Has anyone ordered the Carrera S 991 IPD Plenum?
12-19-2012, 12:48 PM
#16
Race Car
I had an RS-60 and can assure you that the advertised increase in power over the Boxter S had nothing to do with the sport exhaust, which was an option for any Boxter in 2008.
12-19-2012, 01:02 PM
#17
Race Car
Was just wondering, for the sake of argument say, if maybe a lot of us hold the underlying assumption that every motor model Porsche builds is somehow a perfectly optimized example of all that can be done at a given price point- which often seems to be the unspoken assumption- and if maybe that assumption is not so well founded. What I'm getting at is that it very well could also be that Porsche KNOWS it would only take a simple part change to gain 15 hp,.....
But looking at the many internal engine mods needed to get to an additional 30 or so HP out of a 400HP 3.8 normally aspirated engine, it seems very unlikely that just a plenum could get half way there. Modern production methods at leading edge companies no longer leave smoothing castings, porting and polishing and matching component weights on the cutting room floor - for high perfomance cars (optimized for power or mileage or both- like modern Porsches). Put it another way- you already paid for that.
12-19-2012, 01:13 PM
#18
Long ago on another forum this same discussion came up...
Turns out that a 10 HP increase on a 996 was about the same effect on performance as driving with 1/3 Tank of gas compared to a full tank....
Its cheaper than a plenum too and doesnt void your warranty :-)
Turns out that a 10 HP increase on a 996 was about the same effect on performance as driving with 1/3 Tank of gas compared to a full tank....
Its cheaper than a plenum too and doesnt void your warranty :-)
12-19-2012, 01:23 PM
#19
12-19-2012, 03:09 PM
#22
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Hi Chuck,
With all due respect, I do hope that you have considered a "concealed" beer dispensing option just to keep it legal. We could start with this and go from there.
With all due respect, I do hope that you have considered a "concealed" beer dispensing option just to keep it legal. We could start with this and go from there.
12-19-2012, 03:17 PM
#23
When it comes to beer (H) I hold concealment secondary to quality. How's that thing going to maintain adequate carbonation?? Obviously we're talking party pig here.
Last edited by chuck911; 01-28-2014 at 06:51 PM.
12-19-2012, 03:26 PM
#24
Race Car
I hope there is not another application for that where one sits on it on long trips and... (see Garry post re finding gas stations with restrooms). In any case, make sure you wash it carefully before using.
12-20-2012, 12:29 PM
#25
Racer
Was just wondering, for the sake of argument say, if maybe a lot of us hold the underlying assumption that every motor model Porsche builds is somehow a perfectly optimized example of all that can be done at a given price point- which often seems to be the unspoken assumption- and if maybe that assumption is not so well founded. What I'm getting at is that it very well could also be that Porsche KNOWS it would only take a simple part change to gain 15 hp, BUT that if they did that then it would set ripples in motion that would spread across their entire marketing program where at some point suddenly it becomes VERY EXPENSIVE to keep,say, the GT2 or Turbo S an appropriate number of hp above the model just below.
If this is true it would explain a lot of things. It would explain what Gary just mentioned about an engine being initially overbuilt so as to facilitate future hp gains. They get big economies of scale doing that up front. Then they get big marketing profits by dialing in incremental hp as the years and models go by. Virtually all those gains COULD have been done from the beginning. But that would leave marketing dollars on the table. And, in fairness, they learn a LOT more about reliability taking the incremental approach.
If this is true it would explain a lot of things. It would explain what Gary just mentioned about an engine being initially overbuilt so as to facilitate future hp gains. They get big economies of scale doing that up front. Then they get big marketing profits by dialing in incremental hp as the years and models go by. Virtually all those gains COULD have been done from the beginning. But that would leave marketing dollars on the table. And, in fairness, they learn a LOT more about reliability taking the incremental approach.
12-20-2012, 01:25 PM
#26
Chuck, I think you're on to something here...for years we've seen many of the manufacturer's do this with their engines, take the Mustang and Camaro, excellent examples of manufacturers' "tweaking" intake/exhaust/ignition mapping, etc., to add that incremental hp over the life of the model (to fuel additional sales) and help keep interest...while not changing the basic engine a bit. Well Spoken!
12-20-2012, 02:28 PM
#27
Drifting
12-20-2012, 06:04 PM
#28
Burning Brakes
I am reminded of a quote of Bruce Anderson's which I can only paraphrase. "The problem with modding a 911 is that often the new part isn't as good as the one you removed."
11-28-2014, 06:09 PM
#29
Race Director
Was just wondering, for the sake of argument say, if maybe a lot of us hold the underlying assumption that every motor model Porsche builds is somehow a perfectly optimized example of all that can be done at a given price point- which often seems to be the unspoken assumption- and if maybe that assumption is not so well founded. What I'm getting at is that it very well could also be that Porsche KNOWS it would only take a simple part change to gain 15 hp, BUT that if they did that then it would set ripples in motion that would spread across their entire marketing program where at some point suddenly it becomes VERY EXPENSIVE to keep,say, the GT2 or Turbo S an appropriate number of hp above the model just below. If this is true it would explain a lot of things. It would explain what Gary just mentioned about an engine being initially overbuilt so as to facilitate future hp gains. They get big economies of scale doing that up front. Then they get big marketing profits by dialing in incremental hp as the years and models go by. Virtually all those gains COULD have been done from the beginning. But that would leave marketing dollars on the table. And, in fairness, they learn a LOT more about reliability taking the incremental approach.
Was looking up info on the IPD Plenum after thinking about getting one. Found the above theory by Chuck very interesting, and reading about the new GTS even more interesting.
Any comments from you mechanical guys?
http://flatsixes.com/cars/porsche-99...s-new-991-gts/
Quote:
3. How the Powerkit makes its 30 extra horsepower over the standard engine: I was curious how the Powerkit engine made its 430 horsepower versus the standard Carrera S 400 horses. Porsche gave us the opportunity to sit down with Friederich Seiler, the company's Engine Tuning Engineering Manager. If anyone could tell us, it'd be this guy! Seiler estimated that the Powerkit's revised intake manifold was responsible for somewhere around 50% of the power gain, replacing the engine's standard plastic intake for a custom made complicated dual-plenum aluminum intake. It is difficult to describe in words, but there is a large flapper at the top of the intake tract to keep the left bank separate from the right bank until higher RPM, and then a little flapper in each of the cylinder runners that opens up to take advantage of oscillating tube pressure at high RPM to provide a less restrictive flow to each cylinder above . The way it was described, it basically allows the air that is pushed back from the closing of an intake valve to flow into other open cylinders, rather than providing a pressure differential that prevents high flow from entering each cylinder unimpeded. This system is said to help promote torque through shorter intake runners at low RPM, and then when open, allows more horsepower at higher RPM. Hopefully this cutaway diagram will help.
11-28-2014, 07:58 PM
#30
Racer
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Most mass produced products are built around compromise, there is always room for development and improvement by small specialist companies. Induction is just as important as exhaust.....