thecutter64

has anyone tuned their GTS? Did you notice a difference?

is the ECU tune only even worth it? It only bumps up the HP to 601. Is 80hp noticeable?

will the car handle the full tune to 750hp?

Case1906

80hp is significant and yes you will feel the difference. Car goes from ridiculous to absurd on acceleration. It is even more dramatic with a GT obviously which is what I started with.

thecutter64

Did you get a full tune or simply the ECU tune?
Who did the modification?

JSwan724

As everybody here have discussed, be sure you consider that the warranty on your new GT will run the risk of being voided. Also, if you require factory softare updates, you will either need to not do them or run the risk of having your tune overlaid.

Come trade time it could impact the trade or sale value.

Talk with your dealer service department.

Just saying....

guynamedsean

My dealers service department actually sells and installs renntech tunes and my salesperson and service advisor have both mentioned it and talked about other customers cars they have done.

Im pretty confident they would buy the car back on trade and give me normal value. I'm not 100 percent that I won't run into warranty issues with Mercedes though.

AMG 17GT

From what I have heard, it's not so much about peak horsepower as it is throttle response. I don't see you at 7000 rpm on the street, so this may not be an option for you.

Renntech is a 90s relic. Look at eurocharged.

Future search would do you well as this has been discussed ad nauseum.

thecutter64

Thanks

Case1906

RennTech has been around forever but I wouldn't call them a relic. Still a top company with tradition. EC tuning is also top notch, and they are known for customer service and aggressive tunes. EC does a great job and is "cheap" compared to RennTech, Weistec and most of the others. I have a C63 M156 and I think most tuned owners would tell us that EC is state of the art with that motor-- now up to tune version 7. With GTs, I'm really not so sure if there is much difference between the various tunes at this time. That may come later if one or more the tuners continues development work. What we do know now is that EC is significantly cheaper than RennTech, which employs the full "Mercedes tax" that goes with its long standing excellent reputation. But there are always other factors to consider. If we all operated on price motivation alone, very few of us would own our cars and we would have nothing but generic store brands in our homes,

Are you running a tune? Does any one on the board believe that one AMG GT/GTS tune it appreciably better than another? I"m not hearing that and I don't see it in the few dyno results that I have seen. It seems like everybody is generally happy.

Case1906

ECU only + coilovers through MB/RennTech dealer- for reasons previously discussed.

sl600fanatic

Totally agree. As far as I can gather, there is probably a couple companies out there who sell the software to companies like Eurocharged and RennTech who then do a 15 minute tune on your ECU. I doubt each of these companies spends the millions in R&D required to make their own software maps. Complete waste of money to buy RennTech when Eurocharged offers the same performance for 1/3 the price for members on this forum.
The increased torque and throttle response are insane in the membrane.

AMG 17GT

Renntech had this niche deal back in the day, when they were sold physically out of the dealerships. It was assumed that anything that arose problematically from the tune would be covered by either the dealer or Renntech itself and THAT justified the price. As time went on this evolved from reality to vapor.

What is curious to me is what happened to Kleemann? They were well respected and sold othe items such as headers that were as good or better than Renntech, at a much more reasonable price.

Anyway, I'm looking forward to seeing what they're going to get out of the GTR configuration. It will be particularly interesting to see how it affects lap times etc. with the stock Pcars and Macs.

JSwan724

When JRCART checks in here he can update you on Weistec and his GTS tune.

He seemed to be veryhpply with the results and has been a very long time customer of theirs over the years.

AMG 17GT

Weistec lost their head software tuner, and there have been a lot of cars that have had numerous problems such as throwing codes, limp mode etc.

06032

The de-facto standard 'street tune' is a noticeable improvement over stock. Plenty of thread material to search up on. In short, it isn't the HP increase that you'll notice as much as the overall torque/acceleration and smoother throttle response, especially in Comfort. Previously, I would seldom use Comfort around town because of throttle lag. Use it all the time now (albeit with a notch of suspension and sans eco-mode).

IMHO, Renntech is a waste of money.

FourT6and2

Do these maps from Renntech, Eurocharged, and Weistec mess with any of the other functions of the ECU? Like the menus or digital gauges or anything? Or is it JUST the air/fuel curves and timing and whatnot? Too bad they can't add some kind of embedded switch in the car's menu system to go between stock and their maps. Would make it great for people in states that require smog testing all the time.

ericweng

i have a R1 tune from Renntech. Honestly you can't really notice the HP in the city but you will definitely notice how much torque there is. i went with Renntech because they are the most reliable tuner there is on the market for Mercs in my opinion. I had it tune around may this year, and the car has zero problems. i don't think saving a thousand or two in the beginning will help financially if the car starts having problem after the tune with no warranty.

dappersclass

I was looking at trading one of my S class for the new GT and in my experience tuning is always worth it. 80hp is noticeable for sure, however, I find Renntech as a company a waste of money.

I personally use AMR Performance because they not only make more power, but I have no issues at the dealer AND they offer a motor warranty program. There was really no downside when I was considering doing it

Case1906

It is different but RennTech is still operating through more than of more then 30 MB dealers. The dealers are into it for the margin on product and labor charges. They will charge labor to take out the ECU, FedEx it to Florida and pop it back in which any of you can do. There is the U.S. mothership in Florida which is impressive and they have other authorized dealers at certain speed shops.

Great question on Kleemann? They don't seem to be in the business of M178 tunes/products right now.

Jim Brady

On the sidelines but thought I'd chime in.

An ECU tune will bump the torque to 500 Lbs ft at the wheels which is more than a McLaren 720 so you will feel it. Torque is acceleration hp is top speed. Some tune for numbers over the curve (hp) and the smart guys tune for torque under the power curve. 750 hp is very doable but you're putting a whole lot of heat through the system as well as increasing turbo lag. Dime has a 740 hp upgrade but it also includes cooling improvements. Problem is reliability when your that close to the torque limits ont the duel clutch transmission.

Any performacne enhancement company like Renntech that has survived through the burtal 2009 and is still standing deserves a look as they must be doing soemthing right. I've spoken to them and they don't BS you.
I remember the internet tuners Authority, Power Chip, Evosport, all gone gone gone. Most of these companies disapear when things get tough. Hard to find the tuner operating out of his garage for after sale service when a problem arises.
Jimmy

sl600fanatic

Sorry but your numbers are wrong. The ECU tune is 600+ lb ft torque not 500. Even with a 15% powertrain loss it would be way over 500 lb ft torque.

FourT6and2

Where are YOU getting YOUR numbers then? https://www.renntechmercedes.com/ind...gt-s-fl-detail

On a side note, $3500 for $80hp at the crank is hard to swallow.

AMG 17GT

Jim is dead on its 500 at the wheels.

Jim Brady

[QUOTE=sl600fanatic;7269385]Sorry but your numbers are wrong. The ECU tune is 600+ lb ft torque not 500. Even with a 15% powertrain loss it would be way over 500 lb ft torque.[/QUOTE

SL,
Using your assumptions on drivetrain loss, try this calculation .85 x 600=510!
I have a honest dyno and with 105 degree day it pulled 500 on 91 Octane. Remember not all dyno's are created equal. It still overwhelms the 295 MPSC2's. I don't know if it will be any faster on a road circuit if I can't put the power down.

Jimmy

06032

for the OP, the stock ECU hp/torque is certainly more than you'll ever need in Long Island. But as Vic55 mentioned, a tune really makes the 40-100 sweet spot for passing acceleration come alive. My perception is that it also increases the occasional 120mph romp to 140 mph in the same distance. And again, throttle response is vastly improved.

As to the RennTech vs. 'others' value argument, after much research I personally could not justify the 4x premium of Renntech (over EuroCharged). MB dealers want the margin plus labor...but legally, they can deny a warranty claim on a vehicle equipped with Renntech just as easily as with any other tuner. As someone who always used Dinan on my BMW's, I actually wanted to chose Renntech. But when I spoke with them, they truly could not differentiate their tune....how it was any different (or better QA'd), much less how it was worth a 4x premium. The pregnant silence on the other end of the phone was palatable. All things being equal, one can't go wrong with Renntech. However given near identical dyno results and warranty realities between these guys, the tune is essentially a commodity. My $3k savings went into 3M film.

FourT6and2

Great way of putting it. A tune is a commodity. There's nothing hugely proprietary about it. You mess with timing and air/fuel until you get the results you want. Unless there's something else going on in the re-map? And for Renntech to be charging $1000 more than everybody else... for it to be worth it, there's gotta be value added somewhere. Is there?