Coilover Theory 101: Coil Spring Comparison

[MFactory]

Hey guys,

we get asked questions about coilovers, how they work, how they are manufactured, valving theory etc etc on a daily basis, so this gave me an idea; why not make a 101 separated into several, easy-to-read parts?

If you like where I am going with this, please do let me know and what "topics" you would like me to cover, and I'll see what I can do

one of the questions that we get asked quite often by our customers is what is the difference between Swift Springs and the generic Taiwan springs (found on nearly all non-European coilover kits), and what makes them so much more expensive?

to answer these questions, we decided to do a comparison test, and the results are below. What you make of these results, that's for you to decide:

Side-by-side comparison - Swift 7" 10K on the left, generic Taiwan 7" 10K on the right. Notice the difference?

Testing the Spring Rate accuracy on our Intercomp Spring Rate Tester, the Swift is exactly 10K:

And for the generic Taiwan spring, it comes in at 10.25K (15lbs stiffer than rated):

Both are pre-loaded 1" then compressed 1" to get the measurements. Can you say "coil-bind"?

Some have questioned us about the accuracy of the Intercomp Spring Rate Tester, so instead here is a dyno graph of a 100lb sample Swift Spring from our Roehrig Spring Rate Tester, showing the Spring Rate (lbs/in) over an increasing compression force (lbs):

For the weight test, the Swift comes in at 1.1kg:

And the generic Taiwan spring comes in at 1.6kg:

The conclusion from all of these tests? Not only are Swift Springs 50% lighter and extremely accurate (you ask for 10K, you get exactly 10K), they also help reduce coil-bind (i.e the coils hitting each other over large bumps). The Taiwan spring? Maybe after 6 months of driving, it will finally be 10K, then 6 months later, 9K!

I've deliberately made this post short and sweet, so as to encourage questions, so if you have any, please feel free to ask!

 

[RubenZZZ]

Very interesting.

What about the dampener next?

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[MFactory]

Very interesting.

What about the dampener next?

Sent from my 2PYB2 using Tapatalk

If the community decides they want it, the next part in this 101 was going to be valving theory, where I will go into detail on how a damper functions, how the valving affects it, and post up all the dyno graphs that I've accumulated over the years.

 

[draxxus131]

Extra large soda check

Popcorn check

Hole cut out in container check

Commence stroking!

Sent from my XT1650 using Tapatalk

 

[Dpro]

I would like to see the Eibach and Hyperco tested as well. Hyperco I know is better than Eibach as are the Swift. Though I would like to see the actual difference because a lot of people use Eibach. Plus what about KW they specifically mention the fact that they do there own springs. Which would also be ST as they are a KW company.
Also another spring manufacturer is Voghtland what about theirs? All of these companies make coilover springs that will work for our cars and springs that can go on your stock shock set strut setup as well. Except for Hyperco which only makes springs for coilover applications.

 

[M-Sport fan]

No need to sell me on Swift (or Hyperco for that matter) spring quality/function/accuracy/durability, as those are my ONLY two choices.

Even if I bought a setup which came with Eibachs (talking about YOU Ground Control, IF you EVER actually produce an over Koni yellow damper conversion kit for OUR rides, instead of just teasing us by talking about one ), I would swap them out for one of these two company's products.

It would be IDEAL if someone could develop a TRUE, REAL, infinitely, INDEPENDENTLY adjustable, QUALITY 2/3 way coil over damper for these cars, with custom valving, and a BIG height adjustment/spring height range usable, for less than the absolutely insane co$t$ of the 'top shelf boutique' coil over manufacturers out there (i.e.; Reiger, Moton, Penske, Ohlins, etc.).
(Instead of the same old, same old, market flooded, all-in-one damping adjustable, lower quality, Taiwanese 'dreck'. )

I would've considered the KW Variant 3s, save for hearing about so many problems many have had with them.

 

[A7xogg]

No need to sell me on Swift (or Hyperco for that matter) spring quality/function/accuracy/durability, as those are my ONLY two choices.

Even if I bought a setup which came with Eibachs (talking about YOU Ground Control, IF you EVER actually produce an over Koni yellow damper conversion kit for OUR rides, instead of just teasing us by talking about one ), I would swap them out for one of these two company's products.

It would be IDEAL if someone could develop a TRUE, REAL, infinitely, INDEPENDENTLY adjustable, QUALITY 2/3 way coil over damper for these cars, with custom valving, and a BIG height adjustment/spring height range usable, for less than the absolutely insane co$t$ of the 'top shelf boutique' coil over manufacturers out there (i.e.; Reiger, Moton, Penske, Ohlins, etc.).
(Instead of the same old, same old, market flooded, all-in-one damping adjustable, lower quality, Taiwanese 'dreck'. )

I would've considered the KW Variant 3s, save for hearing about so many problems many have had with them.

Lets get a koni yellow damper conversion kit going! even if not im still buying koni yellows in the future

 

[Dpro]

Lets get a koni yellow damper conversion kit going! even if not im still buying koni yellows in the future

It really would not be hard to do. Just get a Ground control collars. The big part is the front Koni Yellow for our cars an insert or a complete housing. If inserts its not hard to take stock housing and well on sleeves for the adjustable collars. Guys in the Nissan community have been doing this for years with 510’s,240Z’s even the road race 240sx guys do it.

In fact if your gonna go do that screw using single adjustable Yellows go with the 8610 line of double adjustable , rebound and compression.

Again this is and has been being done in the 240sx raod race world.

 

[MFactory]

I would like to see the Eibach and Hyperco tested as well. Hyperco I know is better than Eibach as are the Swift. Though I would like to see the actual difference because a lot of people use Eibach. Plus what about KW they specifically mention the fact that they do there own springs. Which would also be ST as they are a KW company.
Also another spring manufacturer is Voghtland what about theirs? All of these companies make coilover springs that will work for our cars and springs that can go on your stock shock set strut setup as well. Except for Hyperco which only makes springs for coilover applications.

Yes, we will be testing all the different brands. For KW, as they are a German company, it will either be Eibach or H&R as they are TUV approved. Voghtland are a good German spring also, but I don't believe they have the same certification (afaik. I could be wrong)

 

[MFactory]

No need to sell me on Swift (or Hyperco for that matter) spring quality/function/accuracy/durability, as those are my ONLY two choices.

Even if I bought a setup which came with Eibachs (talking about YOU Ground Control, IF you EVER actually produce an over Koni yellow damper conversion kit for OUR rides, instead of just teasing us by talking about one ), I would swap them out for one of these two company's products.

It would be IDEAL if someone could develop a TRUE, REAL, infinitely, INDEPENDENTLY adjustable, QUALITY 2/3 way coil over damper for these cars, with custom valving, and a BIG height adjustment/spring height range usable, for less than the absolutely insane co$t$ of the 'top shelf boutique' coil over manufacturers out there (i.e.; Reiger, Moton, Penske, Ohlins, etc.).
(Instead of the same old, same old, market flooded, all-in-one damping adjustable, lower quality, Taiwanese 'dreck'. )

I would've considered the KW Variant 3s, save for hearing about so many problems many have had with them.

The "Big 3" are Swift, Hyperco and Eibach (in no particular order), but there are other high quality springs available. My initial reason though for providing this information (which actually started on our Facebook page) was to educate the consumer why to stay away from a generic, cheap ($5. That's what they cost) Taiwan spring

Regarding the coilovers, that's a different topic for a different thread

 

[M-Sport fan]

In fact if your gonna go do that screw using single adjustable Yellows go with the 8610 line of double adjustable , rebound and compression.

The problem with the Koni Motorsport threaded dampers, for US at least, is adapting top and spindle mounts.

IF a kit could be made for them to fit/work on OUR cars, YES, I would go with those over the yellows, as long as they were available in a longer travel/stroke version, and not just super short, SMOOTH surface, road race versions.

 

[jason0999]

Hello, Just wanted to gauge the interest in further Coilover theory from the YCW brand, as I for one would like a running update on the technologies employed, thanks Jason.