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I am thinking of an ECU tuning for my R172 MY2012. Would like to get opinions, advice and experience with this performance modification.

1. My search revealed two ECU upgrades for the R172 SLK 55 AMG,

one is Kleemann
http://www.kleemann.dk/Performance/Engines/55AMG_M152

the other is Renntech
http://www.renntechmercedes.com/www/node/1057

and Eurocharged does not have anything for R172 AMG, and neither
does Brabus or Carlsson.

2. Kleeman claims a HP upgrade from 415 to 440, at Eur 1,195.00,
whereas Renntech claims an improvement of 421 to 448, at $2,250.

3. Why does Renntech state that stock SLK 55 R172 has 421HP? I have
always been reading 415HP instead.

4. Does an increase of 25HP(Kleemann) or 27HP(Renntech) makes that
much of a difference in performance? If yes, in what way?

5. With approximately $100.00 per HP increase, is it worth it? This is not
a fair question, I know.

6. In another site(MBworld), one member has done the Renntech tuning
on his 2012 SLK 55 AMG. He reported an improvement of 0-60 from
4.4secs to 4.19secs. He appears to be quite satisfied with his tuning.
http://mbworld.org/forums/slk55-r171/470242-2013-slk-55-pp.html
 

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Worth it? That's a completely subjective value judgement. I will say that the Kleemann numbers look very believable. But worth it? Maybe not.

I'll explain. I just had my 2006 SLK55 tuned by EuroCharged last week. Obviously a different engine with a different starting point. But identical displacement.

Peak Power (bhp) Stock= 355 Eurocharged= 379 or 6.7% gain
Peak Torque (lb-ft) Stock= 376 Eurocharged= 402 or 6.9% gain

The peak gains are about 7% for both power and torque. But.....the entire curve is lifted across almost the whole operating range of the engine. See graph below. So, you can feel it more than a 7% peak gain might imply. But it's mainly the torque increase you "feel", especially in the low to mid-range.



The cost? Jerry honored his March promotional pricing of $399 for me as I've had other cars tuned by EuroCharged and I already own their OBDII cable. I like the outcome. Yes, I can "feel" the torque increase and the throttle remap. The car is more fun to drive.

Now for Kleeman and your R172.

Peak Power (bhp) Stock= 415 Kleemann= 440 or 6.0% gain
Peak Torque (lb-ft) Stock= 398 Kleemann= 415 or 4.3% gain

The gains are lower on a % basis so it would indicate your engine is better tuned from the factory. Tuners aren't able to get much more out of it. Not surprising as the factory is trying to get more out of its next generation already. The interesting thing is that Kleemann wasn't able to get the same sort of gains on torque. And that's what you really "feel" in your butt dyno. Also, Kleemann does not publish a graph of the entire operating range so it's impossible to tell if that peak gain is in a narrow range or across most of the useful power band of the engine.

Also, both EuroCharged and Kleeman remap the throttle response as part of their tuning process. This is the second modification that you will "feel". Eurocharged did a great job with the M113 E55 engine in my car. The car feels more like a clutched setup and less like a torque converter because of the more direct throttle response but with no twitchy behavior like leaping off the line or unwanted wheelspin. I assume Kleeman may have done something similar with the R172 engine. But again, whether you can feel it depends upon how the factory tuned your car to begin with.

Lastly, the Kleemann tune is $1,530 (US) at current exchange rates. That's pricey for the gains they offer. Only you can decide if it's "worth it". Personally, I'd want to see a graph of the gains over the entire power band before deciding.

Good luck whatever you decide.
 

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Worth it? That's a completely subjective value judgement.
Seems like fairly small gains for a warranty risk. Maybe if you combine with catless exhaust/silencer, an intake, etc you can get larger "butt dyno" gains along with more intake/exhaust sound.

Also depends on what you're looking for ... if it's track advantage you may be better off with brakes and/or suspension mods, ultralight wheels, etc.

If it's just because you can then getting rid of the cats might give you more power gains with less warranty risk but that's just guessing based on what would work with my M3 motor.

For me, my first mod is going to be trying to get my hands on some e-code headlights so I can get rid of the heinous orange reflector! I also like some of the Chrome-tec carbon fiber stuff but that doesn't do much for the butt dyno : )

good luck!
 

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phs,
You and I have almost the same car (2012 AMG vs 2013 AMG) and I've been looking at these options as well. Let me start by saying that I work less than a mile from the Eurocharged shop in Katy, TX (Houston area) - I can literally look out my window and see the building they occupy across the freeway. Long story short, a couple of months ago, I e-mailed them to see if they have a tune for the R172 (they confirmed that they do, but wanted me to swing by to take a look at it). So the next day I drove over there during lunch to see what they thought. I can't recall the name of the guy I talked to, but he is the one that installs the actual tune and after checking under the hood he told me that if I brought it over at lunch one day, they'd drive me back to work then come pick me up after work and it would be done - man, that sounded great! But then I asked what all they had to do and he informed that they removed the ECU, drilled about a half inch hole in the top of it, did their thing, filled the hole, repainted and re-installed. DRILLED A HOLE IN IT!! I don't think MB would look too kindly on having a hole drilled in my ECU if I ever had a problem, so that kind of put the brakes on the Eurotune option (at least for now). I then checked out RENNTECH and while looking at their website of installers, I see that my MB dealership (MB Sugarland) is a certified installer for them - now that's more like it - surely if the dealer installs it, it won't mess up my warranty? My problem there is the price - $2250.00 OUCH. If I do decide to go with them, I'll have to put away a few more coins for the mod - paying for this one might sting a bit, maybe even leave a few marks!:burnout:
 

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Euro spec is "brake horsepower" = 422. http://www.wisegeek.org/what-is-brake-horsepower.htm Calculated by: disregarding any drain on the power that is due to the water pump, generator, or the gearbox that work in conjunction with the motor of the vehicle. The amount of power loss that occurs due to the action of various belts and pulleys is also added back into the base figure, making it possible to determine the true amount of pure horsepower being generated by the motor. US spec is 415 (power to the wheels), which indicates ~7HP is lost due to the above.
 

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All horsepower ratings by manufacturers are done on an engine dynamometer NOT a chassis dynamometer so none of the ratings are "at the wheels". This means that drive-line losses are not included. This makes sense when you consider that different transmission types have different losses so the horsepower ratings at the wheels would vary depending on the transmission.

Most all US manufacturers now use the SAE standard. The European procedure is EEC 80/1269. There are minor differences. For example, the exhaust configuration and the specified fuel-quality requirements vary, and these can have an effect on horsepower.
 

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Euro spec is "brake horsepower" = 422. http://www.wisegeek.org/what-is-brake-horsepower.htm Calculated by: disregarding any drain on the power that is due to the water pump, generator, or the gearbox that work in conjunction with the motor of the vehicle. The amount of power loss that occurs due to the action of various belts and pulleys is also added back into the base figure, making it possible to determine the true amount of pure horsepower being generated by the motor. US spec is 415 (power to the wheels), which indicates ~7HP is lost due to the above.
this is not true, you would have much greater losses than that.

the difference is that in europe cars are measured in PS, so its actually 421 PS, but most people just say HP anyway, but i believe the HP is 415 from a PS of 421.

Take a renaultsport clio 200 (european car), its 200PS but 197 BHP
 

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cant see the point in messing with the car like this...its scary/stupid fast now, cant believe that Merc engineers left something off the table that these aftermarket guys can miraculously find...would be concerned about longevity and warranty issues...I didnt pay this much for the car to experiment w/ it...IMHO....FWIW...
 

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cant see the point in messing with the car like this...its scary/stupid fast now, cant believe that Merc engineers left something off the table that these aftermarket guys can miraculously find...would be concerned about longevity and warranty issues...I didnt pay this much for the car to experiment w/ it...IMHO....FWIW...
mb tune to meet certain environmental standards, target mpgs, to work with lower grades of fuel etc - tuners can have different goals.
 

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cant see the point in messing with the car like this...its scary/stupid fast now, cant believe that Merc engineers left something off the table that these aftermarket guys can miraculously find...would be concerned about longevity and warranty issues...I didnt pay this much for the car to experiment w/ it...IMHO....FWIW...
You may be right with your M152 engine in a 2013 SLK55. At the same displacement, it's getting a bit more output already. The factory may have pushed a bit closer to the limits.

But the M113 E55 is a different matter.

From Wiki....
The M113 E55 is a 5.4 L (5439 cc) version with the same 97 mm bore as the E500 but with a longer 92 mm stroke. Output is 342 hp (255 kW) to 367 hp (255 kW to 270 kW) at 5500 rpm with 376 ft·lbf (510 N·m) to 391 ft·lbf (510 Nm - 530 Nm) of torque at 2800-5400 rpm.
As you can see, from the factory an M113 E55 from the R171 vintage had a wide range of output depending what platform it was installed in. And at 355 HP and 376 lb/ft our SLK variant was not tuned to even factory limits of 367 HP and 391 lb/ft.

In the Canadian market the R550 people mover used this engine and it was rated at 382 HP and 391 lb/ft. Almost spot on what EuroCharged achieves with their tune.

What a tuner like EuroCharged can do at 379 HP and 402 lb/ft is not anything radical. They are simply leaning out the AFR, advancing spark, and remapping the throttle response. And they post AFR curves to show what they've done as far as pushing the limits. It means you'll want to make sure you're using premium fuel to be safe. Here in CT, our premium grade is 93 octane which is higher than factory specifications. So, I'm not afraid of knock. Tuners just push a bit closer to the limits for gains. The important thing is to make sure a tuner doesn't push it to stupid levels. The good ones don't.
 

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I see that my MB dealership (MB Sugarland) is a certified installer for them - now that's more like it - surely if the dealer installs it, it won't mess up my warranty?
Legally, your dealer is totally independent from MB ... they are simply a local business that buys and sells cars.

If MB finds out you modded your ECU you will likely fail on any engine warranty claim they challenge.

Of course your dealer is the one who will write up the warranty claim - so having a friendly dealer can make all the difference if the issue is a fluke.

... but if it's something MBUSA decides to look in to - or directly asks the dealer "is there mods on this car" - I doubt the dealer will lie for you
 
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