I'd like some feedback from any members who have flashed their ECU with the RENNtech upgrade. The claimed output is 601 hp for a W205 C63S.

 

They get that number by claiming the stock horsepower quoted by Mercedes is underrated and their testing showed the stock C63s made 545 HP not the factory rated 503 HP then they add their gain of 56 HP to the 545 HP to obtain their claimed 601 HP

 

$2,980 for 56 crank hp? Ouch.

 

Better value in the non s then.

 

The performance after is not any different than most if not all other stage 1 tunes. Most others just quote HP gain against the 503spec instead of what the dyno shows. There are cheaper tunes to get to the same level - it’s Renntech. I considered it and decided for Velos instead but not because I think there is much difference in the performing gains.

PS: someone her has it done recently and was very happy.

 

DME claim a higher number too on their website. 600 hp and 620 tq and no dyno chart to show tuned vs stock comparison which is odd

 

I have RennTech Stage 1, and love it.. granted i have not used any other tunes or had any others installed on my car, and my prior MB cars if I tuned them, I went with RennTech (they are up the street from me).

The customer service, support, etc are Top Knotch, and the guys are easy to talk to , they answer questions, and yes they are a bit more expensive then others, but it shows in the quality and support of there products.
I have NOT dyno'd my car, but when I did the tune, it was a whole different animal, so regardless of what ever number it is, its a beast...

 

Thanks FLC63s