General Suspension help.

[Muzz]

Hey guys im heading down to the bank next week to apply for a loan for some car parts, and im after some advice.

Heres my situation.
iv got a 99' ek4 hatch, that iv brought to build into a weekend track car. Im at uni for the next 3.5yrs and cus of a lack of money im concerntrating soley on the handling of the car(also reducing the weight). Later on during my course i wish to go all out on the brakes, but im not thinking of that yet cus its a long time b4 i start tracking. Basically when i finish my degree, I wanna have my civic completly ready for racing, so all i have to concerntrate on is building a crazy wild n/a engine too complete the car. At this point id probably buy a cheap economical runaround and garage the civic for track work.

So far My list of parts im thinking of are:

1. Tein SS coilovers - only cus ill be driving street for 3.5 years yet, and still want a little comfort, upgrade later for track.

2. Swaybars - i already got these, whiteline F 24mm, R 22mm, and an asr subframe brace

3. Camber and caster kits

4. front and rear strut braces.

What else should i include in my list of goodies for awsome handling? im not to interested in extra bracing yet cus id like to have a propper structual roll cage built later on, so till then its just the strut braces.

i feel theres more things im missing on my list, i wanna go all out on the suspension and leave no stone unturned, and pay for everything i need in the one go with the loan.

[ekslut]

I think you got most of it covered. Look at getting some polyurethane bushings to replace the soft standard ones. You can get some lower arm tie bars front & rear, rear control arms (wont really help handling all that much, but the bushings should be better in them, and they should be lighter weight).

Thanks about all I can think of now....

Also why dont you get some better coilovers and run them on their softer setting for the street? Saves you buying them twice, and you can just adjust the damper to get them harder for when you want it.

[Muzz]

cheers mate very helpful, yeh gunna add poly bushes to my list, and considering what ur saying about getting a good set of coilovers straight up.
with coilovers, do they have a lifespan, or with regular servicing do they just keep on going without any change in there performance? anyone here been using the same set for say 5+ years?
some coilovers iv seen say seperate height and spring preload adjustment, does this mean that they can be adjusted in a way that changes the spring stiffness? (adding extra preload makes the spring act stiffer maby???)

[ekslut]

yeah, coilovers like most products do have a lifespan. But if you get a set thats servicable in Australia, then it should be fine. I think Tein are servicable, so its just a matter of getting them serviced when they need it.

You can get coilovers that have 2 way height adjustment. Most height adjustable coilovers have the adjustment using a perch the spring sits on. You can adjust this up/down, but it will change the spring stiffness. From memory, the more you comress the spring, the stiffer the spring will be. 2 way height adjustable coilovers also have the bottom part of the coilover able to screw up/down to adjust the height. This doesn't effect the spring loading.

[BlitZ]

You can get coilovers that have 2 way height adjustment. Most height adjustable coilovers have the adjustment using a perch the spring sits on. You can adjust this up/down, but it will change the spring stiffness. From memory, the more you comress the spring, the stiffer the spring will be. 2 way height adjustable coilovers also have the bottom part of the coilover able to screw up/down to adjust the height. This doesn't effect the spring loading.

I do not believe this to true.

most coilovers have a linear spring rate and shouldnt get "much" harder as u go lower...

the 2 way adjustment is to give more/optismise shock travel... (in the cente) and not for spring hardness

The more u are able to extend the shock rod the better.. that why race shocks have such a short bodies as this allows the shock piston to have sufficient travel. Its a great advancement how they have incorporated this theory into the current coilovers

[ekslut]

Really? Guess I was wrong then. I always though it made the springs feel more/less stiff as welll. Not in huge amounts, but noticable amounts.

You learn something new everyday

[ekslut]

Did some quick research on this, and taken from:
http://www.endlessusa.com/faq/#t12

Q: Can I raise or lower my car by adjusting the spring seat/perch?
Adjusting the spring tension by way of the spring seat/perch and seat/perch lock may slightly affect the height of the vehicle. Tightening it greatly will raise and loosening it greatly will lower the vehicle slightly, but we DO NOT recommend using this mechanism for height adjusting reasons. This is specifically why our Function Series coilovers include the independent, lower, height-adjustable bracket/cup.

Q: Then what is the spring seat/perch and seat/perch lock used for on the coilover? And what are your recommendations on adjustment?
For performance reasons. Adjusting this mechanism creates different "spring preload" or spring tension. Although our systems come assembled and prepackaged at the recommended settings, to reset the spring preload, simply loosen the spring seat/perch and seat/perch lock until you have play with the spring. Do this when the coilover is off the vehicle. Hand tighten the spring seat/perch and seat/perch lock until there is no play. This is considered the zero point. Our recommended ranges are between the zero point and two full turns.


So to find out what the spring preload means when it is adjusted I found this:
http://www.worksperformance.com/html/tpl_desc.html

Threaded Spring Preload is used to change the amount of sag or ride height. You adjust the threaded collar, which compresses the spring, and that will increase spring pre-load. Increasing Spring Preload moves the spring further into its travel and makes the shock “feel” stiffer initially, and makes the chassis sit a little higher.

Spring Pre-Load - Compressing a spring in advance of adding a load.
Example: Using a 100 pound linear-rate spring, preloaded one-quarter inch, would take twenty-five pounds of force before it would further compress. In effect the spring will not compress until 26 pounds of force were applied. The spring in this instance will only move one-quarter inch when 50 pounds of force were applied, as opposed to the half inch the spring would have normally moved.

So from what I can gather from this info is that when you increase the adjustment for the spring preload, it does actually make the spring 'feel' stiffer, as there will be less movement by the spring.

[Muzz]

thanks that helps heaps, can u guys think of any other brands of coilovers that have service support in australia?
What about buddyclub? i see they got dealers in aus but there all in vic and nsw, im up in SE queensland.
Has anyone had any experiance with whitelines group 4 coilovers, there expensive at $2800 but i dont mind paying for quality.

Heres what they say:
"But if you're looking for real road performance get excited about our all new Group 4 shocks. These are height and rate adjustable with no need for yearly maintenance (unlike others) that's right, maintenance free.

Specifically designed for performance road use, the high pressure mono-tube design utilises a class leading 46mm piston. Our unique top mounted composite bump and rebound rate adjuster changes only what you need while height adjustment doesn't require multiple C spanners. No need to lie under the car with a torch to adjust the rate, just lift the bonnet and adjust as required. Non-inverted mono tube design also means no stiction and noise problems like other road/rally hybrids.

Careful attention to spring and damper base rates makes them ideal for serious road and race use right up to slicks and weekend race sprints. Designed as part of the Whiteline system to mix and match with our range of swaybars, alignment aids and chassis bracing.

You can have it all... if you're serious.

Whiteline Group 4's are leading the field in tarmac rally and club motorsport:

1st outright team and driver 2004 Dutton Rally NSW - Whiteline Project EVO VIII
3rd outright team and driver 2004 Dutton Rally Vic - Whiteline Project EVO VIII
2nd outright team and driver 2004 East Coast Targa - Whiteline Project EVO VIII
1st outright team and driver 2005 Dutton Rally Qld - Whiteline Project EVO VIII
2nd outright team 2005 Dutton Rally Qld - Impreza STi 04 driven by Shane Topping"

Being supposedly maintenance free, im shur theyd help with the extra cost aswell.
i like the fact that the shock bump and rebound can also be seperatly adjusted (i used to race R/C cars and the part i loved most was tweeking the cars sussy setup, which was completly adjustable. toe, camber, shock stiffness, interchangable springs & swaybars etc.)

However im even more keen to find a set that has seperate height and preload adjustment. i believe tein flex has this feature, how do they rate for trackwork? anyone have idea of spring rates?, cant seem to find them on the net for a civic ek4 hatch, herd these maby illegal in australia?

Im also looking at maby buddyclub racing spec damper, which are supposedly street - circuit, between the n+ and the track only coilovers. however they dont seem to have seperate height and preload adjustment, and im unshur of weather these can be serviced up here.

Anyone kno of any other good quality coilovers - more orientated towards track work, that has seperate height and preload adjstability, and can be serviced in aust.

[Muzz]

would i be correct in thinking that companies eg. fulcrum suspension, wont service other brands of coilovers?

fulcrum suspension dont seem to stock tein flex, does anyone kno if they can still service them?

[bennjamin]

would i be correct in thinking that companies eg. fulcrum suspension, wont service other brands of coilovers?

fulcrum suspension dont seem to stock tein flex, does anyone kno if they can still service them?

It all depends on the coilover type etc. Some can be rebuilt while others cannot. Its up to you to email or call them and find out !

[BlitZ]

Spring Pre-Load - Compressing a spring in advance of adding a load.
Example: Using a 100 pound linear-rate spring, preloaded one-quarter inch, would take twenty-five pounds of force before it would further compress. In effect the spring will not compress until 26 pounds of force were applied. The spring in this instance will only move one-quarter inch when 50 pounds of force were applied, as opposed to the half inch the spring would have normally moved.

its interesting .. the question is : -

if the spring was 30cm high would the force at 30cm be the same if it was already compressed to 25cm...(where are the engineering students)

considering it was linear i thought it would be the same (as suggested its hooke's law)-


EXTRACT from HONDA-TECH

"sounds like both of you are confused about Hooke's law and how a linear spring works. "preload" doesnt affect anything about a springs function. a linear spring exerts the same amount of force from being compressed 0-1" as it does from being previously compressed at 2" to being compressed another 1", basically 2-3". what is effectively changed is the ride height when you adjust the amount the spring is precompressed and the static cornerweights of each wheel. the fancy shocks that allow you to separately preload the spring allows the adjustment of ride hieght independently to cornerweights. "


Also refer to the link u gave... They are talkain about a progressive spring in a coilover... not a linear spring

So basically u cant preload linear

[Muzz]

(where are the engineering students)

haha strange u should ask but im studing mechanical engineering.
Heres my opionion...

lets say we got a spring of 30cm with a 10kg/mm linear spring rate.
for now consider it OUT OF THE CAR.

lets say the spring is preloaded to 28cm, this is the same as compressing the spring with 200kg of force (2cm x 10kg/mm)

this in effect will mean the spring is pushing up with 200kg of force
(but it wont extend cus the shock/watever stops it from extending).

because the spring is pushing up with 200kg force, it wont compress at all until that force is equaled and exceded. 210kg of force will compress the unit 1mm, without the preloading, the unit will be compressed 21mm by a 210kg force.

After 200kg of force is reached on the spring, it will compress at the exact same rate, as usual.

consider 400kg force:
preloaded spring - unit compresses 20mm
unloaded spring - unit compresses 40mm

this is exactly what ek slut was saying

EXTRACT from HONDA-TECH

"sounds like both of you are confused about Hooke's law and how a linear spring works. "preload" doesnt affect anything about a springs function. a linear spring exerts the same amount of force from being compressed 0-1" as it does from being previously compressed at 2" to being compressed another 1", basically 2-3". what is effectively changed is the ride height when you adjust the amount the spring is precompressed and the static cornerweights of each wheel. the fancy shocks that allow you to separately preload the spring allows the adjustment of ride hieght independently to cornerweights. "

sounds to me like this guys confused
preload does effect a springs function, it causes the spring to push up with a force, which has to be equaled before its compressed any further.
I believe what ek slut was saying is correct.

to compress a coilover unit 2in, the spring will be compressed 2in.
to compress a coilover unit 2in with 1in of preloading, the spring will be compressed 3in, which obviously needs more force.

preloading a progressive spring, is exactly the same as preloading a linear spring, in that no compressin will be achived until the compressive force is exceding that which the spring is pushing out with. both springs work exactly as usual when the preload is met and exceded.

so yes u can preload a linear spring.
The efect is the same as preloading a progressive spring.