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996 Turbo / GT2 Turbo discussion on previous model 2000-2005 Porsche 911 Twin Turbo and 911 GT2.
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  #31  
Old 08-19-2012, 12:37 PM
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hm, so... the ipd plenum should not be smooth inside ? it should be rough surfaced ?

wouldnt that disturb the air flow? i dont get that if its rough it helps with that..?
 
  #32  
Old 08-19-2012, 04:45 PM
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Usually when it is a mixture of gas And air you don't what it perfectly smooth to help atomization.
BUT if it's straight air flow or exhaust flow it should be as smooth as possible..
 
  #33  
Old 08-19-2012, 07:37 PM
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Most times a 60 grit sand paper roughness is what you want.
 
  #34  
Old 08-19-2012, 08:05 PM
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Originally Posted by unvmy996 View Post
hm, so... the ipd plenum should not be smooth inside ? it should be rough surfaced ?

wouldnt that disturb the air flow? i dont get that if its rough it helps with that..?

Hmm I could go into a more technical explaination but lets keep it simple... The rough sand cast surface is just enough to allow the flowing air to not attach or stick to the surface. Air that is attached basically has more drag or friction involment with the surface. The small micro layer of disturbed air that the sand like rough cast surface has allows the main air charge to glide in easier; like a hover craft gliding on its own cushion of air...

Think of a golf ball, it cuts throught the air easier due to its dimples. The priciples are slightly different but the same.

Intake piping especially those with corners benefit from surface roughness too.
 

Last edited by Engine Guy; 08-20-2012 at 12:48 AM. Reason: Eye cant spell
  #35  
Old 08-20-2012, 09:15 AM
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Originally Posted by Engine Guy View Post
Hmm I could go into a more technical explaination but lets keep it simple... The rough sand cast surface is just enough to allow the flowing air to not attach or stick to the surface. Air that is attached basically has more drag or friction involment with the surface. The small micro layer of disturbed air that the sand like rough cast surface has allows the main air charge to glide in easier; like a hover craft gliding on its own cushion of air...

Think of a golf ball, it cuts throught the air easier due to its dimples. The priciples are slightly different but the same.

Intake piping especially those with corners benefit from surface roughness too.
HI,I am not saying you are totally wrong BUT I dont think most head porters that use a flow bench to flow heads,intake manifolds and carbs would totally agree with your above statement..
How can you compare a solid object,golf ball, going thru air AS the same as air itself being directed and flowing thru an object?? Two different things with different principles of airspeed..
Have you every seen a flow bench and watched work being done on it ? I have,so I believe in my above post # 32 statement..
These are my thoughts and experiences that I have saw and encountered that I am sharing, Just saying...
 

Last edited by johnspeed; 08-20-2012 at 09:37 AM.
  #36  
Old 08-20-2012, 09:58 AM
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Originally Posted by johnspeed View Post
HI,I am not saying you are totally wrong BUT I dont think most head porters that use a flow bench to flow heads,intake manifolds and carbs would totally agree with your above statement..
How can you compare a solid object,golf ball, going thru air AS the same as air itself being directed and flowing?? Two different things with different principles of airspeed..
Have you every seen a flow bench and watched work being done on it ? I have,so I believe in my above post # 32 statement..
These are my thoughts and experiences that I have saw and encountered that I am sharing, Just saying...
I have known a lot of really significant engine builders in my time, myself included, every single one of them will tell you a flow bench is a tool not a absolute. Plus you are making blanket statments about your observations not actual experience.

Also the golf ball anaolgy, what does it matter if the ball is whats moving or the air is. Relative motion is what matters and either way you look at it, it is the same. Golf ball moving through the air or the air moving past the golf ball ='s the same end result. Shoot I could use any number of anologies but the golf ball one is just so easy to visualize as it is so obvious and studied.

I am speaking as a person who has worked on some of the fastest piston powered vihicles ever built that travel on both land or in the air. Now I am not saying that just to prove that I am right as there is more then one way to make a wheel go round and round; and there is no one single smoking gun theory that disproves all others in this world of engineering.

Back to the original topic. John not to stomp on you but you are making just blanket statements in some broad manner, staments like mixing fuel and air. How does that relate to an intake plenum prior to fuel injectors.

My thoughts on your 68mm plenium experience is you either had boost leaks or you installed the product wrong. As per your big one, if it worked so well then why did Tim remove it? It's just my opinion that your knowledge of engines is comparable to my knowledge of computers.. I know just enough to be dangerous.... Thats not saying you can not learn, you sound like a very smart individual that has the capacity to learn more and enjoy doing so, so good on you.
 
  #37  
Old 08-20-2012, 11:23 AM
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Originally Posted by Engine Guy View Post
I have known a lot of really significant engine builders in my time, myself included, every single one of them will tell you a flow bench is a tool not a absolute. Plus you are making blanket statments about your observations not actual experience.

Also the golf ball anaolgy, what does it matter if the ball is whats moving or the air is. Relative motion is what matters and either way you look at it, it is the same. Golf ball moving through the air or the air moving past the golf ball ='s the same end result. Shoot I could use any number of anologies but the golf ball one is just so easy to visualize as it is so obvious and studied.

I am speaking as a person who has worked on some of the fastest piston powered vihicles ever built that travel on both land or in the air. Now I am not saying that just to prove that I am right as there is more then one way to make a wheel go round and round; and there is no one single smoking gun theory that disproves all others in this world of engineering.

Back to the original topic. John not to stomp on you but you are making just blanket statements in some broad manner, staments like mixing fuel and air. How does that relate to an intake plenum prior to fuel injectors.

My thoughts on your 68mm plenium experience is you either had boost leaks or you installed the product wrong. As per your big one, if it worked so well then why did Tim remove it? It's just my opinion that your knowledge of engines is comparable to my knowledge of computers.. I know just enough to be dangerous.... Thats not saying you can not learn, you sound like a very smart individual that has the capacity to learn more and enjoy doing so, so good on you.
HI,,Thanks..We all have are own experiences and accomplishmients which is good for all of use to share and be open minded enough to listen and learn more from others.
Some actually do do work on their cars and test things and are hands on guys here on this site. And there are others that read and talk theory.
Also the 68 Ipd plenum was put on first and driven for weeks BEFORE I went to the DYNO.NO leaks..I could tell in the Upper end it didnt pull as hard..Thats why I went to the dyno to do a back to back with the stock one again..Andrew from GIAC shared some notes when I first installed it with the findings.
Also I Had NO leaks on the dyno with the new set-up,as you should read again the complete thread again..Only after I got home it idled high and never when I left the shop nor on the dyno after install..
NOT to brag but you stated about YOUR knowledge >>In my past I was # 1 in winning ALL national Harley dyno shoot-outs in my class and winning all drag racing event for 8 yrs in my class.. BY doing hands on,tuning ,designing,building all my motors..I have been in countless magazines and advertisements over those past years ...My point is that I have done hands on and have a proven record for my knowledge AND I do not know everything and probably never will but I am always learning BUT from experience not bench racers..
Not to throw stones but as you started here with your accusations,as others have seen you do on other threads.
What have you done in real world testing on your car and shared here??
If you want to continue this ,PM me and I will give you my info so we can talk ..
 

Last edited by johnspeed; 08-20-2012 at 11:53 AM.
  #38  
Old 08-20-2012, 12:34 PM
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Greetings Gentlemen,

I’d like to start by asking John to add that the reason he returned his original 68mm Plenum was because the Plenum didn’t perform correctly due to his mechanic not installing the check valve correctly, not because the Plenum didn’t deliver the claimed performance gains.

As a manufacturer we prefer to use 6 Speed as a spring board to launch new products and share test data related to our products and try not to engage in keyboard battles. The 6 Speed community was designed to be a constructive community where members can provide insight and contribute to interesting topics related to all of our mutual passion for Porsches. I know I speak for ALL manufacturers when I say, we much prefer that our satisfied customers speak from their personal experiences to provide positive feedback by sharing their experiences and knowledge of products and services with fellow 6 Speeders.

We are NOT trying to “fuel the fire” but just felt compelled to shed some light on this topic since there seems to be quite a bit of confusion. So at the risk of “adding fuel” we’ll contribute some of our findings over that past decade and address a few of the above issues….

1. Bigger is NOT better. We can make an IPD Plenum that flows like a 747 jet engine but it’s not going to necessarily make more power. Each and every Plenum is designed and developed to deliver the optimum power and torque for it’s given application. The 996 Turbo is no exception.

2. We have conducted countless sessions of flow bench testing back in the day but have found that it’s not indicative of power and does not related to real world performance. Testing the IPD Plenums on dynos and with Pbox (by members) is much more accurate and shows how a given mod performs under the exact circumstances in which it was designed to function. This is even more crucial with Turbo than NA applications.

3. Since the IPD Plenum is a product of efficiency it should be the absolute very FIRST mod you install on any late model Porsche, especially the 996 Turbo. The 996 Turbo IPD Plenum develops 35-40 HP and Torque (@ wheels) of noticeable “seat of the pants” power gains on a bone stock 996 Turbos.

4. The patented “Y” design of the IPD Plenum delivers the bulk of the power, not the larger throttle body. As a matter of fact, the 68mm Plenum and 68mm TB deliver about the same 35-40 WHP as the 74mm Plenum and 74mm TB. The only difference is that the 74mm set-up will support the more heavily modded Turbos (all the way up to 1000+ WHP).

5. The greatest aspect of the “Y” designed IPD Turbo Plenums is the earlier / quicker boost response that minimize lag and allows the engine to get into the power and torque sooner making for a larger and more desirable power band.

6. As far as the surface area is concerned. It has become universally accepted that a shot peened surface will provide superior flow compared to a smooth surface (especially with intake tracts). Although this may seem counter-intuitive it has been proven and supported through laminar flow theory. If you every get a chance to look inside any Modern day Indy car or Prototype sports car intake runners you’ll fined shot peened surfaces. With tighter tolerances on the surface finish we can control the boundary layer to maximize flow. The shot peened internal surfaces allows for even further optimized air flow. Controlled turbulent air creates less friction and "tumbles" over a given area more efficiently.

I hope this helps shed some light on the subjects above. As always, if anyone has any other questions or concerns please feel free to drop us an e-mail or give us a call. We greatly appreciate all the continued support and consideration over the years.

Cheers,

IPD Greg
 
  #39  
Old 08-20-2012, 01:31 PM
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Hi Greg , I sent the 68 mm plenum with the Dyno sheets to Mike back then, as it didn't perform better at WOT.I talked to Andrew at GIAC back then and Steve Kasper from Imagine Auto in which they had seen similar results. You were not with the company then , you were working for RSS selling them also..
I paid Porsche Exchange to pressure test and they did, no leaks.Then Paid to put it on Dyno and then paid to put on the stock one again, same day..
I never brought it to lite in detail before this B.S. TODAY because I know every combo is different..
When Mike got it back with the Dyno sheets with the WOT RESULTS , he gave me my money back..
Then Later on he said the valve was installed backwards? I know it wasn't..After we took it off from Dyno with the hoses and valve , it was just pushed on to keep from losing it.
So now certain members attack others results in which were performed and shared and spent money /time on.
I guess there should be more Dyno tests from people not tied to parts they sell? RESULTS DO VARY ON MODS..
I will be more then happy to use my car and put it on Dyno with any of your plenums for a back to back test...If it does what you say I WILL pay for everything..If it doesn't you pay for it and my time.
 

Last edited by johnspeed; 08-20-2012 at 02:00 PM.
  #40  
Old 08-20-2012, 02:08 PM
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Another little tid bit here..
Ask any professional coating service and they will tell you putting a teflon coating where air only is flowing will increase speed and velocity..Why? Because its smooth..
IPD use to coat the inside also AND as Mike told me himself that he stopped doing it because that little bit of more flow didnt help and it was not cost efficent..
Also those intake tracts you talk of,,is it only air flow OR air and fuel mixture flow ??
 

Last edited by johnspeed; 08-20-2012 at 04:32 PM.
  #41  
Old 08-20-2012, 03:14 PM
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Originally Posted by Engine Guy View Post

OH so I just went and read your entire thread about your Modified IDP plenum....

So if I get it straight you cut the back out of it and made it a T not a Y like it was designed to be. Whoever did that really does not understand the idea of flow dynamics.... Have you ever seen a performance intake port or header that slams the incoming or outgoing charge into a flat wall.

I bet you also used aluminum with a smooth surface finish.

The IDP plenum sure looks like it would do a great job of directing flow, and the rough cast surface inside should also do a good job of separating the surface layer of air around the corners. Breaking that boundary layer of flow is a very small detail in terms of performance on a 500+ hp car that is force inducted but it is a detail none the less. All the small details, good or bad, do eventually make a difference when multiplied.

From what I have seen of many tuners stuff in the P car world is they do not get the principle of boundary layer separation and air flow dynamics.
The engine is out of my car right now and coincidentally an IDP plenum was installed. The first thing I thought when I seen the inside of my intake piping was (Yup, gonna sand blast the inside of this stuff when I get home"

If you want to see a good example of boundary layer separation in practise look at an Olympic bobsleigh and its occupants. They put that sandy grip tape on the outside of the sled in certain spots and on top of their helmets; why, all to decrease boundary layer drag.

WEll I guess its time for me to open my mouth again. I gave john the modded piece. Thats right I DID. You are realy full of yourself my friend. IPD paints the inside of the of their unit. The thick (like your head sometimes) paint is very smooth. And yes most of it was removed. That's right MOST of it. If you really knew what you were talking about you would almost be right if the two intake half's where connected with a cross over but they are not.

Now I can't wait to hear how "my mommy did not give me a lollypop" or some other childish statement from you. Oh I think you super tech lingo will go over better on rennlist.

And yes I spent the money and the time to test the ipd. I found what worked for me. and what made power and where it made the power. Enjoy that ride on your bobsleigh
 
  #42  
Old 08-20-2012, 04:17 PM
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  #43  
Old 08-20-2012, 05:09 PM
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Hey Tim I will give you a rep then..
I guess giving hands on results and sharing info to help doesnt over ride members that know more with out acutually doing it..
Do they think we spend the money/time to try to make things NOT the best they can be when we do a mod??
I have proven theory wrong on my bike dyno testing things and hanging out by flow benches,,,As I am sure you have Tim and the other doers who think outside the box..Thats why there stuff has more power or is better..
Example,,I could have lied and not said it was a modified plenum But I used it because MY comparison results on the flow bench with a 74TB at WOT were better..If I didnt think MY results were good ,do you think I would rent a Dyno and pay a Porsche mechanic to do that switch??..Same goes for renting a dyno and paying Porsche mechanic to compare the 68 plenum because I felt it didnt perform at WOT like it did with stock one.
I have spent alot and am not afraid to spend money to try to get it at its best..As I am sure most of use do,if you can?..
As I said over and over in my posts,,its MY results,My test at only WOT and results vary do to others combos..What more can I say?
Then members ask for proof and it is given on the testers own car with the info it gets attacked...Even know results may vary..
I dont understand some members,So like you said before on another post, whats the use??
I am sorry OP about what has transpired with this topic..
 
  #44  
Old 08-20-2012, 07:52 PM
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Originally Posted by Engine Guy View Post
I have known a lot of really significant engine builders in my time, myself included, every single one of them will tell you a flow bench is a tool not a absolute. Plus you are making blanket statments about your observations not actual experience.

Also the golf ball anaolgy, what does it matter if the ball is whats moving or the air is. Relative motion is what matters and either way you look at it, it is the same. Golf ball moving through the air or the air moving past the golf ball ='s the same end result. Shoot I could use any number of anologies but the golf ball one is just so easy to visualize as it is so obvious and studied.

I am speaking as a person who has worked on some of the fastest piston powered vihicles ever built that travel on both land or in the air. Now I am not saying that just to prove that I am right as there is more then one way to make a wheel go round and round; and there is no one single smoking gun theory that disproves all others in this world of engineering.

Back to the original topic. John not to stomp on you but you are making just blanket statements in some broad manner, staments like mixing fuel and air. How does that relate to an intake plenum prior to fuel injectors.

My thoughts on your 68mm plenium experience is you either had boost leaks or you installed the product wrong. As per your big one, if it worked so well then why did Tim remove it? It's just my opinion that your knowledge of engines is comparable to my knowledge of computers.. I know just enough to be dangerous.... Thats not saying you can not learn, you sound like a very smart individual that has the capacity to learn more and enjoy doing so, so good on you.
I am calling BS on this also. The reason a golf ball has dimples is because it suffers from a shape that is susceptible to laminar separation because it has a blunt trailing edge. The intake tract slowly tapers down and does not have the same issue.

Ever seen the inside of an Indy car? I have, they are very smooth. If the dimples work on everything with airflow why don't airplane wings have dimples or exhaust pipes on F1 cars?

The other guys nailed it, the only reason you want the intake tract rougher is if there is fuel in the air to prevent puddling on the surfaces. With just air you want it as smooth flowing as possible.

I am guessing your work on "some of the fastest piston powered vihicles ever built" didn't include any engineering duties.
 
  #45  
Old 08-20-2012, 09:47 PM
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Originally Posted by JETmn View Post
I am calling BS on this also. The reason a golf ball has dimples is because it suffers from a shape that is susceptible to laminar separation because it has a blunt trailing edge. The intake tract slowly tapers down and does not have the same issue.

Ever seen the inside of an Indy car? I have, they are very smooth. If the dimples work on everything with airflow why don't airplane wings have dimples or exhaust pipes on F1 cars?

The other guys nailed it, the only reason you want the intake tract rougher is if there is fuel in the air to prevent puddling on the surfaces. With just air you want it as smooth flowing as possible.

I am guessing your work on "some of the fastest piston powered vihicles ever built" didn't include any engineering duties.
..Right on..
Also have you ever saw a carb or throttle body or a intake runner that flows air only dimpled or roughened up to cause more surface tension to create drag on the moving air stream??..LOL..I think not..
We both know also about boundry layers of air flow ,even though I am not an engineer..
 

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