This is one of my last mods - gleaming the performance adders from the E81 powerkit that you can buy from Porsche NA to retrofit your Cayenne Turbo into a Cayenne Turbo S for approx $20K.

This will add an additional 40 hp and provide much better throttle response.

So since I did all of my homework, I will be doing this for much under that price

According to this P-doc, this is what I will need to add to get the engine performance bumped up to CTTS specs for a MY08 CTT (not concerned with small handling tweaks and 2-piece brakes in kit, only engine performance):

Note: Unlike the 955, no need to replace intercoolers or chargepipes for retrofit. Unlike the 958, no need to replace turbo turbine wheels for retrofit

Coming into this I already had the primary downpipes replaced without any restrictions - so check that one off the list.

I also already had an ECU tune that I am told by Softronics is identical to the Turbo S ECU tune - so check that one off the list as well.

Along with some basic maintenance, I will have to secure the other items. After a little online clicking, waiting, more waiting, it all finally arrived!

Quick preview pics:





















Pretty sexy, huh? Stayed tuned.. I will be doing the install over the weekend and will update this thread!

 

Retrofit Complete!

Skip to completion post

 

upgraded driveshaft!! dont the turbo and turbo s have the same driveshaft??

 

I was surprised to see that too, but they are different for this year model - verified in the PET system. I am assuming that the driveshaft is slightly larger in diameter to handle the additional torque. I haven't heard of anyone twisting the stock driveshaft, so I am not that concerned if this is true.

The real question is if it has a beefier center support bearing?

Since the support bearing and driveshaft are all listed as one part number, I have no way of knowing without a side-by-side. Also the mounts seem to be the same for the center support bearing, which implies they are the same size on the CTT and CTTS. I tried to do some research on this, but came up empty handed.

If anyone knows, please chime in.

 

I'll be interested to see who this turns out. I just picked up an '08 CTT for the wife to drive. I might just have to throw a few more ponies in it

 

Sounds like a great upgrade, I thought the intercoolers where upgraded as well maybe i was thinking of the 955, but could be a good investment (but expensive investment).

How much $ approx. did the part and tune run, I'm doing some planning at the moment. thanks

 

The 957 has the same intercoolers for the CTT and CTTS - no OEM upgrade option. I know the 955 CTT guys regularly complained of turbo-lag, but never had the issue - even stock. I am contributing part of this to the fact the intercoolers are more than sufficient in the 957 CTT and CTTS.

The E81 performance parts, primary downpipe replacements, and ECU tune was all under $4K. This price alone is enough to secure an additional 100hp+ at the crank, with an additional approx. 50hp+ on top of that with a few other mods (intake, secondary cat bypass). All said and done could be under $5K.

With all of the above, that comes out to about $33 per 1 hp.

 

Subscribed! Do you plan on putting it through the dyno when you are done?

 

Thanks!

Yes, I already have dyno time scheduled. My only apprehension is regarding a side project that I have in the pipeline. Lesitung plans on fabbing up a larger plenum and charge-pipes for a 957 CTTS. This should have some additional gains. However, due to bandwidth and testing concerns, this might be about 60 days out.

To wait or not to wait... hmmm..

 

Update:

So it looks like I am in a holding pattern until I can secure a 30mm closed-ended wrench for the replacement serpentine belt. I am replacing this as part of my preventative maintenance, along with a new set of spark plugs- not as part of the E81 upgrade package

Since I have to remove the intake plenum and charge-pipes to replace the serpentine belt, I might as well wait and do it now.

It seems impossible to get a 30mm wrench locally, so I have one getting overnighted from Amazon

While I am at it, I might as well try to clean the gum buildup around the intake valves. DFI engines are known for this, so I was curious how bad mine would be after around 40K miles (see pics).

In the meanwhile, here is a few pics to whet your collective palates:




Before....



Throttle body and spark plugs removed



Intake manifold removed





Closeup of gum buildup around valves



Will clean as best as I can around the valve stems with B-12 Chemtool and then vacuum out loose deposits. Afterwards, I will run Techron through the fuel system to help with whatever residue is left. I would not pull the heads to do a proper cleaning, unless there was a problem.




Besides the carbon badges and color, the intake manifolds do not look too different





Old intake manifold looks pretty clean




CTT Throttle body measures just over 78mm




New CTTS Throttle body measures just over 84mm.. WOW!

 

looking like good investment in power (and carbonf) not bad bang for buck given horse power increase, usually anything over 45ohp in nat. asp. would cost more than $33:1hp gotta love turbos

 

Can you confirm that these still have the plastic coolant pipes? I really don't know what I am looking for. This is the first '08 Turbo I've seen opened up like this. I don't think these '08s are prone to the coolant leak, but I'm just curious.

Sorry for the OT...

 

No worries.

First of all, from what I have seen, the only reports of broken coolant pipes are from the 4.5L , 955 V8. They changed to the 4.8L V8 for the 957. Not sure if this was a new motor built from scratch or a modified 955 V8. The 4.8 has a different fuel delivery system, different heads, different cams, and different intake manifold. Given the fact that Porsche is still using this engine in the 958, I am assuming they have addressed this well-known problem.

Secondly, like you, I decided to try to take a peek The coolant pipes do not look the same as they do in the 955. A couple were metal, but a couple looks like it could be made of some composite. I can take some closer pics if you want. Either way, it is impossible to tell its integrity or composition by just looking at it installed. I would have to cut them open or have them pressure testing on a bench before I could say anything for certain.

Lets hope I am not the first case of 957 coolant pipe burst

 

Curiosity question, how many miles are on that motor? Just wondering from the standpoint of looking at the intake valve picture.

 

I think I already said it - just over 40K. I also only use the best 93 octane fuel I can find in my area. It is not uncommon for DFI cars to benefit from an intake cleaning every 30K miles - due to the design. There was some rumblings about this when Porsche first introduced DFI. The benefit of DFI is greater efficiency and power output.