IPD Plenum + Fabspeed Cold air intake + BMD filter

[Max405]

Hi,

I am planning on upgrading to the IPD plenum (any chance of a group buy???). I talked to a local shop here NJ and they told me along with the Plenum, upgrade the cold air intake to the Fabspeed and keep the factory airbox. They recommended replacing the Porsche airfilter with a BMC filter. Overall, this doesnt sound like a bad idea. Anyone out there have this same setup? The reason I'd consider it is I am concerned about Check engine lights and fouled MAF sensors. However. I'd like to goose up the power in my 1999 C4 Cab.

Any thoughts?

Thanks, Joe D.

Edited March 31, 2008 by Max405

[Chuck Jones]

I ran the Plenum with the EVOM CAI on my 99 996 and had no problems. I know that some of the guys who have gone to the fabspeed airbox have gone back to the stock one with the BMC. Others have just gone back to the stock filter and had good results just with the Plenum. There's some discussons on the Plenum on Rennlist along with some folks who havd dyno'd it and show increased performance results. Others call B.S. Obviously two schools of thought. I liked the Plenum from a personal perspective.

[Lerxst]

I've been doing a fair bit of research on Renntech, Rennlist, and 6Speed and am planning on running the IPD with an FVD intake.

From what I've read you shouldn't have any problems. Some people have recommended disconnecting the battery during the install to "reset" the ECU to avoid the CEL.

There still seems to be the 2 schools of thought on the IPD, but some skeptics that I have a high regard for, have become believers, and that's good enough for me.

[bmohr]

Count me in on a group buy if the price is right.

bmohr

[Lerxst]

Count me in on a group buy if the price is right.

bmohr

Another forum was trying to get a group buy going but it sounds like it was shot down... I'm speculating by the manufacturer. There have been two GBs over the last couple years, last one ending January 31 '08. I missed out on that but RPM offered me a good price and I'm waiting on pins'n'needles for the IPD to arrive.

[Palma308]

I have a 01 996 C2 and I have installed the IPD plenum from RPM. It took about an hour to install .The install on my brothers 03 Targa was less time! If you compare the IPD unit with the stock plenum, you will be convinced that it has to help. I have seen a post where dyno runs were made with the exact same car, same day, same dyno with the stock plenum and then with the IPD plenum. The IPD plenum showed , if my memory serves me correctly, a 20 to 25 hp gain.

Palma308

[Max405]

I have a 01 996 C2 and I have installed the IPD plenum from RPM. It took about an hour to install .The install on my brothers 03 Targa was less time! If you compare the IPD unit with the stock plenum, you will be convinced that it has to help. I have seen a post where dyno runs were made with the exact same car, same day, same dyno with the stock plenum and then with the IPD plenum. The IPD plenum showed , if my memory serves me correctly, a 20 to 25 hp gain.

Palma308

Thanks to everyone who read my post and responded. This place is a really nice place to visit. My car is a hobby for me and this makes my hobby alot more enjoyable.

I contacted my local Porsche shop and asked about installation. Unfortunately, they told me that a modification such as this WILL void my warranty. I read my contract and yes in fact it says that in the fine print. I bought the car with a 2 year warranty, and I am only 4 months into it.

I will upgrade once my warranty runs out. If I am blessed, maybe to a 997S or Turbo :thumbup: . If I still have my C4 cab, I will be fortunate and try the IPD and a cold air kit of some kind.

Once again, thanks to all who tried to help me. You folks are great!

Sincerely, Joe D.

[flyingpenguin]

Question for Loren:

With opinions all over the map as to the effectiveness of these Y-shaped intake plenums, I am weary to drop $8-900 on a piece of metal (even though I have gotten used to the prices of P-parts by now).

My thought: Could the same effect (smoother air-inflow) be achieved by a simple mod in the existing plastic plenum? I am thinking of cutting and bending a piece of sheet aluminum to fit in the middle of the T and attach it with a couple of rivets.

Does this make sense and has anyone tried this?

Looking forward to your thoughts.

Regards, Joost

:renntech:

[Loren]

Question for Loren:

With opinions all over the map as to the effectiveness of these Y-shaped intake plenums, I am weary to drop $8-900 on a piece of metal (even though I have gotten used to the prices of P-parts by now).

My thought: Could the same effect (smoother air-inflow) be achieved by a simple mod in the existing plastic plenum? I am thinking of cutting and bending a piece of sheet aluminum to fit in the middle of the T and attach it with a couple of rivets.

Does this make sense and has anyone tried this?

Looking forward to your thoughts.

Regards, Joost

:renntech:

I think this might give you some insite... United States Patent 7,278,389

[tholyoak]

You may want to read this before dropping the $$ on a plenum

http://www.6speedonline.com/forums/showthread.php?t=126576

-Todd

[perryinva]

That's a powerful read, indeed. Look's too much to me like the plenum is just placebo effect..but it sure does look cool.

[cyclocross]

That's a powerful read, indeed. Look's too much to me like the plenum is just placebo effect..but it sure does look cool.

FWIW I did some flow calculations assuming that the stock inlet fitting was a tee and the plenum was optomized as a 90 deg ell. At peak RPM there should be upwards of a 2 HP gain. I just don't believe how replacing the stock fitting with only the plenum will give the advertised HP increase.

[pongobaz]

That's a powerful read, indeed. Look's too much to me like the plenum is just placebo effect..but it sure does look cool.

Looks cool sitting on the bench maybe, but you can't even see it once it's installed. Instead spend the $1000 on some interior cosmetic upgrades (shifter, ebrake, etc...) that you can see and enjoy.

[perryinva]

Totally agree. I took off my TB yesterday to do a F&R clean,, Took a real close look at the plenum. First off, the OEM plenum is far from a "T". Each flow path to either side to the intake runners is carefully radiused, and the reflective part of the plenum is a far larger diameter than the TB exit. Everyone seems to forget that the air in a NA engine is SUCKED in, so the air travels the shortest path..there is no way adding a "Y" to the rear will make much if any difference. Perhaps on a FI system, but even then, I doubt it..it's just TOO big. I'm an ME and have done a bit of flow work, (though admittedly, not on engines, but pipes is pipes)..sorry, but I think Porsche did their homework, especially taking into account the reflective waves. I was glad to see NO oil in the plenum at all. BTW, though I've done "front" cleaning of the TB, the F&R cleaning made a major difference in smoother idle...easily seen by the great reduction in the empty passenger seat shaking 90% less....and like everyone else..it really wasn't THAT dirty!....Thanks to Loren for pointing out the rubber grommets that the airbox sits in...both mine were still there, but BOTH were in the wrong holes, so the airbox nipples were just sitting in empty holes, with the airbox on top of the grommets, in the wrong holes. Much more solid mounting now.

[cyclocross]

... First off, the OEM plenum is far from a "T". Each flow path to either side to the intake runners is carefully radiused,...

Yes, I should have stated "weld tee" as the inside branch connection is radiused. I used an L/d of 15 for the ell and 43 for the tee.

[perryinva]

LOL..I wasn't criticizing at all or posting to your post!!! EXCELLENT job..I'd like to see the calcs sometime...doesn't surprise me at all...I was posting for other readers that ASSUME the IPD plenum MUST be better because obviously Porsche just cut corners and used a plastic "T" instead of a "Y".....I've seen posts to that effect, so you obviously noticed the same thing as I did...MAYBE that is how the "improvements" WERE calcualted..as if it was a standard "T"?..who knows? All I know, is my money has to go to a new bumper cover and I just found out that 2 of my 18" lightweight BBS Carrera wheels have small cracks in them from the PO curb damage. I'm sending all 4 of them off to Metro Wheels in Atlanta to be checked & refinished...there's a quick $800 gone...

[cyclocross]

LOL..I wasn't criticizing at all or posting to your post!!! EXCELLENT job..I'd like to see the calcs sometime...doesn't surprise me at all...I was posting for other readers that ASSUME the IPD plenum MUST be better because obviously Porsche just cut corners and used a plastic "T" instead of a "Y".....I've seen posts to that effect, so you obviously noticed the same thing as I did...MAYBE that is how the "improvements" WERE calcualted..as if it was a standard "T"?..who knows? All I know, is my money has to go to a new bumper cover and I just found out that 2 of my 18" lightweight BBS Carrera wheels have small cracks in them from the PO curb damage. I'm sending all 4 of them off to Metro Wheels in Atlanta to be checked & refinished...there's a quick $800 gone...

No problem. I did not take your post as criticism. I figured that as a ME (I'm a ChemE) you would appreciate the term "L/d". Sorry to read about your 18" lightweights. I probably should check mine also.

[perryinva]

Well, I lucked out a little, and turns out there is local wheel repair place here called Wheel Wizards, and they do excellent work. The owner took me out back and showed me some wheel repairs he just did, and the work was excellent. The damage onmine was minor compared to the stuff he showed me. They totally strip the wheels down to bare metal, dye check for cracks, repair cracks, add metal as necessary, re-true and round all flat spots, then do a 400 F 2 coat powder coat plus a clear powder coat. His work on the finished ones I saw was flawless, and a lot more durable than paint by far. 90% of his work is for custom shops and dealers. He's doing all 4 wheels (also found 2 flat spots) for $700, and I'll have them by Tuesday (5 days) He'll mount and balance the tires I took off for $100 to guarantee there is no rim damage. He has a low opinion of the 18" BBS Carrera wheels, as he sees them regularly from the dealer. Crap. They do not do well with potholes. As far as wheel damage is concerned, he rarely sees 17" with cracks, but it goes up exponentially with size from there. He refuses to do anything larger than 21 inch on low profiles, because they are always coming back with owner complaints, and it is always new damage. He sells a nice line of forged alloys but they were way too rich for my blood!