KJI3jflarryfe93

Hi guys,
Do you notice any instability on your 202 amg car when you drive over speedlimits, say over 100 miles/h and on to the cars speedlimit which is 155 miles/h= 250km/h?

I spoke to a Benz specialist, he told me that the old style steering on 202 is sensitive to high speed, and so is the old style E-class 124 model which shares the same steering system.

What I'm trying to say is that the front and the steering wheel likes to move from side to side?
The road wasn't torn by deep marks from trucks, that makes the steering wheel turn from side to side by it's self.
I was overtakin' a car in 120miles/h, changing lane, when I came up side to side with this other car I got a strange feeling my car wanted to go to the left side of the lane into the trench. It was like the wind was goin' to push my car of the road.

I have good tread's on my tyres they are only 2,5 years old. 225/40/18 and 255/35/18
The steering damper is new.
My car's aligntment is adjusted properly. The tyres wear perfect
The tyre pressure is cirka 3,2 kilos, all 4 of them
My wheels are brand new Brabus monoblock V (ET35) both front and rear

What else is there to do on my car?
Is it goin' to be better by getting new shox from Koni yello' ones?
Thanx

RBYCC

If you were doing this on a secondary road you must remember that roads are crowned for water run off.
Any vehicle at any speed will not track straight as the road is not perfectly flat.
So one must know the road intimately and how to correct at speed so you don't end up in the trench !
Faster you go, the more proficient the driver must be

Ausmbtech

They do get a bit of push when it's windy/wind from another car but it's pretty predictable and doesn't feel overly alarming, just "alerting". Later models with a steering rack as opposed to a steering box feel more direct. It's just the steering/suspension design.

C43AMG

Ball joints ?

SeeKlasse

what brand tires are you using? my car handles perfectly well in the 100's, no unpredictable veering from either C43 ive owned...

Z06EATER

i took my car to 155MPH once racing a GTO....n i must say it felt very solid at 155MPH

silence

i drive between 120 and 140 all the time and do not have complaints other than slightly warped brakes.

SeeKlasse

ha! yeah i got those goin on too! friggin warped rotors makin the braking a little wobbly at times....

KJI3jflarryfe93

hey munchkin, ()
I have Good year F1 the old style tread mark, that looks like V-shape, and they are only 2,5 years old with good tread.
I know that when I put more air pressure to the tyres the car will be more unstable, I put cirka 3,2 kilo's of air pressure maybe it's to much?
When driving on motorways it's a little better when the road is flat, but on more worn roads it's scarrier to drive in higher speeds.
Thanks.

bevy

3.2 kg it's to much i think

RBYCC

3.2 ???

You're probably at the maximum inflation pressure of the tire.....
3.2 = 45psi cold....hot you're +50psi very dangerous...

try 2.5 = 35 psi...car will handle and grip much better !

Z06EATER

hahaha i dont get warped rotors bt my buddy does! lol i love zimmermins

SeeKlasse

50psi is WAY too high... no wonder youre gettin squirly at high speeds. do what rbycc said, deflate to 2.5(35psi) and youll be much happier

steve s

if anything, don't go over 40 psi cold.. heck some tires only have max pressure rated at 44 psi. but for a tire that holds up to 51 psi max, 40 is about as high as u should go. (2.8 kilo)

Ausmbtech

Ahhhh..........I've got a friend with those tyres on his W202 C250, very vague at just 60kph/40mph now that they are worn, they were ok when new. I put my spare Pirelli Pzeros on, no problem!

KJI3jflarryfe93

hey guys,
the tyre sellers always recomend to put a little extra air pressure, this will make the tyre to last longer and the car will use less gas, they recomend to put cirka half a kilo of air pressure, if I have 2,7 kilos of air pressure I guess then I can go up to 3 to 3,2 kilos of air p.

BTW don't put in more air that makes the tyres ride on the middle section of the tyre, this will rub in the middle only not the whole tread on tyre.

SeeKlasse

strangely enough, running on very low psi will eat the middle of your rear tires also. i had a friend with a G35 that went through a set of rear tires in 7k miles because she didnt check her tire pressure and both of her rear tires were at 20psi for quite some time....

RBYCC

You are over inflating at 3.2 cold...but it's obvious you're going to do what you want to do.

Enjoy bouncing all over the road and getting abnormal tread wear

fstshrk

When my car did this, it was bad wheel bearings and worn tie-rods.

I just had these replaced and now the car is steady as a rock.

It could also be the shocks.

Remember, when this car first came out, there were a lot of magazine tests and I don't remember ever reading about high speed instability like people complained about in the Z06 or the Audi TT (prev generation).

Again, even tire wear is not a good indicator of the condition of suspension parts.

KJI3jflarryfe93

I'm going to lower the tyre pressure to 3 kilo's and testdrive the car it, will get better grip and less bouncing, of course
however swedish experts who works with traffic, enviroment regulations claim's that there is okay to inflate some extra air pressure into the tyres, this will make the car use less gas and the tyres will last longer.

Btw, the tyre tread gets worn as it should be a cross the whole treadmark section, everything is normal wear.

SeeKlasse

it is well understood that giving your tires a little extra pressure will give you increased fuel economy and treadlife, but it should be overdone. its like drinking a glass of wine every day is good for your heart, so chugging several bottles every day would be even better right?

KJI3jflarryfe93

Hi guys
I testdrove the car with less airpressure yesterday, I did decrease all 4 tyres to cirka
3 kilo's and yes the car felt less bouncy, just about 3 kilo's is ok.
I also checked the sidewalls of my G.Y. Eagle F1 (XL tyres= xtra load), the information said that maximum load is 50 psi= 340Kpa for the each front tyre.
Rear tyres sidewall info say 50psi= 370Kpa for each rear tyre.

So to add up, I was always inflating up to 3,2 kilo's before (cold tyres) but it was bouncing harsh on bad tarmac, now it feels a little better with 3 kilo's.
Tyre wear is all normal, thank god.


The instability I asked about is still the same, I have no sound from my wheel bearings, when I let go of the steering wheel on a straight flat road the car runs straight,the brakes are in good shape, what goes bad on the front axle that is hard to spot that needs a crowbar to see if there is any slack, what problem could it be>?

Here comes a stupid question: Does 340kpa mean 3,4 kilo's which is maximum on my tyre

God Speed with all your AMG's

RBYCC

Why not do something innovative and inflate your tires to what Mercedes recommends in the owners manual or on the label on the car ????

If you are set above 2.5 cold then you are inflating too high.

Do what you want, you have the problem and seems like you have the answer, but the problem still exists.

The max rating on the tire is for carrying the max load of the car which you are not doing.

KJI3jflarryfe93

the tyre label on the gas flap that recomends the tyrepressure is to low for 18 inch tyres, normal would be 2,8 k's cold to 3 k's
this label is only for the 17 inch wheels

RBYCC

You really don't understand....

Air pressure is air pressure regardless of the tire diameter.

Following your logic, the recommended tire pressure of 30 PSI on my 2006 C6 Corvette with stock 18" front and 19" rear tires is not correct ????

Keep on bouncing and hopefully when you do foolish high speed passes on a secondary road you'll live to speak about it