NC Eibach Spring Rates

[Brian]

Finally got Eibach rates for new 2006 Miata. I told several folks that assuming they used near NB rates I could NOT recommend trying to use the Eibachs with the existing factory shocks and that it would be better to wait for KONI and KYBs. I now amend those statements because the rates are much softer than I assumed they would be. Here is what they tell me are the rates:

Front 140 linear
Rear 70/120 progressive.

Thus, it appears Eibach is trying to stick close enough to factory spring rates to allow use with the factory shocks. I found the factory bilsteins under damped as it was but at least this very mild rate change will not alter that issue significantly.

[Fault Bucket]

Wow...those are pretty soft.

Thanks for getting this info for everyone Brian. We Miata owners are certainly spoiled when it comes to aftermarket vendor quality.

-chris

[Yellowcoupe]

Hi Brian,

I have the stock NC with the stock shocks... Do you think I could add on the Eibachs? I think there is quite a bit too much roll with the stock setup but am leery of screwing up the balance and increase the twitchiness by getting the Eibachs... any thoughts?

In addition, are the mazdaspeed springs the same as the eibachs? If they aren't, then what is the difference between them and how should one choose?


tks!!!!

[Brian]

The Eibach springs ARE the MazdaSpeed springs and give a mild increase in rate from stock and a mild amount of lowering. These Eibach springs are an option from the Mazda dealers in Europe. They set the rates to work well with factory shocks. Lowering the car and the slight raise in rate will help reduce the body lean.

[Mini Meg]

Finally got Eibach rates for new 2006 Miata. I told several folks that assuming they used near NB rates I could NOT recommend trying to use the Eibachs with the existing factory shocks and that it would be better to wait for KONI and KYBs. I now amend those statements because the rates are much softer than I assumed they would be. Here is what they tell me are the rates:

Front 140 linear
Rear 70/120 progressive.

Thus, it appears Eibach is trying to stick close enough to factory spring rates to allow use with the factory shocks. I found the factory bilsteins under damped as it was but at least this very mild rate change will not alter that issue significantly.

Ok Brian what's up? I just read from Bagman the OEM/Stock Sport susp. spring rates are 24.5 N/mm=140 Front & 20.5 N/mm rear. What gives?

[Brian]

Stock front is 110.... That's what we measured with the springs off my "Sport" package, that's what Racing Beat measured, Grassroots MotorSports, etc. I have read but not measured that the hardtop gets a slight bump to 113 to account for extra weight. Bagman just got confused with the MazdaSpeed/Eibach spring rates.

[Mini Meg]

Stock front is 110.... That's what we measured with the springs off my "Sport" package, that's what Racing Beat measured, Grassroots MotorSports, etc. I have read but not measured that the hardtop gets a slight bump to 113 to account for extra weight. Bagman just got confused with the MazdaSpeed/Eibach spring rates.

Brian,
I'm sure you know your stuff. But I also belive Jason knows is stuff too! He had Mazda USA call me back and apologize for giving me some info that was wrong! Yes he told me something about an Mazdaspeed part. Then I called Mazda USA two times and the told me something that was wrong. Jason wanted to know who I talk to. It was the Parts Manger for Mazda USA, this same guy called me back the next and apologize for giving me the wrong info! Now I call that some pull! THAT A BOY Jason! And here is his post.:

15th August 2006, 16:50 #11
bagman1
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Join Date: Sep 2005
Location: charlotte nc
Posts: 612 Quote:
Originally Posted by bagman1
Just to help answer some questions.

This is all the info that I could weasel out of Mazda at this time. When they have the spring rates available I will release them.

JMBaggie




Somebody gets to do math.

coilover spring rates
Front-52.5 N/mm
Rear- 30.5 N/mm

just for comparrison

Sport springs
Front- 24.5 N/mm
Rear- 20.5 N/mm

Looks to me that the coilovers are going be well worth it, but thats my opinion and yes I am uberbiased.

JMBaggie
__________________
JMBaggie
OnlineMazdaParts.com
MontgomeryMazda.com

Than another person did the math and they said it's 140 front & 120 rear. I'm not trying to start anything and I respect both you and Jason I just want to know.
Oh, Soren in Abq, NM says Hi.

Thanks

[Brian]

Did you measure the spring yourself?

I did.

Racing Beat did.

Result was 110 front. And I thought I recalled that Grassroots MotorSports published the same. And obviously the numbers from Eibach would not make any sense if the Eibach/MazdaSpeed springs were the same as stock.

Therefore, when YOU measure the stock spring and get 140 front, let me know.... Until then, third party info supposedly from unnamed low ranking Mazda folks who admittedly goofed up the numbers at least once already should be considered still goofed up.

[Mini Meg]

Did you measure the spring yourself?

I did.

Racing Beat did.

Result was 110 front. And I thought I recalled that Grassroots MotorSports published the same. And obviously the numbers from Eibach would not make any sense if the Eibach/MazdaSpeed springs were the same as stock.

Therefore, when YOU measure the stock spring and get 140 front, let me know.... Until then, third party info supposedly from unnamed low ranking Mazda folks who admittedly goofed up the numbers at least once already should be considered still goofed up.

Now that's a good answer !
So the stock OEM rears would be 90, yes?
Say someone doesn't want the car as low as 1.5" F. & 1.3" R could you use a spacer on the top of the spring?
Oh, I read you are now a married man. I pray you found a lady as good as the one I found!

Thanks for your time!

[GT Veloce]

About the Eibach (MS) springrates: I'm thinking they may well be too soft to work properly with the adjustable Koni shocks coming out this Fall. If that's the case, the springs would need to be replaced. Do you know if there are stiffer springs available for the NC?
EDIT: another reason to stick with a proven setup such as the JIC!