spring rates for track racing

[Mr Revhead]

What do you think hard springs will do in a corner?

[strx7]

Makes sense from a drag launching point of view. But mid corner with the weight loaded up on one side...

Im not convinced...

Sorry, im not convinced that it will suit me and my driving style.

thats why they use a considerably stiffer swaybar than you would if you used heavy springs. set up with the correct springs and sway bars you end up with the same lateral stiffness and are able to put more power to the ground in a straight line, it really shows itself in wet weather.

[Flannelman]

too soft springs - severe weight transfer

too hard springs - no weight transfer


too soft shocks - poor spring control

too hard shocks - poor bump control


too soft swaybar - understeer

too hard swaybar - oversteer


Those are my view of the job of each suspension component.
To explain why I dont like the situation is it sounds like people are trying to make the swaybar do the job of the spring. Looking at how the swaybar is mounted to the chassis and to the suspension (there are numerous points) they are just not designed to take the stress of weight control. If this is the case, then I would imagine to see swaybar link upgrade kits being sough as standard ones will snap under the stresses being imposed on them. Once this is done then I foresee swaybar bushings will suffer accelerated wear rates from the increased workload imposed on them.

[Mr Revhead]

um, that's exactly what swaybars are for. Lateral weight control

[Malcolm]

I don't want to get into this discussion at all...but I wanted to point out a couple of things
1 - Body roll/chassis movement isn't the same as weight transfer. When you're cornering at x lateral g's, your weight transfer is the same if you're running 200lb or 2000lb springs. When you accelerate in a straight line at xx g's, it doesn't matter how much the car squats, the weight transfer is the same. I know this isn't easy for everyone to accept but it's pretty basic physics.

2 - Anti roll bars aren't a free lunch, adding more ARB still stiffens the car in single wheel bumps, but to a lesser degree than if you did it with springs

3 - One of the real issues with running massively high anti roll bar stiffness and low spring stiffness is damping. You end up with such a difference in your spring rate in roll vs your spring rate in pitch/heave/warp/ride/singe wheel bump that your damper settings end up having to be a shitty compromise (unless you're awesome and have roll dampers ). I know dampers are a scary subject, but when you're talking about stuff like hitting bumps, running over ripple strips etc, having f-stiff ARBs and not enough damping to control them is a recipe for disaster.

[2jayzgte]

If I was you guys I would go to somewhere like the TRD/English site have a look at the Damper and Spring rates TRD recommend as most of us are looking for the best trade-off between a street/track-day setup.

Use those Damper/Spring rates as a guide if you can't afford to buy there stuff and go from there all this guessing internet stuff will just lead you awry.

But going to a stiffer spring without a matched Damper rate to accomodate the stiffer spring rate is pointless to me and your playing a huge guessing game.

[Mr Revhead]

the key phrases are "too much" "not enough" etc
It's all relative. By saying soft spring I'm not meaning actually soft. I'm meaning as soft as you can go relative to the hard some are meaning.

If you want to look at say V8 supercars which are very very developed in suspension you will notice the fastest ones are the ones that seem to float over the ripple strips etc. They don't do that by going really hard on the springs and soft on the bars.

[matt dunn]

V8 supercars etc

Also the stiffer the chassis the softer the springs you need to run,
so the strength and design of the roll cage has more to do with spring rates than you think.

So the supercars run quite soft springs as there is a lot of strength in the design of the chassis and roll cage.

[Bazda]

That is correct about spring rate vs shock rate.
The shock will only be valved to suit the spring going onto it (well hopefully if its a good brand and they know what they are doing)

Normally you can go +/- 2kg in the springs rates before needing to re valve the shock absorber.

There is only limited sway bars available for the Corollas on the market and they are all virtually the same. So you will have to start with one of those then choose the right spring rates from there.

[KinLoud]

I drove a friends AW11 a couple of times.
It had Tien springs with adjustable Tein shocks.

it was almost undrivable - You could hardly drive it thru roundabouts as it would skip sideways.
I asked what setting the shocks were on... "full hard" i get told.
I suggested he set them to full soft then step up the firmness until the car felt balanced.
A couple of weeks later I drove it again and it was fantastic to drive - nice and balanced - the best setting so the shocks matched the spring rate was about 1/2 on the dial.
Dont presume that harder is always better (on the road or on the track)

[Santa'sBoostinSleigh]

Sorry, im not convinced that it will suit me and my driving style.

and 270,000+ km old original flogged out shocks and springs do suit it?!