blegthbloo

Correct, this is not an acceptable end result. I'm trying to work with RennTech to find a cause and solution for the issue I'm seeing. The most disappointing part about it is their tuner doesn't seem to work there full time (or could just be because of the holidays/timing), so getting a response from him is a waiting game...

I don't believe it is a traction issue. I'm reading more about the modded M278s and it sounds like they consume spark plugs like crazy, so the next question I just sent to RennTech is whether my plugs might be going bad (but not enough to throw a CEL?). I'll keep you guys updated. Might be time to upgrade to the Weistec plugs

blegthbloo

I'm going to replace plugs with OEM, since RENNtech tunes to OEM plugs. If that solves the problem, I might consider upgrading to Weistec/retune when the new ones start to go.

Edit: For the record, from my researching on this forum, the OEM plugs since 2014+ are different than the pre-facelift plugs (which I probably have), and the new ones are one step colder than the originals, so upgrading to aftermarket plugs is no longer necessary. This is why RENNtech pushes the use of OEM plugs, since all W212 models (and surely other models in the MB lineup) are now switched over to the new plugs.

I've been reading this thread, if anyone is interested or finds it relevant to this discussion.

cocobeex

I would be really really upset if the problem is caused by their tune.
They shouldn't release the tune before fully testing it.


But, in your case, we do not know if its from the tune or something else.
Or it might be caused by the quality of the gas ?

For spark plug, every 100 hp gain, spark plug should be 1 step colder.
But again, it depends on the tune I believe.


Also, if you want the sound, don't go with high flow cat.

blegthbloo

It's colder outside now, so the sound is a little crisper and louder, so I think I'll be fine with it as-is. For now lol

Gas quality is a possibility, but I always use Shell 93 and usually have no problems. I put the same gas in my bikes, lawnmower, chainsaw, etc. Should probably buy stock in Shell lol...

As for the colder plugs, yes, that is the recommended rule-of-thumb. RennTech tunes on the OEM plugs for 2014+ W212, which is one step colder tan the previous versions (like what I have). Yearly (~15-20k mile) spark plug changes will just have to be an added expense for the tune, and is something for prospective customers to be aware of (which is what this thread is all about).

I get the new plugs this week, hopefully, and should have them installed before Christmas.

Mike450

Following the thread and thought I'd comment.
In defense of Renntech, what they send you is bàsically a canned generic tune for said mods. It's not that the tune isn't fully tested or faulty, it's that it may need to be tweaked for each individual car, which is normal across all cars. It's the nature of the tuning game. There are 50 reasons why the car may not be performing 100%, and none are the tuners fault.

A data log goes a long a way in situations like this. I know it's not the easiest platform to datalog, but shooting in the dark at what the issue could be is tougher. And more $$.

TBH, I'm surprised a company like Renntech doesn't come up with a package tune/logger system for their platforms. It would take most of the guess work out of situations like this and be seen as a bonus over others, imo.

Of course, it could also be a faulty tune, but I would wager it isn't.

Good luck.

blegthbloo

Agreed... for the money we pay, something extra like that would go a long way to justify the price besides just paying for a name and some badges (which I won't be installing lol)

Also agree... I don't think it's the tune either, and to be clear I don't want to seem like I'm attacking RennTech in this situation. They are responsive and helpful with their suggestions (although I've gotten better help on this forum so far, tbh).

Yesterday I received 12 of the 8 plugs I ordered () so I'll be taking the car in later this week to get those swapped out. I'll update here with the results.

mjec515

here are the pics of what i was telling you about

so the plugs i removed which was original from the factory was Z6S113320
the new supposedly UPDATED plug is Z6S113320R

i thought it was weird how some were perfectly centered and some were more offset to the left or right

the car runs good though.i guess it s safe to say...even smoother and idles better- b4 at idle the needle would kind of go up and down just very little though like .1mm LOL...but now after the plugs...its perfectly steady

so yeah the original plugs were all dead on cenetered. hopefully it wont be an issue with the new plugs i put in

idk how well you can tell on the pictures but trust me they were offset either to the right or left

blegthbloo

Ah, I see what you mean... I looked at the new plugs I got (old part number) and didn't notice any offset, certainly nothing like you see there. It could be the design of the new plugs? Not sure.

AMS_Performance

After years of tuning the m157/m278 cars we have found that the a fresh set of oem plugs on these vehicles; gapped down to .022 makes a world of difference in drive ability and keeping the ever frustrating limp mode away. With that being said the power these 4.6's are making with bolt-on's is super impressive and makes these cars such a great bang for the buck.

There are 70,000 different revisions of software on the factory ecu and each car takes to the new software differently; some torque limitation tables do not unleash havoc on certain cars; and will throw another vehicle into limp mode at part throttle based upon the software version pre loaded on the ecu.

I am glad to see some more power modifications being done to these cars and the community growing around them. Hope to be picking one up for my self to play with sometime in the next few months

cocobeex

are you guys able to put M157 Turbo on M278 engine ? and tune it!!

I hope one day you guys can do it.

blegthbloo

Don't give the man ideas!

(but really, do give the man ideas )

AMS_Performance

Based off what has been read on the forums the m157 stock turbos should bolt right up to the m278's. As well as the upgraded m157 turbos should cross over just as well.

The big hurdle the m278 guys will have is heat exchangers, and getting a calibration dialed in to control the larger snails.

garrettg

What we have seen is the M157 turbos will bolt up with M157 manifolds and bolt into a M278 engine and do well; but it is still not clear if the M278 manifolds can be re-used in this sort of swap. The M157 manifold is an expensive piece of this puzzle. There is some discussion both ways perhaps someone can finally clarify if the M278 turbos can be unbolted from their manifolds and replaced with M157's or if this would even make sense from a inlet/tube size or if early reports are correct that the M278 turbos are welded to the manifolds.

cocobeex

Manifold ? would you please, find the picture for this part ?


As I know, you will need all the gaskets and copper nuts ordered new.
Thought We discussed it few month back.


I have everything in my hand ready to be bolted on. But I have no ECU tuning files at the moment.
And there no one can do dyno tune in my area.

cocobeex

I called into you guys few month back.
One of your guy said the 2014+ E63S Heat Exchange upgrades can be installed onto 2014+ E550.


Would you please, verify that again ?


Thank you

garrettg

Great, hopefully you will post the defining pictures showing the 157 turbos bolting onto the 278 manifolds then when you find a tuner and we will all know. I am new to the m278 engines so I like to see pictures.

AMS_Performance

We have not yet had a 2014 E550 in house to confirm fitment on, based off the oem parts diagrams and what my engineers have mentioned to me in passing; it will require different lines, harnesses, and a pump at the minimum. Where about are you/ the car located?

dmfmtn

Blegthebloo - any update on your tune situation? I'm thinking of getting this tune on my car.

cocobeex

Unfortunately, I am in Vancouver B.C Canada.

blegthbloo

None yet. I have the new spark plugs and have an appointment on Friday to get them installed. I still recommend (any) tune on this car, but as AMS suggests above, make sure you swap plugs at the same time. I even had an A service done beforehand because it was due anyway and I wanted fresh oil as well.

blegthbloo

Update on my situation... had the plugs installed and gapped to 0.022 (per AMS suggestion here) and I'm still having the issue. It's a little better now, but still happens. Also I'm getting better gas mileage now, so I guess that's a plus lol

I'm waiting for RennTech to get back from the holiday break so we can continue to troubleshoot.

In other news, I got a Bluetooth OBDII reader and have been playing with that. Seems like the engine runs at 12.8 PSI and 435hp/435tq... I believe these are close to stock numbers, so maybe the tune spoofs the readings to keep from getting a CEL? Just found it interesting. Only once did I see a spike up to 668tq, which seems about right, but it was after I let off the throttle. Still need to do an actual dyno run... All in all, still fun to play around with and see what the car is doing.

If I knew what else to monitor to troubleshoot my issue, I could do that now. But I'm not sure what else it could be at this point.

J.M.G.

https://mbworld.org/forums/e-class-w...ml#post6931771

blegthbloo

I remember reading this when you posted it awhile back. Makes sense. Would be nice to have confirmation on that, though.

Mike450

Can you log short term knock (stknk), long term knock, and iat's?

blegthbloo

I believe I've seen those in the list of variables I can track. I will do that on my drive home from work today, thanks.