That's absolutely correct - this is just someone else's pic that I put lines on with Photoshop to demonstrate which dimension is different on my plenum compared to my tee. The tee in the pic is a totally different part to the 997S one. Unfortunately I can't get a picture my plenum and tee together because the tee is installed on my car. As it is my daily driver I can't just strip it down to photograph the differences as I have to use it!

As I would like to get to the bottom of this little puzzle, I will remove the tee next time I've got a half day to spare and will photograph the parts side by side with a ruler in shot to confirm the differences.

 

The dimensions on the plenum where it meets up with the intake runners on my car are identical to the tee so it fits perfectly there. The nose just protrudes slightly further towards the rear of the car (only by approx 1"). This means that the support bracket won't fit - it sits right on the very end of the thread (the one on the end of the rubber support) so you can't put the nut back on. The air intake hose goes on fine though as it is flexible and will 'compress' the small amount required to fit.

 

I for one think this dude rocks and his posts rock and he's being honest and that's what we all want. Cool. Thanks Ian.

 

My point is castings don't mysteriousily grow by an Inch.

 

I totally agree. I don't think the IPD part changed. Possibly the UK intake system is slightly different from the US one. At least enough so that the US IPD plenum won't fit properly. I guess we won't know till Ian takes a pic of his stock plenum next to the one IPD sent.

 

I think you rock for saying he rocks, and I guess I rock for pointing out that you rock

 

Couldn't agree more - so either I have a different, larger casting to yours or a different, smaller tee. It is odd though that 2 cars in the UK have plenums that appear to be slightly too big in 1 dimension!

I won't have time to dismantle my car again for the next week or 2; but I will take the tee out again and properly measure it and my plenum when I've got some time. Hopefully we can then get to the bottom of the mystery.

 

You certainly rock for saying he rocks and he definitely rocks for saying I rock...

 

I agree. That's all that's happening when I put the Cayenne in sport mode. The throttle is snappy, but the truck isn't faster.

And yes, I saw a ten peak hp gain, and an even higher max hp gain.The overall numbers on the dynapack dyno read much lower than the dynojets, but it's only the delta between the two runs that is important. Even though the overall numbers are higher than a NA car due to the SC, the actual gains are very similar to other NA dynos I've seen with this product.

Here's the dyno graph:



Here's a chart with the torque calculated in:



Here's a shot of it on the dynapack. Like I said before, we never even took it off the dyno. Did a base run, did the install, then did an after run. No ECU reset or even a drive around the block.

 

IAN,

Do me a favor then measure in the center from Top to bottom from the black pipe to the edge where the TB and the plenum meet. It should be aprrox 2-1/4".

Personally I had challenges when first installing this to get it lined up right so it doesn't stick out and the bracket lines up.

The trick I found was leaving all the clamps loose then bolting up the bracket finger tight. This puts the plenum in the correct spot, then tighten the four clamps around the black boots. The installation directions on The IPD site are great.

Interestingly FRAFOSS from Norway's Bracket was missing after he had it installed. He thought IPD failed to give him the bracket but in fact I bet his installer had similar problems to yours and left the bracket off because his car wasn't running correctly and he had to fix the install himself.

Good luck,

David Dodd

Bottom line - I think your Plenums are the exact same size it just isn't installed correctly.

It will take you no more than an hour to figure this out.

RSS Instructions;

[media]http://www.roadsportsupply.com/PDFs/IPD/Plenum_Inst_Part_97300_97301.pdf[/media]

 

I hear what you're saying, but if you stand my plenum on its nose next to the tee, also stood on its nose, the centrelines of the outlets don't line up. The plenum outlets are further up off the table than the tee ones. As I said, I don't have a pic to show you but the plenum is definitely longer front to back (as viewed when installed) than the tee. Not by much - it appears to be just under an inch.

Problem with this is that if I make the bracket line up, the outlets would be offset from the rest of the inlet runners. That's the problem. Line up the plenum outlets to the inlet runners correctly and the bracket won't fit. Line up the bracket and the outlets are way off!

 

I would take pictures of this and send them to Gregg at RSS.

I would love to see the pics side side too. ddodd100@charter.net

We have established we have the same stock part# for the Porsche Plenum.

My RSS Plenum and Stock Plenum have the same measurements. MY RSS plenum fit pefectly.

Then the Bottom line is your RSS Plenum is wrong in some way.

 

Thanks for the posting Dep.Dog. Must be a quick car. Gains you show would make me happy. Don't know if it is directly comp. to na car. Re sizes and such, has no one called manufacturer about this yet? All this speculation and measuring needs to be taken to RSS for an answer. Many who self installed noted difficulty in getting ducts on properly. Any gross error would have thrown an error code. No comment about resetting DME? This is one strange thread. Gerry