Topic: Soft or Hard - what's best for handling

[DragonSolGXP]

OK... I have my BC coilovers installed and I think I like them. I need to dial in the damping but I'm not sure if I have it right.

Basically the front is a little harder than mid point and the back is softer than mid-point... something like 8 clicks out from hard (0) ... the front is around 4 clicks from (0) hard.

Generally speaking, if you want the car to handle well is it better to have the front end damping hard or soft? I made the rear soft because the bumps were killing me.

[Dave@DDMworks]

Short answer is to firm up the front to get the turn in you want and soften the back to get the grip you want. Another thing to consider is that on the shake rig, the softest settings will produce the most mechanical grip on a car. There is always a balance between keeping road contact with too stiff of a suspension and too soft of suspension.

Hope that helps,
Dave

[Ben L]

OK, right off the bat, I have to confess I do not tune my suspensions for ride comfort.  So if that's the goal, I am not the guy.

I am looking for neutrality, meaning that one end of the car doesn't get way out ahead of the other when you are asking it to turn at the limits of tire traction.

Our cars come from the factory with a terrible "understeer" or "pushing" tendency.  

General rule of thumb is that you want more compliance (softiness) on the end that is breaking traction in an annoying way.  Because in hard turns I would turn the wheel and the front would keep going straight ("pushing"), that means the front was too stiff. So I set my BCs at, like 7 or 8 clicks in the front, and maybe 20 to 25 clicks in the rear (from full soft).  

Soft in front, stiff in the rear.

Now it more or less does what I want, which is to have the rear wheels break traction before the fronts do.  To me its a helleva a lot easier to control a mild rear step out by applying  throttle or countersteering a bit than it is to try to get it tracking in the front again.

While I recommend the front/rear proportions due to how I know the stocker is biased (most factory cars tend to understeer, because for some reason, car engineers think its safer to slide straight in a failed turn than have the rear get loose. Never got that. . . ), you do not have to have everything so stiff if its rattling your fillings.

Try something like 3-4 clicks in the front and 12-15 in the rear. . . .   From full soft, mind you.

Or just do what Dave from DDM said.  Either way . . . .

[kennysabarese]

Not sure if you were kidding... but understeer is safer because the front tires skidding will slow the car down and keep you going closer to the direction you want to eventually go.

[Ben L]

Hmmm.  So that's it.

Actually, I was only partly kidding. 

The friction of pushing (especially on the rock hard stock tires) never slowed me down in time to save all those poor little cones I was trying to avoid. They gave their lives for that questionable idea.  Moment 'o silence, please.   

Personally, I'd rather the fronts turn AND track at the limits.

[Dave@DDMworks]

Also once a tire is sliding it has a lower coefficient of friction than when it is turning, that is why when you lock the tires up, you have to release more pressure than what it takes to threshold brake to get the tires to get back their grip.

The difference between oversteer and understeer is that with understeer you see what you are going to hit, with oversteer you back into it.

A car that is a little loose will usually be quicker, but once again we are talking about so many variables here on a street car, over varying road conditions with a single adjustable coilover setup, and what is the correct setup for one type of condition is not optimal for the next.

Hopefully though we have made setup a little clearer without confusing you more.

Thanks,
Dave

[kennysabarese]

For normal drivers who just slam on the brakes understeer is safer.

Especially for a road course where you have walls to worry about   and are going a lot faster.

[Ben L]

Gee. I guess I just never go fast enough to appreciate the joys of understeering on a road course.

Love to compare notes (and times!) on the track someday.  I dabble a bit there, too.

[kennysabarese]

Why does everyone love to get so defensive sheesh. I'm done.

[Ben L]

Why does everyone love to get so defensive sheesh. I'm done.

Because people who drive cars in competition are competitive insecure a-holes by definition, that's why.  No hard feelings.

[kennysabarese]

Heh. I got respect for your track experience yo. Wasn't meanin' to talk down.

[2kwk4u]

Not that anyone ASKED for my 2 cents, but...

It was always my understanding that most cars understeer b/c the average person's natural reaction to a skid.  i.e. they will let out of the throttle and/or get on the brakes.  That, in turn, loads the front tires more and (hopefully) gives you a little more traction up front as a result. 

Conversely, if you're oversteering and you unload the rear tires, you'll often snap the rear end around, right?

[Ben L]

Forgive my testiness, and the digression into the reasons why engineers build in understeering (which is interesting; I definitely learned something). 

Back to the point, I set my suspension up to balance the car better and reduce the tendency to understeer, because it was limiting the car in autox settings. 

It was not as much of a problem on the street, but I still prefer more neutral handling in daily driving. 

That meant stiffening the back (with higher rate springs, relatively stiff damping settings and the addition of a Pro Beam), and softening the front (lower rate springs and softer damping settings).

Even at 7 clicks on the BCs, the front (to me) seems plenty stiff enough to get decent turn in. 

I think you will just have to experiment and find what works for you, armed with the basic principles discussed here that you will hopefully be able to extract despite all the noise.  For which I apologize again.

 

[kennysabarese]

Not that anyone ASKED for my 2 cents, but...

It was always my understanding that most cars understeer b/c the average person's natural reaction to a skid.  i.e. they will let out of the throttle and/or get on the brakes.  That, in turn, loads the front tires more and (hopefully) gives you a little more traction up front as a result. 

Conversely, if you're oversteering and you unload the rear tires, you'll often snap the rear end around, right?

Correct!

[DragonSolGXP]

Thanks everyone, I did find this very informative and it educated me on what I didn't understand about damping and understeering/oversteering (wasn't sure what was meant by that until now).

I only drive street so I'm opt out for the understeering (no offence Ben). I'd rather not have my rear end swing around (if I understand oversteering correctly).

Interesting however that my "fiddling" with any of the above knowledge yielded a hard from end and a soft back end. I'll continue to fiddle. But now I can do it with knowledge under my belt.

Incidentally, the first time I soften the backend to where I currently like it, I hit the throttle going down a road and I must have hit a slight hump then gone airborne for a second because my "Low Traction" warning light came on. I doubt I was spinning tires... so I must have left the pavement enough for the tire to have no traction.

[Critterman]

I am by no means an expert, but a car pushed to the point of sliding the front is going to go in the direction it was headed until something stops it or it slows down enough for the tires to gain traction and then you are going to have an extreme turn in that direction.

a car pushed to the point that the rear breaks traction, can be controlled a little better and the direction changed by the judicious use of the right foot, less throttle less turn, more throttle more turn.   

I think I would prefer to have a little control.

[Treeman]

Actually, understeering is much easier to recover from.  Take foot off gas, the slide slows the car, the tires bite, off you go.  Oversteering is fine until it bites you and then the car often snaps around.  Interesting review of used S2000s in this months Car and Driver praises its neutral handling but then goes on to say that too many owners regret it when they flip ends.  Once the rear starts going, its hard to recover from - watch a few races to see how quickly rear ends fly around.

I have a bit of a different observation from Ben about the car.  For me, no doubt, if I overcook a turn, the front end plows.  But, just short of that, I find the front end biting well and the rear end getting light and stepping out.  I like this, it is just enough to rotate the car a bit and make a quicker turn.  I don't know how much more I would want that to happen.  I think the biggest problem is that the car squats too much in the front under strong braking and overpowers everything up there - turning a fairly neutral car into a plow machine.  At least, that is what my butt is telling me.

[kennysabarese]

Actually, understeering is much easier to recover from.  Take foot off gas, the slide slows the car, the tires bite, off you go. 

Yes this is exactly right. Especially for inexperienced drivers who have no clue what they are doing (aka most drivers who aren't into driving)

Critterman you are right as well, for experienced drivers who know how to handle the oversteer and aren't getting into trouble.

I bet most of us haven't experienced much uncontrollable oversteer in most cars since they are all engineered to understeer from the factory.

Understeer feels like you are out of control, but it's better to be out of control and straight ahead than out of control and sideways/backwards. With modern cars with airbags and crumple zones, it's probably safest to have an accident head on instead of turning sideways and getting T Boned at 70mph. (especially in our little cars!)

Safety first for manufacturers.

[Uranium-238]

If you think about it it does make sense for the manufacturers to favor understeer. Set the car up to appeal to the most people out of the factory. Which might not favor us racers, but heck they probably figured we'd take car of it ourselves.

[kwtoxman]

This is from KW. The coilovers are independently adjustable for compression and rebound which rocks. So your suspension is going to be more complicated to figure out but here is some good info...

Rebound Adjusting principles:
In general a soft rebound adjustment provides a comfortable ride at low vehicle speeds but the vehicle will have less stability at higher speeds, especially on the front axle (vehicle will tend to float at higher speeds). A hard rebound adjustment offers more stability but could reduce vehicle grip (i.e. the vehicle will tend to skip across road imperfections, reducing traction).

Compression adjusting principles:
Generally, hard low speed compression settings will stabilize the corresponding axle (less over steer on the rear, for example) or offer the front a more precise steering response. Too much low speed compression power will decrease grip! Depending on the valve configuration found inside the kit, maximum compression forces will not influence the suspensions response when encountering hard bumps, such as curbs on the racetrack.

[lil goat]

I set my car up the way that RMR told me to, they helped design the HKS setup for the Solstice. I was told when I did that what I was given was just a starting point and I needed to fine tune to my driving style. The HKS come 10 clicks from soft stock both front and rear. I went up 6 clicks in front and 4 in the back, the back is about where I want it. I can kick it out at will with power. The front needs some tweaking, I think I need to back off a little and I am plowing a bit now that I have replaced the rubber bushings with urethane. Everyone has different styles, so we each have to set it to match our own style.

[perris]

I think I need to back off a little and I am plowing a bit now that I have replaced the rubber bushings with urethane.

I thought our cars came with urethane bushings

[lil goat]

Nope they are rubber, I have replaced both front and back. I backed off the dampening from 16 from softest to 6. The car handles fine at speeds but it does worse on the highway seams, I am going up a couple of clicks to see if it helps.

[kennysabarese]

How was the highway performance worse? Too soft? Bouncy like an old towncar with dead shocks?

When I get coilovers I am most concerned about highway driving. I'd like to be able to make them nice and soft and comfy for long trips.

[lil goat]

With them softer they are a bit more bouncy but just on area's where they highway is cement with those stupid seams, and it seems to develop some kind of harmonic at certain speeds about 45 (traffic) up over that it is hardly noticeable. You will not get a smoother ride with coilovers I can tell you that. It is more controlled yes but not smoother.