JBMCL

In random circumstances(C and S+ modes) where if I mash the pedal, it'll take like a few seconds before the car realizes the pedal is mashed and then goes. I'm guessing this is turbo-lag?

Has anyone experienced this? It's fine and responsive when I'm pushing on the pedal but if I'm pushing it all the way down, it stalls for a little before it goes.

ManiacGT

Manual or auto (which auto, 7/9)

JBMCL

Auto 7G

ManiacGT

Thought so, mine is just the same.

this is partly turbo lag as the 4cyl turbo does have notable lag esp in comfort and eco. Then on top of that you have the poorest auto box I've ever had the displeasure of owning. Built in 1945 on a Friday night.

in combination these systems incrementally make this the slowest car to pickup and realise what you want.

the solution other than selling up is to use sport mode as this keeps the turbos spooled and the auto box in a quicker change time mode.

i have individual mode setup for everything in comfort mode other than the auto which is set to sport. This makes the car much more interesting and predictable.

its never perfect, the drivetrain is old tech in a new car but it's at least improved by sport mode or manual selection of gears.

to be fair, my DCT Z4 also suffers this occasionally as no auto can really predict as a manual car could but given its a DCT it's much quicker and more predictable.

chicago-guy

Agree, I'm in S+ 99% of the time now for this very reason, despite largely city stop-and-go driving. Prior to that, even though C mode was learning that my driving style favors prompt starts, the results weren't reliable.

Mike5215

Sport + is a little too spastic for me in my 16. (7g). I picked up a couple of doodads that help make the car smooth but also produce power on demand.

The first was a Dinan Sportronic turbo boost module. Self install without tools, 15 minutes. It's controlled by a smartphone app. I have it set at +4 lbs of boost. (Race). $399.

The second was a MidCity Eco Stop module. Also self install, minimally invasive, under 30 minutes. It defeats Eco stop, which is nice but the real value is that it will put Agility into the Individual mode at start up. I have steering and suspension (AirMatic) in Comfort, drive train in Sport. ($179)

So I get in the car, it's set up exactly how I want it without any intervention, and the extra boost with the car in Sport mode is smooth and comfortable but punching the accelerator produces a quick downshift and plenty of scoot.

Terminator1

The car is drive-able, but there is a room for improvements. I hate the characteristic of the transmission to downshift to 6000rpm on kick-down, like there is much to do with remaining 200rpm before up-shift. Also, as you approach 6000rpm, it takes more time to up-shift manually, you end up pressing the lever, but there is no up-shift, or it happens after 2 seconds. It's a single clutch transmission and a single turbo, so I guess it's OK to have a lag.

Terminator1

The car is fast from standstill, but if you start a race with a kick-down, you will end up losing it, just because transmission downshifts to 6000rpm and it takes 2 seconds to start pulling.

Mike5215

Yeah the C300 isn't a performance sedan by a long shot. It moves smartly but a T4 is a T4. C43 is the performance bargain in the 205 line up. Or a tuned C400.

subzero05

yep I would 2nd the Dinan sport unit. $299 retail is a bargain for the extra oomph you get from it.

l3gendary

the only way to eliminate "turbo lag" is what people mentioned. You have to tune it


A piggyback like the dinansport like people mentioned does exactly that. Best way to describe a piggyback is it takes less pedal to go the same speed. So you feel you are going faster (even if the 0-60 doesn't show it much) and it eliminates that lag before you feel the kick in power, essentially butt dyno approved. It'll feel like it's in sports plus mode all the time even when you are in comfort or E. Besides that, flashing is the only thing to make it truly faster but that is it's own risks involved of course.

subzero05

no offense but that isn't exactly correct. You would be referring to a "sprint booster" type product which alters the "drive by wire" signal of the throttle itself. The Dinan piggyback alters the boost pressure so it actually adds power/HP to your car as well as torque. A piggyback tuner does produce more power and torque. A throttle signal modifier (such as a sprint booster) does not

l3gendary

no offense taken. We're talking about the same thing. The OP was asking about what it feels like and I was trying to describe it. I'm talking about "what it feels" like to someone whose never done a basic piggyback boost tune before as I've tuned all my cars in the past. Yes I know tunes add power/HP and it adds torque as well (duh) but I'm just telling people don't expect a c300 to suddenly beat a c43, let alone a c63 just by plugging it in. There might be much more room to go on a turbov6 vs a turbov4 like in the c300


For a basic +3 and +4 boost, yeah you're going to go a bit faster maybe .2 to .3 faster to 0-60 on tune alone. You'll probably need stickier and wider tires to get to .5 secs. So it's minimal difference in speed but it'll feel so much faster on that butt dyno as it'll eliminate that lag that the OP is feeling when daily driver or when he wants to cut around a car. a dinansport tuned c300 is probably going to cap around 0-60 at around 5.5 secs or so, I don't anticipate it being a 5.0 second car unless you do a full reflash but still iffy on that.

subzero05

ok, understood and agreed!!!

Mike5215

If I'm not mistaken, the Dinantronic Sport module simply causes the boost sensor to under-report the boost pressure by whatever number you're calling for. The ECU compensates by increasing the pressure to what it "thinks" is normal. So if the normal OEM boost pressure is 20 for example and you want 24, the module tells the sensor the car is only producing 16, and it bumps it up 4 to satisfy the sensor.

Kind of the same principle with lowering links on an AirMatic car.

Hapa88

I have a few things I'd like to add.

"Turbo lag" is defined by the time when you mash the throttle until you actually feel a "rush" of torque pushing you forward caused by the turbo not yet making full positive manifold pressure. This is generally a mechanical issue inherent to the turbo size and design. Larger turbos need more exhaust gases passing through them to get spinning, hence why they don't "kick in" until later in the RPM range (when there's more exhaust gases). Smaller turbos generally take less, so they "kick in" much earlier in the RPM range. The C300 has a relatively smaller turbo and some ingenious MB intake manifold/turbo placement design to minimize lag. "ECU tuning" does not get rid of lag, , since it's inherent in the turbo design, it merely masks it.

Another thing that contributes to a lag between mashing the gas and actually going is the transmission responsivity. Or basically, how quickly the car can rev up and downshift and get into gear. I'm not sure if the OP was describing this or not, but it also contributes to a lag.

On the C300, there is no real way to eliminate lag other than remove the turbo, IMO. Cars like the new 2017 Acura NSX, mask turbo lag by having electric motors driving the front wheels. This gives instant throttle response and a rush of torque while the turbocharged motor builds boost. The driver never feels any turbo lag because it's being masked by the instant torque of the electric motors.

I believe Dinansport is basically an electronic boost controller (or something similar). It either does the work itself, or it tricks the stock ECU into reading something different than it should. The end result is the same though, in that it usually increases turbo pressure by keeping the wastegate closed, or closed longer (a wastegate bleeds boost pressure) and increasing fuel. Again, I'm not certain, but this is how many of those devices work.

I agree with subzero05 here. I think you're getting piggyback tuners and what I call "drive-by-wire gas pedal manipulators" mixed up. Piggyback tuners usually trick the ECU into reading different sensor values than what they really are, and they do so in such a way to gain more performance.

Those drive-by-wire gas pedal manipulators just make things more sensitive (exactly the same thing as the stock Comfort vs Sport+ modes do). Kind of like when you go into your desktop computer Control Panel and adjust your mouse sensitivity.


This is a great way to describe what's going on. I would add to his example, "if the normal OEM boost pressure is 20 for example and you want 24, the module tells the sensor the car is only producing 16, and it bumps it up 4, by manipulating the wastegate, to satisfy the sensor." Additionally, the ECU would probably request the fuel injectors increase flow rate to match..

But again, I don't think the Dinansport does anything to deal with turbo lag inherent in the turbo design... it may help make the transition into boost more smooth, thereby making the lag less apparent.

e2hung

Yep, that's definitely the infamous turbo lag. I experience it on my C300 W205 as well.

I've taken a few steps to counter this, however. Having driven an Audi A7 back home, the turbo lag and the sluggish/boatish feeling of the new C300 made it a nuance to drive for me.

First, I bought a RaceChip Ultimate, it was on sale. I think it was around the 500$ region, it promises 50-60hp gain, and gains in torque, but after driving for a bit, the realistic estimate of the gains in hp is probably around 40-50hp. No dyno, all Seat of the Pants numbers here. There is a definite difference in driving, and the turbo lag is definitely reduced. However, it wasn't enough for me.

Second, I bought a RaceChip Throttle Response/Throttle XLR. It works in conjunction with the RaceChip, goes for about uhh, 270usd. It has 6 or 7 modes depending on if you buy it from the German or the American counterparts. With the racechip and the throttle controller, the car is entirely different. It is finally drivable now. If the turbo lag really does bother you, a few hundred dollars is a great long term investment for the car. I usually have the setting on the throttle tuner set at the 3rd level. The responsiveness is perfectly balanced with acceptable jerkiness between gear changes.

np6345

I have a basic working knowledge on how a turbocharger works but wanted to know if adding tunes like the Dinan sport unit would have any long term effects on the turbo or other components?

e2hung

Yes, adding any tuner or piggyback aftermarket items will add strain to your engine. It is only logical that the addition of aftermarket parts that enhances and asks for more from your car will put more strain on your car. However, there is nothing you need to worry about. Although there are horror stories like engine smoking, or pistons melting together, those cases are very rare. These aftermarket companies need a certain degree of customer confidence and satisfaction or else they get replaced very fast. Dinan has been around for quite some time. Although they main in tuners for BMWs, the head of Dinan is actually a really chill dude that's very, very, knowledgeable in cars and tuning them. Plus, Mercedes Engines are usually designed to withstand up to twice or three times its normal operating pressure, so that there is some transferring when they want to develop the same engine type but in a different model.

So no, there really isn't anything you need to worry about. Just don't go cheap and make sure everything is thoroughly installed and correct.

Shadwell

On my 2015 c250, within a month I added a Racechip Ulitmate and a GFB DV+....
Filled the botuum emd, improved throttle response, maintained boost between gears and holds onto boost a little longer..


I could add a throttle interceptor but now switching to S or S+ does exactly that..


I now drive round in C 99% of the time and its fine..


S+ for hard pulls away from the lights etc just for the shift farts..

Toasty

This chip looks too good to be true!

How did you find installation?

The fact they make it sound so easy to go back and forth is such a huge benefit for warranty, really considering it.

dwpc

Frankly, I think "turbo lag" is essentially an obsolete hold-over term from the early days of turbocharged auto engines that barely showed little increased torque until 3000-4000 RPM, when it kicked in all at once like a booster rocket. My first turbo was a '63 Corvair...now THAT engine had turbo lag! Most of what people refer to as turbo-lag is the computer playing mother with the air, fuel and timing.

gfmohn

A spectre is haunting the C300 forums in MBWorld. Some talk about it in hushed tones; most consider it bad luck to admit that it exists. That spectre is described in two words: "family sedan." In the U.S., "family sedan" is almost a contradiction in terms. Almost everyone who has "family" needs gets an SUV or a crossover. In Germany, the market for C300s is prosperous, middle-class families. Mercedes marketing executives instruct the company engineers to design cars like the C300 accordingly.

My wife is German, so I have a lot of experience driving in Germany. German drivers are fast and decisive. But even BMW drivers do not drive in an even slightly spirited manner without having an obviously hot sedan under them. My wife's brother calls all Mercedes "Berlin taxis" (as do many others). He did so even when he owned a Mercedes himself. (Both he and my wife were born and raised in Berlin.)

Several stereotypes of the German Mercedes driver are well-known. In addition to the aforementioned taxi, there is the businessman ruling the autobahn in an S-class and the young executive in a motorcycle jacket driving his SL or AMG in Razer (racer) style. However, there is another, much less exciting stereotype. That is the retired schoolteacher WEARING A FEDORA HAT driving a 20-year-old diesel MB down a Landstrasse (rural road) at exactly the 70 km (45 mph) speed limit. Mercedes builds cars for those drivers too.

fabbrisd1

I took a look over the thread - and I feel something might have been missed that could be helpful to some...

By and large - in driving my MB's - incl my 6 mile a day C300 - even more useful with the new 9-speed in my new SL450R - "full kickdown" has been replaced:

1. "left-paddle-pull-hold-3-sec" which drops the tranny one gear in the 1st 1/2 second of that pull - hold - then tranny gauges and "jumps" to power gear for that speed (which often can be another 2 or 3 gear single jump)

2. Once in that power gear - accelerate from there (or use that gear to add deceleration into a curve and/or downhill.

The "turbo lag" that most discuss here - by and large evaporates - since it is "tranny lag" .

Yes - there are changes/gains from a appropriate ECU tune.

The fact is most dealer salespeople don't own or passionately drive a Mercedes their own Mercedes - so heck - they don't know what to show you.

As a result - "most" MB owners think the paddles are click-up-and-down - which especially for the 9'er - isn't taking full advantage of the tranny system - really.

Mr. J

I don't know about the c300s but my GLC43 with the 9g allows you to skip a gear by double clicking the paddle. I find this is usually a quicker way to get into the correct power band for passing or accelerating rapidly.