I got the Kleeman tune and love it. It Comfort ride is really smooth and the Sport is truely aggressive (especially the downshifts ... its always ready for you to stop on the gas). It was well worth it. I sent mine to CO on Monday and was driving it (hard) on Weds.

Another happy Kleeman K2 customer here. My car is a DD. No regrets. No downsides.

I thought C/M/S were just transmission modes. Does that affect the tune too? Is it substantially different "crazy fast" in S mode?

I know on BMW the shift modes aren't able to change your fuel map or any of that crazy stuff.

S mode is like running the car in Manual but it actively matches the engine speed with the downshifts. So yes it is not just a tranny mode. If you have ever driven on the track with a fully manual car one of the first fundamental lessons you learn is heel toe braking while downshifting. You want to blip the throttle as you are braking in a straight line so that when you downshift the motor revs are matched to the lower gear ratio.

In a quick and dirty explanation the C63 in S mode will not only downshift the car when on the brakes but blip the throttle to make sure the downshifts are smooth and more effective.

This is the first car i have had with a paddle shift and "smart" tranny computer. I must say that I have been racing for 19 years and have never had a car that does all the right things at the right time (by itself) than the C63. I believe, and this is just my opinion, that S mode will out shift and beat a driver in M mode any day. This is coming from a guy that has been racing against Porsche Cup cars in competition for the last 4 seasons against the newer Cups that come with a sequential dogbox. I am racing a Cup car with a standard H pattern 6 speed that requires the driver to master the heal toe technique to be one of the fast one out there. If I miss a shift or don't match the throttle to gear exchange then i loose a turn and the newer cars can jump ahead of me.

So back to the C63... The driver using the "manual" setting can only make that an advantage if they can master the shifts when going into a turn, or coming out of turn. They key is mastering the art of momentum and carrying it though the turn. The beauty about the C63 is that in S mode the car does this on its own. Yeah, it may be fun to drive in manual mode because the feel of the car is so present. However when you can't feel the car doing what needs to be done you will be faster on any given day. The smoothness of the C63's tranny and engine maps is excellent. I guess if you really practice and learn a course very well you may be able to out drive the computer. However when Porsche came out with the Tiptronic tranny that learned as you drove it I became a believer in the new technology that has only gotten better year after year. **** F1 has had this for years !! Cheers Andy

even though some mail order tunes would be/ are better then others, i recommend getting your tune from some one who has a dyno and can tune your ecu while the vehicle is on the dyno. atleast then you can monitor the efects every little change on the ecu does.

good luck with your decision

If you drove 3 C63's with 3 different tunes....

You would most likely have 3 smiles!

Personally, cost/HP is my favorite direction...

Let me know if you have any questions, I can explain in detail about the tunes.

-Adam

Do you guys do dyno tune? and how much would it cost?

you should go for REVO, i've had the ECU upgrade and crankshaft pulley, the results were amazing ! after dyno: 231 bhp ! image what the results could be over the amg

FYI, just got mine back from Renntech and did a 100 mile "training" session and I have to say I am very disappointed thus far. The dyno #'s are pretty much the same as stock and I cannot physically tell any difference. That being said, I have only recenltly contacted them and made them aware of my concerns. From what I understand they have a great reputation and customer service so I am hoping to get some answers and improvements. Otherwise I will be moving along to Kleeman very soon! Good luck!!

THanks for the feedback on the Renntech. That was my 2nd option so I will go with the Kleeman K2 instead of the Renntech. Thanks and I hope Renntech makes it right for you, they should for that price....

Good Luck

You should be getting a response from renntech and if there is a problem with your tune i am sure they will fix it! My only concern with renntech was always the damn $3400 price tag they have for the same tune I had mine from Kleeman for $1500

I know there's an adaptation period for the tune to break in, but what if I don't drive it particularly hard for that first tank of gas? Will it never reach it's maximum potential? Or will it just take longer to do so?