Swolbynos

just FYI but the "Ram Air" on the 98-02 LS1 F-bodies wasnt really ram air just the hood for more clearance on a stock type cold air intake

GLHS

I have seen a Dodge Neon Drag car, setup with a air box up front and was seeing 3 psi on his n/a in the quarter mile.

Wankel7

Magnehelic gauges that have a usable scale for this type of work are far and in between. You are looking for a gauge that goes 0-50 " of Water (Part number 2050). On ebay they normally under 20 bucks. 56 bucks will get you a brand new one!

I would say the BEST and ONLY gauge you can use to quailify your results and time is a Manometer or a Magnehelic gauge. Like said before a boost sensor or manifold pressure gauge is not a small enough scale.

good luck and good work!

James

88IntegraLS

This is great. This is a thread we have needed for a long time. I can't wait to see what this setup does. I doubt it will produce more than a few mm Hg of vacuum reduction, but who knows . .

I will say one thing. Before I build the form shown in this thread, I had a very crude "cold air box", made from cardboard built around the filter. This box was not sealed but basically a very crude version of what you see being offered for sale by forum members once in a while; two sides and no top.

With this crude box, there was a noticeable change in engine response when the car was going ~60 mph. It could be just from having an airstream of cold, fresh outside air being blown at the filter, or it could just be because my car is magic. But just having that crude box made a noticeable change in the engine's power response "under the curve", meaning transitioning from cruise throttle to WOT.

That is the reason I decided to get crazy and make the box I am making now. I wouldn't be putting effort into something that I didn't think held a chance to make an improvement to the car. But remember, my car could be magic. We haven't ruled that out yet.

sub9lulu

iTrader: (7)

keep it goin

NZConvertible

Magnehelic gauges are just one type of pressure gauge. They are very accurate and sensitive due to their magnetic operation (hence the name). They are available in literally hundreds of variations, with any scale or units you can think of. We mainly use 0-250Pa versions at work to measure the pressure drop across filters.

You can get regular Bourdon tube pressure gauges (like a typical boost gauge) that measure low enough pressures for this, but you'd need to look at specialist industrial suppliers.

Although it's not as convenient to use as a gauge, you can't beat a DIY water manometer for cost and accuracy. I wouldn't go out and buy a gauge to do this unless you could pick one up cheaply.

j200pruf

iTrader: (4)

Hey 88, your box is looking good. Although for this type of a set up, I think that having the airfilter in the front of the car (like in the bumper) and having that sealed tube feeding into a large airbox that would attach to the TB. This way the pressurizing (if any) would be right at the TB. I know that your ideas could work since they have been used on motorcycles for the past few years.
The way that it actually gets pressureized is from the high speed (velocity) air coming through a small diameter pipe, and dumping in to the airbox.
And I will be doing something similar to this when I get my new intake manifold.

Aaron Cake

iTrader: (1)

So he was driving at > 700 MPH?

I remember doing the calculation in the last ram air thread, and that is the velocity required to generate about 1.5 PSI of "boost"...

jimmyv13

I would be interested in seeing the difference between having the filter in the box right at the AFM versus having the filter outside the engine bay and have a wrapped pipe feed the AFM...

J-Rat

iTrader: (2)

Shoot, I am having a good time just learning how to lay fiberglass...

Keep up the work!

Jarrett

NZConvertible

double post...

NZConvertible

That's not necessary. Any pressure generated at the inlet of the system will still be present at the TB (apart from duct losses). Adding an airbox at the TB wouldn't make any difference to this pressure.

More likely his gauge read 2.9psi when stationary.

jinx22630

Ok, now im REALLY into this. I went to the salvage yard and got a new bumper (its cracked), and I'm thinking about eliminating the bottom half in favor of a fiberglass duct spanning the entire width of the bumper. Only a few inches high though, and running tubing to a sealed box which will contain the air meter and filter. Am i wrong thinking that more surface area collecting air will be better? And also, would it be better to place several tubes in the duct and then collect them together before the sealed box? NZconvertable, thanks for the link to the meter. And really, when I say that I have time on my hands, I mean lots of time on my hands, so I i do this, It's all out of boredom baby!!!

BDoty311

Ive seen drag neons with the manifold sticking straight out of the hood because their intake is on the front side of the car, as opposed to facing the back like most other 4-cyl. I dont think hed get too much boost though, but it would help in the competetive world of drag racing.

jinx22630

I found this to be very informative, I think ill build this, and check out the stock intake system before I go dicking around with it, just to have some numbers.

Thanks again for the link.

88IntegraLS

Here is my vacuum gauge. It's just an old VDO ebay cheapie, but I like it's euro style so I bought it.



I'm guessing that WOT will put the needle barely in the red zone. If I see any change due to the pressure box, and it can be repeated through many tests, then I will know that the box and dynamic pressure are doing their jobs. Quantifying this change might be tricky, however.

It's a far cry from what you would call "professional instrumentation". He he, that's what you get from a broke engineering student like me.

jinx22630

oops, double post. Sorry

jinx22630

I also found this to be a very informative read on the development of a successful ram air application.

http://www.vararam.com/reality_of_ram_air01.html

I'm learning stuff now that I never would've known before, so whatever happens with 88IntegraLS's project, it was well worth it for me.
Reading this article, and the other one that Nzconvertable posted, has taught me that ram air applications do always have to produce a positive charge to be successful. But with the elimination of pressure drops in the factory intake system between the air inlet and throttle body, coupled with ram air could produce very desirable results. by reading this article http://www.autospeed.com/A_0637/cms/article.html
It really makes me wonder just how well replacing the stock air box with a cone filter really works.

Rex4Life

A word to the wise!!

If you do the manometer, which can work very well, install an equilizer line to apply the differential pressure only when a valve is closed, otherwise, you could end up with the fluid all over the place. A single surge or large pressure variation is all it would take to blow the liquid out. When you are at cruising speed, slowly close the valve and measure the differential.

good luck,

Scott

88IntegraLS

That link is awesome. I found it thanks to Evil Aviator a few months back and it got me thinking about velocity stragegies for intake systems, their runner cross section areas and the resulting acceleration of lack thereof of the airflow.

My airbox is so small because I want the fresh air charge to smash into the filter on all sides. This is why the top of my box is closer to the cone than the bottom. The bottom will be rounded like the top, however, to encase the cone filter with ~1 inch clearance on top, expanding to ~2 inches on the bottom where the ram air enters. The shape of the box is the way it is to keep its inner volume not much larger than a similar sized section of the pipe leading up to it, in hopes of keeping the velocity of air through the filter higher than would be seen with a larger, square box.

Of course, that is just an idea hatched by my imagination. I don't know if it is virtuous or not. We'll see . . .

Rob XX 7

iTrader: (8)

its always nice when someone tries to do something different, good luck to you, if anything you can stand back later and say "I did that myself"

with that said, try putting some metal foil tape on the cardboard so that you can remove it easier after the FG, some wax on the tape will make it remove even easier,you can even use some 2" masking tape, but sometimes the heat of the FG makes it hard to get the glue off after.

good luck!

Ronac

About that round shape and hoping it will smash into the filter. I think that you need to smash it in the direction of the afm. If you just smash the filter from its sides, don't you think it'll just smash right back out the other side? The only force that makes the air go into the direction of the afm is the vacuum created by the engine. I think this set up will only provide 0 negative pressure.

88IntegraLS

Good observation. If the air is coming into the filter from all angles, what would keep it from just going out the other side?

It's called fluid resistance. When the air passes through the filter element at a certain velocity, it must use up energy as it wicks through the fibers of the filter. This energy use comes in the form of slight heating up of the air and more dramatically, velocity reduction.

In other words, the air that hits the filter from the outside will be moving faster than the air that just entered it due to friction. One objective of some of the Varam systems is to overcome filter resistance by smashing relatively high velocity airflow into the element.

When used on LS-1 powered Corvettes, Varam's systems gained a measureable amount of power because of intake vacuum reduction . . in the order of 5-10%. That's just like adding a header. On a ported engine, intake and exhaust mods are even more dramatic for power increase. A ported rotary with full intake and exhaust is said to gain 60% power over stock NA levels. Who knows what intake vacuum reduction could do for a ported rotary. I'd like 230+ FWHP, how about you?

Wankel7

88IntegraLS, I might just be my tired eyes but it seems like you are ignoring all of the talk about the manometers and magnehelic gauges. This is what you need to show results.

Your vacuum gauge is not going to do what you want.

You do realize a vacuum is only found after your throttle plates? If you have a vacuum before your throttle plates this is a restriction. That is great that you put a gauge after your TB. But what if as the air travels to your tb it is restricted? How are you going to show your deal works? You need some that can measure where it is happening. Not two feet down the intake track.

At WOT you should be getting slightly less than the current atmospheric pressure.

Let me give you the skinny on making a DIY manometer.
1. You get a two litter coke bottle (Could be bigger and doesnt have to be coke).

2. Fill with water (Maybe use food coloring in water)

3. Get a clear hose that has a small inside diameter. Hose lenght needs to be maybe 5 feet long

4. Now slide the hose into the coke bottle. Just so that the bottom of the hose touchs the bottom

5. Now find a two foot long dowel rod (approx lenght) and tape this to the bottle so it is pointing up.

6. Then tape your hose to the dowel rod.

7. This is optional. But find where the water sits. And make marks with a marker than can erase. So you can make your unit of measurment.

8. A passenger will have this thing in the seat with them.

Done. A gauge better than your VDO. Cheaper than a real gauge. But the same accuracy.

Now, you put that other end of the hose in your intake where you want to test. If the fluid level gets drawn up the rod you have a restriction. If it drops you have created a postive pressure.

This costs under $5. This way you can sell your vacuum gauge vdo on ebay and get your money back.

If you want the real deal please read the autospeed artical. Otherwise that vacuum gauge will most likely wasting your time.

I am saying this because if you go to all of this work man and say whoa this works! I can feel it! You need to qualify your feeling with numbers. Something some of us wants to see to prove this works. If you read the autospeed artical you can see how his work.....worked....with numbers to prove it.
Granted you do not have the gauge....but your coke bottle will do just fine.


James

Wankel7

It seems like you would only need to do that if your hose was installed after the TB. If it was before the TB it would not mater?

I guess my question is where was your hose at when you had this fluid spray

JAmes