First off, lets say the CTT is king AND THERE'S no argument there.

However, I come from an American "Iron" musclecar background. My second car was a "V8" Vega, a 1973 4 cylinder POS with a racing frame/cage and a 500hp small block Chevrolet engine, hehehe...

I had a 1993 "Pro 5.0" Mustang with an all aluminum 400CID V8 a full frame/cage and tubs... a 10 sec drag car.

So I "know" of what I speak

However, the CTT... king as it is, is 100K USD. It is hampered by a bit of lag and "relatively" heavy weight and low CID.

So... us V6 owners have about 45k in our rides...15K short of a CS and 50K short of a CTT.

It MAY be possible to swap out the Cayenne V6 for a GM small-block V8.

One such GEM is the General Motors Z06/LS6 crate engine. It comes assembled in a box ready to run for $7300USD. It is a 23 degree V8 engine, all aluminum block and cylinder heads.
It recently was tested by an online site and tested out of the box as:
417bhp, 410lb.ft torque flat curve from low rpm to 6600rpm redline.
This was with stock factory cast iron exhaust manifolds. When they bolted on tuned tubular "headers" the max hp went up to 450hp.

So... first problem, the fit. Physically there's plenty of room there, GM V8 is nearly same size as Porsche 4.5. It may have a slightly higher deck height, but nothing a modded hood can't solve.

In th olden days, that was the major hurdle to pass... the physical size. But for this mod to be viable in Cayenne, you'd need to make adapters for Porsche's peripherals, like AC compressor, PS and Alternator. You'd need to adapt the Cayenne transmission to the V8 engine output.
Finally you'd have to adapt the electronics and harness. And fuel delivery, too.

Even with todays "highly" inflated custom shop work, I STILL can't imagine that a shop would charge more than 10-12K for the swap.

That'd total up to about the price of a CS for CTT power. And let's make itclear... that GM V8 is 100% daily driver material, very tractable and smooth.

Still "hungry"?

OK, turn to the aftermarket for the Z06/LS6 then. Different software and throttle body will get near 500hp and for the daring, a 50 state smog-legal Vortech supercharger kit will add a tidy 133hp and 80lb.ft... to make approximately 650hp and 510lb.ft of torque. That adds another $7100.

So at WORST you'd have a daily driver way faster than a Turbo S for the price of an 03 CTT.
Oh and btw, GM V8 love nitrous a cheap and simple 250hp system would give like 800hp and probably 11 sec ET's...

Any custom fab shops like to express an opinion?

 

Interesting.

My first thought is that the time, money, and energy to make the pepper run would make it more viable just to buy a (used/new) CTT...but if it can be done, it would certainly be a fun project for US to watch.

 

I think you are missing the point. If you want a fast american powered suv, buy a Trailblazer SS, or a Jeep SRT8. Putting an American engine in a Cayenne would be a disgrace to the cayenne. German engines are so much more refined and effecient than American engines. Not to mention I think its a little ridiculous to try and mod a Porsche on the cheap. That kinda defeats the whole purpose of owning a Porsche. You like things that are done right the first time, and are willing to pay for it. That doesn't mean don't mod your porsche, it means mod it right.

 

Hmm, thats a different idea. I know people do V8 swaps in 944's, but I would think with the amount of electronics involved in a Cayenne might cause a problem. Hell I wouldn't mind seeing it, ideas from outside the box are always fun to watch and see the end result.

-Markus-

 

well my other option is to wait for vf engineering vortech SC kit... which'd give it about 350hp... supposedly Gemballa has a 440hp V6 TT, though...

 

SRT-8 with a s/g or n2O would also be a hoot! I currently drive an 01 Grand Cherokee LTD with the 4.7, and "if" anything was to happen I will see if the 5.7 will drop in.

Fun Idea though but I would just buy the VW Toureg and do the same thing. No extra name plate charge!

 

On second thought, it'd probably be cheaper to get the V6 modded. A good shop could rebuild the engine, I'd venture a guess that you could bore/stroke the engine with custom made pistons, con rods and even a crank. Get maybe 3.6-3.7l Get the compression down to about 8:1 and run up the PSI on the Vortech SC, 14psi should do it