KW, HKS, and Teins coils are all interchangeable I believe.

They won't sell the coupe stuffs to sedan people because the damping and springs rates are relatively stiffer for the coupes and they would require different settings for us. That also means more production cost for the companies that leads to not pushing sedan products.

Obviously, sedans aren't as popular with modding than then coupes... even tho' now we have more sedan modders.

I don't know. Why don't you contact HKS and KW to see if you can get them? Oh, and BTW, HKS already makes coils for the sedans. You just gotta get them imported from Japan... or get a hold of a HKS dealer in the States.

EDIT: Go check on JapanParts.com for the HKS coilovers. I believe they were around $2600 last time I checked.

I just don't understand that if they are the same, why aren't they listed as applicable to our vehicles? Do they not want us to spend money? lol

Thanks for the info. They still don't have the JIC's listed for our sedans even though you did the prototype a while ago.

The vendors I contacted said the KWs and HKS don't apply to the sedans. I guess when the time comes closer, I can start contacting them.

You're welcome. Just trying to help out a fellow G driver.

I'm not on this forum as much these days... so I can be slow on things. I need to catch up with some newer info as well. hahaha

And I'll talk to John (owner of JIC) to see if they're available for you.

Cool, thanks for the help. I'd love a set of JICs or KWs. Like you said, it would be simple for them to swap out spring rates for us, but who knows, maybe it isn't financially feasible to them.

KWs are proven on the BMW forum, with little (or no) complaints from members who have them installed.

The spring rate on the production version JICs will be 10k front and 8k rear. JYI.

I think I read that in one of your threads somewhere.

I had H&R supersports on my previous car, and they were stiff. I don't think they list the spring rates, but they were probably close to the JIC ratings. I doubt I'll mind

It shouldn't be too bad. I have 12/10 front and rear right now and it's bearable with damping setting at 7 all around... that is with stiffer damping rate than the production version as well.

I'm pretty sure you'll be satisfied. I'll keep you posted.

What is the measurement of that rate? The JIC site says it's in kg, but what's the other value (do you know)?

H&R lists theirs as lb/in, so I'm trying to run JIC's rate in comparable numbers.

I guess its not a rumor lol

This is great info but i dont want my car to be super stiff.
I'll just wait lol

10 kg/mm and 8 kg/mm which equals to 559 lbs/in and 448 lbs/in. These rates are significantly firmer than stock, but not crazy stiff considering our cars weigh over 3600 lbs.

As a point of reference, Tein coilovers for the 1st gen G35 sedan are in the neighborhood of 14 kg/mm F and R. The Tein Flex they have listed as "in-development" for our 2nd gen sedans are 14 kg/mm front and 12 kg/mm rear.

Great info, thanks!

They're a little stiffer than the H&Rs but not much more. Are they linear or progressive?

Not sure, but I assume if they only list 1 rate, they would be linear rate springs. You can also tell by how they look. Progressive rate springs are wound tighter at the top or bottom and have wider spacing in the other portion of the spring. Linear rate springs have even spacing throughout.

I don't think H&R makes coilovers for our cars. Their street performance coilover part# 53055 appears to be listed in error for 2003-2007 G35 sedans. We all know the mounting points for the shocks on 2007 G35s are not compatible w/ the 2003-2006 G35s.

This is further verified by the fact that they don't have coilovers listed for the G37 coupe. G37 coupe suspensions appear to be cross-compatible w/ 2nd gen 07-09 G35/37 sedans.

I emailed KW tonight. I'll post up their response when it comes in.

I looked up the H&R rates, and they were:
700-760 front
275-300 rear
Progressive rate. So the front was much stiffer and the rear was less. Trade off I suppose, but probably more of a weight issue (of the car) than anything.