What do dampers do for the car?

[BigKahunaSeca]

Although I've raced GT since GT1 and over the years have reasonably learned to tune my car but I've never messed with the damper 'cause I simply didn't know what its purpose was. Thanks, I know it's kind of a noob question.

 

[Stotty]

A damper controls the rate at which a spring compresses and un-compresses.

 

[Chadwicksracing]

Spot on Stotty.

Here is some further reading into springs and shock compression.

Shocks: http://www.racelinecentral.com/RacingSetupGuide.html#shocks
Springs: http://www.racelinecentral.com/RacingSetupGuide.html#springs

It also explains rebound which is damper. I know its for Nascar, but the same principals that transfer to street cars.

 

[nd 4 holden spd]

Basically, you want a sort of soft compression setting and stiff rebound setting to keep weight balanced throughout the track. One thing I've been struggling to understand myself lately. More weight on a tyre gives it more traction, unless you overload it is this correct? But then, having less weight at the front of a car means it can turn better as well right? Is it possible to have too little weight at the front causing understeer because not enough weight is pushing the car to the road? Also, say I make the compression ratio of the shocks softer on one side, that side would turn more because more weight is on it and it would have more traction right? How does that go down with the "less weight at front= more turn" theory? Or is it that normally the weight of the engine is overloading the front tyres, so getting some of that off the tyres can be a good thing? I think softer springs at the rear are better anyway, for FR cars anyway, because then the weight transfers onto the back wheels, and you can use stabilisers to control side to side and put more or less weight on the front/rear.

 

[BigKahunaSeca]

Thanks fellows, your replies and your time are much appreciated.

 

[Stotty]

Haven't got time for a long answer, but basically, a tyre with more weight on it will have more grip if there's no lateral force exerted on it. Once you exert a lateral force, the same principal applies up to a certain level, at which time the grip levels will deteriorate.

So, in simple terms... more weight at the front makes a car turn better...

In a FWD car, you want the weight over the front to turn the car in - hence techniques like left foot braking or trail braking that encourage a forward weight shift and hence encourage turn in. A combination of too much weight (to heavy braking) and too much lateral force (ie; too much speed) will result in understeer though.

At the opposite end of the scale, a 911 will tend to understeer on turn in due to a lack of weight over the front tyres... the trick in a 911 is to balance a little trail braking against the natural tendancy of the car to want to oversteer once the rear is unloaded.

A MR car will tend to have good turn in not because of low weight over the front but because it has a low polar moment of intertia - it's weight is mostly contained within it's wheelbase and this encourages it to turn more quickly.

As well as providing ride comfort, springs and dampers are used to help control these weight shifts.

 

[NLxAROSA]

As well as providing ride comfort, springs and dampers are used to help control these weight shifts.

Which is why changes in damper settings are most noticeable in corner-entry and corner-exit (places where weight is shifted the most). So if you have problems with under/oversteer in those places, you know what probably needs some attention. (Though you need to take the spring configuration into account as well)

 

[BonzoHarry]

so let's say the car slides a little bit for on-throttle corner exit, you need to...lower the damper number?

 

[Terbeaux]

so let's say the car slides a little bit for on-throttle corner exit, you need to...lower the damper number?

Yes, lower the damper number for the rear. Damper (as I understand it) is for transitional handling, like when you first hop on the brakes or step on the gas while turning; corner entry and corner exit.

If you decrease the damper setting, you get a more slow responding handling (takes longer for the car to "take a set" in a corner), but what you gain is a decreased rate of weight transfer. Decreasing the rate of weight transfer in the rear will help mitigate the sudden oversteer you observe when you jump on the throttle in Expert mode!! (Which is what I assume you're alluding to in your question)

My only complaint with GT5 Prologue is I don't have the capability to also tune the rebound. I don't understand bump and rebound interaction 100%, but it would be fun to play with...

Terbeaux.

 

[Scaff]

Follow the link in my signature to the GT Planet GT4/GT5 tuning gudies and download the first guide.

It covers (amongst other things) damper tuning, its a .pdf document (around 2meg) so its nice and easy to print and covers all areas of tuning.


Regards

Scaff

 

[Stotty]

I don't understand bump and rebound interaction 100%, but it would be fun to play with...

Terbeaux.

Bound controls the compression stroke of the damper and rebound the extension stroke... some racing dampers also allow adjustment of these settings at high and low speed.