Could someone please explain the difference between hot wound and cold would springs, or rather the benefit in cold wound silicone wire springs. ie like eibach, and from what I know kings have just started to replicate the same manufacturing process.
So what is the benfit to either manufacturing process, is one better or give a different feel? Also are there any distinct benefits to a progressive wound spring to a more liner wounded spring?
I heard mention of somthing called a 'higher helix angle' but I have no idea what that means. Help!
Cold wound Vs. Hot wound springs
Moderators: timk, Stu, zombie, Andrew, -alex, miata
- KIJIMA
- Racing Driver
- Posts: 1729
- Joined: Sat Sep 03, 2005 12:26 pm
- Vehicle: NA6
- Location: Gembrook
- Contact:
Cold wound Vs. Hot wound springs
Money can't buy Talent, but it can buy Horsepower and sometimes that's enough
- Matty
- Racing Driver
- Posts: 1652
- Joined: Wed Apr 23, 2003 11:00 am
- Vehicle: NB8A
- Location: Melbourne
- Contact:
It's to do with the manufacturing process, the metallurgy and so on. Either method has merits. I'm sure google or wikipedia will have some info.
There wouldn't be any difference from the drivers seat. One may last longer than the other though (but there's many other factors affecting it that you can't make a blanket statement).
The spring shape is a helix. The helix angle is the angle the coil makes to horizontal when it is standing upright. A higher helix angle has less turns in the same height, which means that spring should be able to compress more without binding.
There wouldn't be any difference from the drivers seat. One may last longer than the other though (but there's many other factors affecting it that you can't make a blanket statement).
The spring shape is a helix. The helix angle is the angle the coil makes to horizontal when it is standing upright. A higher helix angle has less turns in the same height, which means that spring should be able to compress more without binding.
- ndragun
- Fast Driver
- Posts: 376
- Joined: Thu Apr 24, 2003 11:00 am
- Vehicle: ND - 2 GT
- Location: Brisbane, QLD
- Contact:
Re: Cold wound Vs. Hot wound springs
KIJIMA wrote:So what is the benfit to either manufacturing process, is one better or give a different feel?
No difference whatsoever to the end-user...
Cold forming might be somewhat cheaper - since it costs more money to make stuff hot?
Cold formed materials are probably stronger since they'd be work hardened... and would come from an extruded wire with a distinct grain pattern? Hot forming would alter the grain structure........ that could be altered by heat treating the part afterwards, anyway - but again it would be more expensive.
Thats all i can think of
1994 MX5 Clubman
Jenvey ITBs, ported head, Kelford 203-D cams, stock-ish bottom end, Maxim Works header, MS2
XIDAs, Wilwoods, 6ULs
Jenvey ITBs, ported head, Kelford 203-D cams, stock-ish bottom end, Maxim Works header, MS2
XIDAs, Wilwoods, 6ULs
- Benny
- Speed Racer
- Posts: 2607
- Joined: Wed Apr 23, 2003 11:00 am
- Vehicle: NB SP
- Location: Gorgeous Sydney
- Contact:
The machinery required to make cold wound springs is far more expensive than the machines that make hot wound springs.
As cold winding is akin to forging, the metal holds its \"springiness\" for longer and won't sag as quickly under H/D conditions as hot wound springs would.
Also, when hot winding springs, the temper of the metal is altered and so it is harder to control the exact spring rates when the springs cool down, so cold wound springs are more equal to each other.
As cold winding is akin to forging, the metal holds its \"springiness\" for longer and won't sag as quickly under H/D conditions as hot wound springs would.
Also, when hot winding springs, the temper of the metal is altered and so it is harder to control the exact spring rates when the springs cool down, so cold wound springs are more equal to each other.
ALWAYS RUNNING, SP with Bilstein Coil Overs and Doof Doof sound. Member of the Fat Bastards Racing Team
- KIJIMA
- Racing Driver
- Posts: 1729
- Joined: Sat Sep 03, 2005 12:26 pm
- Vehicle: NA6
- Location: Gembrook
- Contact:
Re:
Benny wrote:The machinery required to make cold wound springs is far more expensive than the machines that make hot wound springs.
As cold winding is akin to forging, the metal holds its "springiness" for longer and won't sag as quickly under H/D conditions as hot wound springs would.
Also, when hot winding springs, the temper of the metal is altered and so it is harder to control the exact spring rates when the springs cool down, so cold wound springs are more equal to each other.
Thanks for your answers guys! I did a little digging around, and benny you are 100% correct, its dearer to cold wind a sping (like eibachs) but they do prove to be better in the long term ie sagginess over time.
However, it I was told that a novice like me, wouldnt be able to tell the difference in the drive of the two anyway. Im stil lnot fully understanding the helix angle buisness completely, as to what is the most desired helix angle you want, but Im getting a basic idea.
Thanks again.
Money can't buy Talent, but it can buy Horsepower and sometimes that's enough
- Matty
- Racing Driver
- Posts: 1652
- Joined: Wed Apr 23, 2003 11:00 am
- Vehicle: NB8A
- Location: Melbourne
- Contact:
Re helix angle, if you're trying to achieve the same spring rate you can either have lots of coils of a heavy duty wire, or less coils of a thinner wire.
Obviously the more coils you have (assuming both springs are the same length), the lower the helix angle.
However, more coils of heavier wire will have a greater solid height (ie the height at which all the coils bind), and therefore less available travel.
On the flipside, the more coils you have (of heavier wire) the lower the stress will be in the compressed spring. Minimising stress is important to preventing the spring from sagging.
a higher helix angle also puts more shear stress in the spring.
In a nutshell, lower helix angle is generally better for preventing sagging, but needs to be high enough to prevent binding and minimise weight...
Obviously the more coils you have (assuming both springs are the same length), the lower the helix angle.
However, more coils of heavier wire will have a greater solid height (ie the height at which all the coils bind), and therefore less available travel.
On the flipside, the more coils you have (of heavier wire) the lower the stress will be in the compressed spring. Minimising stress is important to preventing the spring from sagging.
a higher helix angle also puts more shear stress in the spring.
In a nutshell, lower helix angle is generally better for preventing sagging, but needs to be high enough to prevent binding and minimise weight...
Return to “MX5 Wheels, Suspension, Brakes & Tyres”
Who is online
Users browsing this forum: No registered users and 124 guests