Retarder Problem (overbalance)

[smoothmode]

when i turn on the retarder and little turn the wheel while i'm driving, the truck (any one) overbalances suddenly. Does anybody know why? It shouldn't that

[bozont_svk]

well i tipped over my truck once when turning the retarder off on a straight road , just bang and on the side....second time i had hairy situation too...

[Rev Counter]

I think you have to slow down gradually or the wheels lock up. One moment I an happily cruising at 90km/h, use full retarder to slow down for my exit and BANG!

[room217au]

Never happened to me. The retarder shouldn't lock the wheels. It's a friction action, but not near as savage as brakes.

[\/|P3R $RT]

Haha, this is the new game physics and got nothing to do with retarder.... :) The latest update is all about tires remember ;)

With "Runner" brand, well, You get more grip and milage, and truck stops faster. But while taking corner at higher speeds, You probably tip over. Use Trailmaster tyre to reduce the tip over, but then, Your truck handling is compromised a bit and these tyres take more distance to stop, also milage reduces... Choice is Yours :) Use the tyre which suites Your gameplay....

What I do is, if I'm are at high speeds, break hard before the turn in a straight line, and then take the turn, feathering the brakes if required.... If not follow racing line and prevent tip over.... Was a bit hard in first few days, but You'll get used to new physics in some time :)

[room217au]

ah, well, I got 50Keda's wheels and tyre mod. That explains it.

[Rev Counter]

Yeah, every time SCS update the physics in a new patch I think I've just about perfected driving and can do a delivery without any crashes when I crash. :P

I use 'Runner' tires but didn't like the white decals so I spent ages changing the colour to what I consider to be 'tire' colour. It just makes the game a little more realistic in my opinion as my truck isn't heavily customised :)

[smoothmode]

Thank you for your comments!

[Randox]

Think about the physics of it, and how the brakes work. When you brake normally, the brakes on the trailer do a lot of the work, which prevents heavy loads from taking significantly longer to stop, and also keeps the entire system stable.

When you use the retarder or engine brake, the only wheels doing any braking work are the ones connected to the drive shaft on the back of the tractor. When a vehicle brakes, there is a toque force that can be most simply understood as a shift in center of mass.

If you brake with the retarder in a strait line, this isn't a problem, because the center of mass just gets pushed forward toward the front wheels, causing the the tractor to dip it's nose a bit. But if you turn, the momentum of the trailer is pushing the center of mass towards the side of the truck. If the center of mass get's pushed beyond the outside of the tractor or trailer, you are going to tip.

I'm simplifying a lot for the sake of not making diagrams or writting a textbook chapter, but that's the gist of it.

[smoothmode]

Hi Randox. Thanks for information. I hope to be fixed.

[Randox]

Your welcome. It's not really an issue that needs fixing though I think. Now, I don't have access to the physics back end for the game, so for all I know, they have exagerated the physics to make this an easier thing to happen than in real life, and it's quite possible that they have. Someday I might get bored enoguh to work out the math by hand and see how realistic this actually is.

That said, the physics principles as I outlined them are very real, and in the right conditions, it's absolutely possible to flip a tractor trailer on it's side by braking to hard with the retarder while turning too sharply. At the end of the day, the retarder isn't really intended for primary braking. The retarder, engine, and exhaust brakes on a tractor are intended to control your speed when descending down a hill, since heavy prolonged use of conventional friction brakes can cause them to fail (especially when you have a heavy loaded trailer behind you). For normal braking, where you actually want to slow down and not just control your speed, it is much safer to use your airbrakes, since they will assist in keeping your loaded trailer stable.

[AYKO]

Originally posted by Randox:

Think about the physics of it, and how the brakes work. When you brake normally, the brakes on the trailer do a lot of the work, which prevents heavy loads from taking significantly longer to stop, and also keeps the entire system stable.

When you use the retarder or engine brake, the only wheels doing any braking work are the ones connected to the drive shaft on the back of the tractor. When a vehicle brakes, there is a toque force that can be most simply understood as a shift in center of mass.

If you brake with the retarder in a strait line, this isn't a problem, because the center of mass just gets pushed forward toward the front wheels, causing the the tractor to dip it's nose a bit. But if you turn, the momentum of the trailer is pushing the center of mass towards the side of the truck. If the center of mass get's pushed beyond the outside of the tractor or trailer, you are going to tip.

I'm simplifying a lot for the sake of not making diagrams or writting a textbook chapter, but that's the gist of it.

That's very nice explanation. Thank you for your efforts. One thing i noticed is, trucks with 6x4 chassis seem to be more stable than 4x2 chassis on this matter. I may be wrong tho, i usually try not to turn with retarder brake.

[Rev Counter]

I've noticed that a 6x4 seems to tip less than a 4x2 as well.

[Glassburn]

The 6x2/4 seems to be the most stable. 6x2 and 6x4 seem to be affected the most.