I think you are right on the money - I have no doubt that factored into other kit builder's thoughts.

Given the adiabatic efficiency* of a twin-screw or positive discplacement blower, (typically 65 to 70%) the high compression ratio would rull them right out without significant intercoolers.

Similarly, a typical oil-fed centrifugal supercharger, although better in adiabatic efficiency than a twin-screw (typically 70 to 75%), still can count on heating the air charge prior to the throttle body to a point where intercooling is also required.

If we build this kit, I will be using a self-contained centrifugal blower with a very high adiabatic efficiency of nearly 85%. This means the charge air is cooler, and less likely to spike the internal combustion temp to where pre-ignition would occur.

Our impeller is ceramic coated (like a turbo) to prevent heat transfer, and the unit runs cooler, at under hood and front-of-the-engine temps. An oil-fed supercharger runs at internal engine temp, because of thehot oil being pumped thru it.

I feel if we can keep the charge air cool enough and the boost low enough, we can get some performance without damage to the engine.

*adiabatic efficiency In this usage: the ability of an air compressor to compress the air without heating the air is measured as adiabatic efficiency.
See: http://en.wikipedia.org/wiki/Gas_compressor

But to be sure - the high compression ratio does give pause and is a challenge in this installation.

 

These are my design objectives at this point:

a) it will be an externally mounted bolt-on kit
b) it will not require disassembly of the engine to install
c) it willnot require any special engine preparation before installation
d) the Air Conditioner will remain in place and functioning
e) the polution control equipment will remain in place and functioning
f) price target to be between $5k and $8k

This kit will not produce turbo-like power from the NA motor, but should move the NA motor up into the gap between the two nicely.

 

g) The kit should be visible when the hood is up to impress the ladies !
Some red or black anodized tubing would also be nice

At the lower range of the price point for sure you will sell more - I will be one of them !

 

Just came back from the Porsche dealership where we studied the base Cayenne V6, and the Cayenne S V8.

The V6 is certainly do-able. There is room for the centrifugal supercharger and we were also able to sketch out the routing of the charge air tubing including an air-to-air intercooler without too much difficulty. The factory crank pulley is small at under 6" in dia, but I saw we could add our own drive pulley on the nose of it.

The V8 was not at all the same story. The bifurcated intake uses two separate MAF sensors, and that complicates things immensely. We could not find room for the SC head unit, nor the tubing to it or from it.

In both cars, the question of the advanced engine management software poises concerns. We must be able to knock the fuel system off of Stoich to fuel the supercharger correctly, and I have some concerns that the Porsche engine management system will fight these changes tooth and nail. There is a fair amount of anti-theft circuitry in the system, and even the V6 model had 3 O2 sensors showing per bank!

In conclusion, we only really see the V6 model as plausible, and then that limits the market sharply.

Given that the V8 is only $10k more than the V6 on the used vehicle market – it does not make sense to supercharge. Now… the turbo was $35k more than the V8 – so an aftermarket kit does fit nicely into the price line and make some sense. If it was possible for us, which it is not.

 

Once again - My dreams dashed before my eyes.

If it helps at all, there is a seller on Ebay that has been selling intake manifolds, plenums, fuel rails, pistons, cranks and what have you, from cayenne's. They are a race shop and these are all take off parts. The question I have is, what the hell are they replacing these parts with and how are they using these engines. Anyway, its a "medium shot" but here are the links if you think its worth a call.

HERE IS THERE DESCRIPTION (Maybe the engine is going in a different chassis?)

"We buy New Cayenne factory replacement engines from Porsche dealers for race engines we are developing. We only utilize the block, cylinder heads, and valve train components. We have no need for the accessories or most external bolt-ons. All parts not needed for our racing engines are carefully removed from the engine when it is received, before it has been run."


http://cgi.ebay.com/ebaymotors/Porsc...Q5fAccessories

http://stores.ebay.com/Pro-Race-Supply

 

We are brushing the dust off of this idea again and looking at it anew...

 

Well it's certainly not cost effective and N/A Cayenne compression ratio is way too high. So why do it? HP per dollar comes much much cheaper.

 

So, no hope for my S?

 

Let's be realistic here. You can buy a nice turbo pre 06' for around 10k. Not only do you get a whole lot more Cayenne, but you get the power with potential for about 100 more.

 

Being realistic? 10k for a 06 turbo is outta whack. Show me a NICE 06 turbo for 10k ill buy it today.
Buying a used car, you never know what problems you're getting also.
I guess you also don't have a connection with your car, like most people do...

 

It is whacked, there's aan 05 ctt immaculate on Austin Craigslist for 9500. I talked to the seller and he said it belonged to a Porsche exec and got a new engine @ 100K
I have to disagree here. I think if your a smart buyer you most certainly can know what your getting into.
My connection is good I assure you, but let's talk about yours for a minute. Is it good enough to lay down the 5k+ for a supercharger kit that you will always be limited on boost with because of compression ratio? Is your connection that good?

 

I'd spend 5k+ any day for it. I love my truck. It's insanely quick as it is, I cant picture how it'd with a supercharger. I know that the turbo would be quicker but I've got so manny memories in this truck and honestly I think the S looks better on the back of it than the turbo badge.

 

Eventually fate will prove you are the minority and that's why we Cayenne owners don't get all the cool stuff that we'd like.

 

Minority? Because i'm black? Not cool man...

 

Black? As in? As if- I don't think so. Clown.