Not sure if I missed it, but is there anywhere where the 'official' results from the dyno day are posted? Would be great to see some before/after dyno's from all the cars in attendance (997's, 996's, Caymans, etc.)...

 

^^+1^^

 

I was wondering when someone was going to ask that question.

 

There must be a problem with their Photoshop software. Can't figure out how to massage the chart to show 20+ peak horsepower gain. People who rely on dyno's to translate into performance are all horseposers anyway.

 

1999Porsche911, that is so funny.. LOL. I agree, they should take these cars to the track and see how it performs with and without. Also, did they dyno'd one with tiptronic?

 

I was there and didn't see any tiptronic. All 6speeds

 

^hi Mark^

 

Now that I look at the graphs on their YouTube vid, it's clear that the area under the curve has increased by a noticeable margin.

You do state facts in your post, but in a manner that seems to question the results rather than aggrandizing them and their good work that this part in fact makes your 911 faster because it delivers more power to the wheels.

So why cast aspersion on their efforts/results? Heck, you are the same guy who recommended 15w oil in an 0w-40 Porsche backed world on the M96s.

 

Now you've gone and done it Choi! Plenum and oil viscosity in the same post. You have made 1/911's day Gerry

 

The change in the plenum DOES change power in the mid range and it should because it is changing the velocity of the air entering the engine. However, their claim of more than a 20 hp at the peak is funny and untrue. However, if you are one that believe dyno always releft reality, then I guess there is no convincing you otherwise.

The fact is, that simply running back to back dyno's on an engine and resetting the ECU before the second run, will often result in a similar change in the dyno chart. This fact is proven by a poster here who only got a 4 hp peak gain after the install but increased the gain to 9 hp after an ECU reset.

At no time have I suggested that the plenun does not provide a performance improvement, but only have corrected their false claim of increased peak power.

You'll notice that they have backed off their peak power claims after I started questioning it.

 

Actually, there is a direct link between your oil and your plenum. Those who run Mobil Water will have more oil in their plenum than those who run a better oil.

 

LOLOLOLOLLOLOL

 

Your maple syrup is better on pancakes

 

Wow! I really try to stay away from all the technical engineering debates since just about all of us here are enthusiasts not engineers. The absolute fact of the matter is that the IPD plenum provides power and torque throughout the entire rev range, Period. This has been proven on the dyno time and time again. It delivers more power than a full exhaust or any software (for naturally aspirated applications). The IPD plenum is a more efficient design that allows for greater air flow over the factory air diffuser. I don’t know what else we can do other than announcing a new RSS program where we come to your home or work with a portable dyno and perform the install while you wait (kind of like a windshield replacement company).

Most of the people here just want solid reliable power they can feel and enjoy, which is exactly what we offer. Customers feel the additional power because there is additional power. Almost 1000 IPD plenums have been sold with a full 100% money back guarantee and only 4 have been returned to date, not a bad track record. We wouldn’t sell the product if it didn’t deliver the performance that it does. We stand behind all of our products and we’ve gone above and beyond to prove that as well.

But for all you internet engineers, I’ve consulted with our in house engineer who has worked for some very reputable Tuner and Motorsport teams. If you crave the “tech talk” then pull up a chair for this short novel that I’ve attached for your reading enjoyment.

1999Porsche911 said, “Peak power cannot be changed using only an intake (in any engine) unless the change increases the volume of oxygen to the cylinders”

I really wish this statement was true. This would void any use for CFD analysis on intake systems. What you are neglecting to take into consideration is resonance and subsequent affect on volumetric efficiency caused by the intake geometry. One way to calculate an intake (or exhaust) system is by using a differential equation. I’m guessing with the bold statements regarding engine design you’re quite familiar with the solution to an inhomogeneous second order ODEs and how it relates to intake geometry. But here is a refresher, if you view the system as a spring-mass-damper (which, I repeat, is ONE way to solve intake geometry), your “m” (second derivative term) is the “force” of the air which relates to its mass and velocity, which is what the plenum serves to alter. Your first derivative “c” term is a function of the damping effect, which is set by the density and viscosity of the air. Then the “k” term is the spring effect, which relates to the runner length and diameter. Lastly this is obviously an inhomogeneous equation because the forcing function (aka piston) is going to put varying demands on the air traveling through the system because an engine operating in steady state isn’t too useful for racing.

Another theory I’ve found on intake geometry is by using Helmholtz Resonance. This relies on the pressure exerted on the air volume in the plenum by the back of the intake valve. The effect of this can be seen and tuned (especially with the use of a resonance flap, as seen in many Porsche engines) with the plenum geometry. Porsche seems to be very fond of this method. Again, I’ve personally spent hours on an engine dyno tuning the resonance flap trying to move the power band and gain PEAK power. So you’re using pressure to increase volumetric efficiency and gain peak power, not volume like you suggest. But they are related, which brings me to the next theory.

It sounds like you’re a firm believer in the flow theory of intake design. So lets look again at our non-turbulent pipe flow text books. The claim on the IPD intake plenum is to reduce the headloss at the diverter section of the intake plenum (as seen in the patent filed years ago). V^2/2 + gh + P/rho = constant. So pressure relates to velocity, thanks to our friend Daniel (Bernoulli). And since velocity relates to flow rate, for the same amount of time and cross sectional area, for a higher velocity, you got more volume. So I guess by your own definition of engine performance the plenum does work. Thanks for backing us up.

I don’t quite understand why you distinguish the NA vs. Turbo plenum (others do as well). In my mind the plenum should work the same. One occurs with more pressure then the other, but the plenum’s effectiveness is based on the flow / 1999Porsche911 theory of intake design which has worked for the 5 satisfied customers of the IPD plenum dyno day and the hundreds of thrilled customers that have used the plenum for years.

What’s beautiful is all this flow analysis also applies to the exhaust, but instead of trying to pressurize your combustion chamber you time the geometry to scavenge it. You seem to have a grasp on that concept.

Next on the RSS product line; a remote activated battery kill switch for an instant gain of 15 hp peak! Pre order yours today or wait for the group buy coming soon! (This is obviously just a joke, please don’t call us to order one).

Thanks for all your time.

 

We NEVER said you gain 20hp at the peak, ever. We (like every other after market company) claim the max gains received from each of the plenums, which is 15 to 35 hp depending on the application. But unlike most after market performance mods, the IPD plenum provides power from beginning to end (very rare).

We never "backed off" from any of our claims. Why would we want to claim 20 additional HP at the peak when it is more to our advantage to claim 20hp in the mid range, where it is and where we all want it.

I would also like to thank everybody for stirring up the pot. We've shattered our previous IPD sales record 3 times this week. Keep it coming.

Cheers,
Greg