C300Sport

I was surprised and dissappointed yesterday morning with the handling of my C with the stock 17s and Michelins. I was on the connecting ramp from 75-285 which is posted at 45. It was pretty empty so I took it at about 85 and was very disturbed at the fact I couldn't get the car to take a set in the curve. It seemed to be squirming all over and I had to actively drive it through to keep her inline. I had done this many times in my old Millenia S and that car would simply take a line and stick like glue...maybe pushing a little but very stable. I had to take that same corner again yesterday afternoon and the second time was the same as the first....just felt very unstable, not confidence inspiring at all. I have been pretty happy with some slower speed off ramps but this high speed instability is pretty dissappointing.
Is this the tires or the car??

TB5...

i've taken my C300 4matic onto ramps at about 100 Km/h...
in comfort mode its horrible
in sports mode it's much nicer... but it could be better

i assume it is the wheels to some extent... but i was also wondering if there are any struts that are out for our cars that would help with the turning for sure.

berkut_g

@C300sport : you got the wrong brand ... look at BMW

in other words, i love MB for its smooth ride ... but i wanted to get rid of all that woobling feeling in the curves , so what i did : 18" wheels + sport springs .
it does come with some minuses , but you get MB suspension and BMW curve capabilities

C300Sport

MB is probably the right brand....considering it took me 7 months to find out about the high speed cornering...
I really love my car so I guess any shortcomings seem to stand out. It seems like the steady state cornering is very good but when you throw in undulations and expansion strips, it kinda disturbs things a bit. As long as she breaks loose smoothly(ie. no snap spins) I think I can pretty well handle her at the limit...it's just something I don't want to experiment much with at 80mph...

berkut_g

i have tested the car on a high speed corner ... before the mods (i.e. springs) the ESP would light at 140km/h (87.5mph) after the mods no more ESP light on at that speed ... but no more guts to go faster either :">

TB5...

i did a search on google didn't see any... who knows??

Derspeed

This may actually be due to the stiffer springs on the sport. I have had cars with very stiff suspensions. They are great on smoothly paved curves. As soon you threw in some bumps, the cars would hop and bounce. This type of thing gets even worse when you add thicker anti-sway bars. Your Mazda probably had softer springs and taller tires that did not allow you to feel what was actually going on. Therefore, you didn't have to be as good of driver in that car. Also, it is possible that the sport suspension on the W204 overpowers the 17" tires.

I have the sport with the 18" optional wheels and I think it handles quite well. The springs are a bit stiff for what they deliver though. Suspension tuning is tricky. I'll bet the Bilstein HD shocks available for the W204 would do a much better job of controlling the sport option springs than the OE shocks.

mikestyle

get some h&r supersports and then try the same thing..... HUGE improvement in the handling department, makes the car less squirmy and makes the car much more confidants inspiring.

dmatre

It may have been your ESP stepping in, because it thought disaster was imminent. It's not a problem - just a difference in the tuning between MB and BMW/Porsche/Audi. The MB system intervenes very early compared to the others.

I've found that when the ESP is active (actively working), the car feels somewhat "mushy", almost like there's a tire going down. Because the ESP is activating different brakes at different pressures/times, the feeling is one of instability, although the car actually maintains the arc that you've dialed in.

I've found the same thing that you've commented on: At 80%, the car feels rock solid. As soon as the ESP gets involved, it goes to mush.

You can test this yourself by putting the car into "DYNO" mode, and hit the same corner again.

(If you do, be certain that there's nobody else around - and if you write off the car, it's your own damn fault . . . MB puts the ESP there for a reason)

qwqwerertyty

I only found these sway bars:
http://www.mkb-tuning.de/content/en/...&prod_gruppe=4

I was going up a spiral parking lot yesterday and I was a bit surprised too how easy the tires start squeaking. I thought a big part of it was because of the contis...

german-anger

So upgrading to the 18" rims made a big improvement on the handling I' m considering it...

C300Sport

same here...thinking about the 18" Mandrus Mannhiems...only 10mms wider per tire and probably about the same weight as the 17s due to the pressure casting method and more open design.

Krytech

I couldn't find the thread but another member on here was commenting that his car seemed to handle better in turns when he upgraded to the C63 18" wheels, particularly the 235 front tire vs 225 on the regular C.

So are Eibachs or H&R Sport springs going to make the car worse in high speed turns because it will tend to skip more, or will it make the car more stable? I'm referring to typical crappy roads not smooth perfect roads or the track.

There is so much conflicting information out there that it is discouraging to even try to improve it upon what MB gave us. Really burns me we don't have the Advanced Agility Control here.

duboisi

Advanced Agility only give you standard suspension and softer suspension. NOT standard and harder. However W204 with AA has the car lowered by 15mm.

QuadBenz

I would highly advise not to do what dmatre said regarding dyno mode. IMO, that's just too dangerous. If you didn't know, it completely disables ESP, ABS, and BAS+. A high speed corner + No ESP can = disaster. Try just hitting the ESP off button first. It won't intervene as early/much.

mikestyle

ok honestly its not that hard to figure this out!!!!!!

MB rides very nicely because of: tire/rim, springs, struts

all of these components are made to give the best ride possible, Not the best handling!!




Now to make the car handle better:


Note, the law of diminishing returns applies to all cases

Wider tire= more tire contact to the ground (?)
Bigger rim= less side wall therefore less tire squish (18")
Tire type= summer tires will have more grip (r-compound)
Springs=stiff the springs the less body roll (h&r super sport)
Springs= the lower car, lower center of gravity (h&r super sport)
Struts= the stiffer struts are the less body roll (hd blisten)


thus
better handling=wider tires+bigger rims+tire type+springs+struts





now im my opinion on the w204 be biggest increase in handling will come form a proper tire/rim combo.

with the tcs in off mode (not dyno) the tcs should not effect you unless you are driving improperly

and btw i believe no speed archived on a on ramp is "high speed"

Glyn M Ruck

+1 - Also - what tyre pressures are you running? Take the tyre pressures up 10 to 15% & try again - As long as the ESP is NOT interfering the 204 should transfer weight a bit (due to soft springing) & then settle into a constant radius. It should not go lurching around corners even standard. I'll bet your tyres are too soft. Standard pressures are for comfort.

If you want snap spins then buy a BMW - they don't let go gracefully & the back breaks away. The W204 is a terminal understeerer & will push the nose at the limit. Made for safety so that the first reaction of an inexperienced driver is to back off the throttle & the 204 will settle back in line. The BMW will snap into oversteer.

And - BTW - the thought that wider tyres is always the best route is wrong - It's weight per contact patch area that really matters - Go too wide & you actually reduce grip because you don't have enough vertical force to keep the contact patch firmy pressed to the road aggregate.

C300Sport

Gotta disagree with you on most of what you said.
The sport model has plenty of tire for a 3500 lb car, the center of gravity is already low enough to prevent any sort of top heavy type roll and the shock/spring set up is already quite stiff. The Michelin Pilots are not sticky summer tires but should be quite sufficient for simply doubling posted limits(I am running a couple PSI over recommended). The car was not pushing or rolling but simply did not feel stable and would not take a set line.
I think Derspeed got it right in stating that it is more of a compliance issue as my car has been really impressive in very smooth conditions. If Glyn is right, at the limit, the car would have simply started understeering but I did not want to find that out at 85mph with a big drop on the other side of the old, small guard rail...just curious, what would you consider as high speed...I figure any speed where the car would end up as an unreconizable lump of metal is high speed enough for me...

Doyler

Personally, all the BMWs that I have owned in the past have handelled better with wider tyres, seems to make the car 'slither' around corners it's a very cool feeling.

New Mercs are usually pretty low as they are but if you could go lower without losing practicallity then that would be something to look at.

Glyn M Ruck

C300 - If it is a compliance issue & of course explaining the exact conditions you were unhappy in is difficult - Then the only way to reduce compliance is to go to harder bushing all round. Pre facelift W203s like mine came with harder bushing & this brings with it problems of bush life, some comfort issues & tyre noise transmission into the cabin. At facelift they softened the bushing by 22% on the front axle & a massive 56% on the back axle. My car only has 30,000 miles on it but I moved to the softer bushing & I prefer it. I find the handling just fine. We have a 4 cylinder 204 in the family & it's handling is great. Do remember that the US market does get softer rate springs & lighter steering settings.

Please don't think I drive like a maniac on the roads. I don't. I have been invited to press days and driven these cars to the limit on track. Including the SL63 AMG which has me smiling from ear to ear still - What a fabulously balanced vehicle. It's just right. I look forward to driving the V12 but doubt it will have the balance of the V8 - Black series - I can only hope!!

TB5...

shooot yea eh...

so it's the whole setup... it's awkward no one makes this... with these installed turning will improve 10x easily...

one thing abut BMW i love... is making hard turns because you wouldn't move around in the seat like you usually do... you just stay put. the 5 series of course had a sway bar.

dmatre

I think that your reasoning is sound - up to a point.

Once the ESP controller determined that you were understeering, it would apply inside rear and inside front brakes, to turn the car into the corner more. This intermittent application of the brakes would feel like the car is wallowing.

If you want to test this theory, find a big parking lot and run a skid-pad test. Drive in a circle, and feel how solid the car feels. Then increase the speed until the ESP activates, and you will feel the car start to feel "mushy". It's still going in the arc that you want, but now the computer is helping you to steer the car around the arc. Because the computer is digital (on/off), you don't get a gradual application of braking assistance, but rather you get pulses.

With each pulse, the car rotates inward just a bit, you correct by steering out, the pulse stops, and now you're headed outside your arc. Basically, you end up trying to 'compensate' for any yaw induced by the ESP.

Give it a try, I think that you'll be amazed/amused.

If it were truly a compliance issue, then once the car was loaded over on the bushings (as when hard in a corner), there would be no more compliance, and the car would be solid (unless you change steering angle or hit a bump). In other words, you would feel it in sluggish transitions, but not in steady-state cornering (typically).

I've run the car into offramps at 80+ (depending on the ramp), and there's one ramp on the way home from work that you enter around 45 and exit close to 80 (increasing radius) and the car takes a moment to find a set, but most of the way around the 270-degree ramp it's solid as a rock . . . .unless I step over the line and ESP intrudes.

Glyn M Ruck

Yes - going up a little in size can help because economics come into standard tyre fitment on cars. This dumb attitude of the wider the better is simply wrong. I ran race teams for many years with Michelin as our tyre partner & they will tell you the same thing. On a number of occasions they said to us - Too wide - drop a tyre size. - They were always correct.

If I understand your "slither" comment you were probably approaching the limit on size.

People frequently don't understand why FWD cars being raced (like Honda's) have larger tyres on the front than the rear. It's because the weight is in the nose & they are tail light. The only time this can be negative is on take off with FWD weight transfer off of the front wheels - but that is a whole subject on it's own.

kaku

you might wanna check out the CG-Lock.. it's a device that tightens the tension on your seat belt.

i use it for one of my cars and it works quite well.

Glyn M Ruck

This is exactly the behavior I would expect