Handling Setup

[d1nzfe]

I have a few questions that i am not too sure about.
- too much negative camber on wheel only helps in downslope turns and make it worse on uphill ones?
- suspension set too hard,lost in traction on uneven ground,how about smooth ground?

Can anyone advise?

[ddongbap]

Negative camber helps on cornering. Not just up or down.

Hard suspension would cause understeer. Depending on what suspension you have, you'll get different results. Most of what you have to worry about is the shocks. High class shocks'll compensate for uneven pavement, even if the springs are harder. But that'll only go so far. Suspension thats too stiff, is simply suspension thats too stiff.

[d1nzfe]

any info on how to set the compression and rebound on the suspension correctly?

[eTiMaGo]

what suspension are you running?

[largeorangefont]

Originally Posted by d1nzfe

any info on how to set the compression and rebound on the suspension correctly?

It depends on what you are doing, and what springs you are running. We need more info.

[jronald]

Originally Posted by ddongbap

..
Hard suspension would cause understeer
..

I set my suspension hard, and it's oversteer..

[ddongbap]

Originally Posted by jronald

I set my suspension hard, and it's oversteer..

Probably cause your rears are super stiff. I should have specified that if you made your fronts stiffer, and/or added a anti-roll bar, you'll experience understeer.

[cleong]

Actually understeer or oversteer is a function of which end of the car has more grip.But a car can understeer or oversteer on the same setup, it just depends whether it is accelerating or braking. That is down to weight shift.

People run stiff suspension to fight weight shift in corners and improve handling response.Otherwise you want to run the car as soft as you can get away with, in order to obtain the most amount of grip. Soft suspension has more grip than hard suspension assuming there is no distortion of the contact patch as a result of body roll.

There are several things you can play with, geometry, ride height, sag, tire pressures, rebound and/or compression rates. They all conspire to create the car's handling characteristics. Even if a factory stock car, adding or substracting air from the front or rear tires can have a marked effect on the car's handling characteristics.

- Negative camber helps the car grip better in the bends. While it is possible to adjust your rear camber by means of shims, I shall assume that you are only talking about the more-common front end camber adjustment. More negative front camber gives more grip to the front end in the bends as compared to the rear. Generally, a car pointed uphill would be more understeery than when it is pointed downhill, that is my understanding of weight distribution.

- Suspension set too hard, the wheels do not follow the dips and bumps in the ground well. This translates into loss of traction. If the ground is extremely smooth (eg. prepared race circuit) you might be able to get away with it. Racing suspension are tunable, because it is necessary to optimize the spring and damping rates for each particular track condition. For road cars, a softer setting that suits a wider range of conditions would be better.

[eTiMaGo]

Originally Posted by cleong

Actually understeer or oversteer is a function of which end of the car has more grip.But a car can understeer or oversteer on the same setup, it just depends whether it is accelerating or braking. That is down to weight shift.

People run stiff suspension to fight weight shift in corners and improve handling response.Otherwise you want to run the car as soft as you can get away with, in order to obtain the most amount of grip. Soft suspension has more grip than hard suspension assuming there is no distortion of the contact patch as a result of body roll.

There are several things you can play with, geometry, ride height, sag, tire pressures, rebound and/or compression rates. They all conspire to create the car's handling characteristics. Even if a factory stock car, adding or substracting air from the front or rear tires can have a marked effect on the car's handling characteristics.

- Negative camber helps the car grip better in the bends. While it is possible to adjust your rear camber by means of shims, I shall assume that you are only talking about the more-common front end camber adjustment. More negative front camber gives more grip to the front end in the bends as compared to the rear. Generally, a car pointed uphill would be more understeery than when it is pointed downhill, that is my understanding of weight distribution.

- Suspension set too hard, the wheels do not follow the dips and bumps in the ground well. This translates into loss of traction. If the ground is extremely smooth (eg. prepared race circuit) you might be able to get away with it. Racing suspension are tunable, because it is necessary to optimize the spring and damping rates for each particular track condition. For road cars, a softer setting that suits a wider range of conditions would be better.

Great explanation cleong

My coilovers have adjustable damping that I can change in-car so I have been testing quite a few combinations, and just like you mentioned, it's always a compromise between grip and responsiveness...

Only thing I can add is... go play Gran Turismo or Forza Motorsport, yo can seriously get very good concepts of suspension setup from them, especially Forza which has a lot of telemetry data during replays...

[d1nzfe]

well,the suspension can go 40 setting on compression and 30 on rebound.
i'm on front,Compression-5 turns(from softest) Rebound 5 turns,Rear C-3 turns,R-1 turn.
rear still feels very firm,only over humps.Cornering wise not testing on track yet.
So uphill and downhill affects the weight distribution so i feel understeer is normal.How do i go fast in a uphill corner then? More -Camber in front?

[largeorangefont]

Originally Posted by d1nzfe

well,the suspension can go 40 setting on compression and 30 on rebound.
i'm on front,Compression-5 turns(from softest) Rebound 5 turns,Rear C-3 turns,R-1 turn.
rear still feels very firm,only over humps.Cornering wise not testing on track yet.
So uphill and downhill affects the weight distribution so i feel understeer is normal.How do i go fast in a uphill corner then? More -Camber in front?

It really depends how serious you want to get here. 2 degrees for negative camber in the front, and no toe, or just the slightest bit of toe in should do it for alignment.

Im assuming the car is understeering on power off the corner? If it is you need to stiffen the rear compression to keep more weight on the front wheels, also you can stiffen the front rebound a bit, and this will also help with body roll. Adjust those two until the car starts to turn better. You will want to make most of your adjustment to rear compression and fine tune it with front rebound.

[cleong]

It depends on the speed that you are going over the humps.

If you want to go around a corner faster, I'd ask you to get more sticky tires. That is the most effective.

If the suspension that you have got comes with a factory recommended setup, set it to that first. You can come back to playing with it later. Try simpler things first!

I found that running equal pressures front and rear of the car makes it more lively. Put it on an alignment rig, run neutral toe angle, or slight toe-out of the front wheels, set your car up with about negative 1.5 degrees of camber, and run about 1 finger's gap higher on your rear ride height (essentially its my setup).

You'll find that you get a car with good corner entry bite (ie responsiveness). If you have a sensitive butt you might even feel that the rear end has a bit of drift (sliding sideways) during corner entry, but I like neutral cars that turn in willingly. In comparison my brother's FD Civic is quite a plough-on understeerer. Don't like driving it on twisty roads.

[cleong]

Originally Posted by largeorangefont

It really depends how serious you want to get here. 2 degrees for negative camber in the front, and no toe, or just the slightest bit of toe in should do it for alignment.

Im assuming the car is understeering on power off the corner? If it is you need to stiffen the rear compression to keep more weight on the front wheels, also you can stiffen the front rebound a bit, and this will also help with body roll. Adjust those two until the car starts to turn better. You will want to make most of your adjustment to rear compression and fine tune it with front rebound.

Given that he seems to be complaining about a stiff rear end, I think in this case stiffening the rear to bring weight distribution forward would work for the uphill climb but doesn't improve the daily ride comfort.

TS will have to decide whether he wants comfort or performance and live with the compromise.

[largeorangefont]

Originally Posted by cleong

Given that he seems to be complaining about a stiff rear end, I think in this case stiffening the rear to bring weight distribution forward would work for the uphill climb but doesn't improve the daily ride comfort.

TS will have to decide whether he wants comfort or performance and live with the compromise.

The fact that he has everything at basically full soft and is complaning about the ride tells me he didnt know what he was getting into anyway. We still dont know what coilovers they are, or if they have adjustable droop.

To be honest, the ride quality should improve a bit (or at least not get any worse) when he turns up the damping to match his spring rate. At full soft, he may be over sprung.

[cleong]

Its why I asked him to start over and go back to a factory setting (if there is one)

[d1nzfe]

there is no recommended factory settings.
These are HotBits.
Spring rate is 6kg front and 4kg rear.
Comfort is not a problem for me,i will go all out for performance.
Thanks for the info,i'll try and see whats the outcome.

[rob323]

I have found the following link to be a good, easy to understand guide of how to set bump and rebound properly. Hope it helps.
http://www.salug.org/~davidm/cars/koni.html

Didn't know that Hotbits now have separate adjustments to bump and rebound, are you able to show me some pics please. Do they have the external canisters? (I have external canister hotbits on one of my other cars but bump and rebound adjustments are not separate).

[cleong]

Great link