Damper Setup

[hardhgear]

Damper is always the fianl touch in car setup and we have bump damper slow and fast ,rebound damper slow and fast.So what i would like to know when engineers deside to increas or decreas the stiffnes of the damper( fast or slow bump or rebound)

[Monstrobolaxa]

marsuch (sorry if I didn't get the nick correctly written) but probably he's the best one to explain.

If I 'm not mistaken the bump is the deflection caused when hitting a bump, the rebound is the time taken to return to from the deflected stat to the normal postion (same as before hitting the bump)....I won't develop much on what I said...cause I'm not sure....

[hardhgear]

I'm talking about damper setting in case of bump dampers & rebound dampers.When i need to increas the stiffenss or decreas it ?

[Monstrobolaxa]

I know...but since I don't know if my explanation is 100% correct I cannot continue writting, because I do not want to mislead you!

[Guest]

this is a complex theme and I´d be pleased to try and explain.
Damping is a very strong setup tool and you can heavily influence over or understeer tendencies with the low speed damping.Modern dampers allow for very soft springs and give very good traction as well as they help to keep the aero platform stable.
The finer points of damper setup are quite complicated and damping strategies are something of an art.
I´ll try to come back on the topic next week as I have to leave for a (you guessed it)Damper evaluation at the Nürburgring...

[Reca]

For a start you can download one of the technical manuals from http://www.penskeshocks.com/technica.htm
Just for the basis, as previously said, damper tuning is an art

[Guest]

sorry for the delay in replying on this sub.

I´m a bit busy at the moment but will try to figure out something undestandable over the weekend.

marcush.

[RacingManiac]

What I usually look at damper is this, spring, is for steady state tuning, they will control mainly the maximum capacity of many cornering chracteristic, while dampers by nature is for transient effect, meaning how they get there. Bump damping is used to control rate of suspension compression, while rebound damping is controlling rate of which it returns, as well as droop travel I believe. High speed low speed refers to the speed of the joit. In cornering, it is genrally consider as low speed bump, as the car rolls and settle to it's final roll angle. High speed is usally used to control how cars handles road's undulation.

[Krispy]

All good points guys, However here is a question to ponder...if you could change one pair of damper settings (only high speed or low speed) which would you change and why?

[DaveKillens]

Dampers are just one component of the suspension that controls the interaction between the chassis and road. It can be extremely complex, and confusing.
But when you wish to change the settings, you need to know what the car is doing, right or wrong, and what direction you wish to go to alter this characteristic. Just asking whether to go hard or soft is not defining the needs. Broadly speaking, and trust me, this is broad, if your car is understeering, you may want to soften the front shocks to allow more compliant movement at the front. Or you could stiffen the rear. Or a hundred other things. Change roll stiffness, camber, air pressures, just name only a few options.
Just like a doctor needs to diagnose the illness before prescribing treatment, you need to define what the car is doing, what you wish to change, then finally, what steps to be taken to make that change.

[Jersey Tom]

I cant imagine there would ever be a scenario where you get to adjust ONLY high speed vs low speed damping. I've never heard of a damper being 2-way adjustable, ONLY high or low speed.

4-ways are nice but not necessary, and a pain to bleed.

If you are REALLY losing grip at a bumpy track (Sebring?) in a braking or on-throttle zone then its certainly a good time to soften up the high speed damping.

[Belatti]

There is an empirical approach and there is a Mathematical approach.

Empirical: depends on driver and engineer experience. Modify what you feel needs to be modified.

Mathematical:
* Relevate the frequencies the forces induce (time passing through a curve, weight transfer, kerbs -circuit- and the circle of traction -driver- ).

* Then relevate the mass (suspended and not), damping parameters according to the shocks, tires -incl. pressure- used and elastic parameters (tyres -incl. pressure- , torsion bar, springs and chasis stiffnes depending on detail level)

* Make a model that can be unidimentional, focused in only one wheel, or can be multidimentional (suspension geometry needed)

* Insert the forces in the model (start with a simple SIN X that resumes a frequency if you don´t know how to modelize the force)

* Fix all parameters but dampers characteristics and play with those values

* All results may lead to nothing when you change one of the parameters you fixed above so use DOE

* You will realice that all this study is just for learning comprenhension, if turned more complex can help a lot to design a good car, it helps to reinforce understanding of suspension to your head, but it is very complex to implement in the track when your driver is crying because he is 1 sec. off the peace and his car understeers in one curve and oversteers in the next.

Resume: as Dave said, It can be extremely complex, and confusing.

[PlatinumZealot]

Can somebody just answer the Question?!!

Ok let me set an example scenario..

You have a bumpy track with alot of turns.

You have a smooth track that is hard braking...

How would you set the dampers for each one?

[Jersey Tom]

That's pretty vague.

I'd take a run of the track, and look at laser rideheight sensor and damper potentiometer data. Can make a map of the bumps etc the car sees through the course.

I'd then use that to generate a drive file for a 7-post rig and set the dampers to minimize TLV in critical parts of the track... bumpy braking zones, corners, or where the car is going to be on the throttle and traction limited.

If I only had damper pots and maybe pushrod load cells I'd run the track a few times and minimize TLV again, in any critical areas for overtaking or leading onto long straights.

If I didn't have anything I'd start the dampers full soft, run the compression harder until the car feels like its skipping over the track and back off a few clicks... and run the rebound stiffer to where the driver likes.

[Belatti]

Sorry Jersey Tom, I missed the instrumentation, some plain mortals from stock car series down here doesn´t have it.

The empirical approach can also have methods, like the one you described: you can even disconnect dampers! and then begin to make things stiffer.

Can somebody just answer the Question?!!

Ok let me set an example scenario..

You have a bumpy track with alot of turns.

You have a smooth track that is hard braking...

How would you set the dampers for each one?

OK, I got it, you want to setup your F1 racing sim! Wrong forum! We are too nerds and will overanalize those questions

For a bumpy turny track, soften all.
For a smooth track, stiff it all.

It still depends on driver taste. I made my lap records in Monza using the 4 sttifer dampers and the max torsion bar+springs values and 0 wing. Of course its just a game and it has flaws.