i wouldn’t spend the extra $ on Renntech. I would look at Eurocharged.

I can tell you that having driven the car at COTA it definitely needs a tune to maximize all that suspension. The GTS I’ve driven tuned are monsters, but the lack of traction holds it back. The GTR with the extra wheel width would really wake up that car.

I have a Renntech tune and coilovers on my GT and I couldn't be happier. Renntech has the rep and the long history and they charge a premium for that. Eurocharged (EC) is clearly a market leader these days particularly with the C63 boys and probably the best value out there. Excellent customer service there by all accounts. We do know that there are no significant difference in the tunes of the top reputable tuners. The companies do have different sales strategies. I currently have a Kleemann tune on my (out of warranty) C63, but will probably be moving over to EC in the near future for that car. One significant difference between the companies is that there are over 30 authorized Renntech dealers residing in MB dealerships in the U.S. No guaranties, but you can get the best assurances from your SA at these dealerships that they will work with you through any potential warranty issues. "We will take care of it." There is a value in this to me. That's my situation. Most of us throw money at our cars and in this regard I would simply say that you should get the tune that you feel most comfortable with based on the circumstances. If you are really watching your budget, EC is the way to go. Really no bad choices.

Are your tunes ‘discoverable’ by a MB dealership during servicing? I suspect yes?

I’d love to see this car timed on the Ring. I bet it would shave 10 seconds on those long straights and out of corners.

whats curious about the stock car is the level of torque with the bigger turbo and all.

I’m sure it would be somewhat faster, but 10 seconds faster would be huge, especially for a car who’s top speed is probably drag limited on the straights.

coming out of corners at COTA were not quick. Having 700 hp would give you the extra time in the straights.

Have you tracked your GTR yet?

I haven’t unfortunately as it’s still awful weather here currently. Looking forward to it greatly though. Will be an interesting contrast with my ‘15 Z06/7.

Bish

I was actually surprised to find that the GT R makes very little downforce. Tobias Moers states in an article that at 124mph, the front end is aerodynamically neutral, no lift or downforce, and only has 110lbs of downforce at the rear. That big of a horsepower bump may make quite a bit of difference in the straights.
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Which Renntech GT R tune is rated at 773hp? Got a link?

Renntech's tune only number is off of their baseline stock GTR that they dynoed, which was 600+ HP. We generally know that MB HP numbers are understated. What they are really claiming is another 50+ HP, closer to EC's math.

Renntech 773 (crank) number is with upgraded turbos, exhaust and downpipes.

My vote goes 100% to Eurocharged. Renntech’s mark-ups are insulting.

I have upgraded turbos on my GTS. EC flew to California from Texas when I asked and spent 2 days on the dyno making sure my car is rock solid. It’s pushing 648 to the wheel or so (765 crank). Tune and turbos ONLY. No downpipes or exhaust.

It’s also dead reliable and consistent and I’m taking it to the track twice a month, back to back runs (I run in 2 groups) and ZERO issues whatsoever.

Can’t beat EC price and customer service.

PS: People that say the GTS with a tune has traction issues... eh... not really. I don’t love the car, it has a lot of flaws but traction isn’t one of them. Brake fade is my biggest ennemy at the track. I don’t have CCB. Ease up on the throttling exiting corners or maybe try new tires. The Michelin 4S are pretty decent.

/thread