the motor's actual displacement for a four cylinder. If peak torque is at 4000, then do 40%, and if it's at 6000 do 60% etc. I don't know what it is for larger motor, so don't ask me! Honestly, I'm pretty rusty on that formula, and I'm too lazy to look it up right now. I'll look it up later and come and change it if I'm wrong. You can find some cool information from this by looking at your dyno, your peak volumetric efficiency will be where you make your peak torque.

So what does all of this get you? Torque. It will not help your horsepower as much as most people, honestly. Having the larger volume is what that's all about. All of this wavelength pulsating crap is to give you gobs more torque, and if you're anything serious you know that torque is what it's all about.


There are other little quirks; such as placing a bend in your runners will cause your power band to shift to the left, while a straight runner will keep the power band orientated with the right side of your dyno.

--Figuring out the math with all that pulse stuff--

There are two methods, one is the Vizard method, and the other is called the Helmholtz method. Helmholtz was used on the new Mazda Rotary, which is worked marvelously, but I'm going to tell you the Vizard method. Because I dont know the Helmholtz method, you can learn it here though: Helmhotlz

Here's the hard way, I'll show you the easy way at the bottom!

This is David Vizard's method; I've got this part saved because I can't remember it. I like the easy way, because, well, it's easy and I'm a boost addict

Runner Length:

"The general rule is that you should begin with a runner length of 17.8 cm for a 10,000 rpm peak torque location, from the intake opening to the plenum chamber. You add 4.3 cm to the runner length for every 1000 rpm that you want the peak torque to occur before the 10,000 rpm."

Runner diameter:

SQRT [ (target rpm for peak torque x Displacement x VE)/ 3330 ]

And the easy way...

Easy way: http://www.rbracing-rsr.com/runnertorquecalc.html

Turbo
When it comes to turbo, you simply want pure volume with clean flowing surfaces. Intake manifold tuning doesn't make as large of a difference as it would for a naturally aspirated motor, although a general "close to wavelength timing" is nice. So you take the plenum with the largest volume.

Now, select your runner length. Keep in mind, runner length will alter your RPM and power band. The longer the runner, the more bottom end torque you will have, and the longer the runner, the more up top horsepower you will have. But, you're turbo, the power band is mainly based off of your turbo selection.

Naturally Aspirated

When it comes to being naturally aspirated, you're going to have far more complications building a proper intake manifold. My suggestion is to go turbo anyways, but I'm a boost addict. You've got to figure out three things.
1. plenum volume
2. runner length
3. runner area

This is where intake manifold tuning comes into play. Turbo guys don't care about this nearly as much, since our air is already being shoved down the ports with the incredible force of physics. If you're looking to build a manifold and design it yourself, be well versed with tuning and design. Slapping on a larger manifold with non calculated runners could very well cause you to lose torque and power band."

 

can you please LINK that whole long page of stuff.. theres no need to clutter the thread with the theory of intake manifolds and such. we are debating the differences in the manifolds, not explaining the theory of how an IM is designed..

please delete all that info, and put a link to the site from where you got it from.

 

whenever I set about trying to improve something i always take in the factor of price vs. performance gain and availability.

I have found some really great mods that I have done on both my cars and my compound bows that are cheap and very reliable. then again I have found some mods i wish I had like the airram . but from what i have researched in terms of fitment and higher rpm torque that my car normally doesnt see so why spend more on a "used item" that what the original price was.

I have read that you see a great amount of power increase in the 4500 to 5000 rpm band, something like 35% to 40% compared to stock. I normally shift around 4000 rpm so i feel its not needed.

another thing I have read was fitment issues with the airram hitting the underside of a stock hood. if this IM was built specifically for this car why would I hear about this fitment issue.

now i am sure someone will "don't knock until you try it" and i'm not truthfully but i feel like i should support people like Tim and his IM that he offers rather than someone like R-side that either went out of business or quit selling it due to lack of sales.

another thing about a airram i dont like is the fact that you can't use a strut bar unless a person with a airram builds one for you. R-side truthfully screwed up on this when designed this making it higher or bigger than the stock im when they could've just subtracted a little heigth in the runners to compensate for the plenum.

whenever someone goes for higher horsepower numbers the better the rigidity of your chassis and the better your brakes are the more you will be in control of your car. having no front strut bar while trying to increase Hp is just plain silly in my book. call me gay on this point, i dont care. (i know a airram won't increase a major amount of hp,its just the idea with me is all.)

since it is a rare item I would pay the original MSRP but nothing else just so someone can have some extra dime in their pocket and most likely laughing internally thinking about how much they hosed me for a "used item" , simple as that.

 

Well I paid $600 for my Airram a month ago, bought it from a guy on here. Now let me explain why... Call me silly but i bought it because of a few reasons. 1 it is a nice upgrade from stock. 2 it isn't stock equipment, i like knowing that i am in the select few that own one for our cars..You can p/p a stocker but when it comes down to it, it is still just that a stocker.. But that is just my silly opinion..3 Also i love the way it looks under the hood, it just makes the engine powerful...LOL

Thats my 2 cents worth on the debate...

 

FLOW BENCH!

I know somebody's got access to one. Go test a stock intake manifold. If you search you'll see a thread by me and veiltib01 where we tested cfm flow of ported stock intake manifold and airram (but no stocker, so we had no base to compare to). Airram wasn't considerably higher (nothing amazing), but higher. I can't remember the numbers.

Or if you have access to a stock intake manifold, ported intake manofold, "tims manofold"?? .., an airram, and a flow bench... GO TEST THEM ALL. First one to make a new thread with the results gets free RDT business cards via me. (sorry, that's all I have to offer).