[Fatzook]

Hi all.

I am having a play with this ATM cos I will be ordering new springs for the uterus in the next 2 weeks.

I am having trouble taking a corner weight and arriving at the correct lb/in numbers.

What would be a good kg/cm or lb/in spring rate for a light 4wd?

I'm looking at some 2.5" ID Eibach coils, probably 14", maybe 16". I have no idea how many turns there are, what thickness wire has been used or any of that shit.

Any help?

[alien]

From outers:
Zuk springs:
Zuk fronts ~ 37" e-e, ~ 255lbs/inch
Zuk rears ~ 40" e-e, ~ 155lbs/inch

As for how to calculate it - i expected a spring manufacturer to be able to do this, and none of them could (from an earlier argument on here lol) - i think you might need to consult an auto engineer to work out the thickness and number of leaves given your pre-specified spring length and width.

arent you running lux front in the rear of yours? If you are and you're getting a set of rears done to softer specs i'm keen to get a set also.

[alien]

oops i didnt read the bottom about coils...

[Fatzook]

alien wrote:

oops i didnt read the bottom about coils...

Still usefull info on the leaf rates though. Might help me estimate what I need for the coil rates.

[alien]

i'd estimate rears of around 145lbs/inch would be perfect with a nice stiff shock, as i dont run rear seats... i was aiming to get custom leaves made but no one knew how to make them. When i get motivated again i'll talk to the guy who engineered my car about it... he'll probably crunch the numbers for a bottle of bourbon.

[atari4x4]

[alien]

atari4x4 wrote:

does any of this mumbo jumbo mean anything to you?

blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah

call an engineer =)

that makes sense to me!

[93zook]

im using 14inch 175 lbs in the back of my thing, coilover aprings so 100mm outside diameter.

i made a spread sheet in exel..ill apload a pic...



theres still more i can add to get a corner wieght.

the yanks use QA1 coils for their zooks
http://www.summitracing.com/search/bran ... toview=SKU

[Fatzook]

93zook wrote:

So are the compressed figures up top for static height? So For the 150lb spring.....

For every 150lb I add it will compress 1 inch?

EDIT: any chance you could send me the spreadsheet?

[93zook]

yeah pretty sure, thats what i figured anyway.

edit: haha, i dont know how...or i would.

[LAY80N]

Have you checked out the BliiaVista coil over bible -
Link Part 1: http://www.pirate4x4.com/tech/billavist ... rs/Part_1/
Link Part 2: http://www.pirate4x4.com/tech/billavist ... rs/Part_2/


Are you setting your rig up via ride height, or suspension frequency calculations? Looking for single, dual or tripple rate/helper spring coil setup on the coilover.

If you PM me your email address i can send you all the spring calculators i have. I have some chassis design and analysis/simulation software too i might be able to help you out with. I have a fair bit of stuff floating round.

Also take into account that spring rate and availability. Last few i have done have had to be fiddled with a bit due to availability and cost of getting custom coils made.

Also you can slightly fiddle with the compression spring rate by altering the nitro charge (until you hit the max allowable pressure anyway )


Layto....

[Fatzook]

LAY80N wrote:

Have you checked out the BliiaVista coil over bible -
Link Part 1: http://www.pirate4x4.com/tech/billavist ... rs/Part_1/
Link Part 2: http://www.pirate4x4.com/tech/billavist ... rs/Part_2/


Are you setting your rig up via ride height, or suspension frequency calculations? Looking for single, dual or tripple rate/helper spring coil setup on the coilover.

If you PM me your email address i can send you all the spring calculators i have. I have some chassis design and analysis/simulation software too i might be able to help you out with. I have a fair bit of stuff floating round.

Also take into account that spring rate and availability. Last few i have done have had to be fiddled with a bit due to availability and cost of getting custom coils made.

Also you can slightly fiddle with the compression spring rate by altering the nitro charge (until you hit the max allowable pressure anyway )


Layto....

No coilovers being used here. Just shocks and springs.

I'm going for standard off the shelf Eiback coils with 2.5" ID. No idea on wire diameter.

Corner weights are:
FR = 360kg
FL = 320kg
RR = 250kg
RL = 210kg

This includes my weight (120kg) full tank of fuel, but excludes all unsprung weight. ( diffs and half the driveshafts, links etc)

[LAY80N]

Sorry, my bad though you were using coilovers. But the calculators should still be of use.


Layto....

[Fatzook]

What do the guru's think of this?



I don't know how to calculate them based on Frequency, as I am missing too much information.

I'll use 16" coils for the front and 14" coils for the rear. Should give me a static coil height of about 12" all the way around.

[Damo]

Just to muddy the waters a little more are you going to use a linear rate coil or rising rate?

I raise the point because I had linear rate coils in my ute (Kings 150lb/in from memory) and IMO I would have been better off with a rising rate spring. I'd also go with a higher rate spring too. I never weighed my thing though so it's a bit hard to compare apples to apples.

[93zook]

i dont know if i would put different rates on each side/corner as that may affect handling in rough conditions, cau you make the mounts at different hieghts to get the same ride hieght all the way round? that what ill be doing...making drivers side higher than passenger.

[Fatzook]

93zook wrote:

i dont know if i would put different rates on each side/corner as that may affect handling in rough conditions, cau you make the mounts at different hieghts to get the same ride hieght all the way round? that what ill be doing...making drivers side higher than passenger.

Not sure an engineer would like that much. And if you have a look at most springs they are labeled left and right for this exact reason. The rates and even heights can be different to accomodate the drivers weigh etc.

Mounts should be made the same. Besides, the springs can always be changed later if need be.

[Fatzook]

Damo wrote:

Just to muddy the waters a little more are you going to use a linear rate coil or rising rate?

I raise the point because I had linear rate coils in my ute (Kings 150lb/in from memory) and IMO I would have been better off with a rising rate spring. I'd also go with a higher rate spring too. I never weighed my thing though so it's a bit hard to compare apples to apples.

Linear. And you are probably right. I have ordered the above rates, and will use them as a starting point.

[93zook]

thats fair enough.