Rotory

iTrader: (1)

cant we just all get along...im sure his ram air will do as much or more than alot of the other things people are doing or trying to do...and the box looks absolutely killer already and its just cardboard. Why do you need such a huge frontal area?? The trans ams running around dont have huge frontal area and the openings arent much bigger than our ftp holes...i think it will work. but im a noob.

5 point whoa

I love your stuff, I'm making a cold air box eventually, and keep doing the good work

88IntegraLS

Some pics of the fiberglass lay-up process:









I like to lay up the fiberglass on the cardboard and then scrape it away once the resin cures.

RarestRX

Yo,


Cool beans man, way to "DIY" it!

I look forward to your findings!

Kevin
1989 GTUs "Anything that makes more NA power..."

amused

I hardly think "I question the engineer part when I see a AFM held in place with a string and rag" was said as anything other then to criticize.

I'd be pretty pissed off too if I was trying to find out something that could possibly be a new way to gain hp, and some *** clown took a shot at me.

Oh, btw, what if you were running an EMS and removed the AFM? how much of an improvement would that be for this kind of system?

Icemark

Sorry you couldn't take a little good fun ribbing about the string and rag... Oh well... Good thing I didn't comment on the AFM being upside down like I was going too... Maybe it’s people too uptight to take a little good fun ribbing, that making the board frustrating for you. However if you feel insulted, that is your problem, not mine. And just for your satisfaction, I almost never spell check here, and nor do I generally care too. #1 It’s just a forum. #2 And I certainly don’t get paid for anything I do here.

And as to "explorers of new knowledge": Multiple Ram air paths have been tried for 20+ years on the FB and FC, by companies such as Racing Beat, Rotary Racing and Reliability, & even Millen with his FC rally car.

So, maybe some of the "self appointed experts" as you call them (and seem to be offended by their comments) are just trying to save you from wasting your time; so that you can put it to use in a direction that has not been tried. Your bumper project for example was quite attractive. If you could build it out of urethane and make moulds I am sure you could sell them for a pretty penny.

Either way, I said: And stand by every word of that.

Of course I hope that you do get some gains, and prove everyone wrong.

I hope that you do have a dyno sheet of the car or time sheet in the stock configuration to compare too and provide a reference for your studies on this subject.

Bio-Weapon

Let's just lighten it up a bit... I love reading about 88IntegraLS's projects... the write-ups are top notch, and it's nice to see someone putting out quality work themselves, rather than paying someone to do it. Theres no sense in critisizing, even if it doesnt work, he has a nice new cold air box. I'm just getting into fibreglassing myself, its quite fun. No need to fight over this subject, since he's offering to put the rumors to rest once and for all, and put out actual data. Good luck, i hope this works out ok

Black13B

iTrader: (1)

88IntegraLS

I believe I am misunderstanding you. How are you going to trace results? How is the gauge going to work?

Wouldn't it be better to test something like this with an aftermarket ECU of sorts so you can get the actual readouts from the MAP and IAT sensors? If there is any type of ramming effect, won't it peg the AFM? Just the simple fact that the AFM is there is drastically reducing any potential that I could forsee.

However I may be just misunderstanding how you propose to view your results..

Best of luck to you in the project, I am very interested to see what you come up with, I have been impressed many times before by your work.

ForsakenRX7

Well, I would assume if this ram air system makes any kind of gains, these gains could be seen on a dyno. However the problem testing a "ram air" system on a dyno is air! Hurricane fans would have to be used in front of the car to simulate air while driving. But most, well good dyno shops anyways, have em anyhow. just my 2 pennies.

NZConvertible

I think you're taking yourself a bit too seriously. You are not exploring new knowledge. Contrary what you said earlier, the effects of ram air are fairly well known. There are small but noticeable gains, but you have to be doing a fair speed to see them. Lots of racecars have their intakes arranged to take advantage of this, F1 being the most obvious example. I believe most of the gains you'll see with your intake will come from the consistently lower intake temps, but that's not to say there won't be gains from ram-air at high speed.

And in answer to your earlier comment, I am developing my own intake system that will ensure the filter only gets cold air and will have some degree of pressurisation from the brake duct (but probably not a lot). It won't be groundbreaking, but it will be very effective. I'm just looking for a replacement washer bottle suitable for relocation.
If you don't want your efforts to be "judged" then you shouldn't post them. You seem to have no trouble when people wax lyrical about how amazing your projects are but get testy when others point out areas of potential improvement in them. It would be very foolish for anyone to think that anything they post is beyond criticism or comment. Old-fashioned engineers listen to what other people have to say without dismissing them sarcastically.

You seem to have started fabrication so I guess my suggestion of a bigger box was dismissed. I'm still curious to know why you rubbished my suggestion. From my knowledge of fluid dynamics, clearance around the filter seems like a pretty logical idea, but perhaps you had some practical reason for the box's size?

I think your intake is going to work very well, but not necessarily because of any ram-air effects. You might find this link describing a similar system interesting reading. This forward-facing ram-air intake generated a pressure of 9inH2O (0.32psi) at 140km/h (87mph). Not exactly huge, and it required quite a high speed, but it produced measurable benefits. The vacuum gauge you plan to use to measure the effects of you intake will need to be able to measure very low pressures (a manifold vac gauge won't work), and a water manometer is probably your best bet. Measure the vacuum just before the TB to see the overall effect.

A dyno would be the worst place to test a ram-air intake system. The cooling fan used on a dyno would not come close to replicating the complex airflows happening at the nose of the car. Before-and-after on-road testing would be the only way to prove the performance benefits.

Mr. Gadget

This thread is getting way to personal, can't we just keep it on track and let the workmanship and results speak for themself.

DragonRx7

I would have to agree with this and let's all just appreciate that someone is taking the time to show how this could be done and keeping us well informed. No, this isn't something new but it is one of the few times where it was shown in detail on how to do it.

Erk

Group hug.

Black13B

iTrader: (1)

And let that be all that's said about it before this thread gets gruesome.

Waiting for 88IntegraLS, let's get back on track..

88IntegraLS

Effectiveness of the intake will be observed with an intake temp gauge and manifold vacuum gauge.

Despite the restriction of the airflow meter's flap, relatively small size of my inlet, and relatively low velocity area of the FC nose where it is placed, this intake is not made to utilize velocity ram charging. It is far more simple than that. The point of this system is to tap into the only blunt face on the FC, where aerodynamic ram pressure (not velocity) will be greatest. Mazda put the stock radiator inlet down there for a reason, because it has the greatest pressure difference possible between an outside area of the body and the inside of the engine bay. My system builds on that principle, but instead of the pressure difference being based on ram pressure vs. engine bay pressure, it is ram pressure vs. manifold pressure.

Tests will be performed by first estabilishing a baseline average manifold pressure and temperature reading at wide open throttle with the intake box removed and bumper duct blocked. The cone filter will be bare in the engine bay and the afm will hang from its infamous string. Once the baseline pressure and temperature readings are recorded, the box will be installed and wide open throttle pressure and temperature readings will be observed from a standing start, ~60 mph, and ~90+ mph.

The molar mass of oxygen which actually enters the engine is a function of the engine's displacement, manifold pressure and manifold temperature. This amount of O2 is the limiting agent to NA engine performance; the more the better. It is very easy to increase fuel flow to the limit of the air flow meter, stock injectors, and ECU but that fuel is worthless without more O2.

Once numbers are recorded, air volume calculations will be made based on the baseline vs. ram box temperatures and pressures. These calculations will be based on the ideal gas law (PV=nRT) to find the amount of air reaching the combustion chambers, and a percent increase or decrease will be calculated.

At most, I expect a 20% increase in air volume and at worst, a reduction. Only time will tell. I'm an engineer and a designer, not a salesman. This thread is meant only to be educational, which is why it pisses me off when it is turned into a debate. Oh well. That's the RX7club and I hear what you guys are saying . . . if I don't like it . .

88IntegraLS

Here is the lid after being soaked with resin:



Sides trimmed, cardboard removed, and the lower box after a few layers of glass were laid up:



Oh Icemark, next time rib someone with a smiley, okay?

Rex4Life

Lately there was a good thread about this and I think evil aviator had some real good links explaining the aero of how all this works.

Before I say any more, let me say I applaud your efforts, hope it works, and hope you and others learn in the process--right or wrong.

In a nutshell, you won't get more ram air pressure in the intake than that of the dynamic pressure. The dynamic pressure is related to the local static pressure, local air density and the velocity of the vehicle. Any aero eng. / aviator knows this one. Look it up on the net, I could repeat it here but why bother. Net result is about 0.3 psi increase due to dynamic pressure. Better have a real good calibrated gauge to measure that difference.

Inlet sizing is very difficult and ususally engineers take a best guess and then test in a wind tunnel or actual vehicle--experience is always very good to have. Low speed aero is not an exact science, you could CFD this thing to death and still be way off. Make the inlet too big and you cause spillage and more drag, too little and you don't get enough for the job. You need to look at how much air the engine is ingesting, this is the amount the inlet should pass at some design operating condition. Basically this amount of air ingested forms a stream tube ahead of the vehicle. Your job is to get that amount of air into the inlet without spilling it out. If the engine can't pass all the air, then the inlet will spill and cause drag.

To prove anything, I would measure the the differential pressure from within the intake system to local atmospheric--while travelling a several velocities over 60 mph. That way everything references from ambient pressure. Do it on the same day to avoid density changes due to temperature. Then repeat several days to show the measurements are repeatable.

The links on the other thread had some real good discussion about sizing the inlet too.

Good luck,

Scott

BrandonDrecksage

wow...great job...i'm amazed....i like how u say o2 instead of just oxygen....shows u know a lil about chemistry too because oxygen doesn't exist on its own in the earth.....if ur project turnsout good results...i bet u can patten the air box...then sell the pattents to a company

NZConvertible

Like I said, you'll need a gauge with a much smaller scale than a normal manifold vacuum gauge. The example I posted should prove this to you if you don't believe me. The pressures you'll be reading will probably be below 1psi, certainly not much more.

I'm not telling you this to prove you wrong or anything silly like that. I'm simply offering you advice that'll make your life a little easier. I'm as interested in the results as you are, so I'd rather you had this info now. If you don't like it...

jinx22630

Ok, now I'm interested in this as well. I know it's all been tried before, but, I have some time on my hands, and I'm taking a break from another project. I do have a question that either 88IntegraLS or NZconvertable can answer. say you build a sealed box which had a tube running to a naca duct. You then placed this assembly on top of a vehicle witht he duct facing forward. what sort of sensor would you need to measure the pressure inside the sealed box? I know its a very elementary question, but can someone give me their input?

Rex4Life

Yes the differential pressure is less than 1 psi--really the pressures are close to amospheric (14.7 psia). Your cheapest way to do this is use a liquid manometer sized for the job--though it will be difficult to set up in a moving vehicle. Otherwise your're looking at shelling out $500-1000 for a decent pressure transducer. And you'll need 0.2% accuracy for it to be any good--that's one order better than what you are measuring.

88IntegraLS hope you're getting this. Oh yea, good looking fab work on that glass. Looks like those glass skills come in handy.

Scott

88IntegraLS

A boost sensor would be best for that, but probably wouldn't read anything measurable on its turbo-magnitude scale.

A more direct measure is the change in engine manifold pressure by tapping into the vacuum line leading to the boost sensor. The changes would probably be very small in either test.

NZConvertible

Water manometer or a pressure gauge that can read very low pressures. Click here for info on building a very cheap manometer.

The Unforgiven 7

I beleive these are called Mangahelic guages right? They measure in inches of water if I recal properly. They aren't very expensive at all. I have seem them sell for around 50-60 dollars on ebay.com

unforgiven

Bio-Weapon

i was just curious... wouldnt it be really difficult to pressurize the area around the cone filter? Wouldnt it be alot easier to run a pipe from the AFM, skip the cold air box, and go down into the brake duct, then make some sort of collecting cone device that directs air right into a cone filter? I was just thinking that might be alot easier, since it seems that the airbox might be difficult to pressurize?