Does anyone know the actual spring rates for the KW and MP HAS kits?

[mindspin311]

Everyone says they look exactly the same, that KW makes the MP parts, but is there any significant proof?

[FTP20]

Originally Posted by mindspin311

Everyone says they look exactly the same, that KW makes the MP parts, but is there any significant proof?

Based on photos and fairly extensive research I believe these two kits have different spring rates but that is all I know. Maybe it is time to buy a spring rate tester

[HP Autosport]

Originally Posted by mindspin311

Everyone says they look exactly the same, that KW makes the MP parts, but is there any significant proof?

Have you tried to contact KW for their specs?

[CanAutM3]

Originally Posted by mindspin311

Everyone says they look exactly the same, that KW makes the MP parts, but is there any significant proof?

BMW said so in the press launch for the MP-HAS:

Originally Posted by Jason

The kit is developed in conjunction with KW and it is based on their sleeve-over suspension kit. The difference with the BMW M Performance coilover kit is the M Performance Specific spring rates, bumpstops, and assorted hardware. [...] The springs are manufactured by KW specifically to BMW M’s spring rates and the kit has been tested on a four post rig and fine tuned at the Nurburgring.

No word yet on the spring rates though. Rumor has it that the MP-HAS have the same rates as the Competition Pack, I however do not believe this as the MP-HAS have a variable spring rate design and the CP don't.

[mindspin311]

Originally Posted by CanAutM3

BMW said so in the press launch for the MP-HAS.



No word yet on the spring rates though. Rumor has it that the MP-HAS have the same rates as the Competition Pack, I however do not believe this as the MP-HAS have a variable spring rate design and the CP don't.

Interesting. The reality is, KW makes a great product, and the cost is lower. I'm just concerned that the MP rate is specific because BMW knows what the dampers can handle. KW might have a different philosophy and have different rates. Which may, or may not, affect the life the dampers.

[CanAutM3]

Originally Posted by mindspin311

Interesting. The reality is, KW makes a great product, and the cost is lower. I'm just concerned that the MP rate is specific because BMW knows what the dampers can handle. KW might have a different philosophy and have different rates. Which may, or may not, affect the life the dampers.

I would not be too worried about the life of the dampers. KW work in tight collaboration with BMW, hence they know how BMW specced their own springs. The MP-HAS might be a bit costlier, but they are fully warrantied matching the car, which to me is another plus. My MP-HAS on my M4cs cost me a tad below $3,000CAD (~$2250USD) installed including alignment and the installation of GC camber plates (the plate were purchased separately). Not too bad IMO.