Hi all. I'm a new member that is doing some due diligence on a C218 550 purchase. I'm interested in the tuning and modification options available to create a practical and fast daily driver out of the 550. An AMG is out of my price range but the 550s seem like a great value. The 4.7L seems like an amazing engine with a ton of capability but I'm just not finding a ton of info out there about how well these cars take to a tune, especially at higher mileage. Maybe it is not a typical 'tuner' car? I think its one of the best looking cars on the road and would just like it to have a little more oomph than stock. This is a crosspost for another on benzworld. It seems like this forum is a little more active for the 218 so I thought I would try it here too.

Here is what my google research has yielded so far plus some open questions I have about the C218 and the car's reliability on a tune. I'm getting a general sense that these twin-turbo 4.7L engines can produce waaay more power than they do in the 550. The question then becomes, can the rest of the drivetrain handle it?

Logic tells me that, if the engine and drivetrain could be pushed this hard, MB would have done something more impressive from the factory. On the other hand, AMS, Weistec, and Renntech are all pushing similar numbers on their tunes with no modified drivetrain components. Selling something the car can't handle would be bad for business and I'm also not seeing any posts about damaged transmissions or engines. Maybe that says something? I'm also wondering, does the average Mercedes owner simply own the car for so few miles that issues don't crop up? Or, when they do, they just pay for a new transmission and not worry about it enough to discuss it online? I will need to know the car can last 100k+ miles though. I'm more of a budget-constrained car enthusiast and not your typical Mercedes buyer.

I think there are some answers to the question in the highest power applications where MB uses the 7G-tronic transmission (before the switch to 9G in 2015). The highest torque levels I can find this transmission used is on the W222 S550. That car has 516lb/ft by Mercedes measurements, which I read is an average over a range of RPM. It is probably more like 560lb/ft by industry-standard peak measurements. Mercedes switches to the 7G-Tronic Plus for the S600 V12, which has 616lb/ft (per wikipedia), so maybe it's more like 660ft/lbs by more standard peak measurement. I can't find evidence that the 7G-Tronic Plus is any stronger than the standard 7G-Tronic though. If that's the case, that would mean that this transmission could probably handle this tune pretty well.

I also can't find evidence that the CLS 550 and CLS 63 S use any different prop shaft, rear end, and 4matic front-end components. If that's true, it would confirm that the 550 can take substantially more power than it comes with from the factory. I would love it if someone could confirm or deny this!

One other thing for consideration here is that these transmissions limit torque through software and that might be why Renntech et al can push so much torque through them. Torque limitation would be good for reliability but might also mean that the performance post-tune is much less impressive than one might think. Does anyone have quarter-mile times for a CLS 550 post-tune? I've seen some numbers on tuned 4.7L E-classes in the low 12s. That seems pretty terrible for an AWD car with 700ft/lbs of torque. I think these do 12.8 seconds stock.

I would love to hear from those with hands-on experience with these cars! Thanks for taking the time to read this and for any info!

 

For me, I have not run it very long but I have done a lot of research:

1) It's not exactly plug and play, you need new sparks, I know they don't like to say that anymore but it's true imho, it may reveal some weaknesesses in your engine, like check valve etc. It basically to me reveals issues that were there.

2) The computers in this car do a ton. I wonder if anyone has updated the ECU with a stronger microprocessor

3) You have to change the oil more. I've been told like 3-5k miles

4) there may be more pressure and tension on the chain. They updated the chain at some point, I believe the updated one has thicker center links, you can check from looking at the oil

5) I would change tranny fluid more, add an oil catch can, and upgrade the cooling too. Lower thermostats, always on IC pump, remove air dams, etc.

6) updating the air inbox and filters does add quite a bit of power

 

Thanks for the response! So you aren't worried about the 4matic components handling the power? Do you get any sense that all the power isn't getting to the wheels?

 

But the thing is, even if Mercedes tuned the engines to produce more power from the factory (which they obviously could easily do for the 4.7L Biturbo engine), then some people would not purchase the AMG's, as 0-60 times would be so close to each other that paying an extra $15-30k wouldn't be worth it for a couple of tenths. I have a CLS400 and it's pushing 430hp/460 lb/ft torque after my EC tune, so it's pretty much a stock 550 with a bit more power, but they share the same tranny, etc, so I know the transmission can handle the added power of the tune. The 2015's use the 7G-tronic, and the 2016's have the 9 speed.

There are plenty of people here with a 550 tuned that could tell you their 1/4 mile times, but I don't think many of them are equipped with 4matic.

I'm sure if you're afraid about reliability, you could ask the tuner to decrease the torque for example? But I do know if you go with a highly reputable brand such as Renntech/Eurocharged, you won't run into many problems. I know that Eurocharged has a 2 year/20k warranty on the engine, more details are on their website though about that.

 

I can't speak for the 4Matic vehicles, but as I am told, a Transmission Control Unit, TCU, tune is recommended, not required, to "remove" the torque limiter. Just like there is a speed limiter. That TCU tune will allow you to produce as much torque as possible based on your ECU tune and you might have a hard time having good traction starting from 0mph unless you can "master" it haha.

I'm on Stage 2 tune by EuroCharged and, as they claim, it is rated at 585hp and 690tq. They can create a bit more aggressive tune by bumping up the turbo boost tad a bit, but they don't recommend it, I think. Unless you upgrade your turbos to M157, then they can up the boost and you can gain close to 100hp, as far as I've read, not a factual number. There are plenty of people running Stage 2 tunes on the 550 and I have not heard anything breaking or falling apart, YET. The major issue I can see from upping the power is that not doing much about the AIT and engine cooling temperatures. For that, the Methanol/Water Kit can take care of it or upgrade your IC pump and radiator/heat exchanger.

 

I spent along time reading through the scoring issues and valve issues. I think that MB should have installed a BOV or larger diversion for charge air and that oil catch would have also been useful.

I would consider getting a BOV and catch can before tuning (or shortly after).

I've also heard hard launches can be a bit hard, even stock apparently reports of motor mount damage.

 

There are some threads buried in here which I've read basically a fully built 278 vs 157 w/7g is going to be very similar in terms of times because of the torque limits. I would guess a limit for the 278 is like 800-900 hp, and the 157 is like 1000 maybe 1200 with rods and things. It's just much easier to get to the 700-800hp I believe with the m157. But they translate into like mid 10s and low 3s maybe on street tires. With launch control I'm sure it would drop those. The 63 vs 550 are different tho, the 63 drives better, dialed in. It doesn't have air suspension all around so it's not quite as good as a GT. One is a mercedes one is an AMG the engines are very similar. I would guess a tuned SL600 and SL65 are actually fairly close too. You're basically paying Mercedes to tune their cars, very well.

4matics should launch faster and may distribute torque better. I think you can change turbo back pipes without dropping the engine on a rwd (maybe even turbos themselves).

 

I'll budget a BOV and catch can for the build then. And upgraded cooling. I think I would try to get some miles out of the stock spark plugs and motor mounts and then plan on replacing the plugs with colder ones and upgrading the mounts when they fail too. It looks like there are plenty of stronger mount options out there including some OEM ones off amg models.

In general, I'm learning that these 278 tunes are less plug and play than I thought if I want to keep things reliable and low maintenance. Once all these odds and ends, tune, exhaust, and intake are done, I'd probably have 8k into the car. I could buy an AMG for the total build cost. I'd need to come up with the cash all at once though. With the s550, I could build incrementally over time.

I'm intrigued by your comments on the 156 vs 278 too. Those 156s are really good for 1000hp stock, huh? Maybe I'm better off going for a 219 cls 55 to get that engine instead?? Those are beautiful cars too. Its probably easier to find a clean, low mileage AMG on the used market compared to a 550. 550s probably tend to be daily drivers. But regardless of power levels, it sounds like the limited transmission is the bottleneck. Like Roop94 said, TCU tunes can apparently delete the torque limiter but has anyone have luck with those? If those worked, and you can get the power to the ground, I'm just surprised that these cars aren't faster with a tune. With no limitation on the transmission, you're putting down 650ft/lbs. I would think 11s are no problem. The weight of the car plus AWD should have any traction issues covered. Whats holding this car back?

 

I would do the TCU tune, but it costs roughly $1,400 range. So I don't know haha. I follow this one guy on IG and he recommends it. The car will have less traction if you're just gunning it from 0mph, unless you can launch it properly. AWD should have a better traction. Mine ir RWD and I already get decent wheel spin and I rather not have more of that haha. With that high tq and no tq limiter, it will be hard for me to have good traction. I'm currently at ~690tq and planning more mods, so it will def reach 750-800tq once I'm finished with all the mods.

 

I have realized I was wrong about the M156 being in the CLS 55. The M156 was apparently the engine for the CLS 63. The CLS 55 had the M113 but that engine sounds like its a beast too (and probably more reliable than the M156 from what I'm seeing).

 

I am tuned for 18k miles with a rwd cls400, I've yet to have any drivetrain issues. I do however have a very hard time launching from a start. I have the 7g-plus trans. I can't really say what is going on until i actually data log . These cars are definitely able to handle the extra power , just pretty difficult to put it to the ground from a standstill. Roll race is a whole different story, Definitely surprised a lot of naysayers tho..lol.. but the real question is how fast do you want to go?

 

M113 is easy to get like 700hp maybe 800. But then it’s a wall.

M157 is the bigger m278 v8 bi turbo which should be the best engine for tuning. There is a non turbo version i guess i confused that some places.

11s are fairly easy. >10.5s are doable too. Anything lower than that is hard (though there is at least one guy who did low 10s/high 9 with stripped interior on ethanol) because as i understand it. Your supposed to limit some of the torque at like 800#/ft or so. I recall it being more complex than that but that was an easy way to remember.

 

almost positive you have the 9g tranny. In usa post 2015 cls with 7g (mct) are the cls63.

The pulling power is very good. Surprisingly good.

 

Are you saying that the M157 and M113 can easily get into the 11s, but not the M278? I'm assuming that's the case because I think that all applications for the 157 and 113 also have upgraded transmissions (tronic plus or MCT speedshift) and that seems to be the bottleneck.

I found a post somewhere with a bunch of quarter mile times for various M278 E550s. I don't think anyone was in the 11s but I'd appreciate it if someone can direct me to a build where someone is hitting that with any 278 (especially on street tires),

 

Several members on here have low 11s m278 in e and cls. There are some deeper threads about the torque limits. It actually is about why the 278 and 157 get really close towards the end. The transmissions arent that different. The lock up is.

almost any 278 stage 2 cls should be high 11. And some stage 1 will be too if they have a tranny tune.

https://mbworld.org/forums/w212-amg/...bo-faster.html

nota_amg runs low 11s for example.

 

I’m hoping to break 12s with my m278 Id be pretty disappointed if it didn’t

 

No i'm definitely 7g plus, wish i was 9sp tho or even the CLS-Class 63 speedshift.

 

Thanks for the info, I need to give eurocharged a call for tcu tune. Its definitely holding my car back from a dig. Every time i try to launch, even with a little brake boost the car pulls back until 3rd gear. Its annoying to say the least.

 

You should be high 12's stock. With a stage 1 tune.. high 11's low 12's most definitely. The newer stage 2 tunes are producing even more power.

 

I’ve got the stage 2 Weistec tune which claims crazy hp and tq and the car actually feels great it’s finally been driving right tuned with downpipes since Saturday and it’s pretty fun around town just gotta find time to get some slips.

Now I was thinking about a tcu tune because of the things I’ve read about it increasing the life of trans and drivability and then I’ve heard it’s not worth it and not necessary....... now i dont care about spending a few bucks on improving driving experience as well as longevity just don’t know how true that is and i honestly would like to know if anyone has ever had the tcu tune and it be detrimental? Now one would think common sense if you are applying an ecu tune claiming 159 extra horsepower and 322tq that the transmission would have to be adjusted to be able to handle those gains as well but my little bit of research hasn’t brought all the results I would like to know. I’ll be digging for info right after this post to see what I can try and come up with and I’m going to ask Weistec as well and see what we could come up with I also have another friend at titan motorsports in Orlando with a lot of experience tuning really high end cars and pick his brain for a few.

Would love to know if anyone on here has their car ecu and tcu tuned.

 

Here is the link cls5504matic provided, very good reading. Are you rwd or awd? Do you have any issues with your car cutting power from a launch? Im rwd so i definitely could use the tcu tune. Even when i put my car in dyno mode, it falls on its face because of torque limiters. My best 60" at the track was 1.9 feathering the gas. Right after launch, i feel the limiter kick in and i have to wait till 3rd gear to finally get full boost. I wish i could boost off the line, i feel that the car has so much more on the table. Any links on people who have said its not worth it?

 

Will check the link and yes rwd and funny you said that tonight I went to go do a couple practice launches, I’m lucky enough to literally have a mile and half maybe 2 mile country road right outside my gate where I live and long story short I went to do a few launches and i turned off the esp and when I took foot off brake it went limp and Said inoperable and my traction control light and another light came on so I stopped the car, turned it off, Turned it on and went to try again and got off maybe to 2nd gear and same thing happened. Then I threw 2 CEL lol one for turbo under boost? And I can’t remember what the other one was But I cleared the codes and drove around more they never came back on and I went to do a few more pulls before I decided to give it a rest and it seemed to be better but I didn’t try to launch with the esp off, I dont know if it needed to be warmed up a little more or what. Tomorrow I’m going to do a few more pulls after I drive around for a few miles and lighter pulls before I try to do it again. So I’m wondering if it’s the transmission..... it’s only come on when I floor it. Sometimes I wish I had the 4matic because of the launch and I LOVED my C300 4 matic and the handling was awesome but I also love the feel of the rwd but anyway would love to get this thing dialed in

As far as where I read it wasn’t worth it, was somewhere on reddit I believe dude said something to the effect of its 500 and you don’t get much for that but a few extra horsepower and said he couldnt justify the cost or something to that affect and there was a lot of back and forth but nothing I could find in my brief search that made me feel like it was something I should, or shouldn’t do for that matter. I’m going to check out that link from cls5504matic im really new to all of this actually, never had a car before the c300 which I only had for 6 months before I bought the 550 last year but I am super grateful for this forum and the info I get here.