MWS

In my '09 C4S when the engine is fully warmed up and I park the car and shut down the engine, the fan comes on after the car has sat for two or three minutes. The fan may then run for several minutes.

My '09 C4S has a rattle that to me seems to be coming from somewhere in the dashboard. It does not occur on smooth asphalt roads but on textured highways I hear it. I've gotten used to it but I am annoyed that in a $100K+ car my dealer was not able to silence the rattle. It is not very loud but it is persistant. I would describe it as sounding like a small hand full of paperclips in a gently vibrating paper cup. I believe I have seen other posts on this website about this problem.

In "Sport Mode" I don't think it is an issue although I'm not entirely certain because when I am driving in "Sport Mode" I am probably driving a bit more aggressively and don't really allow the RPM's to drop very low. I notice the engine laboring the most in routine slow "City" driving especially when I have to slow down considerably such as crossing an intersection where i am trying to not scape my front end and then want to accelerate quickly to keep someone from driving up my tailpipes. MWS

I have PDK in my '09 C4S. I agree with you that sometimes I feel the transmission should downshift so that the car is more responsive and the engine not laboring. My solution is to use the paddle shifters to manually downshift into a lower gear,

Make certain your stereo is turned OFF and see if the sound goes away.

I had the same message appear twice on my '09 C4S when I had about 15,000 miles on it. I had just started the car and it would not shift into any gear until I shut down the engine and restarted. I took it to the dealership and they supposedly reloaded the PDK software. It has not happened again since. I now have a bout 61,000 miles on the car and have had no further problems with the PDK. Of possible interest - that last week I took my C4S in for the 60,000 mile service. This included changing the oil in the PDK and servicing the 4-wheel drive. The dealership said my C4S was the first PDK on which they had performed the 60,000 mile service. The service cost over $2,100.00? OUCH!!!! Car runs great - perhaps even better than when it was new. MWS

My 09 C4S with PDK is my daily driver. It will have 60,000 miles on it in about three weeks. So far no problems with the PDK. I have never wished I had a manual transmission instead of the PDK. Every time I set the PDK to shift with the paddles on the steering wheel and I put my foot into the accelerator I am amazed at the virtually instantaneous shifts that occur when I hit the paddles. There is no way that a human could shift a manual transmission as fast as the PDK will shift. It is very impressive technology. Plus with PDK you can experience gut wrenching wide open throttle 6,000 RPM launch starts with all four wheels straining to break loose from the asphalt. It's an experience that will get your adrenaline pumping and nearly always causes passengers to say something like "Holy Shi#!" or perhaps "WTF!" I love the PDK. I would buy it again. For what it is worth, Nissan is using a similar transmission if the GTR. No matter which transmission you choose, you will still be driving a dream car that will be a tremendous thrill to drive. MWS

For my '09 C4S, about a year ago, I looked at the Champion Motorsports Tubi exhaust mods with ECU remapping to be done at a Porsche Dealership in Houston. The conversion would not void the warranty. The cost was somewhere in the ballpark of $4500 for a gain maybe of 30 horsepower. I felt this was too much money for the small gain in horsepower. I feel that my money would be better spent on taking performance driving courses that would help me to get the most out of my "stock" vehicle. I think that unless I really know how to really drive the car in a manner that it is capable of, the increased horsepower would really only be useful for straight-line acceleration. Don't get me wrong, I would love to have the increased horsepower and throatier exhaust sound. Just my $0.02. MWS

I would not want my 911 to be confused for a Peugeot. :D

My '09 C4S has about 54,000 miles and I will soon need to replace my front tires. The front tires are Michelin Pilot Sport "N" rated tires. They have been on the car for almost 35,000 miles. I had Michelin Pilot Sports on the rear but they only lasted 16,000 miles. My current rear tires still have plenty of useful life in them although honestly I may change them as well. Currently I'm running Hankook Ventus V12 tires on the rear. They are not "N" rated tires and I must say that although they have worn well and still have plenty of useful life in them after 19,000 miles, they do not have the performance feel to them of the Michelin Pilot Sports they replaced. They don't grip the road and handle the way the Michelin Pilot Sports did. I guess I traded performance and handling for durability and price. All that now said, I am asking for input from the group about experience with replacement tires. I am thinking of putting a new set of "N" rated tires on the front now. Then in a few months when the Hankooks are more worn replace them as well with "N" rated tires. However, I am not opposed to replacing all four tires and just put the Hankooks in storage in case I need them in the future. Does anyone have any comments about which "N" rates tires to get or avoid? I'm not looking to get into a debate over whether or not to get "N" rate tires - I've been down that road before. I'm simply asking for recommendations about which "N" rated tires people like or dislike. I drive about 100 miles a day on good highways in central Texas. I have plenty of opportunity to get my C4S up to autobaun speeds, not that I would ever exceed the speed limit. I like a quiet tire but I realize that a quiet ride in a C4S is something of an oxymoron. Any feedback?

My '09 C4S does not make a "chirp" when I lock or unlock the doors using the electronic key fob. Is there a way to get the car to make a "chirp" when I lock/unlock the doors?

I considered doing basically the same mods you are talking about. I think in order to get the increase in horsepower you are hoping for you will also need to reprogram the ECU. I suspect without reprogramming, the stock ECU will automatically make adjustments to your engine that will prevent you from achieving the gains in torque and horsepower you are seeking. For me I think my money is better spent taking a driving course from someone that can teach me how to really drive my car the way it is designed to be driven. I suspect I am really only utilizing about half of its performance and handling capabilities. Adding more torque and horsepower definitely is fun for rapid starts and acceleration so the mods you are considering plus reprogramming the ECU I agree are very appealing, but for me I think I will take some performance driving lessons. Then if I think my C4S is too anemic I will consider dropping some bucks into the mods. Keep us posted on what you decide to do. I would love to hear how the mods work for you and see a dyno of the changes in performance you achieve. Good luck! MWS

ADias, you certainly made some interesting comments. My question to you is are these your Opinions are do you in fact know that what you have stated about mixing "N" rated and "Non-N" rated tires to be harmful to the vehicle. If what you have said is FACT then I would like to know the sources of your information so that I might review the information for myself. On the other hand, if what you have stated is merely YOUR OPINION that mixing two tire types may be harmful to my vehicle then I will certainly take your opinion and inferred advice into consideration. I think it is important to clarify what is FACT versus OPINION. Everyone is entitled to their opinion That being said, I now have a couple of thousand miles on the Hankook Ventus tires. Perhaps they needed a "break-in" period because they are handling much better now. Although the car still tracks a little loose in that it drifts left and right unpredictably it does seem to have improved. Likewise the traction control system has not kicked in in quite awhile as I go around corners although the C4S does not feel as solid as it did with the Michelin Sports I previously had. I still don't think I would recommend the Hankook tires on a C4S, but maybe a set of four instead of two as I have, might perform better. Bottom line, however, is if you can afford the "N" rated tires buy them instead of the Hankooks.

OK, so I have been driving on the Hankook Ventus V12 tires on the rear of my C4S for about 800 miles. I still have the old Michelin Pilot Sport tires on the front. I wanted to give the group my feedback at this point. I'll start with the good: Attractive tread design. Quieter than my old worn out Michelin Pilot Sport tires. Less expensive than the Michelins. Unfortunately that's the end of my favorable impression. On with the bad: Car does not track in a straight line. I'm having to constantly steer to correct the car's tendency to drift unpredictably in the lane. I probably look like a drunk driver to anyone following me. Traction control system engages as I go around corners. This occurs while driving in conditions and at speeds that in this car previously never caused even a hint that tire tires were about to lose their grip. I absolutely wound NOT recommend putting these tires on a 4S. I read favorable reviews for the Hankooks from people with Boxters, Corvets, and BMWs. It makes me wonder what kind of lousy tires had they been driving on before buying the Hankooks. My plan at this point is to continue to drive on the Hankooks until my front tires need replacing then I will replace all four tires with a set of "N rated" tires. Costly lesson learned. Hope this helps.