Jack_88

Alright, I'm trying to decide if I should at some point put a tune on the car. This is less about overall power output and more about removing that pesky limiter. My concern, however, is that nearly all the tunes I see add 100hp and 100lb/ft or more, which makes me wonder about reliability. The car is already around 600lb/ft, how much more can it take before parts start coming out the back? Anybody here been living long term with a tuned twin turbo? All I can find on reliability is don't run it with slicks at the track and Eurocharged tunes on the supercharged AMG's seem to starve cylinder 8. Eurocharged does offer the best value, but Renntech offers a plug in tune you can take on and off at your leisure. How much do these tunes affect day to day driveability and fuel economy?

I plan on taking the Dodge to Bonneville next year, and it would be nice to have the Mercedes tuned up a bit and delimited, although I don't know how much I like moving the rev limiter...

Any input or experience would be very much appreciated. I've done research but most the information I found was from people with a fresh tune, not those who have lived with it for a while.

ZephTheChef

The Eurocharged tune is also re-flashable yourself any time you want. You shouldn't need to worry about reliability at only 100hp extra...these cars are still only putting out 50hp per cylinder with a tune, which is a joke. Tons of cars do that stock. I don't usually start to worry about eating engine parts until I get up around 100hp per cylinder. My tune has only been on the car a year, but no problems apart from having to replace one coil (which was due with 90,000 miles on an original coil anyway).

The transmission/driveline is what you'd have to worry about...and mostly only would have problems like you said if launching hard with lots of traction and sticky tires.

ZephTheChef

As far as day to day drivability and economy, I saw no difference in highway MPG. I think the throttle response (at least in sport mode) is a lot better after the tune. I really like the way it drives with the tune, the sloppy throttle response when it was stock always bugged me. I have both the ECU and TCU tunes.

tusabes

Get the tune but remember you'll be buying Coils and inverter shortly

mcguirja

If you are more interested in removing/increasing the limiter see if you have someone near you with Star and they can change it for you.

With that said, I have the Eurocharged tune on my SL63 and really like the difference it made.

AlexMercedes

I have a Renntech tune, and I have gone through 2 sets of coil packs now... so beware, there are some nasty drawbacks to the tune but at the end it is so worth it.

Jack_88

What is it about the tune that takes out the coils and inverter? Any way to protect them? Habitually, I have a pretty relaxed driving style, easy off the line and easy around corners. I like to save the full throttle runs for the opportune moment and go right back to driving Miss Daisy. On rare occasion, I would go to the drag track with it, just to mess with the Camaro and Mustang crowd.

Jack_88

For my purposes, this may be the better option. Will it remove it entirely or will the 187 limiter still be in place, as Car and Driver found when they tried to max a CL55 that Mercedes said they removed the limiter for.

ItalianJoe1

Star can raise it, I bumped mine to the 155 limit most MB's have using star, I believe there is another option to remove it totally but I would have to experiment as it's all in german. I tried one of the several "no limit" options and it moved the limiter to 100mph.

ZephTheChef

Not sure if anyone really knows the exact answer to that. Several possible theories though. Most likely, it's just that the higher cylinder pressures from more boost will require a higher voltage in order for the spark to jump the gap. This has the same effect as worn out spark plugs with too large a gap...it places a lot of stress on the ignition system, which has a lot of high-fail parts anyway. Other possibilities include higher heat produced under load, or the tune may even adjust ignition dwell which would increase the coil duty cycle, again overstressing them.

ZephTheChef

Is your problem the top speed limit, or the transmission torque limit that occasionally causes limp mode after a hard run?

Jack_88

I've never heard of this torque limit and limp mode. What's the behavior that to look for? The top speed limit is my primary concern for a Bonneville run, but extra power would be nice. I don't want to start burning through components, though, just for the odd occasion I do plant my foot.

ZephTheChef

I believe it is in the transmission control module. It seems to me like it only happened after the ECU tune and before I had mailed off the TCU to be reprogrammed (but I could be mistaken on that). Basically when the transmission computer thinks the engine has exceeded a safe torque value, it will shift really hard and then lock itself into that gear until you shut the car off and restart it.

Top speed runs can be extremely hard on cars, stock or otherwise. I mean you're essentially wide open throttle for MILES. That's obviously going to be a lot more stressful on things than the few seconds of WOT accel you can get away with on the street (before you're doing 100+), or even the 10 seconds or so during a drag race (the only really rough part there is the launch). If you're really worried about breaking things, I wouldn't recommend you go do 5 miles straight at wide open throttle.

tusabes

Get coils from oreilly or auto zone , they have lifetime wArranty and are oem
you'll need them sooner or later regardless of tune or stock

Speedriven1

About 300 more lb-ft consistently. After 900 lb-ft at the wheels, it's time to beef up the trans.

Speedriven1

Exactly why we're working on an individual coil pack kit.

Speedriven1

You won't burn through them. The 600 is one of those great vehicles that was artificially de-tuned from the factory to preserve some distance between the 600 and the 65 AMG cars. You won't stress the car by letting it do what it was built to do before the marketers got to it.

Jack_88

$2470-$2500 for the pair. Good to know you only have to pay for them once, though.

ZephTheChef

Good luck actually catching them in-stock though. I had Oreilly's trying to get me one for over a month before I gave up and went through FCP euro. I can't imagine how long you'd be down if there was a warranty problem.

ZephTheChef

That's great news! Is it based on the newer Mercedes coils or an aftermarket solution?

Speedriven1

Still very much a work in progress. We drove the car last night, though- so that's cool.

ZephTheChef

This only applies with the aftermarket ECU then?

Speedriven1

I want to say no, but- at the moment- those are the guys who are willing to pay for R&D time.

ZephTheChef

Gotcha. In other words, everything is still theoretical but the proof of concept works. This will be a big deal if it works and is priced not too out of line with stock replacements. Keep us posted.

mcguirja

From what I've read it tops out at 186 (300kph) as you've suggested. I've only used star on my SL63 so far and it has the tune (limiter removed) so I haven't tested it conclusively. I can play around with one of my other cars on Sunday and see if the 186 max is truly the case.