i wanna check the springs im running on the 5

am i right in thinking i need to corner weight the car,
then disconnect the strut top and weigh the weel/brake/hub/suspension....
then work it out from there?

is there a better way?

any1 got any advice?

then how do i work out the rates i need for the new springs? i think i had a program somewhere that works it out but will have to check later.

 

any1?
I found the program i need to work out what rates i want, just need to figure out what ive got now.

i think ive done it wrong working it out?

i did it by measuring the floor to wheel arch, then i stood on the turret and remeasured, it dropped 8mm.
to make the car drop 8mm with 80kg = 10kg per mm
10kg/mm = 560 lbs/in

that seems very high to me so guess i did it wrong lol

any1 got any other ways of doing it?

 

Put the spring on a scale and compress it 1" the weight shown on the scale is the poundage of the spring.

 

I wouldnt say it's high.

But measuring over such a small distance can leave room for error. It also assumes the spring is vertical, and did you measure compression height of the actual spring, or the car ?

The car bodywork will sit outside the spring, so there is more leverage applied to the spring for any height measured a few inches away from it

 

good idea dan, only problem is i gotta find something heavy enough and stable enough to balance on the spring wheile measuring/reading... lol

and stevie, id say thats very high for a renault 5 with an engine in the back lol.
the weight on the front wheels is an average of 230kgs per wheel.

the spring was verticle, or as near as.
and i measured the compression of the car, it was a rough estimate.


im going to strip the suspension apart at the weekend to measure the unsprung weight and do the spring test above.
i will also measure the thickness, height and amount of coils on the spring to see if i can work it out that way too.

cheers guys

 

Have you got access to a hyd bearing press? Wood on top scales underneath sorted.

Take a measurement from floor to arch on the front then Jack the car up in the centre of the back "axle" an inch and remeasure it at the front and do the same on the front end and that will give you a bit more info to if your springs are too "heavy" and also how much weight is on the front and rear it will also show you if you have the axle sharing the weight equally when you adjust it if you have no change you might need to jack the platform up on the back to bring more weight on to the front - Remember when you adjust the platforms it the diag opposite corner to move.

 

How you tested it, you were measuring the spring effective rate on the car not the actual rate, and you were also adding into that the rollbar as well.

you cant test springs the way you are tying to unless you compress from the centre and measure both sides, and then do some maths to work out the rate based on the angle of the compression of the spring etc

Just take it and off and measure it.

 

Have you checked the spring poundage isnt written or scribed on the end of the spring?

 

Yea i checked it isnt written on the spring lol.
Couldnt be that simple. Lol

Im just gunna measure it at the weekend lol.

 

These can be handy little tools for testing springs on a press etc Or other presssure measurements

You can buy them in various ranges, or else just change the gauge itself for a different one.

http://www.summitracing.com/parts/PRO-66834/