funkyr

Has anyone seen a dyno (or performed one) of their C43 before and after racechip?

Thanks

user33

I installed a RaceChip Ultimate Connect on my 2017 C43 (w/Performance Exhaust). Though I won't be checking it on a dyno, I did take it out and do a few 0-100 kph runs (du-oh!) using Harry's LapTimer to grab the car's data via a KiWi3. I did the runs in the same place using the same techniques as previous runs I'd recorded pre-RaceChip ... except that there was a moderate rain falling and the temperature was about 14 deg. C/57 deg. F (instead of 22 deg. C/71.6 deg. F for the non-RaceChip runs).

I found that the car was about .3 seconds faster to 100 kph (at 4.37 sec.) with the RaceChip in Race mode (i.e., compared to previously captured 0-100) -- about a 6.5% improvement. Note that when measuring times using Harry's LapTimer, there's no "roll-out" footage -- i.e., it's pretty much from zero. In addition, both the RaceChip and non-RaceChip runs show the peak lineal G-force is developed at 3 seconds/67 kph except that it was 0.83 G without the RaceChip and 0.90 G with the RaceChip -- about an 8.4% improvement. At 100 kph, it was still 0.47 G versus 0.52 G with the RaceChip -- about a 10.6% improvement. To me, this indicates that the RaceChip has a similar torque curve but develops meaningfully greater torque (as expected). I'm also guessing that the differences will be more pronounced in a 1/4 mile run than a 0-100 kph run.

Since I put the traction control in sport mode (push console traction-control button, shows mode on center screen), there was a bit of tire spin so I'm guessing that some time was lost ... maybe more that could have been gained by the lower temperature. The LapTimer graphs show that the throttle was limited to about 90% for the first second or so.

The weather forecast shows rain for a few more days (it's _that_ time of year, here!) but, when it's dry, I'll do some more instrumented 0-100 runs and report back. If I can find a safe place, I'll also do some 1/4 mile comparisons with and without the RaceChip turned on ... however, given the speeds achieved it's difficult to find a viable place.

In case anyone is interested, I purchased the RaceChip via
https://www.racechip-usa.com/chiptun.../43-AMG-270kw/
where it's currently on sale for ($607) $107 USD off, shipping included to US/Canada (I have no affiliation with RaceChip, other than being a recent on-line customer). It was shipped promptly, arrived when it was scheduled and all is well. Shortly after the order, they emailed me some high-resolution pictures of the C43 engine's connectors (the shipped manual hasn't yet been updated) which made the install very clear.

Update: that site is now being redirected to another company ... one in which I have zero faith. Looks like the only US choice for RaceChip is now:
https://www.racechip.us/shop/mercede...-384lb-ft.html
... and the price has gone up ... so I'd now also consider the BMS JB1 piggyback:
http://www.burgertuning.com/mercedes...00_Stage1.html

The RaceChip install took a couple of hours because I'm fussy about routing wires and it was the first time I'd taken the cover off the C43's engine ... so I had to geek out 'n look around a little. I feel it's important to pay attention to the cable routing to ensure that things don't vibrate and make noise and/or rub against other hoses/wires and cause damage through chaffing. The harness is long enough that I was able to route the cables away from any hot components and to attach the control box to the aluminum cross-support tube on the motor-side of the battery compartment. This gives it free surrounding air for ventilation but also keeps it protected from the elements. It did, however, require a little work to cut the plastic on the wall of the battery compartment to allow the wire to enter (and file/sand the edges smooth ... neatness counts!). There are spots where this can be done and it looks like maybe other models have cables that use those same spots (i.e., they appear to be "knock-out" tabs).

Though I've not yet had much (or any non-rain) experience with the RaceChip's performance, a significant improvement is clearly evident via the ol' butt-dyno device. The RaceChip's iPhone app has also worked flawlessly. Thus far, I'm quite happy with the purchase.

Here's a video of the 4.37 sec. 0-100 run:
(update: also see other posting in this thread with video of 0-100 in 4.0 sec.)

user33

We had a non-rain day and I had an opportunity to do a 1/4 mile test using the DashCommand app and the KiWi3 ODBII-to-bluetooth to capture the car's telemetry. I only was able to do 1 run:
- RaceChip on Race (du-oh!)
- Sport + (PE on)
- Traction control off
- auto-shifting

The good news is that DashCommand app reported the run as 12.41 seconds at 112.2 MPH. That's with a driver, about 3/4 tank of (92 octane, 10% ethanol -- standard for Washington state) fuel and an outside temperature of about 11 deg. C (about 52 deg. F).

The bad news is that I quit the DashCommand app after the run and when I got home and tried to look at the detailed data (expecting it would have been saved), I found that nothing was saved (seriously lame app behavior!).

I still plan to do some direct comparisons with and without the RaceChip enabled under the same conditions and will report the results when I do.

Update: I later was able to recover the telemetry data from my iPhone (using a utility).

I've found that getting consistent launches from a C43 is a significant issue. One will be "great" and the next three, seemingly doing the same thing, will be 1 second slower (e.g., to 100 kph). The launch on this run was mediocre. A better 1/4 mile run is definitely available, with a good launch.

Here's a video of the 1/4 mi in 12.41 sec at 112.2 mph run:
[BTW, the boost PSI seems high ... I assumed the OBD reading was in bars and applied a conversion, FWIW]

user33

No opportunities to do additional 1/4 mi runs but, having been reading about different C43 launch techniques, I did get a chance to try some 0-100 runs.

The best results were using the "go on increasing RPM" technique that's been discussed (brake, step on gas and release brake as RPMs hit about 2K ... don't wait, just release brake while RPMs are still rising and don't wait for the turbo-boost to get to maximum). The outside temperature was at 10 deg C (about 50 deg F) for the 4.00 sec result and at 15.5 deg C (about 60 deg F) for the 4.07 sec run, the roads were dry and the altitude is a few meters above sea level. I also turned traction control to the off setting and, of course, was in sport+ mode (with PE on). Even so, getting consistent launches/runs is very difficult in the C43 (stock or RaceChip). If I'd gotten a good launch with my 12.41 sec 1/4 mile run, it would likely have come in at around 12.15 to 12.2.

Car telemetry was captured by Harry's LapTimer and I was also using a Dual XGPS160 10 Hz GPS (though the speed for the timing data comes from the wheel speed, not the GPS).

My 2 best runs yielded a 0-100 time of 4.00 and 4.07 seconds (RaceChip set to Race mode). This compares to a RaceChip disabled mode of about 4.6 seconds, though maybe that would be down to 4.4-4.5 with this type of launch technique.

Since I've switched to winter rims/tires, it's unlikely that I'll get any more performance-run opportunities 'till next spring.

BTW, the RaceChip install hasn't changed the wonderful exhaust sounds that the C43's performance exhaust makes.

Here are videos of the 4.00 sec and 4.07 sec 0-100 runs:
[BTW, the boost PSI seems high ... I assumed the OBD reading was in bars and applied a conversion, FWIW]

funkyr

Thanks for the detailed review!

funkyr

Did you get the app to adjust the tune from your phone?

If so, when you switch off and lock the car and then back on again does it go back to the stock tune program or back to the last used racechip tune program?

Also interested to know if when using a racechip tune setting does the sports and sports+ modes still function in the car?

Thanks!

user33

[1] Yes, I'm able to switch between the RaceChip eco, sport and race modes via the iPhone app, even while the car is running. For me, the app has worked flawlessly except that there seems to be a typo in the RaceChip-enhanced HP it displays in its "info screen" (I reported it and received a nice response -- Update: the next release of the app fixed the bug I reported, nice!).

[2] Yes, the currently-set RaceChip mode (eco, sport or race) persists across stops 'n (re)starts. Nice.

[3] Yes, the C43's dynamic mode settings function as they always have ... as does everything else in the vehicle ('cept performance and fuel economy).

The RaceChip people seem to have thought things through. According to one article, one of their key people really likes the C43 so I'm gussing they "eat their own dogfood" with the C43's tune ... and that normally yields better products.

waisoserious

What happens if you leave the app in race mode, but your car is in comfort mode? I ask because sometimes my sister drives my car and would not have access to the app.

user33

Disclosure: I have no affiliation with RaceChip (or any other such business entity) but do have >30 years of software engineering experience and am also a licensed electronics technician ... which is only to say that I have enough knowledge to be "real dangerous." ;-) The explanation provided below is conjecture based upon my software/electronics background/experience and my understanding of recent automotive technology. I'd bet this explanation would match any of the piggyback tuning devices (except that some monitor only 1 or 2 sensors while others monitor more than 3).

The car's dynamic-mode settings still do what they always do (comfort = comfort-mode suspension/drivetrain with eco-stop on, less aggressive throttle response, etc.). The RaceChip also still does its thing for any given combination of conditions it's sensing ... i.e., optionally performs sensor-signal modifications and sends them on to the ECU.

At a more detailed level, the progression of "command flow" is as follows:

- the engine control unit (ECU) does its "normal" job:

+ based upon the car's settings (e.g., its dynamic-mode setting, such as comfort) along with values received from a slew of sensors (including environment, engine, transmission, etc.) the ECU drives various actuators (e.g., throttle, fuel injectors, ignition and valve timing, etc.) according to its program (a collection of rules) to achieve various engine-running and other objectives

+ this means that when in comfort mode, for example, the throttle position is mapped to a much less aggressive request for fuel/performance than when in sport or sport+ mode so the ECU will open the throttle less at 1/3 throttle in comfort mode than when in sport or sport+ mode

- when enabled, the RaceChip Ultimate is constantly intercepting the values produced by 3 sensors and, based upon various rules related to its mode setting (eco, sport or race) and the values these sensors are delivering, the RaceChip may alter the value that one or more of the sensors is producing prior to forwarding each sensor's value to the ECU:

+ such altered values are designed to cause the ECU to achieve the RaceChip's objectives

- at all times, the ECU is in final control in that it's the only device sending engine running actuator requests/instructions -- this means that it can override the RaceChip's objectives if the values that RaceChip forwarded are beyond what the ECU's rules consider safe (or even applicable in a given situation -- e.g., transmission sensors say "hey, too much torque" so ECU says "whoa, throttle ... adapt timings ...")

As you can imagine, with a myriad of sensors, many actuators and an ever-growing collection of (often competing) objectives (performance vs fuel economy vs longevity vs environmental vs safety vs comfort vs ...), the development and optimization of the programs/rules for an ECU get very complex and involves a number of tradeoffs relative to many of the operational objectives in any given mode.

I hope that helps.

MB-350

They recently posted an acceleration video of a C43 AMG:

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One day’s experience with the GTS black on my C450 and I’m delighted. My Dinan Sport seemed to do nothing, whereas this increases everything, including mileage! How is that?

waisoserious

They lowered the boost at lower RPMs is how they achieved increased mpg. You can see it on their other Dynos (non C43 dynos).

funkyr

Would be interesting to see a dyno of the GTS black!

MBkent

18bora

I would like to see 1/8-1/4mile trap speeds. Dynos are nothing more than a tuning tool and the numbers from dyno to another could vary by as much as 100hp. Stock vs. tuned dyno usually gives you a good idea of power increase. However, the car with a higher trap speed will win.

\/ BMS jb1 launch

user33

My post at https://mbworld.org/forums/c450-c43-...ml#post7309364 answers that question (and more) ... but the short answer would be "yes" and "yes" -- in that order!. ;-) RaceChip in Race mode will give the most performance, regardless of the car's mode. Sport+ sets the car to give the most performance, regardless of the mode/map any piggyback is set for. A lot of what Sport+ does is related to the transmissionn program, as opposed to just the engine's behavior.

Now that's a good question. I don't know but, with the RaceChip Ultimage I have, there's no externally accessible adjustment so I assume it'd always be in Race mode (since nothing else would make much sense). The current models -- RS, GTS and GTS Black -- all appear to have an externally accessible map/mode adjustment. The Ultimate has such an adjustment, but you need to take the cover off the case in order to access it. So, to be more accurate, without the app, I assume the RaceChip Ultimate would always be in the map/mode you have set on the internally accessible setting (which, when delivered, is set to the Race map/mode).

waisoserious

I dont think the cars drive dynamic mode has anything to do with power. I think it modifies:
- What gear you start in
- What RPM to shift in each gear / how long to hold each gear
- Throttle Response

The Racechip App should only modify:
- Boost

MBkent

Great, I missed the Xmas sales (10% off). I will get it next time when they go on sales since the car is still under 1k miles. Can't wait to go into Sport+

MB-350

It's on sale today! (Link: https://www.racechip.us/)

MBkent

Yea, I actually bought it with a promo code (GTS_USA) at 15% off!

DameMD

Since RaceChip states that that they can custom tune their piggyback for power adders like exhaust, downpipes etc... has anyone done this yet? Curious as I want to go a step further than my JB1 and install downpipes. If BMS did a JB4 for the 43 platform I wouldn't even be mentioning this.

For the GTS-Black, RaceChip site states it comes with 7 customized maps "to tailor your driving needs". Are these standard maps that they customized for the 43" engine or are they custom tuning these maps based off of metrics that we are sending back to them to customize? Can you customize any of the maps for like boost, fuel and other stuff?

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DameMD

Cool. Are the settings locked in so that every time I turn on the vehicle the tune will be set for "Race"? I like to have more power even when driving in comfort and eco mode.

That's interesting that they are stating that they have 7 customized maps for your driving needs, but they are maps that they have altered and not based off of "my" vehicle. It would be nice if they provide me a custom map and I do some beta testing, then provide them my logs, and then they retune it to get me optimized performance for "my" vehicle. I will call them and ask how do they customize the tune for specific upgrades and vehicles.

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MBkent

Yes, Racechip remembers the last mode you used, and if you did not setup the warm up timer, then it will be turned on immediately.