This assumes that the stock plastic plenum has the same flow capacity as the IPD plenum. If the plastic plenum is a restriction downstream from the intercoolers (and before the charged air enters the intake manifold), then the improved flow of the IPD plenum could make a difference and that's supposed to be where it helps. We just don't know with certainty that it results in the claimed gains, and I personally don't have enough concern about it to bother finding a four wheel chassis dyno and downgrading to reinstall the plastic piece to do before and after dynos.


What I like, though, is how people who don't have one, never have driven a CTTS with one on it, and have never dyno tested it are so quick to claim it's "snake oil." I'm willing to be convinced it is, but at least offer some proof other than an opinion.

 

You don't need to own a CTTS or drive a CTTS to understand this. There is little to be gained in simply enlarging the plenum and using an aluminum one over the plastic one. Porsche isn't really known for leaving HP on the table with a part as dirt simple as this. Look at the factory air box compared to the after market open air elements. At first glance, there is a ton of efficiency to be gained when you make a more efficient element, and remove entire aspects of the air box. Yet, everyone knows we're talking about 5-10 HP at most. And all the sellers of a performance intake system have a dyno sheet. Yet, everyone that sells the IPD plenum all quote the same HP and torque figures, and none have a dyno sheet.

I think the metal vs aluminum aspect and eliminating the cracked plastic is a valid reason to get the IPD plenum, but you're kidding yourself if you think it's making you 30 hp.

The IPD plenum is right up there with the marketing behind diverter valves needing to be replaced because you're running more boost. The after market parts industry relies heavily on the idea of confirmation bias when selling parts to you.

 

Source for this claim presented as a "fact"?

Again, I'm not claiming the naysayers are necessarily misguided; the problem is they are offering as much proof it doesn't work as the proof being offered by those believing it does.

If given one, would you install it on your Cayenne?

 

Source? Just look up any reputable supplier that shows their own dyno. Most intake setups never end up making that much power on PAG and VAG cars because the stock air boxes flow really well to begin with.

Personally - I would not pay the asking prices they currently have for the IPD plenum. I'd pay $400 bucks for one, but not nearly $900. And, I'd buy it purely from a maintenance standpoint from the cracked plastic ones, not as a mod.

Here is a link to a dyno from IPD's website for a 997. Mind you, this is a Turbo S putting down way more power than a CTT, and it's also running 1.2 bar of boost.

http://ipdplenums.com/news/dyno-product-test-news

Here is what IPD says about that plenum:

"Power and torque increases provided by the IPD plenum are impressive and stay well above all factory power curves from launch to redline. Maximum power increases take place in the midrange where it's most needed, most critical and most enjoyed.

The 997.2 Turbo plenums deliver smooth and linear power with considerably quicker boost response creating a longer and more desirable power band."

What I see is a small bump in power-mid RPM, as they claim. I'm not seeing this "stay well above factory power curves from launch to redline." I see torque onset and peak power look exactly the same on the dyno. I'm also not seeing this "creating a longer and more desirable power band." Again - power is exactly the same early on and at the top of the RPM range.

If you integrate a torque curve, you get the area under the curve, or "work." You could calculate the area under the curve for the bump in power that the 997 has and come out with a number. You could then take that work value, and create a new increased power curve that starts small early in the RPM range, and increases to a larger value at peak power in a somewhat linear fashion. This is the type of power increase most people are looking for. My guess in eyeballing that would be something around 5 whp increase in theoretical power.

My bigger issue is that if IPD designed this on a CTT, they must have tested it multiple times on a dyno to get it right. So, where are the dyno charts that they used to gain these power numbers they are advertising?

If an IPD plenum does make 30+ HP at peak power, and there are measurable increases through the entire RPM range, then I could get on board with paying their asking price. Anytime I see a precision engineered part listing a specific power increase without a dyno sheet, I roll my eyes. I mean, if you put in that much effort to create a high quality part (and the IPD plenum is most certainly high quality), wouldn't you want to list the dyno sheets you probably have to substantiate your claim so there no disputing what it does. <- I didn't put a question mark there because I don't think rhetorical questions need them.

 

Fair point. Clearly the dyno charts showing the 30HP remain an enigma clothed inside a mystery.

I sent an email yesterday to IPD requesting that they contribute to this thread as a Board sponsor, but obviously they haven't done so yet and likely won't. Why let the facts get in the way of a good story?

 

I for one have been following IPD plenums for many many years going back to when I owned a 996TT. To date I have not found any evidence that this mod alone gains 25-30HP like they claim... most of the time it's when used in conjunction with x,y and z..... at this price point 900+ I think they should provide as much supporting evidence as possible. Also I have yet to see a cracked plenum...I've owned 4 Cayennes with 3 of them being CTT's one with over 120K miles and another with over 75K miles and my current 2011 with 20K miles. The plenum on my 996TT was perfect as well with over 60K miles.

If IPD could prove definitevely that their product "alone" gains 25-30.. then this would by far be the cheapest mod for the amount of power you gain. I would have been a buyer many many cars ago....

just my 0.02$ and my experience....

 

I can't help but read this and think fondly of the torn TBB on the ol' B5 S4. The IPD plenum is like a short and fat APR Bipipe, but at 3 times the cost.

 

+1 180k and a disabled engine and my plastic plenum is fine as well.

 

I have access to a 4 wheel dyno and thinking of contacting IPD to see if they would do a "money back" guarantee.... I would definitely buy this product if it works as advertised.

 

So you bought this item, installed it, and found that it offers no perceivable gains.

Just wondering what proof you had that convinced you to buy this.

Was it clever marketing?

Some of us aren't quick to believe the hype.

I place this power gain fallacy into the same category as the unapproved alternative oils and fluids that make people believe in miracles.

I repeat.....snake oil.

 

Here's what I originally posted:



What part of that do you not comprehend?


Unless you have some actual facts to back up your "snake oil" opinion, it's worth about as much as my opinion that there are some benefits to be had. At least I have actual experience with the item in question to base my opinion on; more than can be said for yours. We can agree you're not a fan of IPD. Next topic, please.

 

No, I'm not a fan boy for IPD, but I respect your right to be.

You probably could still get a refund if you send it back.

 

Unfortunatly for Cayenne owners, there ARE so many opinions and so little facts.

 

Indeed.

 

I sent Sam at IPD sales to inquire and see if any graph is available or data sheet.