GMBALL

Perhaps I have explained it in a wrong way, let me try again.

I've read in a different thread instructions on the installation of this thing. It said that in order not to get a fault code and get a power reduction (see this: https://mbworld.org/forums/c450-c43-...functions.html), this "installation" must be done only in a specific way. That is when the car is locked, they key from the car is not anywhere close to the car and therefore the car is in this "sleeping" mode & locked. Only then this disconnection & connection would not result in a fault code.

If you do this installation with the car unlocked, or with the key close to the car, or with the trunk opened (and therefore the car unlocked and "awake", as in my case), the ECU will detect that the original flaps were disconnected and will put the car in that low power mode and you won't even know it unless you use Xentry diagnostics. So, it must be done in a way that a car's ECU doesn't "notice" it. So, just unplugging the flaps and plugging the simulators is a bit risky, but thank you anyways.

TECHNICIAN

As I've said previously I highly doubt the flaps are your issue. Plug them in with the key off and engine off. This isn't anything special or hard to do.

GMBALL

Okay, it seems to me you don’t really want to understand me. I am not stupid and can do it in a way you describe. However, as mentioned in other threads, it will cause soft limp mode again and would need fault code delete on Xentry.

I have no issues with the car anymore, once the original valves were plugged back and codes deleted with Xentry, the performance was strong again, that is long solved. I am dealing now with how to safely remove them and plug these things on. If it was as easy as you say, then no questions would be asked.

Have a pleasant weekend.

nota_amg

just lock the car, then open the trunk. Use something to "close" the trunk latch on the body(pen, screwdriver) so that the car thinks the trunk is closed(LEAVE THE TRUNK LID OPEN). Get the key away from the car and wait for 15 minutes to ensure car is asleep. remove flaps and plug in simulators. When you're done, remember to hit the switch to reopen the trunk latch(make sure it is open where the trunk lid 'catch' can interact with the 'latching mechanism' on the body correctly) so you don't attempt to close it manually and break the latch. Good luck!

Like TECHNICIAN said, flaps are more than likely not your issue, but this should allow you to properly test your theory.
Make sure you have something to log your car(Torque Pro app works well) and talk to your tuner about what to log. Without any logs, I would assume a power loss due to a boost leak, but the logs will help narrow down on what to look for. The only real diffenence between stage 1 and stage 2 is they turn off the O2 monitors so you don't throw a CEL. The power increase is just the result of freeing up exhaust flow by removing the restrictive Catalysts. 200 cel's are pretty free flowing so you should still see a massive increase, I know I saw/felt a huge difference in my car going from stock cats, x-pipe, & no mufflers(all stock OR 2.5" pipes) to MBH catless 3" downpipes, x-pipe and dumps(All 3" pipe). With no other changes I saw 0.5 second decrease and 3mph increase in my 1/4 mile ETs/Speed(from 12.0@117 to 11.5@120). There is no way your car should be slower with that exhaust.

NoVAe63s

Just pull both batteries. One in front, Aux in the trunk.

mercshepherd

I have measured 0 to 60 mph times on my Renntech tuned 2012 CLS550 4Matic both with a Dragy and a G tech Pro Meter.

The G tech Pro meter (50 hertz sample rate) measured 3.6 seconds while the Dragy (10 hertz) measured 4.1 seconds on the same run/test.

The Dragy was measuring 0 to 60 mph times consistently 0.5 seconds slower than what I believe to be the much more accurate G tech Pro meter.

So your times may be better than you think from my experience with the Dragy

billvp218

I think I had a Gtech Pro in the 1990s. Why do you think that old-tech accelerometer is more accurate than the GPS based Dragy?

mercshepherd

The G Tech Pro is GPS driven as well, gathering position and therefore distance data from the GPS satellites.
I believe both meters use GPS position data to determine distance traveled over time (with their internal clock) to calculate velocity (distance over time) or miles per hour.

The G Tech Pro has a GPS position sampling rate of 50 Hertz ( or 50 times a second) which is 5 times greater than the Dragy GPS position sampling rate of 10 Hertz (or 10 times per second)
This higher sampling rate of the G Tech Pro may make it more accurate

I measured my stock 2012 CLS550 4Matic 0 to 60 mph time to be 4.3 seconds with the G Tech Pro. 4.3 seconds 0 to 60 is the published time for the CLS550 4Matic
After a Renntech Tune along with a muffler delete (straight piped for louder exhaust sound and less back pressure for more horsepower), I measured the 0 to 60 mph to be 3.6 seconds with the G Tech Pro
I measured the 0 to 60 mph time simultaneously with the Dragy which showed 4.1 seconds which seems slow for a 540 HP Renntech tune along with straight pipe exhaust (the Renntech tune alone was reducing 0 to 60 time by 0.5 to 0.6 seconds for
around 3.8 seconds as measured by the G Tech Pro) The Dragy was measuring 0 to 60 time 0.5 seconds slower consistently versus the G Tech Pro

The Dragy should be accurate, but I find it to not coincide with the G Tech Pro which measured the CLS550 0 to 60 mph with Renntech Tune/muffler delete at 3.6 seconds, a time that makes more sense.
Im wondering if anyone else has had experience comparing Dragy 0 to 60 times with another high quality performance meter

thesaintusa

I wonder if the OP ever figured this issue out?

NoVAe63s

This was my old g-tech. Pre GPS. Featured cutting edge red LCD readouts!

thesaintusa

I had the same unit.

Found it incredibly consistent. Remember trying to dial in the weight of the vehicle by tilting it forward and then back. haha

Probably still have mine sitting in a box in the garage.

NoVAe63s

Oh man that brings back memories dialing in the weight. I never did weigh the car, I think I used a C&D or R&T article. Had a few friends ask about my "radar detector".

billvp218

Plenty of people have compared dragy times to dragstrip times and they are super close, like maybe 0.02 seconds apart. The trap speed is really accurate also.

Magazine times include a 1ft rollout adjustment. Dragy has results for with and without rollout. Which are you comparing? It's also possible that the magazine semi-professional driver had a better launch than you did. Does the newer gtech pro include rollout?