spring rates for track racing

[ton123]

what spring rates are people using in there corollas (ae92 levin)at track events

[touge_ae101]

what tracks and what kind of shock absorber setup/swaybar setup have you got?

for a ae92 i would go for either a 400lb or 450lb front, 550lb rear with uprated swaybars front and rear. we have just done this in dads ae82 which should do 1.21's easily this weekend at manfeild (still only making 100kw). has whiteline adjustable bars front and rear. bout the same weight as a ae92 its about 900kg with no driver. has koni adjustables all round.

but with my ae101 i'm looking to do 400lb-450lb (need to test both and see what its like) in the front and 600lb in the rear. going to use 19mm chromoly bar in the rear. this is still untested just collecting springs etc atm.

a lot depends on the tyres you run and their age as well. you won't get the same handling characteristics out of road tyres as a new race slick.

[RomanV]

Harder rates at the rear?

weird

[1I1]

Yeah seems like the Jap tuners love running harder rear spring rates than in the front in their FWD's. (spent too much time watching BMI DVD's )

[touge_ae101]

Harder rates at the rear?

weird

thats fwd for ya pretty much. rear is just there to follow the front wheels around really. most fwd race guys will use a similar setup.

[ton123]

has white line sway bars and bilstein 30mm has 175 and 150 pound for rally set up is this too soft for that too ?
,and after weekend of tarseal hillclimbs was no good lifting rear inside wheels and lots of under steer on semi slick

[touge_ae101]

sweet bilsteins are awesome they should do the trick! yes i would say that is definitely a far too soft setup for the track... my setup I've got atm with 300lb front and rear on my ae101 is the perfect setup for hill climbs and targa type events. have tested with semi's on saddle/gorge and the like and it works pretty bloody well!

but a track setup is much harder again. as can be seen from pics of my car at taupo it is far too soft!

[strx7]

in my 4wd turbo ae104 - same basic platform just with the added rear weight of a diff which does aid some grip, i started off running 450lb fronts and 325lb rears, and found it too soft on hill climbs and way too soft for the track, i then switched to 550lb fronts and 400lb rears which was alot better, especially when i tried it on the track with full slicks. for a dedicated track car i would probably go to 600lb fronts and 450 or 500lb rears.

stiffer springs in the rear than the front is a common way to set up a fwd circut car

[fxgt race]

I run 550lbs front and 300lbs rear, My rears are low because when
I turn the in cabin adjustable swaybar to hard , which makes the sway
bar solid between both back wheels joining both sides together in turn doubling the spring rates and more as it lifts the inside rear wheel so I
would say 700lbs on a corner.
I don't run a front swaybar at all.
I do have 40mm bilsteins valved fairly hard.
Suspension is a trickly thing to perfect, it has taken 5 yrs
to get my car to where I think is near perfect but I know I will
always be looking for ways to improve it.

[ton123]

thanks guy what about castor how much to run on front

[fxgt race]

I would try 500lbs front and 600lbs rear starting or somewhere thereabouts. With castor I run 6degs positive which is at the upper end,as much as you can really for the track, it gives you more negative camber as you turn a corner keeping the rubber flat on the ground.
I have 3degs camber on front and 2.5 on rear.
Understeer will be your biggest problem, lower your spring rate for fronts to help with this, set the rear swaybar harder.

Try this site

http://www.se-r.net/car_info/suspension ... erstanding Vehicle Dynamics

[Bazda]

Since everyone keeps referring to AE82 which has a totally different weight to a AE92 I will have my say now .

8-10kg front and 6kg rear works well for me.

Putting an uprated rear bar on the rear = super dangerous on the track.
My self and many others have tried this using 6kg rear springs and it just doesn't work out well. So the stock bar stays there and works good for me.

AE92s seem tail happy for some reason compared to the other models.

Also it depends how your shocks have been valved also! And how different F&R valving has been done.

[GOLDAE86]

You want to use the least amount of spring as possible otherwise it will feel like ur driving a brick. Different cars act in different ways so you will need to start with a rate and work from there. The v8 touring cars I worked on had 550 lb springs in the front and 300 lb in the rear with huge anti roll bars.Same with the supercars they run between 250-350 lb on each corner but have huge bars. I'm not a fan of running no bar front or rear and having huge springs to stop body roll as it can be dangerous on cornering, braking and hitting a ripple strip/bump etc and throwing u off into a wall.
That's my 2 cents worth hope it helps

[Flannelman]

Hard saybars with little spring pressure sounds like a torsion bar set up, something valiant chargers ran in the 70s...

[Mr Revhead]

No.
it means you are not all over the place on bumps and things stiffen side to side in corners. When you need it.

[Flannelman]

It is well documented on many cars that have too much rear swaybar makes a cars handling "snap oversteer". Good for the drifting crew, but wont be good for anything elce

[strx7]

harder sway bars and softer springs = more squat, more weight transfer and more power to the ground

[Bazda]

Possibly more weight transfer in the wrong situations.

I guess its a combination of both and is something you need to experiment with to get right.

[Mr Revhead]

It is well documented on many cars that have too much rear swaybar makes a cars handling "snap oversteer". Good for the drifting crew, but wont be good for anything elce

Well you hit the nail on the head

[Flannelman]

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.