Coilovers and pre-load?

[JasonGilholme]

hey guys,

I've had a set of coilovers in my car for a short time now and i've got my height where i want it and i know what kind of damper i want for different situations but i was wondering what altering the pre-load of the coilover will do to the ride?

I'm interested because i'm competing in a tarmac series this year and i'd like to be able to tune my suspension better for the different events.

Any words/experience that people could pass on to me would be fantastic.

Cheers

Jase

[InsaneAsylum]

hey, there are a lot of guys who are involved in circut racing on performance forums. if you have no luck here, try posting these sort of questions there.

[JasonGilholme]

Got any links???

[Lt Ketch]

I got one

http://www.opelaus.com/

[JasonGilholme]

Thanks Lt Ketch :p

[Lt Ketch]

No probs, glad to help! :D

[InsaneAsylum]

No probs, glad to help! :D

it's ok, i already sent him the link to www.fastnfurioushondavtecpower.com

[gslrallysport]

I've had a set of coilovers in my car for a short time now and i've got my height where i want it
Height for what? Is the height where you want the car to look good, or perform good? Varying front/rear height variations has a significant effect on the car's overall balance... For an event like a jimna rallysprint (tight and twisty) i'll actually make a point of having the front sit lower, to get an oversteer balance, whereas, for an event like Rally QLD, I'll run a more neutral balance, so that it gives me the confidence to throw the thing sideways between the trees at 150km/hr without the fear of it swapping ends...

Don't disregard ride height as one of the best tuning tools when on the limit... Also, the more weight you shift foward with ride height adjustments, is less weight transfer you'll have under braking... something to consider given different circumstances...

and i know what kind of damper i want for different situations but i was wondering what altering the pre-load of the coilover will do to the ride?
What do you mean by pre-load? Do you just mean winding the spring up higher along the collar? This does SFA to the spring rate, as you'll never be able to pre-load the spring more than weight of the car, so all it does is change ride height... It does however give you less shock travel, which is generally a bad thing...

Dampening is entirely depending on the car's setup, and your driving style, and is just something you'll have to play with, there's no right or wrong answer... eg. The dampening for a open-diffed FWD car that doesn't run an upgraded front sway bar, will be different to an lsd equipped FWD car that can get away with running an upgraded front sway bar... for everything else being equal..

What sort of adjustment have you got on the shocks? Bump? Re-bound? High speed bump? Has it got adj strut tops?


I'm interested because i'm competing in a tarmac series this year and i'd like to be able to tune my suspension better for the different events.
Sweet as! What series? Hillclimb, sprints, circuit? Rally? :D

[rjastra]

Are you changing weight distribution when raising lowering either end or are you changing the roll axis?

[platypus]

i thought pre-load was bad and was set in the suspension bracing, whether static or non static..

[JasonGilholme]

So far i've found out that pre-load can be used to minimise weight transfer around the car in certain conditions.

I know it doesn't change the spring rate but does minise the travel of the shock to some degree therefore minimising weight transfer.

I'm still new to the whole world of suspension tuning so i've got much more to read up on.

As for my coilovers they've got the following features/adjustability:

Damper adjustments (@ the strut top)

Height adjustment at the bottom of the assemblye (you basically screw/unscrew the fitting at the bottom to change the length of the coilover, NOTE: This doesn't change the shock travel on my model of coilovers.)

Pre-load adjustment (Adjustable collar at the bottom of the spring. This is what limits the shock travel)

Camber: Camber is adjusted by the upper control arm cause i have double wishbone sussy front and rear

Spring rates: My spring rates are 11kg/mm front and 7 kg/mm rear.

Any more info is great guys.

Jase

[platypus]

Pre-load adjustment (Adjustable collar at the bottom of the spring. This is what limits the shock travel)isn't this called rebound?

i understand what you want - you want to reduce the lift and therefore the weight transfer

[JasonGilholme]

nah i've been told by many that its pre load. Mainly because you're "pre" compressing the spring before any "load" from the car is applied.

Damper could be rebound?? not sure. Rebound might be a common term in other suspension setups maybe??

lol Another thing for me to look up lol.

Yeah you're right tho, i'm looking to reduce the lift/compression of the coilovers to minimize weight transfer but i dont' know what i should try to fix certain situations (ie. too much over steer, too much understeer, wanna get sharper turn in etc.)

cheers

[platypus]

stiffen up the rear
of course seeing a suspension specialist would be the easiest way, most i've dealt with have been fairly pleasant and happy to explain

is this for drag racing?

[JasonGilholme]

nah its not for drag racing. Its for motorkhana, hill climb and tarmac rally.

[platypus]

of course re-reading your first post would have told me that :p

[gslrallysport]

motorkhana, hill climb and tarmac rally.
Not so much for the tarmac rally, or hill climb, but DEFINATELY for the motorkahana, if possible find the easiest link in your front sway bar and undo so that your front sway bar is disconnected...

1. Won't tend to pick the inside wheel up when trying to corner and power-down at the same time.

2. Will pick the inside rear up, making it easier to bring it around.

3. As a result of the above two will shift the weight where you want it...

The above is also somewhat applicable to gravel rallying, and infact when we re-shelled my rally car, the first thing i did was remove the front sway bar and use the bolt holes to mount the sump guard to, makes a world of difference to turn and power down, and of course sends the balance from understeer to oversteer...

Experiment when you're hill climbing, as those type of circuits can vary considerably, and for tarmac rally, the generally accepted thing is to upgrade the rear sway bar, and leave the front std.

[JasonGilholme]

Yeah i was thinking about it on the weekend, for motorkhana in a FWD i would much prefer it to over rotate around corners cause i will always be able to pull her straight with a bit of power.

I've got plans to stiffen up the rear with some subframe re-inforcement and larger rear sway bar. I'm thinking of getting some new LCA's and some new bushes as well.

Also, if i undo the endlinks on the front sway bar will they bang up against the LCA??? especially considering that my car is alot lower then stock now?

Thanks

[gslrallysport]

I'm thinking of getting some new LCA's and some new bushes as well.

Urethane or rubber? If you're chasing urethane ones, Noltec are generally more price competitive than either superpro or Nolathane...


Also, if i undo the endlinks on the front sway bar will they bang up against the LCA???

May do, I wouldn't worry about it... Though, to prevent damage to your link it maybe worth removing both ends of it. Novel thought, try removing the entire FSB altogether and see how it goes... It will help that its lowered, and most of the time they're only there to give a car 'dummy' factor understeer, and prevent it from swapping ends...

Still the best handling car I have EVER driven was a stock '94 G200 Charade on decent rubber... Why? Cause they ONLY came with a rear sway bar... Turned in ever time, regardless of how much power/braking I have it, and put its power down like it had an LSD...

Also remember allignment... In a FWD you want AS MUCH front caster as possible and AS LITTLE front camber as you can get away with... Obviously the more caster you can pull, the less camber you need, and will assist braking and traction.

[JasonGilholme]

i'm lookin into uerthane bushes. I was looking into energy suspension but i'll definately check out Noltec's prices as well. thanks.

I'll definately have to see what its like without the front sway bar. Might be a bit to "drifty" if i have a larger the OEM rear sway bar as well as a removed front sway bar. But for motorkhana that should be ok. Hill climb's and tarmac will be a different story.

I'm getting an alignment done soon so i'll see what the camber, castor and toe is set to and then i'll be able to go from there.

Any opinions on what i should set the front toe to and the rear camber?? There would be different setups for motorkhana and hill climbs wouldn't there???

[gslrallysport]

i'm lookin into uerthane bushes. I was looking into energy suspension but i'll definately check out Noltec's prices as well. thanks.

No worries... when you work out what you want, and get some prices, if ya want a second opinion on price let me know! ;)


I'll definately have to see what its like without the front sway bar. Might be a bit to "drifty" if i have a larger the OEM rear sway bar as well as a removed front sway bar. But for motorkhana that should be ok. Hill climb's and tarmac will be a different story.
Yes and no... Don't focus on the motorkhana setup too much. If you were to setup a car up purely on motorkhana, the thing would be an-undriveable bucket of crap everywhere else, including driving it to and from the event... Just find a balance that still feels nice to drive daily...


Any opinions on what i should set the front toe to and the rear camber??
Front toe i'd be looking at 1-2mm toe out across the front total.. Obivously more if you're trying to setup purely for motorkhana...

Rear camber, about 1.25-1.5 degrees... or just a fraction more than what you're going to run on the front...


There would be different setups for motorkhana and hill climbs wouldn't there???
Yes, but as with point 2, just find a compromise and learn how to drive...Too many people (myself included sometimes) worry too much about car setup, and not enough about driver setup... Just find a compromise and learn how to drive around it...

One of the best experiences I had was at Rally QLD last year, when we poped the left strut top halfway through the saturday, didn't have a spare and wouldn't have a replacement up from brisbane till sun morning... I learnt how to take left hand corners twice as fast, and despite having to back off lots for right hand corners, we lost surprisingly little time...

As with any motorsport (esp. motorkhana and hillclimbs), just go out to enjoy it, learn how to drive (that's always the biggest factor in any car's performance) and come away knowing more than you did before...

If you can't drive a slow car fast, you'll never be able to drive a fast car fast... or at least what I keep telling myself everytime I get into the Lada! :p

[JasonGilholme]

Cool man.

Thanks for your help. I've been reading up on alot of suspension info and been sending people emails in regards to different setups etc. which has helped me heaps.

But as you say, its the driver most of the time. alot of people say that its 20% car, 70% driver and 10% luck. lol

Can't wait to get out there and start to have some fun.

Thanks for the help to mate.

[J]

Hey JasonGilholme, in case you've yet to go to this:

http://www.suspensionparts.info/

Try posting your question there and see what you get :)

Cheers.

Regards,
Jeff

[JasonGilholme]

Thanks Jeff.

I'll post it there as well.

cheers

jase