King - Whiteline - Lovells Springs...

[Ronin 09]

Looking for rear springs for my R32GTR - want a spring rate of ~250lbs, 60/61mm ID, free height of around 250mm (?) with tender coils.

What's the difference between the three spring manufacturers?

King 'pro sport' coil springs are 'Hot rolled, oil quenched and tempered', whereas Whiteline race springs are 'chrome cold wound'... what's the go with them?

Questions:

1. will i get away with a shorter spring, say 220mm, with using tenders as well

2. two choices will be

Kings - KPS-042 250mm free height, 250lb

Whiteline - CS61220045 220mm free height, 252lb

are they more or less both the same?

3. do lovells make linear rate 60ID springs?

Cheers in advance

[Roy]

LOL...your a mech engineer, get out those old metallurgy texts and have a read if you have forgotten...

[Roy]

As always, i recall Sydneykid posted on the subject ages ago, i cant recall the exact differences myself, other then the rate of cooling/quenching affects the grain structure after being heated beyond a metals eutectic point (does it get heated that high???) so requires controlled cooling to stop the grain structure from becoming too martensitic and becoming brittle.

Cold working also has dramas, and requires a steel with slightly different mechanical properties, and cold workign normally hardens the metal...so there is a trade off in there as well when the spring will have very high cyclic loads and likely heat up during operation.

LOL...i bet i have confused martensite with austenite etc...i cant remember that crap. i bet GTR_Geoff or someone else knows it off the tops of their heads though

[Ronin 09]

You've been ever so helpful... lol

thanks for added confusion

will have a read of the old books tonight

[Sydneykid]

I will avoid the metallurgy. Whitleine use cold winding spring steel from BHP (to the German Standard) , it is specifically designed for the cold winding of coils and to maintain its grain structure during that process. This requires high powered hydraulic coil winders. This the same basic steel specification as used by Eibach, Jamex, Koni, Bilstein etc This process is good if you are making small batch runs, as the set up time for different coils is short.

Kings, on the other hand, use spring steel, also from BHP, that is designed for hot winding. This requires a much lower powered coil winder, but tempering is an additional step in the process. Many OEM coils are made this way as the process is good for long batch runs, due to the longer (than cold winding) set up time.

The bottom line is, neither process is technically superior as long as the procedures (for that grade of spring steel) are followed.

cheers

[Ronin 09]

Thanks Gary,

My other questions was, is there any problem with going to a shorter spring (from 250 to 220mm) if I am using tender coils and have plenty of threaded shock body to wind the lower spring seats up a bit?

cheers, marcus

[Sydneykid]

Thanks Gary,

My other questions was, is there any problem with going to a shorter spring (from 250 to 220mm) if I am using tender coils and have plenty of threaded shock body to wind the lower spring seats up a bit?

cheers, marcus

<{POST_SNAPBACK}>

No, just be aware of the increased potential for coil bind and make sure the bump stops prevent it. Coil springs don't like coil bind.

cheers