Article: RENNtech M278 twin turbo 4.6 liter V8 ECU tune upgrade - +70 horsepower, 530 crank horsepower for C218 CLS550

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Originally Posted by 427

Is anyone currently running this tune in their CLS550... if so, may we please have some feedback?

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I have a new 2014 MB CLS 550 with Renntech upgrade
One word: phenomenal
Performance over stock is startling
Much better power band with no rev limiter or top speed governor(factory is 149mph...Renntech is 189 mph)
Acceleration is superb..pins you to the seat back
Still, admittedly, some momentary turbo lag, but not as bad as Porsche 911 Turbos I have owned for instance
Performance is even greater with the CLS when you realize it's a big heavy 4 door coupe, not sedan, as MB refers to it as a coupe due to no center window pillar
Mid range acceleration 50-130 is incredible
Very smooth, but tons of power when you need it..or want it!
I might add that handling is also superb...the huge rear tires make a big difference, but for a big car, the is remarkable..stabler, solid and quick
I have had many high performance cars and currently also have a Dodge Viper
which is a different type of fast!
I chose the CLS over a Panamera...liked the styling better and performance with the twin turbos..engine is just awesome!

I'm not certain why a question asked nearly 2.5 years ago has now yielded a negative rep... so be it.

As for your comments regarding a Renntech tune, I have to agree. They tuned my ECU over a year ago and I wrote a very favorable review (with pre/post dyno results).

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Originally Posted by sixgun

I have a new 2014 MB CLS 550 with Renntech upgrade
One word: phenomenal
Performance over stock is startling
Much better power band with no rev limiter or top speed governor(factory is 149mph...Renntech is 189 mph)
Acceleration is superb..pins you to the seat back
Still, admittedly, some momentary turbo lag, but not as bad as Porsche 911 Turbos I have owned for instance
Performance is even greater with the CLS when you realize it's a big heavy 4 door coupe, not sedan, as MB refers to it as a coupe due to no center window pillar
Mid range acceleration 50-130 is incredible
Very smooth, but tons of power when you need it..or want it!
I might add that handling is also superb...the huge rear tires make a big difference, but for a big car, the handling is remarkable
..stable, solid and quick
I have had many high performance cars and currently also have a Dodge Viper
which is a different type of fast!
I chose the CLS over a Panamera...liked the styling better and performance with the twin turbos..engine is just awesome!

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Welcome! Glad to hear your impressions.

Quote:

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Originally Posted by 427

I'm not certain why a question asked nearly 2.5 years ago has now yielded a negative rep... so be it.

As for your comments regarding a Renntech tune, I have to agree. They tuned my ECU over a year ago and I wrote a very favorable review (with pre/post dyno results).

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Here's a positive.

Quote:

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Originally Posted by 427

I'm not certain why a question asked nearly 2.5 years ago has now yielded a negative rep... so be it.

As for your comments regarding a Renntech tune, I have to agree. They tuned my ECU over a year ago and I wrote a very favorable review (with pre/post dyno results).

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What was negative about my reply re my CLS550 with Renntech?
If you are referring to my reply i see nothing negative in what i replied!
Im baffled...i said Nothing negative! All was praise
for the 550 and the Rennetech!

Thanx, Sticky.

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Originally Posted by Sticky

Here's a positive.

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sixgun- I was not referring to your comments at all when I mentioned a 'negative reputation' (essentially, there is a means to give someone a thumbs up or thumbs down for their post). Somehow, somebody recently decided to give my old post a negative rep. It could have been accidental or on purpose... one can not determine the intent or who actually created the 'reputation'. I purposefully listed the rep in itz own paragraph... that was NOT directed at you. Sorry if you misunderstood.

In a separate paragraph, I did agree with your comments and assessment of the Renntech tune... you were spot on.

Quote:

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Originally Posted by sixgun

What was negative about my reply re my CLS550 with Renntech?
If you are referring to my reply i see nothing negative in what i replied!
Im baffled...i said Nothing negative! All was praise
for the 550 and the Rennetech!

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Quote:

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Originally Posted by 427

one can not determine the intent or who actually created the 'reputation'.

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I can. Don't worry about it I balance it out when necessary.

No offense taken, just didn't quite understand
Thanks for the clarification
The Renntech upgrade is amazing

Quote:

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Originally Posted by 427

Thanx, Sticky.



sixgun- I was not referring to your comments at all when I mentioned a 'negative reputation' (essentially, there is a means to give someone a thumbs up or thumbs down for their post). Somehow, somebody recently decided to give my old post a negative rep. It could have been accidental or on purpose... one can not determine the intent or who actually created the 'reputation'. I purposefully listed the rep in itz own paragraph... that was NOT directed at you. Sorry if you misunderstood.

In a separate paragraph, I did agree with your comments and assessment of the Renntech tune... you were spot on.

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