suspension mods affect on non-track conditions

[mccarthv]

so i've been learning a lot about springs, swaybars struts, etc, and i have a pretty good understanding of how they affect the ride of a car. but my question is, will putting stiffer springs and swaybars in adversely affect the car's ability to perform well in snow and icy conditions? cause lets be honest, thats what subarus were made for, mobbin up the hill to hit the slopes and drifting in parking lots and roads when no one elses dares to go out and drive. i don't want to mess that aspect up with changing the suspension.

[Garrison]

I wouldn't think so, traction is more a matter of tires than spring-rates. Rally cars for instance run ridiculously high spring rates.
It might slide a little more, but you shouldn't be driving fast in snow/ice anyway (unless that drive is solely for recreation!).

[Huffer]

Stiffer springs will affect the cars flexion during a hard corner - and typically during a countersteer movement the rigidity will result in more of a "snap" of the car chassis.

Put simply, if you bounce a flat ball off a wall, it reacts and compresses slower, and it's rebound isn't as high - bounce a properly inflated ball off the same wall, with the same force, and it'll bounce more forcefully.

It's still controllable, but it is less forgiving during a panic situation - in terms of a car, particularly if you are prone to spinning the steering wheel a lot during a slide.

I would recommend a softer setting for the rear swaybar in the winter, to minimise snap oversteer, but spring rates aren't a huge deal unless you have coilovers and have the rebound cranked up really high.

[Wiscon_Mark]

Huffer explains it well.

I would almost recommend swapping swaybars back to stock for winter if you find it to be too much a of a problem with an upgraded one. It's not a terribly hard job if you have some ramps.

I have an adjustable 18-20-22 swaybar on my car and I have it on 18 in the winter and sometimes it does cause a bit of skid in the tail end. Nothing I can't handle, but it all depends on the ability of the driver. I also have good winter snow tires (Michelin X-ice). I don't think I'd want that stiff of a setting with all seasons.

[Huffer]

^^ 18mm RSB is what the GT comes stock with, so it's fine to have that. I have an adjustable RSB (like Mark) and dial it back to 18mm in the winter. I have run all-seasons and they're fine; the issue is not so much going sideways, but more so when your tires break traction. On ice, nothing but studded tires will cut it, and when you're heading sideways nothing is going to grab much anyway because the wheel is spinning perpendicular to the direction of travel.

The idea is that in slippery conditions you want your suspension to absorb more of the sudden impacts and changes without affecting the overall steering feel of the car. You won't see a rally car setup the same way a track car is - rally cars need to roll with the punches, track cars need to punch through corners and stick to the tarmac. But as soon as they hit grass, gravel or an oil slick, they lose all steering feel. It's a bit of an extreme example, but hopefully you get the idea.

[Huffer]

^^ all that being said, your tires are numero uno for traction. You have 4 little strips of rubber that connect you to the ground. Great tires will help a crappy car steer it's way out of trouble. Crap tires on a great car will result in crying every single time.

[Soul Shinobi]

Very stiff springs and shocks will be more liable to lose traction in rough conditions; bumpy roads, fallen tree branches, potholes, etc...

Stiffer suspension in general, but especially swaybars, will make the car react more quickly. This is a good thing for a skilled driver, but if you're not smooth being rough on the controls can cause you to lose traction more easily from fast weight transfer. Just as you brake more gently and gradually in the winter time, you have to be careful with the gas while cornering and the steering. Shouldn't be a huge deal unless you setup is very stiff.

Props again to Huffer, great explanations here. Especially the note on softening the rear swaybar.

Reducing unsprung weight (lighter tires, wheels, brakes, lower suspension parts) will always increase traction over rough surfaces because the reduced mass allowed the suspension to track up and down more quickly.

[Huffer]

Reducing unsprung weight (lighter tires, wheels, brakes, lower suspension parts) will always increase traction over rough surfaces because the reduced mass allowed the suspension to track up and down more quickly.

Quick note on this, this is true, except in instances where the rebound rate of your suspension overpowers the weight of the vehicle. For example, if you install suspension designed for a 3500lb vehicle onto a vehicle weighing 2500lbs, when that vehicle hits a bump, the suspension is literally going to act like a spring (and on the landing, will eject the vehicle back into the air), and not like an absorber.

The idea of good suspension is that it keeps the vehicle as parallel to the ground/road as much as possible, but in the event of a launch/jump, it absorbs the impact as quickly as possible. Time spent bouncing around controlling a landing is lost lap time. Example, watch RallyCross in the Xgames vs. Monster Truck Jam.

So, rebound rates and suspension travel length is also an important consideration when building a vehicle.