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Coil spring compression
Posted: Thu Jul 08, 2010 12:21 pm
by Struth
Just want some feedback on the process of shortening coil springs by compressing them.
My SAS front end is too tall for my liking and as to be expected the rear has to be too tall just to get a good ride stance.
So a local company can compress my front coils by however much I want (about 1.5").
Other than the obvious problem of coils contacting one another under compression, does anyone know of any other disadvantages from this process.
I am told the spring rate should not noticeably change.
My only other option is to get custom coils made which I don't want to do ATM.
Cheers
Re: Coil spring compression
Posted: Thu Jul 08, 2010 4:00 pm
by DamTriton
My 2c worth....
If the technique they use is to compress the springs until all coils bind I wouldn't think the springs would last too long due to internal stresses causing failure within the metal matrix (ie into plastic deformation in parts of the cross section with shear faults, rather than the desirable elastic deformation across the entire cross section).
They would need to reheat ands retemper then perhaps shot peen them to make sure the internal stresses were relieved.
Might as well order springs the right height and rate as the only thing they wouldn't be doing would be supplying the spring wire if they were to do it properly.
Re: Coil spring compression
Posted: Thu Jul 08, 2010 4:35 pm
by bru21
Springs are about $70 a pair new from the right place.
It has been a few years since I bought them though.
I LOVE the new higher tensile king springs,
I'm not sure what they are worth as I was sponsored by them.
cheers bru
Re: Coil spring compression
Posted: Thu Jul 08, 2010 5:56 pm
by Struth
Thanks guys, but what companies make springs to suit custom app's?
Cheers
Re: Coil spring compression
Posted: Thu Jul 08, 2010 6:04 pm
by Mr DJ
Think Twisty had some custom ones made through Dobbinsons, maybe send him a PM.
Re: Coil spring compression
Posted: Thu Jul 08, 2010 8:31 pm
by fester2au
Pretty sure King Springs will do them as well but not sure how much technical info you actually need to provide or how much they will help you in designing when it's a one off.
How properly are the other mob going to do your existing ones. I've heard of people who simply pull them down to whereever then heat them up so they reset/sag to that position.
Re: Coil spring compression
Posted: Thu Jul 08, 2010 9:06 pm
by TWISTY
Yeah, the old owner of my old zook had a few sets of custom coils made for it through Dobinsons.
Re: Coil spring compression
Posted: Thu Jul 08, 2010 9:57 pm
by Struth
fester2au wrote:Pretty sure King Springs will do them as well but not sure how much technical info you actually need to provide or how much they will help you in designing when it's a one off.
How properly are the other mob going to do your existing ones. I've heard of people who simply pull them down to whereever then heat them up so they reset/sag to that position.
I don't know yet, I only spoke to them for the first time today to see if they made coils. They don't but said they can press them to acheive a new height and regularly do this.
I am basically over chasing coil set after coil set and not getting the desired result, so need a firm in melbourne to assist me with custom coils, as I am sure they would need to have my current springs at least as well as their lentgh when the weight of the car is on them.
The other alternative is to move/modify the spring towers and stick with my current coils, but that is a shiteload of work.
Cheers
Re: Coil spring compression
Posted: Fri Jul 09, 2010 10:20 am
by djroberts
Moorabbin Spring Works
62 Levanswell Road, Moorabbin, VIC 3189
p: (03) 95533446, (03) 95554777
give these guys a shot. My old man got them to do work for him back in the 70's.
Re: Coil spring compression
Posted: Fri Jul 09, 2010 10:38 am
by Struth
djroberts wrote:Moorabbin Spring Works
62 Levanswell Road, Moorabbin, VIC 3189
p: (03) 95533446, (03) 95554777
give these guys a shot. My old man got them to do work for him back in the 70's.
Will give them a call on Monday and report back, thanks.
Cheers
Re: Coil spring compression
Posted: Fri Jul 09, 2010 3:15 pm
by Struth
I thought today was Saturday
But then I remembered it's friday so gave them a call.
Seems like they will be getting one of my springs with some dimensions ans specs next week.
Fingers crossed they can make a 1" lower slinky coil set for me
Re: Coil spring compression
Posted: Fri Jul 09, 2010 5:31 pm
by Slunnie
also try Browns springs down there. Aparently their springs are cheap and good. They're a small spring manufacturer and apparently manufacture the Les Richmond springs for Land Rovers.
Re: Coil spring compression
Posted: Sun Jul 11, 2010 4:48 pm
by Bush65
Struth wrote:Just want some feedback on the process of shortening coil springs by compressing them.
My SAS front end is too tall for my liking and as to be expected the rear has to be too tall just to get a good ride stance.
So a local company can compress my front coils by however much I want (about 1.5").
Other than the obvious problem of coils contacting one another under compression, does anyone know of any other disadvantages from this process.
I am told the spring rate should not noticeably change.
My only other option is to get custom coils made which I don't want to do ATM.
Cheers
True, the spring rate should not noticeably change, as material, diameter of wire and coils isn't changed and so long as the number of active coils is not changed during the shortening process, only the free height.
If the coil pitch is changed so that some coils come into contact with adjacent coils at loaded height, then the spring rate will change. Also if some coils contact earlier when the wheel load increases (e.g. bump travel) then the rate will change at that point.