S550 RENNtech ECU Upgrade
I wouldn't do it. You're only gaining 22hp and the HP is already darned good as is. On the other hand, I did it on my 600 and gained 100HP and gained 120 ft/lbs and noticed a major difference. If you still want to do this, talk to Adam Goodwin with Evotech. He advertises on here all the time. He'll do a great job for you.
Last edited by trumpet1; Jan 12, 2008 at 05:09 PM.
One thing I did notice was how much sooner the power and torque begins. Without Renntech, after kicking down, it seemed to me it took the surge about one second to kick in. Now it happens immediately. Just my observation.
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“There is a lot more power in our ECU tune than we publish, over 20 HP at the wheels and about 25 lbs of torque. This is good for about 3/10 of a second quicker 0 to 60. The only thing I have seen that is better is the ECU and headers we have on our S550, 0 to 60 in 4.8.”
If you have any questions, please call me 561-845-7888 or email Bobb@renntechmercedes.com
Bob Brady
RENNtech
Last edited by trumpet1; Feb 7, 2008 at 08:55 PM.
As with all things electronic (or mechanical), things can go wrong. Computers crash. Software can become corrupted or may require an update. As a result, ECU's are fitted with "limp home mode". If an electronic or mechanical problem arises, the ECU enters "limp home mode", which limits the engine revs beyond a certain RPM limit, won't allow fast acceleration, or may limit the maximum speed to 40 mph (or so).
Bad? Not really. The alternative would be operating the vehicle at regular speeds, with the danger of damaging the car or inconveniently having the vehicle shut down completely.
I'm hoping to go down and see Bob Brady in early May to have it all tweaked and dyno'd. My MB techs know by looking at the Renntech badging that I had this done and hopefully the tech had enough sense to not mess with it. They came out and asked me how it was performing and I said it was awesome power.
The Renntech upgrade for my S600 gave my car extreme torque and speed. It is downright frightening sometimes. Just yesterday I pressed down on the pedal while at 60 mph and I believe I hit 110 mph in less than 4 seconds.
















On another note, the rear seat package and rear a/c get ooohhhs and ahhhhs from my passengers.... that too is a desired option for me. That option really matches the price and luxury of the car.... so i am weighing money versus options.... very confused at the moment due to being a bit poorer in the obama age.
On another note, the rear seat package and rear a/c get ooohhhs and ahhhhs from my passengers.... that too is a desired option for me. That option really matches the price and luxury of the car.... so i am weighing money versus options.... very confused at the moment due to being a bit poorer in the obama age.




what is the top speed of a renntech chipped s550?
Last edited by kafklatsch; Nov 10, 2009 at 10:44 PM.
Just kidding! I would imagine a non-limited S550 should be in the 170+ range. Is that fast enough for you? My CL55 is chipped, but I never pushed it past 140 I don't think... Debating whether to do my S550...
You can also take a look at this company for ECU re-programming, would save you a few bucks if you all you care about is the limiter to be removed:
http://www.singhautosport.com/
what is the top speed of a renntech chipped s550?
you'll feel the 20hp gain with the ECU tune, hell the Brabus ECU tune is 5x as much and the same gains
you'll feel the 20hp gain with the ECU tune, hell the Brabus ECU tune is 5x as much and the same gains
I might go low end and then have a friend with a Star Diagnostics system take a look at the settings. We'll do the same thing on a Renntech or another tuner's settings and do a comparison: which changes were done/not done, what the settings where - etc.
From what I understand so far - fuel map changes, the pedal/potentiometer ratio or when it engages changes to make the car feel quicker (makes gas pedal more sensitive), shift points, timing. Anything else?
Would someone with a decent dyno be able to tune the car with similar results?
If anyone knows the technical side of this, would be good. I completely agree that Brabus, Kleemann, Renntech have the R&D capabilities and come out with quality products. But this isn't rocket science - folks should be able to come to similar conclusions with the right tools with a dyno.






