Mercedes Benz Performance- ECU Upgrade
 

I was talking with the performance guys at MB of Buckhead last week. They are offering an ECU upgrade for the C300s and claim at the very least 20-25 HP increase over stock. They are asking $895 but it sounds like they may be willing to deal a little...but that remains to be seen.
Anyhow, I like the fact that this is coming from the dealer so I don't have to worry too much about voiding the warranty. The thing I really like is they claim to keep the specs on the tune saved for the life of the car. Basically, if I ever lose my tune, they will reload for only the cost of labor (1 hour).
Does 20-25HP seem to be what all the other chip tuners are claiming?
Does the fact that they offer to keep the specs and reload relatively cheap really offer much value? How likely is it to have to reflash? I am thinking that would only need to be done if MB comes out with some major software recall/update and all cars would need to be updated.

Is that Wheel HP or Crank? For reference, Powerchip offers 18 Crank Horsepower for their chip which I do believe is along the lines of 700$+Shipping. This MB Chip seems like a pretty good deal.

It's hard to believe that's coming from your dealership, but I would take it in a heartbeat. A competitively priced chiptune that doesn't void your warranty is priceless.

Do all dealerships offer this? I'd love to have a tune, especially an OEM one.

I doubt the chip is an MB chip. Its probably a product like Kleeman or Renntech. I would check to see the actual warranty on the chip. And NO aftermarkets can ever void your warranty just because you installed them...just fyi

Yes all dealerships will offer a tune through partnerships with a company. Most around me either partner with Brabus, Renntech, or Kleeman and non of the chips void warranty but the actual chips themselves are not warrantied through mercedes.

Apparently only 27 MB dealerships in North America are AMG Performance Centers. They actually have cars shipped in to do some pretty in depth tuning...way more than the cost of my entire car...lol

http://mercedesofbuckhead.reachlocal...reachlocal.net

So the performance centers offer MB chips and not aftermarket chips? That doesn't sound right to me.

Not so sure...these guys apparently do a ton of dyno runs to adjust the programing there at the shop. I don't think it is per car unless you have an actual AMG and pay the price.
You are right about the warranty but these guys claim that there is no risk of warranty issues. I guess if you are running chips from other vendors, they could claim burnt valves, blown heads, etc, could be caused by the more aggressive tune.
Of course, I would want everything in writing form MB USA.

pretty sure the simply reprogram the OE chip

They are selling you an aftermarket vendors tune. Just get it in paper that this will have no effect on your warranty.

Exactly what I thought.

Absolutely untrue, and I have it in writing.

In fact you should be written a new warranty after this service is performed that states that your engine, etc warranty will remain honored by Mercedes, and the other details like them reflashing it for the life of the vehicle. I can even give you a sample of what the warranty should look like if they give you a dumb stare so you can have something for them to sign that can be legally enforced.

A couple of things I wish I would've known before I did my ECU tune and thought I'd share with you:

ECU tunes, especially for NA engines (Naturally Aspired, meaning no turbo/supercharge, etc) like ours, rely on remapping the ignition timing. By doing this, the computer ignites the mixture when the pressure inside the chamber is much higher and as a result you get more power. Pretty nice, huh?

Here is the catch (besides the $$$)

Ignition 101: Piston goes up - spark plug ignites the fuel/air mixture - explosion pushes piston down creating mechanical power, right? Well, right now your ECU ignites the mixture just as the piston starts to goes down, and it has a small "buffer". Ideally it would ignite it when the piston is at its peak (thus the most pressure is created), which is when the ECU tune comes in. But there is a good reason why MB (and every other car manufacturer) do it like this, and it is not because they don't want to advertise their cars with an extra +20 or +25 HP. They have this "buffer" (it is actually a range on which the stock ECU is allowed to delay the ignition) to accommodate a wide range of fuel octanes and quality while protecting the engine (and, needles to say, ensure its lifetime).

Octane, contrary to what many believe, it is NOT the amount of power the fuel releases when it ignites, but the amount of pressure the fuel can withstand before it ignites. The higher the octane, the higher the pressure at which the ECU can ignite the mixture. This is the reason why ECU tunes come married to an specific octane fuel. And, needless to say, the more HP the tune claims, the higher octane they require.

So what happens if you get an ECU tune for, let say, 98 octane and you use 93? Very simple; pre-ignition. The mixture ignites as the piston goes up. You will get engine knocking, and with that comes permanent damage.

I see a lot of tunners talk about gains with their ECU software, but very few tell you the octane requirement. You may be purchasing an 105 octane software for all you know.

The reason why I'm telling you all this is not to scare you away. I purchased an ECU tune from MKB for much more than what their are offering yours, and now I have to PAY my local dealer to get me back to stock because they didn't even tell me the octane requirement and the highest grade fuel here in Dominican Republic (where I live now) is not near enough. I just want anyone thinking of an ECU tune to know the risks.

And if you still decide for the ECU tune, make sure that you ask the octane requirement and that you are able to feed your car that octane for the rest of its life.

What are you talking about...you warranty cannot be voided just because you install aftermarket parts. There is a law for this?

Your first sentence is chip tuning 101. Seriously, simple research would have revealed that info. I don't trust most of the MB tuners. You can never get a straight answer. I have tried. It's best to just leave NA motors alone anyway. Unless you crack them open or add headers with a tune, you're gains are negligible.

Long ago a I had an MKIII Jetta (NA). I installed a Techtonics chip (when you could DIY) and exhaust. I got a little boost in power from the chip alone. The gas mileage improved and the engine was much smoother. I was specifically told to run 91 octane and up.

I had a 1.8t Passat after. I had an APR reflash done via the OBD II port (did you hear that MB tuners? ...OBD II port tuning not caveman-style ECU box removal) that required 93 octane only. No higher and no lower. I also had them install stock programming. It was nice to be able to switch between the two programs.

Why are the MB tuners so far behind in ECU tuning technology? And why is it so difficult to ge a straight answer from them?

With all of that said though, C300Sport, 20-25 hp sounds reasonable. Probably closer to 15-20hp. If they back it, go for it

Your warranty CAN and WILL be voided by aftermarket parts...BUT, they have to prove that the aftermarket part is what in fact caused the electrical/mechanical failure.

For example, if you swap out some springs and a control arm bushing fails the dealership will not cover it. However, if you install springs and your headlights start throwing errors they can not correlate the two. ECU tuning gets tricky and since the ECU has to be physically opened (caveman style Derspeed) to flash/tune/reprogram it, ANY electrical failure that the car experiences from then on can be attributed to that. Good luck getting Mercedes to fix something when there is a clear reason they might not have to.

Yes, there is a law for aftermarket warranty work and this is where it comes in. The dealership must prove that the failure was related to the aftermarket install. If they see the ECU was opened...and its impossible to hide that fact...then that is really all they need to void your warranty. It won't void the entire cars warranty but the electrical system will be noted in their nationwide database and they can even go so far as to section 8 the car...meaning people that want to play, WILL pay...I too am one of those people.

Dealerships vary, people's relationship with their service managers vary and certain things can be overlooked but for the most part, they ain't gonna be going out of their way to help you out.

You forgot about that thing called a knock sensor, which the M272 engines are equiped with.

Also, keep in mind Octane is measured differently in different countries/parts of the world. 93 octane in the US is not the same is 93 octane in europe. Just FYI.

Good post. Another thing that ECU tunes often do is remap the fuel curve, which results in a richer fuel/air mixture, which in turn decreases fuel economy.

In any event, 28 hp is a 12% increase over stock, which sounds way too optimistic from an ECU tune alone. IMO, ECU tunes on NA engines are a waste of money, as you are not going to get any noticeable power gain. Turbocharged engines, on the other hand, are a totally different matter.

Ok we are saying the same thing. I was saying that if I go to the shop and get a tune my warranty is not void. IF someting goes wrong AND the part caused it, then yes of course your warranty will not cover the damage. But simply installing something has no effect on warrranty.

Well that's a little rhetorical isn't it? if you install a part and nothing goes wrong then you have no warranty claim to begin with...so what's the issue?

If you modify the ECU and nothing goes wrong, excellent. But if it does, than they will try to prove, and most likely will that it was a result of that modification...it would be fairly obvious.

I have a pretty good relationship with the head of the service dept at my local dealership (when I go to them, which if it can be at all avoided, I don't) but he still has be able to justify looking at something he knows I installed. And then take the time and labor hours off the floor to do so. Its like pulling teeth but he knows I have a half way good understanding of what I'm doing so he tries to accommodate me.

The bottom line is...except for the MB dealership in NYC they are ALL independently owned and don't have to do anything they don't want to do.

^ Yeah but there are some dealers that will tell you that your warranty is void because you put on springs. The statement doesn't even make sense as you have different warranties but none the less some dealers will tell you that. or maybe its just the honda civic and mitsubishi eclipse dealers. This is my first merc and I haven't received it yet so I don't know if they are different.

check out the Singh Autosports ECU tune for our W204. I have it on my C300 and i love it.

Spec_Davis do you have Dyno results? What were your gains? And how much? Thanks!