Swapping Out KW Springs for Swift Springs

[markw10702]

GTS suspension question - looking to upgrade to Swift springs and noticed that the Swifts are 60mm ID while the KWs are 61mm. For those of you who have performed this swap, what spring perches and isolators did you use?

Thanks.

[daveishi]

Just the stock perches. The Swift's are flat top and bottom though so you should remove the plastic/rubber adapter. FYI the stock springs that come on the KW's are actually Eibach.

[SYT_Shadow]

I'd love to see some part numbers for replacement springs on the GTS

I'm sure the stock valving can go up 150lbs front and rear, but what are the lengths and part numbers?

[markw10702]

Originally Posted by SYT_Shadow

I'd love to see some part numbers for replacement springs on the GTS

I'm sure the stock valving can go up 150lbs front and rear, but what are the lengths and part numbers?

I am also interested in the spring specifications (above).

[markw10702]

Originally Posted by daveishi

Just the stock perches. The Swift's are flat top and bottom though so you should remove the plastic/rubber adapter. FYI the stock springs that come on the KW's are actually Eibach.

So if Eibach - that would presume they are 60mm vs my assumed KW 61mm or are the Eibachs a 2.25" spring?

Thanks.

[Track/S]

Originally Posted by SYT_Shadow

I'd love to see some part numbers for replacement springs on the GTS

I'm sure the stock valving can go up 150lbs front and rear, but what are the lengths and part numbers?

You can ask kw directly, I bought a set of springs a few days ago.

[daveishi]

Here are the part numbers for the Swift's I went with, 8" rear and 7" front however if I were to do it again I'd do a 6" front because with the Swift assist springs I put in the front is as low as it will go and I could use a bit more adjustment. As far as rates I did 16k rear and 11k front which puts them right about 200 lbs over stock which is what KW says will work with stock valving:

Z60-178-110
Z60-203-160

[daveishi]

Pic for comparison (front springs)

[SYT_Shadow]

Super useful, much appreciated

[SYT_Shadow]

Originally Posted by Track/S

You can ask kw directly, I bought a set of springs a few days ago.

In the US, KW is not well supported. I called a couple dealers asking for the springs, they treated it like a request for enriched uranium.

+200lbs gets us into better territory. The kw 3w is a good suspension, but the spring rates in the GTS are ridiculously low

[M3SQRD]

Why didn’t you increase the F and R springs the same % from gts stock rates? Your front rate is 69% of your rear rate whereas stock gts it is 58%. Are you concerned about adding understeer?

[Track/S]

Originally Posted by daveishi

Here are the part numbers for the Swift's I went with, 8" rear and 7" front however if I were to do it again I'd do a 6" front because with the Swift assist springs I put in the front is as low as it will go and I could use a bit more adjustment. As far as rates I did 16k rear and 11k front which puts them right about 200 lbs over stock which is what KW says will work with stock valving:

Z60-178-110
Z60-203-160

According to conversation with kw, the rear springs are 16kg

Originally Posted by SYT_Shadow

In the US, KW is not well supported. I called a couple dealers asking for the springs, they treated it like a request for enriched uranium.

+200lbs gets us into better territory. The kw 3w is a good suspension, but the spring rates in the GTS are ridiculously low

I speak directly with kw department, the dealers have no idea about spring rates

[M3SQRD]

Originally Posted by Track/S

According to conversation with kw, the rear springs are 16kg



I speak directly with kw department, the dealers have no idea about spring rates

I thought the OEM GTS spring rates were 400/685 lbf/in and the CS 3-way kit from KW has 500/800 lbf/in?

[SYT_Shadow]

From what I remember:

GTS comes with 400lb/in front and 685lb/in rear springs.
Stock KW CS 3W are 575lb/in front and 800lb/in rear.

When I reached out to a kw dealer, they reached out to kw and got this: "According to KW, you would need 457 lbs/in front springs and 914 lbs/in rear springs"

[Track/S]

Originally Posted by M3SQRD

I thought the OEM GTS spring rates were 400/685 lbf/in and the CS 3-way kit from KW has 500/800 lbf/in?

Originally Posted by SYT_Shadow

From what I remember:

GTS comes with 400lb/in front and 685lb/in rear springs.
Stock KW CS 3W are 575lb/in front and 800lb/in rear.

When I rea he'd out to a kw dealer, they reached out to kw and got this: "According to KW, you would need 457 lbs/in front springs and 914 lbs/in rear springs"

I would like to know where you got that information from, kw has given me other info

[SYT_Shadow]

Originally Posted by Track/S

I would like to know where you got that information from, kw has given me other info

From one of their dealers. Who knows if it's right! But the regular cs 3w should be real information

[Track/S]

Originally Posted by SYT_Shadow

From one of their dealers. Who knows if it's right! But the regular cs 3w should be real information

Yes kw cs v3 I know it is correct because a friend has them and he increased the springs rates by 20nm.

[M3SQRD]

Originally Posted by Track/S

I would like to know where you got that information from, kw has given me other info

Originally Posted by SYT_Shadow

From one of their dealers. Who knows if it's right! But the regular cs 3w should be real information

iND got the M4 GTS spring rates when KW originally released their CS 3-Way. Supposedly the GTS spring rates came directly from KW.

[daveishi]

Originally Posted by M3SQRD

Why didn’t you increase the F and R springs the same % from gts stock rates? Your front rate is 69% of your rear rate whereas stock gts it is 58%. Are you concerned about adding understeer?

That's the main reason, I have been trying to dial out the understeer since I got it (mostly with alignment and square tires) especially since I started out tracking in the very oversteer-y S2000. These rates have worked well for me, but always open to hearing other's experience and feedback.

[M3SQRD]

Originally Posted by daveishi

That's the main reason, I have been trying to dial out the understeer since I got it (mostly with alignment and square tires) especially since I started out tracking in the very oversteer-y S2000. These rates have worked well for me, but always open to hearing other's experience and feedback.

I’ve owned three s2000s and I loved the stock balance. I had upgraded the suspension with a Tein Super Racing setup on one of them. It was such a blast to drive!

If you’re trying to dial out understeer you’d want to raise the rear rate more than the front rate. You increased the front rate by 11% relative to the rear. I’d expect something closer to 50% F-R ratio vs. the GTS stock 59%. However, with stock ASBs, the higher front rate could be providing better front role control and better maintaining of the front camber curve, therefore reducing understeer? With my MCS 2WR I’m currently running F/R 700/1100 lbf/in rates and the balance is great with 63% F-R ratio which supports the increase in front rate relative to rear, does dial out understeer. Have you had a chance to really test the new spring rates?

[Samo6556]

Originally Posted by daveishi

Pic for comparison (front springs)

Any feedback changing to these springs? Compared to prior rates.

[Samo6556]

Originally Posted by daveishi

Here are the part numbers for the Swift's I went with, 8" rear and 7" front however if I were to do it again I'd do a 6" front because with the Swift assist springs I put in the front is as low as it will go and I could use a bit more adjustment. As far as rates I did 16k rear and 11k front which puts them right about 200 lbs over stock which is what KW says will work with stock valving:

Z60-178-110
Z60-203-160

I gambled and bought these exact rates. And did a 6inch front with the swift assist. Thanks for posting the information.