Hi, I purchased a CPO'd 2015 CLS63 AMG about 6 months ago. I am dissatisfied with 2 areas of the car that I am hoping can be resolved with a ECU and or TCU tune. I do not want to tune the car until I hear from someone with experience to tell me if I would just be wasting my money. If a tune would not help then I will likely just sell or trade in the car for something else.

I am highly annoyed that my car keeps having a serious delay in throttle response at low speeds. Aside from having one of the weakest takeoff's I have ever had from a high horsepower GT car, sometimes when I am slowing down to say take a turn and then hit the gas, there is seriously no response at all for probably a full second to 1.5 seconds and then it starts to accelerate hard. I literally put the pedal to the floor and nothing happens...WTF. I hate this and if a tune will not make this go away then I am done! I am considering using RENNTech for both an ECU and TCU tune but if this will just make the car faster but not fix this lag issue then no more for me...it makes the driving experience very non-rewarding.

Anyone have some info for me please. Thank you all in advance and regards!

 

for some reason, most MBs in the past 15 years have that lag ... it is correctable with a tune, and probably just as good of a reason to get one as wanting more power

 

Hi, thanks for the reply. I have been an AMG owner non-stop since 2005...CL55, Renntech SL600 with AMG package (only non-amg), S65, CL65, E55, ML63 x 2, SL63, and now CLS63. All my other AMG's, except my 2013 SL63 that had my same M157 current engine, have had instant throttle response. My SL63 was tuned and had less of a delay but still a small lag. It was less noticeable because the car was rear wheel drive and would spin it's tires when I got on it so I was not sure if the delay was the tires breaking loose or just poor throttle response? My current 4matic CLS63 is a total dud off the line and when slowing down then mashing the pedal when taking a turn is horrible sometimes. I almost got killed when I was taking a right turn as traffic was coming and my car literally stalled for 1.5 seconds with the pedal to the floor. I had a Charger Hellcat for about a year as my daily driver and just got use to instant throttle response. I thought that all wheel drive would be amazing for launching the car and spirited driving but it has been a total disappointment. I am hoping the tuners will be honest with me and let me know that this can be resolved before I waste money trying to fix it. If not I would consider the the new C63S with the 9 speed transmission...I have not heard any complaints yet regarding that transmission set up. I was hoping someone who experience my problem had it fixed completely with a tune and would discuss their experience how the car feels after the tune. I have read in the E63 forum that many had the same problem as mine and a tune did not really get rid of the problem. None had the Renntech TCU tune so I am trying to find someone who did this upgrade. Thanks again!

 

Yeah. MIne has a lag too. But every car with turbos have some type of lag unfortunately. If you tune the car, it would or should drastically increase throttle response. The major tuners promise not only increase HP and torque, but increase throttle response, speed limiter removed etc. Renntech is on the very pricey side. Try the AMS Alpha performance tune.

 

Hi, did you get the TCU tune now? I have a 2015 cls63s, and also hate about that lag

 

HI, I have not done anything yet to my car. I have been debating whether to get rid of it or not and maybe step up to a 2018+ E63 S so I have better throttle response an no lag. Also newer electronics and better launch control. A whole Renntech package would cost me between 6-10K and that would likely solve my issue but for 10K more I may be able to find a preowned E63S so I have been debating with myself. If I get the ECU/TCU tune I will report back. I am likely going in that direction.

 

I plan on adding a custom dyno tune in November with my new to me 2015 CLS63S. My 2012 E63 had that lag until I tuned it. Then it was a complete monster in Sport or Sport+.
I also know some other settings effect these cars at low speeds too. For instance what mode are you in C, S, S+ or M, what mode is your traction control in? Comfort, Sport, or Off.

I've read a few W212 E63 guys who have done the TCU tune and it just raises or removes the torque limitations and boost limitations in earlier gears which would primarily effect the heavily modified or tuned vehicles, not so much a stock car.

IF I was you, get a tuner to help you and see what can be done and have them do a dyno tune.

 

It sounds like your car has awful adaptations from the previous owner and they need to be re-set or re-flashed. My ‘16 launches like a raped ape and kicks down hard because I had everything reset and adapted to me.

 

I would have the transmission checked by a Indy MB tech...When I had my Son's 2016 CLS 63S transmission fluid and transmission filter
changed the shifting and lag was greatly improved...

Good tuners can re-map the ECU and change the shift points as well change dwell times...in effect get rid of most of the turbo lag you are
experiencing.

I would say .5 to .95 second initial turbo lag delay for the M157 is normal (bone stock)...I would also check the dual air filters to see if they
are dirty...

Good luck.

 

Hey thanks for the response. I live about 1 hour from Renntech so I will likely get the ECU/TCU tuned, the BOV, and high flow filters. This will likely fix the issue. I never drive in anything other then S or S+ with in sport traction mode. There was a software update for my TCU that my mechanic was able to download and add to my car...made a huge difference. Much less lag while driving but still off the line. I believe it is the torque limiters protecting the drivetrain. Hoping the Renntech TCU will solve that issue because I love a strong launch and my car just does not have one. Using race start is not bad but without it the 1st 0.5s of mashing the pedal is very disappointing. I will report back!

LF

 

I can't stop watching your GIF....Lol! I love the guy gets out of his car and starts to run...LMFAO...hahahaha

 

When I go for the ECU/TCU tune I will address the issues you brought up. Appreciate it, thanks!

LF

 

Agreed

 

Hey Larry,
For sure doing the ECU tune/Renntech upgrade will take care of the lag, this has always been common with Mercedes, even with the old NA engines that few second delay was always a complaint that has been apart of the DNA of MB cars. Whenever you do the right tune and programming of the ECU it makes the car have a completely different driving experience.

 

+1 on a tune. I have a '16 and when compared to my previous one (an '09 non turbo), the lag was noticable. I got a stage 1 Eurocharged tune and the car woke up.

 

My Sons 16 CLS 63 S AMG is now running brand new Ultimate Performance & Design Performance Air Flow Kit, soon it will have the MBH
high flow cat-less down pipe system installed...he is contemplating either a Shop CT or Renntech Stage 1 Tune to complete the overall
M157 goodness...He was contemplating a Weistec turbo back system & tune, but the sticker shock kicked in and with the cost of the
install was quite expensive vs. the performance gains to be had...

Getting back to the original question, yes a tune will greatly improve overall performance and help to get rid of the turbo lag and such...On my
Sons 16 CLS 63 S AMG the New Tranny Filter and Fluid change made a huge difference in shifting and helped the turbo gain full boost faster
with less lag ( a full service was done during the tranny filter and fluid change including engine oil and filter change, new cabin air filter, new
air filters, etc.).

Only thing really left to do is to install brand new spark plugs as those M157 engines need frequent (comparatively) spark plug changes with
there high boost and hot running hp engines.

Best of luck with yours, thanks.

 

Thanks all for chiming in! Here is my concern... I have had many AMG's over the past 15 years: 2003 CL55, 2004 E55, 2005 CL65, 2006 S65, 2005 SL600 with AMG package, 2010 ML63, 2014 ML63, 2013 SL63, and currently 2015 CLS63. I have been and active forum member since 2006 as a side note and this is truly the best forums that I have ever encountered! Most everyone is so nice, helpful, and great to converse with! Back to my point, I am not a neophyte regarding these cars. My 2013 SL63 (same M157 engine) had a stage 2 Renntech tune on it and I still noticed a slight delay upon launching the car...even when not trying to race it but actually trying to offensively drive when necessary. The lag was a little less then my current CLS63 but never the less it was there and noticeable. It was rear wheel drive and I was able to break loose the tires often so I thought maybe the delay was the traction control (even when off it is never truly off) possibly? I was hoping it would be cured by 2015 model yet here I am with a 2015 AWD and still with the friggin' delay off the line...ugh. I think the ECU upgrade with make my car go like hell after the initial delay but I believe unless the torque management of the TCU can be suppressed the delay with continue. I feel the delay is trying to protect the drive train due to AWD and excessive torque. I would literally love my car so much more if this could be addressed. Apparently Renntech has a TCU tune but they seem to not give me a straight answer about the delay when I called to speak with one of their sales guys. The TCU tune is rather expensive...approx $2,500 and if it will not help me off the line I would go crazy that I spent that! I am thinking to do their R1 package, basically a stage 2 ECU tune and mufflers for some better sound. Hopefully I am wrong and the ECU tune will address the slight hesitation off the line. I would consider downpipes also but $4k is a bit much for downpipes IMO. I will bet the sound with the mufflers would be sick however. Any suggestions of cat back exhausts instead with a valve control for sound instead of the mufflers?

Thanks again for all your input and regards,

LF

 

Hey Larry,

You and I got to have a pretty good conversation about the exhaust and some of these other mods. I was hoping you would have gotten more info from the guys at RT, but maybe calling and talking to Hartmut Directly might provide you with some better info about their results with their options. In regards to the exhaust, I know that doing the Valve Control exhaust definitely cures that need for the increased sound, and being Valve controlled you can tame it, or have wide open. At the same time this option still provides the correct amount of flow keeping the torque and horsepower at the maximum level.
If you are having concerns about the low end torque and that initial jump off the line, doing some of these straight pipe configurations might help with the sound, but you also put the low end torque at risk having too much flow as the backpressure in the exhaust can flow too much and could jeopardize your performance.

The BIG name tuners like Brabus and Carlsson offered their HP upgrades for these cars, Brabus or Carlsson would do their power upgrades with a power kit/ECU tune, air filters, and the Valve Control exhaust system, these packages all had to be tested and TUV approved, so the performance numbers and results from these options were proven and tested upgrades that were by the book results. That is really the nice thing about companies like Brabus, and even Carlsson back in the day, but the engineering that they do is one thing, but because they are required to produce these products with TUV approval, this pretty much is like the written bible for what is fact on what they produce.

At times some of the HP numbers are off by maybe 7 or 8hp due to our lower Fuel Octane here in the States, in Germany and other parts of Europe they have 98 Octane, so the dyno numbers if they are off is due to this and usually it is only this 7 or 8hp that reflects on the dyno. Under normal day to day driving, you probably would not notice.

Hope this info helps. I know in the past when I did Brabus engine upgrades on various vehicles, that delay has always been a complaint from MB owners, and with every engine/ECU upgrade I did from Brabus the customers always raved about the performance and how the car felt more responsive.

 

The m157 makes serious torque in first gear, especially tuned ones so this is why is has that lag, to prevent the transmission from self destructing on a hard take off.


Did thise who who did the TCU tune on the e63 have reliability issues?

i have the same car as well, a 2015 cls63s with ecu tune, air filters, and catless downpipes. Still never fixed that lag off the line, and it’s been bothering me from day one.

The throttle response and power once the car gets going like from 2nd gear roll+ is mind blowing and out of control fast, but off the line it’s a dud.

Even if a TCU tune may fix it, I heard anyways that doing this if no torque limiters can break the transmission on a hard launch which is why they had to put it their in the first place.


Only other thing I can suggest is brake boost to about 2k-2.5k rpm then launch it, I do this sometimes and it doesn’t lag as badly but I understand it’s not really as practical as just going off idle. I’m thinking of getting the new m5 just because of this annoyance.

 

Hi, thanks for the response. Still thinking about your exhaust but I have some reservations. I have never heard a Carrlson exhaust personally...although I a fairly confident that it would sound very nice. Since Carrlson is really no longer the same company, I worry that I have no recourse if something bad happens to the exhaust. Example, if the sound component breaks down would I have a resource to get another one? Thanks in advance.

Regards,

Larry

 

Hi Larry,

I emailed you the Youtube link for the fire up on a CK63 CLS with this exhaust, and I will try to get you a sound clip from the guy who did the other one last year.
Carlsson is still active in Germany under new ownership and this exhaust is still an active part of their product lineup.
In terms of a failure, I don't really hear too often of an exhaust failing, especially this one being brand new, people here are selling used exhaust systems all the time, so for the price of this one I am offering that is brand new, I don't think you have much to be worried about.

 

Hi. I have a 2016 CLS AMG 63S and same problem. Seems if you drive in traffic a lot and aren't very aggressive, the response is a bad lag when you do need to step on it. Had the same problem on our 2014 ML 350 Bluetec, the turbo diesel had bad lag. So, I put a Pedalbox on it and it solved the lag. I haven't done it yet for the CLS, as I'm considering the Renntech tune, but the Pedalbox option is a cheaper and easier fix (link: https://www.pedalbox.com/en/ )

Try that first if you don't want to invest in the tune ($250 vs $3,000).

 

Hi, thanks for the response. I tried the sprint booster which is the same concept as the pedal box. It didn't help at all. Still the same leg but then it went like hell after the lag. I returned it. The only thing that will fix it is a TCU tune that will either eliminate or significantly decrease the torque limiter.

Regards,

LF

 

And doing that with hard launching might destroy the transmission , that’s why it’s there in the first place.

The best thing would be to figure out exactly how much of the torque limiters can be decreased without compromising reliability but definitely cannot be removed completely. I am not sure of a TCU tune out there that is designed that way

 

Renntech has a TCU tune that supposedly will address a good majority of this but it is $2,600! I would consider it but I find it hard to believe that no one has tried it and is raving about it here on the forums? This is a know issue with our platform and the W212 E63 with the same engine and transmission. If it was so good why do we not hear about people recommending it? I do not want to take a chance with $2,600 just to be disappointed. Plus they told me that doing the TCU tune by itself does not help that much and it must be in conjunction with their ECU tune...ugh. I was planning on them doing the ECU anyway but why will the TCU tune not help without the ECU tune. Just does not ad up to me. WTF, Tesla can launch like a mother****er, Porsche 911 Turbo/Turbo S jumps hard with launch control, why the hell can't Mercedes figure a cost effective way to reinforce the transmission for us to not have to have a friggin' lag off the line. Pisses me off!