adjust to softer = compromise traction?

[adliz]

hi fellas,

i have a coilover set on my car.. i've recently set the damping to almost the softest setting for daily drive comfort..

only earlier tonight, i was taking a bend i normally take at 1++km/h without trouble.. of course i anticipated a stronger body-roll due to softer suspension.. but i didnt expect the car to loose some traction.. anything to do with this? or is it time to change tyres?

 

[adliz]

Re: adjust to softer = compromise traction?

no input? anyone?

 

[adliz]

Re: adjust to softer = compromise traction?

where're all the sifus?

 

[TripleM]

Re: adjust to softer = compromise traction?

It's kinda hard to be 100% sure to allow us to figure out what went wrong.
1. The road could a be alittle slippery (maybe some dogs pee'ed too much just before ur last attempt),
2. Your rear tire pressure bit too high this time?
3. The road had some gravels this time?
4. Your tires might have picked up some water or any other liquid substance perhaps this time w/o you realizing it ?

Anyway..
You are right that a softer damping will cause the car to float a bit more hence some bodyroll. And when you are doing some high speed ard the bend, the body of the car gets rolled/pushed side ways a little bit due to the presence of the g-force and since there is a noticeable transfer of weight bias, this can essentially lead to loss of traction.

Having said that, you could have done some drifting...must be quite fun in that situation....hehehe...

What coilver are you on?

 

[eddie]

Re: adjust to softer = compromise traction?

btw, anyone knows what the best setting for PSS9....

care to share.... thanks in advance

 

[BlackStealth]

Re: adjust to softer = compromise traction?

Front 2, Rear 2. Thats my own level of comfort and performance.[

QUOTE=eddie]btw, anyone knows what the best setting for PSS9....

care to share.... thanks in advance [/QUOTE]

 

[TripleM]

Re: adjust to softer = compromise traction?

Eddie
There is no fixed best setting for any coilover. It all boils down to preference by taking into account several factors such as : road conditions, passenger load etc

I'd think for daily driving with occasional spirited driving , u can go with 4/4

BS is a hard core one, he likes everything hard one ...LOL

 

[Shaun]

Re: adjust to softer = compromise traction?

The likelyhood is plain change in feel of the car changed your perception of available grip and that grip levels never were reduced. In fact you probably gained grip unless the turn was so rough that you were packing down your dampers from relative lack of compression damping matched to over damped rebound . I don't think you were taking such a turn at triple digit speeds.

=======

Damper changes affect transient balance, not so much absolute grip - especially in the middle of a corner on a smooth track like SIC. At softer damper settings average grip throughout the turn is often increased by the best averaging of tire loads. Downside is slower response to driver inputs. A good driver is able to pick a line and commit to it with least amount of adjustment and even if there were some adjustments to be made would compensate and shift input timing to match the lag in response. Within the range of wheel travel that a particular type of car allows, the better drivers will always run on the softer side of the matching damping range unless trying to purposely put heat into tires as with a qualifying run starting on cold tires where no consideration of tire management over any significant period of time is necessary.

Dampers don't affect steady state part of the corner balance wise, neither do they affect degree of body roll. Degree of body roll is dictated by spring rates and suspension geometry. How quickly degree of roll happens before and after steady state part of a turn (entry - initiation, exit - recovery), is determined by the dampers.

Lateral weight transfer is a function of CG and track width. Ride height adjustments via springs or spring perches vary CG, so can affect weight transfer. Damping adjustments alone do not affect CG or track width so do not affect weight transfer.

 

[Shaun]

Re: adjust to softer = compromise traction?

Stiff springs and/or damping aid driver confidence via speed of response to inputs, and confidence alone can yield speed within the physical limits of that setup, but talking strictly in terms of grip (the physical limit), there is almost always a reduction as stiffness increases. Building confidence and ability to control a softer car is tougher but yields the best speeds by providing the most average grip through a turn or round a track. The physical limit here is higher, and all that's left is for the driver to build confidence based on true ability to manage the car.

Both posts above relate to the other post on vehicle natural frequency I made on some other handling thread some weeks ago but never did finish.

 

[Shaun]

Re: adjust to softer = compromise traction?

Exceptions to damping affecting total degree of roll above are short duration smaller vector change turns where a car never has time to reach steady state. These are not so much turns as they are high speed kinks. Locally we don't even have these types of turn - neither PG nor SIC... well actually running race cars or extreme street-sedan-type cars (high avg. speed, high grip) 2 or 3 turns (out of 12) at PG may qualify, but still not any at SIC.

Further exception to statements on tire loading / heat would be a vehicle with a very low tire loads for a given contact patch and mass. This would require low vehicle mass, and/or low power and low downforce. Street cars (even sportscars) don't fit this set because they run relatively narrow tires and are heavy. Almost all race cars don't even fit this set because they are high powered and run more aero load and the compounds are very soft relative to street tires.

So nearly without exception tire management is always a consideration and softer damping helps this, keeping average grip higher, over a longer period of time - double positive.

 

[TripleM]

Re: adjust to softer = compromise traction?

It's been specifically said that he took the turn at triple digit speed.

 

[adliz]

Re: adjust to softer = compromise traction?

thanks!! at last, some wise words from the sifus..

emm, only yesterday, i went for a 'drive' with some gt3, 360s, cs, cooper s, maserati and a version 9 sti.. we met at karak and went up genting before coming back to kl using ulu yam (anyone familiar with this superb b-road? very popular for convoys, be it cars or bikes).

i was worried initially cos i didnt find time to change the hardness for the drive.. i still had the car on the softest setting.. but to my surprise, the suspension performs fairly well.. but i still think it rolls a bit too much, and the change of steering direction wasnt too sharp either.. wasnt as nippy as i had wished.. oh, and the car dived hard on braking..

this comes to the next question,

more dive = less braking effectiveness? i think it doesnt as the brakes still have to stop the same amount of rotational force.. but i'm inclined to think it had a harder time as the car dived, hence more weight transfer to the front wheel?

aiya, my physics not so gud leh.. thanks again fellas!! and thanks in advance for the answer to the braking effectiveness.. cheers

 

[TripleM]

Re: adjust to softer = compromise traction?

What coilover are u on?

 

[adliz]

Re: adjust to softer = compromise traction?

pss9..

btw, how long wud this last? assuming i go to track 6-8 times a yr..

 

[eddie]

Re: adjust to softer = compromise traction?

Eddie
There is no fixed best setting for any coilover. It all boils down to preference by taking into account several factors such as : road conditions, passenger load etc

I'd think for daily driving with occasional spirited driving , u can go with 4/4

BS is a hard core one, he likes everything hard one ...LOL

Thanks mate, will try 4/4 this weekend... i am on 6/4 now.... still needs to be harder me thinks...

wah 2/2 = respect

 

[TripleM]

Re: adjust to softer = compromise traction?

Dunno how long can it last. It all depends on how u drive the car. PSS9 should be very durable. Some of our forumers have tracked their cars more than 10 times and their PSS9 are still going.

IMO, PSS9 is too soft for track use. I am gonna part mine soon.
For street driving, it's great but again, u dont set to softest for this coilover. 4/4 will be just nice.

 

[Rastaman]

Re: adjust to softer = compromise traction?

Adam - yes i would think more weight will b transferred to the front but whether it will require a longer dist am not quiet sure - but its poss. U will need to harden the front to reduce the dive (and prevent the rear fm unloading too much, which may result in sliding, loss of control) and this will lessen the load up front, i.e spread more evenly to the to front/rear when u brake hard.

Jack - u r the first one i know that is saying PSS9 is too soft for the track but honestly i concur with u. Reason i say this is becoz i set mine 1/2 for track and i still think its not hard enough, on the other hand maybe its the sway bar (maybe thicker ones will do ?) to reduce further the body roll ?

 

[TripleM]

Re: adjust to softer = compromise traction?

Rastaman
The softness in the PSS9 is in the springs, not the adjustability of the damping.
To me the damping works fine on the hardest setting but the spring rates are too low and comfortable for track use. They are ard 450lbs which aren't that great for track use. For daily driving (cruise + spirited ) cum 4-5 times track days per year, some 550-600 will be better.

 

[adliz]

Re: adjust to softer = compromise traction?

thanks rasta..

jack, can u not just change the springs? somehow..

 

[eddie]

Re: adjust to softer = compromise traction?

thanks rasta..

jack, can u not just change the springs? somehow..

adliz,

i think u can, there are 2 guys in KL that manufacture springs according to your needs...

but then again I wouldnt advise it.....

have u changed your sway bars yet.

I got UUC from Willman and they are superb with the PSS9.

i also did the front and rear struts + ordered adjustable lower control arms...