Overall I am very happy, the diffuser looks epic in person but the install was a pain and yes i had to remove the bumper. Surprisingly bumper removal was super easy, so that was not an issue but i had to use a dremel and shave some parts of the bumper as they would prevent the diffuser from sitting on the bumper tabs. The diffuser itself was not perfectly molded and i had to use a heat gun and some pressure to sort of mold the diffuser to the bumper. Everything else went according to the renntech install procedure. You can get the diffuser in usa spec or euro spec with the 3rd brake light opening and i learned that my car was already prewired for it and the bumper had the mounting as well but didnt know this prior to buying diffuser. I wish renntech offered an affordable diffuser with cheaper materials and not pre reg carbon, even with all the work, the diffuser only cost around 600usd vs 3.4k.

 

Did you buy it from RW Carbon or just off eBay? $600 sounds good to me. RW charges $1,100.

 

Yep bought it off ebay. You can bargain with them using the best offer button, and you get a discount if you buy different carbon pieces from them like mirror covers etc. I believe there are 2 suppliers that make these replicas, one of them has tabs and pre drilled holes like renntech and mine which was cheaper but has just one solid piece that slides into the bumper and you drill your own holes for the fins. Not sure which one rwcarbon uses but from what I understand you get some sort of warranty and a better quality control from them.

 

Either way it goes that thing looks amazing man. You did a great job with the fab work. Hopefully I can get this kit thing down to a science. However here's a quick update..... I picked the car up today and dropped it off to get the R1 package. It felt very fast and very responsive to the pedal but I didn't have long to play. Had the car all of about 30 mins before I had to hand her over.

Now here is a quick question for you guys, does the mBrace app work with the 2014 CLS63??? And also can I run high octane fuel with the Renntech R1 upgrade???? How much more HP with high octane give me if applicable????

 

Let us know how the renntech tune feels. When i bought the car it was already tuned, i wasnt sure who the tuner was so i bought a eurocharged tune and according to them I had a renntech "low boost" tune. To get the the point the pedal feel was super sensitive, at a stop pushing down 10 percent felt like 40 percent and at speeds half throttle felt like 80 percent, the power came on aggressively, took some getting used to but with the eurocharged tune the throttle was much more linear so i was happy about that, full throttle felt similar but hard to tell between tunes. Another thing is cold start was disabled on my car which is cool since i will be installing catless downpipes so i think there wouldnt be a need for a cold start besides sound. Im curious if the pedal feel and cold start disable is something renntech did to the ecu as a special request.

The ecu will definitely adjust for race fuel not sure how much hp you will get though.

For mbrace you have to make a mercedes me account, then add your vin and afterwards stop by the dealer, have them verify the vin with your account and finally you will be able to set up an mbrace subscription.

 

So I will pick up the car on Friday June the 16th which is my Bday and I'll drive it about 100 miles back to my home town where it will be garaged. I'm going to run Michelin Pilot super sport tires and wide as I can go on 20's. I also spoke with Renntech today about the high octane race fuel. He said its perfectly fine to run 108 RON but he'd recommend a 101 octane because you wont get much more out of the 108 and the price is a big difference. He also said that he would recommend a 30/70 split on race days and a 50/50 for daily use. The slit would be between 93 octane and what ever race fuel your decide to run in addition with it. I plan on going to the extreme with these tires and the race fuel as long as its safe stable. My only regret is NOT having my car in stock OEM mode for longer than 30 minutes so I could recognize the difference. But I'll take pictures when I receive my car and also make a short video link with my gopro for youtube.

 

I'm not sure of the hp gain, but you should pick up 1-3mph using race fuel on track days. Had this tune and consistently pulled better traps with 93/100 mix.

 

Oh wow, sweet man.... I don't think many people are getting their cars dyno'd after a fuel octane increase because of price. It may cost you 400 bucks for (3x) pulls on the dyno and that may or may NOT come with a tune. I'm going to do a 30/70 split with 93/101 and see what I can put down on the dyno. I'll have pics ready by next Monday for sure but I doubt I'll make it to the track by that time. Do you still have your Renntech R1 setup with 93/101? Does anybody know where to get some quality race fuel from in ATL area? Any help would be appreciated.

 

No prob. I'm sure you will the love the car and the Renntech goodies! My car has become a bit of a mutt with Renntech stuff, KW stuff, Weistec stuff, UPD, and Eurocharged ECU config.

 

So I got my car back with the Renntech R1 package and there is much to talk about. I'll try my best to stay on track because I have so many pros and cons which are related and non-related to the mod itself. I may just start another post for my additional mentions.
The R1 package is quick to me NOT fast as I was able to put down a 11.7 and the track this past Friday. I say quick because the car makes it to its max power band within it rpm range very quick. I say not fast because I own another car that spins through 4 gear and can do 140mph in a quarter mile where as the CLS63 did 119mph. However in the CLS63 defense there is a learning curb that I'm still trying to master with launch control. I'll start a new thread for launch control because to say the least I am not fu&$ing impressed.
But for the most part his car is torque strong and has a very aggressive pull until it reaches it max rpm power band for the gear your in then it falls off like a 46 year old hip hop artist. Paddle shifting can help with this a tad by shifting prior to reaching the limits but this leaves room for human error. The BOV that comes with the R1 package sounds lovely and the harder you push it the louder it sounds. I think if you can get out of the hole and get the jump this car is capable of low 11's and possibly high 10's. Renntech should offer a TCU upgrade for the initial pedal to power lag that is a problem from initial launch.
I would also like to note that Renntech DOES NOT affect your factory warranty as my install was executed at Mercedes Benz of Buckhead in Atlanta GA. This is a plus because you dont have to detune your vehicle just to bring it in for a oil change. Reason being is because the previous president that was over Mercedes Benz AMG department is the owner of Renntech. But over all I'm seeking more HP yet happy with the R1 package.

 

Also I have pictures of the times I ran in addition to the videos. I'll post all that soon as I land in Texas..... let me know what you guys think.

Keep in mind these factors..... I could NOT get launch control to engage at the track. I could NOT get traction control to shut off. And I could NOT get the paddle shifting to work in my favor.

Sorry I let you guys down but it's been about 5 years since I've been to the track. I forgot how to race LOL.... there is a method to the madness.

 

Awesome man. I'm sure you're enjoying the car! If it's as hot and humid in Georgie as it is in fl right now, you made a good time for this car and your mods. Trap speed could be higher but again with weather factored in, it's not bad. What octane fuel did you run?

Thanks for sharing.

 

Thanks for all the info!! A tcu tune would wake these cars up but as far as I know, no american company has figured it out yet. GAD Motors can tune the tcu but not sure to what extent.

You have to be a beast to effectively use the paddle shifters, the delay when pressing it is just not worth it so better to stick with sport plus mode.

Were you able to get into race start mode? It will only engage in sport traction mode and then it will only hold the rpms for a couple of seconds before it turns off. Also the car has to be at operating temperature.

The renntech diverter valve looks like an interesting product, I am considering purchasing it but am curious as to how well it works with stock turbos, I can definitely see the benefit with bigger ones.

 

My only real concern is a tuned cls63 only trapping 119mph...

you should be at around 600whp, and even stock
cls63 are trapping over 120mph. With tunes these cars usually trap 125mph+ so I wonder if all is good with the setup

i know the weather wasn't the greatest but not sure if it should be taking away this much power?

 

That's fair. However, I bet he lost at least 3 mph due to weather. I ran my car yesterday with some friends and we were all down several mph (90+ degrees and > 55% humidity). I was able to run consistent 125.xx but no more.

 

i took this into consideration, which means he would still be at 122mph, close to stock performance.

124-125 would of made more sense for sure with a tune.

do you think it all comes down to bad weather and launch?

 

From what I've seen, there are very, very few stock m157s trapping 122 stock. It happens, but it's not as common as the internet would have us think. Weather, car, driver, tires, etc all play a factor, as usual. Race gas prob would've gain 1-3 mph as well I imagine.

​​​​

 

Yea I'd say stock we usually see about 120-121 at the track, I agree 122+ is very unusual.

Regardless, for tuned m157, 122 is on the low side of things assuming at least 93 octane fuel was being used.

OP what fuel are you running with the tune?

 

I look forward to feedback from the op as well. Sharing is goooood.

....when I had a renntech tune, which was awesome by the way, I would trap 122.xx on 93 octane and 124.xx on 100/93 mix (with one run of 126.xx). That's catless and with BMC filters as well.

 

Wow and catless... I'm sure your weather conditions must of been terrible or something.

 

I really appreciate everyone chipping in to keep this awesome circle of good information going.
I'll tell you what.... I can't remember the temperature Friday evening at Reynolds GA. Silver Dollar race track but I'm sure it was somewhere around hot as fu#$. As for the gas.... I had plans on buying a barrel of 104 octane but storing that at my house with two Siberian huskies and two daughters 3yrs and 1yr would probably go all wrong for me. I may find a pump next time in ATL that has the goods on tap. However, I was running 93 Friday which should have been good enough to do some decent times and reach a respectable mph.
I read above in another post that the car has a fail-safe feature that won't allow you to launch when the temperature is a certain degree. Well, that makes a lot of sense seeing how I could not get the system to engage in launch control at all . I wonder if that was the reason I couldn't get the car to go into that other mode where you hold the TELEPHONE button and the OK button for 3-5 secs. I'm not sure but I still can't get that to engage again as of this day.
Guys let me know what you think and any help will be greatly appreciated. See below for track times and I'm going to try to upload these videos as well so you can see how things went down.

 

I'm thinking the TCU torque limits was cutting a lot of power when trying to engage race start which never worked. That could be the reason why the traps are so low, otherwise I really am not sure why.

I would contact renntech and let them know, maybe they need to check something out.

 

I just don't understand



I just don't understand again

 

Videos are poor quality but I can't drive and shoot the video and my family obviously can't be quiet and shoot the video.

 

Lol "what are we gonna do when it gets dark??" SO cute! haha

Anyway, man i say contact renntech. Show them the results and say that even a stock one should be doing these times so what exactly did the tune accomplish. Seriously