Hey Guys and hello from Germany!

I wanted to give you a quick review on my tuned GT-S and the current mod

Why I went with Renntech: Interestingly some other crazy tuners in Germany were advertising ECU tunes for the 4.0L before it even came out but until now I am positive noone else has this experience yet on the 4.0 L like renntech has already.

I asked a few tuners I went to (with other cars) before renntech was in Germany and they said, they don't even have access to this new ECU...

Not sure if I ever saw ANY dyno result of a tuned 4,0L apart from renntech yet.

I know they not only had engines and different parts since last year, they have a Turbo upgrade ready which is now on their development car doing rounds and rounds on the track and dyno. Last dyno printout I saw was already well over 670hp Crazy...

Their C63 now has 900Nm torque, but unfortunately they told me the DCT is too weak to hold that much without modifications

1st of all I wanted to upload a video today which we did on the autobahn last night but I might need the guys from renntech to do this for me, I am not on Youtube or something

Or I will ask my son to do this

Anyway, the video will show the potential of the car now running stable 620PS and 730Nm... 0-300kp/h in well under 30s is really good now. I think I need to get a performance box or something.

Stock it took "forever" to reach speeds above 260kph, especially since you can't reach 300 in 6th gear and the 7th is like a what we call "Spargang" (to save fuel I guess)

I ran the engine and transmission in properly and brought it to renntech nearly 2 months ago already, they had to fix a few minor issues and get some ECUs updated together with the dealer, I guess it's not the best idea owning a car from the first batch. But yeah, I just had to get this one

Having driven with it over 8.000 kms already and being let's say 9X% happy just today a friend of mine came over with the SLS I used to own a few years ago... To be honest: the SLS is and will always be a classic, but the GT-S is the much better ride. Completely.
It almost feels like driving a horse-drawn carriage when it comes to comparing the "stubborn" ride/suspension of the SLS with the superb GT.

I have the feeling that even with the over 100Nm more torque than in the SLS I can still get the power better on the road than I ever could with the SLS.
I am on racetracks relatively frequently but the car is already more fun to drive even with "just" the superb Michelin Pilot Super Sport than the SLS was with the Cup2. Can't wait to get those on the GT

What's next:

Aching to see Renntechs Stage 2 dyno numbers soon... I already got used to the extra power of the ECU tune

Waiting for them to get TÜV for their stage 1 now but this shouldn't be a problem. This will make it street legal in Germany, I think even in all EC countries...

Will keep you posed if I manage to upload the video or provide the link when my son or guys from renntech have uploaded it.

Don

 

PS: Here you can see my baby in the RENNtech workshop:

https://www.facebook.com/RENNtechEur...type=1&theater

 

What is the HP and TQ increase with the ECU tune?

 

I am running a new tune now on 98 Octane RON (93 US octane) with 626 PS at crank and 733Nm of torque.

RENNtech Engineering named 620 PS and 730Nm for this tune before, so that's where it should be.

The car had already 538PS at crank from factory (on the dyno after 2,000kms of run in) but less torque than rated, 635 instead of 650. Seems to be normal for the GT-S.
Sport Auto Magazine measured 534,3 PS and 640Nm of torque.

With my car the increase is 88 PS and over 100Nm / 74 ft lb of torque, each at crank.
According to the phone app of my son the acceleration time 100-200kph improved by around 1,3 seconds. It was 7,8 before and now is 6,5

 

The video done with my car on the autobahn is part of this

 

Is your car the one Renntech has on their Instagram page running at the drag strip? I would have expected a much better time than a 11.28 @128mph after two months of testing on the dyno, Autobahn and Nurburgring. I ran an 11.4 @126.4 mph in my week old, bone stock GT-S on my second ever pass at the drag strip in this car.

 

Nope, I'm living in Germany...
My car is the one the autobahn acceleration video (part of the video above) is from.
The white one: https://www.facebook.com/RENNtechEur...type=1&theater

I'm running a different tune now.
I heard from RENNtech in Germany that it was very hot and humid the day RENNtech US guys were in Palm Beach and they were testing a milder tune.
My car improved in the acceleration time from 100-200kph well over a second now (my son says 1.3) so I am very happy...
Last night I raced a 650hp tuned GT-R from a roll and "noone won"...
The GT-R has more power and torque but is heavier, so that makes sense...

 

This is my car, waiting for the next round at the Nordschleife (Nürburgring):

 

I bet that's great fun to drive on the Ring!

 

My car is actually the silver car that RENNtech has at their Florida facility presently

check out my Instagram @_la_mercedes_

 

Did you ever do the post-tune run? I saw the vid for 11.4 and I'm quite interested in the end result...