True Cold/Ram Air Induction

[MidniteBlues]

Originally Posted by JRinKY

If I read correctly, the 164 and 168 hp charts are both with all of the mods, but with a change in hose length.

Any charts he has with no mods will be of questionable value, due to the different atmospheric conditions that certainly exist for the runs.

It is also pretty unreasonable to ask that the exhaust mods be reversed, just to show the intake only. Now if another car just happens to be sitting around, unmodified .......

It would be nice to see the before-and-after for the intake change, assuming that the conditions for the two runs are the same, or close to it.

I would expect a proportional gain for a car without the exhaust, even though the absolute numbers would be different.

No way are they gonna remove mods done to their demo car to date just to see numbers for his new experimental mod only. I certainly would not remove them. BUT as JRinKY states, if another 2.4L comes in that is still in stock form, now that can be done with a before and after. Of course, we donno if he's gonna remove the existing mod from the demo, or cut up the volunteered cars OEM's air box--Besides, RPI has not really stated that they are developing this for sale, if that happens, I am sure they would let us know in due time to see if it's even feasable--

[Momil]

No, I think you are not understanding me fully on this. I don't expect someone to take off any mods. However, I am sure Eloy has done some dyno runs with only the exhaust when he developed it. Some people are jumping up and down about 20hp gain over a stock car with only the intake when in reality if I read correctly the exhaust has been changed as well. I would fully expect a good aftermarket exhaust to be able to provide 20hp gains with a stock intake. I am curious what the actual value of the modified intake is.

[JRinKY]

Momil : No, I think you are not understanding me fully on this. .....

I was referring to Ag94Whoop's post, not yours.

[Ag94Whoop]

JRinky
I got that you were replying to me....I wasnt asking Eloy to do those, simply stating that is what I would like to see...

I have spoken with Eloy numerous times and I wouldnt ask for that....but he HAS done numerous pulls on base Skys and he has a real feel for what this adds....he (along with others) have consistently stated that the CAI sounds and looks great but doesnt really do anything

this modification actually DOES and I have told him its a great idea....I also think there might be a market for a kit of this type....as I have also told him in private

[RPIpower]

Before the intake, the car dyno'd 157.3whp

Here are the conditions:

65.8F
54% Hum
29.94 Press

The conditions were the same with and with out the intake as they were done within 10 minutes of each other. Base dyno was done after 10 pulls so its on a heat soaked car. I'm sure if I let the car sit to cool down, open the hood, etc. it might show different numbers.

[JRinKY]

RPIpower : Before the intake, the car dyno'd 157.3whp

Thanks, Eloy.

So, 7-11 hp gain. Pretty good for what is a really simple change.

When you changed the tube length, how did you do it ?
If you stretched out the tubes, it may have been a diameter or roughness change rather than a length change that made the difference.

[RPIpower]

Originally Posted by JRinKY

Thanks, Eloy.

So, 7-11 hp gain. Pretty good for what is a really simple change.

When you changed the tube length, how did you do it ?
If you stretched out the tubes, it may have been a diameter or roughness change rather than a length change that made the difference.

Hehe, a bunch of you guys called about the intake today. The tubes/hoses we are using are the same ones NASCAR, F1, etc uses for brake cooling and bringing air inside the cabin. They are usually connected to a naca duct, etc. Anyhow, they are different than lets say a hvac hose where the hose is like an accordian. The sprials will help with air flow. As far as he friction or turbulance change, it could be a combination of the stuff. The length helps with velocity though. A way to think about it is the speed you gain going down a slide. The longer the slide, the more velocity/speed you'll pick up. Same goes with the air coming in. Thats why going with large intake pipes dont do much for the speed of the intake. The faster you can get the air to flow, the more air you can cram into the engine up to its VE potential.

Please note that the 168whp is with the car running at 70mph (wind/air simulation). Obviously at lower speeds, the gain is not as significant. The average from stop and go was 161whp. The cool thing was that everytime we set the fan at 70mph, we made the same peak hp. Hows that for consistency?

[Nemesis]

Originally Posted by RPIpower

Before the intake, the car dyno'd 157.3whp

Here are the conditions:

65.8F
54% Hum
29.94 Press

The conditions were the same with and with out the intake as they were done within 10 minutes of each other. Base dyno was done after 10 pulls so its on a heat soaked car. I'm sure if I let the car sit to cool down, open the hood, etc. it might show different numbers.

RPI, I used to work with a lot of ram-air systems when I had a 73 mach I and went to shows. All the ram-air and cowl induction systems were pretty simple. You may be able to make it a bit more efficient if you built funnels out of stainless that would fill the space to the left and right of the radiator. The funnels actually work by condensing the air and "ramming" into the smaller pipe opening. Currently, at speed, you are working with whatever air will go directly into the pipe, but if you put funnels onto both pipes you willhve condensed air. Take my word for it, go out and stick two ugly giant funnels from your garage onto the intake portion of the pipes and watch the difference. Then, if you like it, you can fashion some nicer funnels that fill the space better. The ones you build don't have to be round as long as long as they are funnel shaped and the center point of the funnel is the tubing. I was really suprised that they didn't do this to improve the brake cooling vents on the RL, but maybe it gave the front end to much lift.
Try it!

[JRinKY]

RPIpower : ....... The length helps with velocity though. A way to think about it is the speed you gain going down a slide. The longer the slide, the more velocity/speed you'll pick up. Same goes with the air coming in. Thats why going with large intake pipes dont do much for the speed of the intake. The faster you can get the air to flow, the more air you can cram into the engine up to its VE potential.

Odd. I've always been told, and experienced, that long and/or small pipes create drag, which removes energy from the airflow, and slows it down. So just making the intake longer and/or smaller won't help airflow by default. And, as you say, making it shorter and/or larger won't either, and doing either could hurt.

The tuning of pipes for length and diameter is hitting the exact combination of dimensions the results in a pressure pulse reaching the open end of the pipe at the same time that the valve opens at the other end, giving the airflow a little extra push. That tuning, unfortunately, is very RPM specific, and what helps at one RPM may actually hurt at another. I have seen multi-stage injector setups that had different lengths of velocity stacks, one set for low RPM, and a much shorter set for high RPM.

[RPIpower]

Originally Posted by Nemesis

RPI, I used to work with a lot of ram-air systems when I had a 73 mach I and went to shows. All the ram-air and cowl induction systems were pretty simple. You may be able to make it a bit more efficient if you built funnels out of stainless that would fill the space to the left and right of the radiator. The funnels actually work by condensing the air and "ramming" into the smaller pipe opening. Currently, at speed, you are working with whatever air will go directly into the pipe, but if you put funnels onto both pipes you willhve condensed air. Take my word for it, go out and stick two ugly giant funnels from your garage onto the intake portion of the pipes and watch the difference. Then, if you like it, you can fashion some nicer funnels that fill the space better. The ones you build don't have to be round as long as long as they are funnel shaped and the center point of the funnel is the tubing. I was really suprised that they didn't do this to improve the brake cooling vents on the RL, but maybe it gave the front end to much lift.
Try it!

100% agree. I may either make something to fit the corner there or just put two velocity stacks.

Originally Posted by JRinKY

Odd. I've always been told, and experienced, that long and/or small pipes create drag, which removes energy from the airflow, and slows it down. So just making the intake longer and/or smaller won't help airflow by default. And, as you say, making it shorter and/or larger won't either, and doing either could hurt.

The tuning of pipes for length and diameter is hitting the exact combination of dimensions the results in a pressure pulse reaching the open end of the pipe at the same time that the valve opens at the other end, giving the airflow a little extra push. That tuning, unfortunately, is very RPM specific, and what helps at one RPM may actually hurt at another. I have seen multi-stage injector setups that had different lengths of velocity stacks, one set for low RPM, and a much shorter set for high RPM.

I'm not sure who told you the small long runners hurts performance. Many race teams increase the runner length for the purpose of increasing air velocity. If you look at some of the oem intake manifolds now, you can see that the intake runners have increased in length and some use smaller dual runners to help speed velocity. Some use the "butterflies" also to do the same thing. Thats why you see a lot of riceboys who swap out for large intake manifolds but they dont always help.

[Ag94Whoop]

Bernoulli's principle
reducing volume or increasing distance increases air velocity

this principle is used in everything from rocket nozzles to aircraft wing lift

[Midnight Sky]

Okay, switch gears. What does it sound like? Does it sound stock?

Also, I glanced at the front end of my RL and it does not look like your radiator pic. Does this setup fit the RL at all or would I need to swap out radiators or did I just not look close enough?

[Valistener]

Originally Posted by JRinKY

Odd. I've always been told, and experienced, that long and/or small pipes create drag, which removes energy from the airflow, and slows it down. So just making the intake longer and/or smaller won't help airflow by default. And, as you say, making it shorter and/or larger won't either, and doing either could hurt.

The tuning of pipes for length and diameter is hitting the exact combination of dimensions the results in a pressure pulse reaching the open end of the pipe at the same time that the valve opens at the other end, giving the airflow a little extra push. That tuning, unfortunately, is very RPM specific, and what helps at one RPM may actually hurt at another. I have seen multi-stage injector setups that had different lengths of velocity stacks, one set for low RPM, and a much shorter set for high RPM.

Ever look at the LSx series engines intake manifolds? They have very long runners.

[RPIpower]

Originally Posted by Midnight Sky

Okay, switch gears. What does it sound like? Does it sound stock?

Also, I glanced at the front end of my RL and it does not look like your radiator pic. Does this setup fit the RL at all or would I need to swap out radiators or did I just not look close enough?

Ah, sorry, its because my car is turbocharged. I disconnected the intercooler and took off the turbo but didnt remove the intercooler for the test. Its a tad bit louder than stock but it wont sound like the cars using an open element filter.

[JRinKY]

Ag94Whoop : Bernoulli's principle
reducing volume or increasing distance increases air velocity

this principle is used in everything from rocket nozzles to aircraft wing lift

Actually, no. We are not talking about generating thrust by expanding a gas through a nozzle, or about developing lift by accelerating a gas across a shaped surface.

We are talking about the ram effect of a tuned pipe. Intake, and exhaust, flow is not steady-state, it is pulsed. The pulses result in pressure waves that travel along the pipes, and reflect from the ends. Properly timed pulses reinforce each other and increase flow, improperly timed they will interfere with each other, and reduce flow.

Valistener : Ever look at the LSx series engines intake manifolds? They have very long runners.

You are referring to the runners that lead to the individual intake valves ? Each of those runners is dealing with airflow from a single cylinder, which is at much lower pulse frequency than a grouped pipe from a collected intake. Lower frequency equals longer pipe length for the ram effect to work.

All of this is off-topic, of course, and quite irrelevent. You have made a nice advance in intake performance, for which you are to be congratulated. I just think that the physics principles you are quoting are a little less than correct.

[RPIpower]

Originally Posted by JRinKY

All of this is off-topic, of course, and quite irrelevent. You have made a nice advance in intake performance, for which you are to be congratulated. I just think that the physics principles you are quoting are a little less than correct.

Yes, off topic...somewhat. The basic principle applies and I brought up those points so people can undersand why slapping on a pipe and filter are not always the best solution.

[Ag94Whoop]

interesting...

I designed accelerated cooling systems using blowers for 15 years to cool optical elements, lasers and fiber optic systems

I have been taught and proven in over 30 products that reducing volume (properly of course with least turbulence) increases velocity.....

however, I have never dealt in a pulsed system...I hadnt thought about that fact and that could change the dynamics of the system, if indeed it does, then I stand corrected

however, Eloys numbers speak for themselves

I can attest to watching "CAI" testing in person with closed hoods and actually seen a drop in HP even when owners swear to a gain

[JRinKY]

Ag94Whoop : interesting...

I designed accelerated cooling systems using blowers for 15 years to cool optical elements, lasers and fiber optic systems

I have been taught and proven in over 30 products that reducing volume (properly of course with least turbulence) increases velocity.....

I am not suggesting that velocity does not increase with reduced flow area (volume). That is, as you stated earlier, the basis of Bernoulli's principle. What I am saying is that a pure velocity gain is really not what we are looking for. We need increased mass flow, and that is where the tuned pipe ram effect comes in to play. If all we do is reduce the flow area we will, indeed, achieve a higher flow velocity, but we will also create greater energy losses because of that higher velocity. We gain some back due to the increased cylinder scavenging that the higher velocity results in, but it is not linear, and it is RPM specific. So the whole thing is a balancing act.

[RPIpower]

Its got to be a balance of both when it comes to engine tuning. We dont want to stick staws in there as intakes. Restriction becomes a problem then. The best way is to try different diameters, lengths, intake area, etc. until you get the powerband that you like. Some people like peak power way up high, where others like a flat powerband.