jctevere

I have always said/believed that my car always felt CONSIDERABLY faster than other c300's, espeically c300 4matic's for that matter. And last night I seemed to have gotten some "proof".

I was driving around last night and a c-class cam up to me and we seemed to be playing a bit of cat and mouse. Eventually this turned into all out racing. This consisted of about 2 WOT pulls from a red light, and 2 races from a roll, about 30-40mph.

I don't actually know if the other one was a c300 or c350 or c300 4matic or whatever. Because I never saw the rear of the car. However, I think it must have been a c300 4matic. I CONSISTENTLY walked on it, and by a good amount too. Especially when we would go WOT from a roll (I would get ahead by at LEAST 1-2 car lengths before slowing down).

The only mods I have done to my car are magnaflow x-pipe, and K&N filters; and I HIGHLY doubt that this alone could account for this difference. I also got a 6.2 second 0-60. (I recorded myself going WOT from a stop and later timed the video with a stopwatch. The video is on YouTube, and I can confidently say, it is within a .1 second tolerance.

http://www.youtube.com/watch?v=yZWTwHosyWQ

With all that said, what can cause this? I have aftermarket rims (maybe they are lighter) also, TCU settings? (I do drive VERY aggressively) but I would think that with the volume of runs and differences we did (espeically from a dig) it would have eliminated this? Very odd... Maybe I got a c350 4matic.


lol...

Carsy

I thought by your heading that you may have a kipper hidden in your A/C.

Your increased performance could be in the way you ran your car in. Did you do it by the book or did you throw the book out of the window?

In my youth I ran in a new GMH farm utility ( pickup) without any consideration . Just drove it flat out with lots of high revs & heavy accelleraton.

It was very free & revved very easily. A GMH mechanic test drove it once & asked whether it was a 149 or 179 cu. I thought he should have know as he drove them all the time. It was the smaller engine. As it happenned rust was the killer in the end not my heavy foot.

bringtherain

6.2 is 350 speeds. whattttttt. xpipe adds high end torque while k&n filters just help overall. Thats crazy fast though for a c300. maybe you bought a sleeper 350 ;]

Sportstick

Good thing he wrote this down, as I'm having trouble with my herring.

Anyway, the answer is most likely a combination of small effects. There are variations in engine build tolerances, and in combination with all the other improvements, including variations in gasoline, the aggregate gave superior performance. I can assure you, given all the issues in powertrain development and certification, it's (unfortunately!) not a C3504MATIC

jimmythegreek

I kinda did the same thing. My mom got a 2010 C350 last year, she loved my white 08c350 and then in april when my lease was up I got a 2011 C350. Before I sent the ECU out at like 800 miles my cuzin (who drives an S4 and a 99 911) helped me make a couple runs to guage the speed of the cars. I took it easy til 800 miles, that day was my first WOT runs. He drove hers for a few minutes getting on it and clearing it out. I did a ecu reset on it too before we started. My car took at least a car length on hers every time and had more power, we even did trac off and C and S runs and i got him everytime rolling or dead stops. After I got the ECU back 2 weeks later we tried again and it was even worst, although I didnt really notice too much difference for the ECU tune. I think like sportstick said, its just the tolerances from the factory, they arent all created equal, but pretty close. U probably just got a good one, an X pipe and k&n filters wont really give u any HP, may change the feel of the powerband but thats about it

jctevere

I am pleasantly surprised. I did not do the conventional "break-in" procedure. But did a mixture. I either did the procedure to a 'T' and then got bored and would drive like a maniac, WOT after warmed up. I think that the way I broke it in must be why my car performs the way it does. I have heard that most "race" cars do brutal WOT break in procedures (under proper conditions) in order to get the best seats and seals...

I was curious and drove my sister's completely stock 2011 c-class. The only way I can describe it, is that my car doesn't feel "restricted". I think it might have to do with air-flow, perhaps the x-pipe really speeds up the exhaust leaving and takes a huge load off the engine. The stock c-class just seems "bogged down" and doesn't go through the RPM's nearly as fast and not nearly as torquey as mine.

To be honest, between the stability from taking off (especially in rain) versus my father's 2004 SL500, mine almost "feels" quicker to about 50mph. I think it also has a lot to do with the 5-speed auto vs 7 speed, and perhaps the TCU settings. I guess this is why I find people a little crazy when they say that the c300 (especially 4matics) aren't fun to drive. But they are right, my sister's isn't. But I love the way mine drives...

Scat01

I am glad you are loving your car jc, but have to question your concept of the x-pipe taking a load off the engine and creating torque - Everything I have read came true when I had a magnaflow tru-X pipe installed on my CTS - It clearly reduced the amount of low end torque as the research said it would. Prior to the install I could punch it from a dead stop on cool roads and fry the tires leaving posi marks until I pulled out of it - after the x-pipe, not even close. I added it for the exhaust note only, so got what I wanted there - plus the tires last longer now...If you read all the techy stuff on exhaust (pulses scavenging) you will find it well documented that the x-pipe reduces low end torque - wish I had the time to dig it up and provide you the more technical information...

jctevere

Well, I believe to be politically correct, adding an x-pipe doesn't make your vehicle "lose" any torque, but rather, shift or change the torque curve. X-pipes will shift the torque curves upwards to have more torque in the mid range, but less torque at the bottom end. I'm no technician, but perhaps this shift in torque can explain for my faster speeds (more efficient or more power generated at that RPM). Also, I say that it takes "load" off the engine, because it reduces back-pressure. Which, contrary to the believe, in our N/A engines, will not have the engine work as hard to force the exhaust gases out of the valves and through the manifolds and out the tail-pipes. Allowing more energy focused to propelling the car.

keith100

Droll, sir, very droll

Nice to see some wit on the forum

LandSeaAir

Do you put premium gas in it?

jimmythegreek

when I first drove moms 2010 C350 it felt sluggish too. Remember that the new ones always start out in C mode, the older 08-09 and maybe 10 models keep the last setting. Doing a ECU reset and driving in S makes a huge difference in moms car, even she notices it. I will say that in my RWD 350 if the trac is on and it blinks, it KILLS the momentum of the car. Even with it off if u get squirrely on a deep dig or hit a good bump at high RPM WOT it will blink. On my new 2011 I have paddle shifters w dynamic handling and have a C and M mode, and a Sport button on the dash, in sport mode and M engaged it barely blinks the trac, its a pain to have to push 2 buttons tho when u wanna jump on it in a whim ya know what I mean

LandSeaAir

When you say reset the ECU do you mean the TCU? Where you hold the pedal down for a couple seconds? Does this really help? I am afraid to do it because I read someone did it and it made the car sluggish.

jctevere

Always use premium gas, 93 octane, never any less. But I do find more power out of the Cheapo gas USA. I get it for about 20cents cheaper per gallon vs shell. If I need gas I also fill up at Sunoco which is cheap. So I don't care about the brand, more, the octane. Just don't go to any old crappy stations that probably have leaks, only newer ones with new tanks, etc.

I also run a bottle of Techron fuel cleaner every now and then and have never run my car below 1/8 tank.

ucfbeta92

I've flirted with that idea as well, but reluctant because of insufficient anecdotal evidence. How many others here have tried this and what have the results been?

Note to moderator: If it is better to have this topic be it's own thread, please let me know (or feel free to split it into it's own thread; whichever's easier).

mac911

jctevere -

That is pretty wild. I looked at your Youtube video. Your car is fast for a 300 and 4MATIC. That is wild. I think your mods must have helped. We don't have 93 octane on west coast, maybe that helps too.

Despite the extra weight, maybe the better 4 magic traction helped too.

I have no idea, but that is pretty crazy. I'd be pretty happy with that acceleration from a 4MATIC. Well done! Maybe you weigh 90 pounds too, the would help.

ucfbeta92

Sometimes I shed a tear when I see my receipt print out at the gas pump.. In Saudi Arabia, where I grew up, your choices are either 91 or 95 octane, and a liter of either is cheaper than a liter of bottled water.

Scat01

there are numerous threads on this, search "sneaky ECU reset"...and it honestly works, there are numerous testimonies as well....its not BS, it is fact.

mac911

I can say I believe it works too. I have always noticed a difference after the reset. Sadly, it does seem to revert itself rather quickly.

ucfbeta92

Per Scat01's suggestion I did the search and read many positive reviews. The only thing I wonder is if there is any downside to doing this repeatedly since it keeps reverting back after a few long, steady drives.

Either way, I plan to do this tomorrow morning before going to work (if I have time), or there's always tomorrow evening.

jctevere

I did it once, then I noticed my RPM needle would get "jumpy" or not really steady while driving. Seems to me it may have affected the ECU a bit or something. I wouldn't do it if I were you. I would just drive more aggresively for a bit. (I think changing the mode also helps, I think they are separate profiles).

ucfbeta92

I've decided to throw caution to the wind. Heading out for lunch in a few, and I'll give the ol' ECU/TCU a swift reset. Results to follow later in the afternoon.

Pete7874

Very nice. Just to be objective, you should have done the same run going in the opposite direction and averaged out the results to eliminate potential culprits such as wind direction and/or slope of the road.

joshg1001

I just did the transmission reset after 3 years of ownership. In the past, when I floored it from a stop, I would get the .5 second lag before I got any power to the wheels. Now, it is quite nearly instant.

The other issue is that the car has always felt like it was braking when I let go of the gas especially when it is in the first two gears. This seems to have more of a presence since I did the reset. However, I have had this problem since the start.

ucfbeta92

I'm a believer!! Followed the steps, waited 2 minutes, started the car, put it in C to make results more noticeable, and the car feels SO MUCH LIGHTER! I feel like a weight's been lifted off my car's shoulders. Definitely eliminated the sluggish acceleration.

Another reason to love this forum!

I thought back to a few times when I picked up my car from the dealership after an overnight service visit and my car would feel zippier for a little while. I wonder the ECU reset was behind it (either by performing the step, or leaving the battery disconnected for an extended period of time).

LandSeaAir

Why is it bad to run below an 1/8?

Do you think techron is the best cleaner?

I put 87 octane is which I know is too low, but I have done some research and supposedly it won't damage the engine, just limits your performance while you have that gas in. The only thing is it makes the car ping and pinging can damage the engine so I try not to accelerate hard cause that's what causes it. But anyway, once in a while I put in 93 and I would like to start putting fuel cleaner to make up for the all the 87 I put in. I just can't afford 93 all the time? And can you even get 95 on here on long island.