johnvkumar

Hi I am interested in the ECU for my convertible car, can any one help me answer the questions. I greatly appreciate the help & favour!

http://www.renntechmercedes.com/index.php/products/mb/e-class/e-212-2014-present/e-550-biturbo-4matic/renntech-ecu-upgrade-e-550-4matic-w212-530-hp-606-tq-for-m278-2014-detail

Possible Performance Breaks
http://www.renntechmercedes.com/index.php/products/mb/e-class/e-207-2014-present/e-550-biturbo/renntech-performance-brake-package-1-detail

& BMC Performance Air Filter

http://www.renntechmercedes.com/index.php/products/mb/e-class/e-207-2014-present/e-550-biturbo/bmc-performance-air-filter-for-mercedes-benz-m278-m157-biturbo-engines-detail

& recommend a good Exhaust system maybe Eisenmann Performance Exhaust Systems?

What will this do to existing MB Factory warranty?

How many years warranty does your product have?

What is the impact to the car, its terms of Stability/Reliability, if any others?

What is the impact to the milage per Gallon?

johnvkumar

Appreciate if any one could help me!

PaulE550

Gee, almost all the same questions I sent to Renntech over a year ago. Amazing how so many people have the same concerns. Well anyway from several threads on this site, I can at least answer your first question. MB has an official position that if you have engine problems and they discover the tune and can trace the problem back to the modified ECU, then the repair would not be covered by your warranty. MB may also flag your vehicle in their computer maintenance tracking system, so you just can't go dealership hopping to get the repair done under warranty elsewhere. Hope this helps a little.

johnvkumar

Thank you Paul555, appreciate it. Thank you for taking the time to answer, I kind of figured that MB will do, assuming that the car is still under warranty, if it is not so, individual have to bare that expense anyways... My car is still under warranty and have another 30K or 3 years left!

Have you installed the renntech ECU? How long has it been? Any issues? What is your recommendation ?

PaulE550

No I did not have my car tuned by RennTech or anyone else for two reasons:

1) I asked a series of what I thought were simple, straight-forward questions and could never get them answered. All I received back several times were sales piches promising everything would get great, lots more power and just ship us your ECU now for a discount. None of which addressed any of the questions I asked. I wasn't interested in a sales pitch, as I had already narrowed down the type of tune I wanted from RennTech. What I wanted was a few specific questions answered at the time.

2) I was interested in having the tune done by their local RennTech dealership, so I could be in and out in a few hours tops. Assuming I would waiting around a bit. Coming from the software industry, downloading and re-programming a computer, which is all an ECU is, with a new file or series of files is a straight-forward process. Probably takes no more than 20 to 30 minutes for RennTech to do each tune given the amount flash memory in most ECU's today. Well it turns out that the only thing the dealerships do is pull your ECU out for you and send it off to Florida and then plug it back in when it comes back in a day or two. Our ECU's take like 5 minutes to pull out ourselves, so why would we need a dealership just to do this?

Anyway, I've owned other cars, not MB's, and had them tuned locally. That way if there is a problem, you can either drive the car back and have it checked out or have it flat bedded and brought back to the local performance shop for diagnostics and repair or reprogramming after the dealership over-wrote your tune file with their latest ECU update themselves. The notion that, for me anyway, I would have to Fed Ex my ECU 1,200 miles away and potentially have to play musical Fed Ex shipments if there was an issue ot a requiremet to run a diagnostic or re-load the tune just wasn't attractive to me. That's just me of course. Many people apparently find this approach completely acceptable.

If RennTech were to change its business practice and allow their local dealerships to do the tune themselves, then I might re-visit having a RennTech tune done. Of the tuners out there, they seem to have the best reputation and have been doing MB the longest. That is important to me from the perspective of having the best knowledge base from which to diagnose any issues that might pop-up.

Oh by the way if you go forward with any tune to your car, depending on which tune your select, you may have to change your plugs out as well. It seems that is one of the common items that may need upgrading in a number of MB vehicles post tune. Not a biggie, but you might as well have it all done at the same time.

Let us know what you do.

johnvkumar

Hi Paul, thank you for this verbose details, I had the same concerns running through my head, I am in S/W industry too and I hear their concerns about piracies practices and reputation of the company, if I were them I would probably do the same, they don't have notion of software key/security/ encryption etc., because it not mean't for such.

PaulE550

So their current argument is they fear piracy of their software, if they were to provide a means to have their own dealerships do it locally? Ha! That is a good one. So in other words, they don't really trust the business partners they've signed on as dealerships. You have to love this stuff some times. It wouldn't take much to do a software activation key tied to the specific ECU serial and model number, supplied from RennTech HQ for each order placed and paid for, to prevent the local dealerships from going the piracy route.

Honestly the best solution to all of this would be if MB simply offered ECU tuning as a services option through their dealership service departments. Charge the same amount as the tuners or even a small premium and I bet people would gladly pay for it. Since the tuning service coming from MB wouldn't automatically void your warranty. It's not like MB engineers in Germany haven't already figured out how to do everything all the independent tuners already do and don't have all the data required to build these tunes quickly themselves.

johnvkumar

I agree 100% with you if MB could do it, it will be a big win!

johnvkumar

Hi I am back again. ....lol for ECU upgrade

I have 3 Companies I am looking at now... OEtuning, RENNTech and KLEEMANN.

Which is best and popular ? Appreciate your help.

PaulE550

The sound of crickets is deafening. :-)

WilliaMooh

For me I would go with weistec tune👌🏼

mercshepherd

Thank You Paul
I have considered getting a Renntech or Kleeman Tune (as it is $1500 versus $2800 from Renntech and also a very reputable company). However, you are absolutely right. The Renntech Tune or Kleeman Tune (or any other) will absolutely void your original or CPO warranty. If you ask Renntech or Kleeman, they should tell you that it will void the warranty. They arent being truthful if they dont.
The link below is a good article an attorney wrote about how modifying your car voids the vehicle warranty:
http://www.newyorklemonlawlawyer.com...modifications/

Of course there is the Magnuson Moss Warranty Act which states that a manufacturer cannot void a warranty if the modification did not cause the failure.
https://en.wikipedia.org/wiki/Magnus...s_Warranty_Act

But a tune increases horsepower and torque and therefore puts greater stress on the engine, transimission and driveline, and even accessories if maximum rpm is increased. So if anything affected by the increased hp / torq from the tune fails, the manufacturer can and will deny warranty coverage.

By the way the M278 Mercedes Biturbo uses the 7G tronic transmission which has a maximum torque capacity of 700 Nm or 516 lb ft. This is not by coincidence the maximum torque output of the M278 engine in an S Class.
The transmission's first gear has a maximum torque input from the engine of 516 lb ft. Because of its high torque multiplication from gearing, the first gear clutches would slip if the engine input torque were higher. Just a design limit of the transmission.
Other gears can handle more engine input torque because of lower torque multiplication from lower gear ratio.
Therefore tuners cannot exceed the maximum torque the transmission can handle in first gear (516 lb ft) and thus a great deal of acceleration performance gain is left off the table as WOT in first gear takes these Mercedes to approx 40 mph.
(Dont know if tuners are maximizing torque curve in 1st gear up to 516 lb ft, which would increase performance times in 1st gear).
So 0 to 60 times are not really all they can be with claimed 540 hp and 700 lb ft Renntech (and similarly Kleeman) tunes. And of course quarter mile times suffer also because of inability to maximize engine torque in 1st gear.
That is why some owners may be disappointed with their before and after tune acceleration performance increases.

http://www.europeantransmissions.com...edes-trani.PDF