Hypercoil or Swift Springs w/o Coilovers

[dmw16]

Currently on my E46 M3 I have Billstein HD shocks and Eibach springs. I bought the setup upon discovery that my factory rear spring had broken and at the time hadn't really thought about track-duty.

I am now getting my car ready for track-duty as a more primary focus (it's not my DD) and I'm wondering if I'd do well to upgrade/change-out the Eibach springs with a set of linear springs like Hypercoil or Swift?

If so, how do I go about selecting spring rates, length, etc?

Thanks.

[M3SQRD]

To make sure I understand what you'd like to do...you want to keep your stock dampers, and switch to constant-dia linear race springs on the front struts (as well as replace the stock rear springs)? If this is what you are trying to do then...

GC, TCK, Dinan...make sleeve-over kits for the stock dampers (EDC only?). The GC and TCK (not sure about Dinan) kits also come with front camber plates. They all come with rear height adjustable spring mounts. Finally, GC and TCK offer a limited range of spring rates that are suitable for the stock dampers.

If track duty is the "primary focus", why not switch to an aftermarket suspension setup? JRZ, MCS, TCK, Ohlins...all make suspension setups for the e9x M3 and will perform much better on the track than a sleeve-over kit as well as provide a much better street ride!

[dmw16]

Originally Posted by M3SQRD

To make sure I understand what you'd like to do...you want to keep your stock dampers, and switch to constant-dia linear race springs on the front struts (as well as replace the stock rear springs)? If this is what you are trying to do then...

GC, TCK, Dinan...make sleeve-over kits for the stock dampers (EDC only?). The GC and TCK (not sure about Dinan) kits also come with front camber plates. They all come with rear height adjustable spring mounts. Finally, GC and TCK offer a limited range of spring rates that are suitable for the stock dampers.

If track duty is the "primary focus", why not switch to an aftermarket suspension setup? JRZ, MCS, TCK, Ohlins...all make suspension setups for the e9x M3 and will perform much better on the track than a sleeve-over kit as well as provide a much better street ride!

Thanks. You understood what I thought I wanted to do correctly

I'm going to drive the car as-is for at least a season before upgrading the suspension and at that point I'll just get a proper coilover setup.

[Vic311]

Originally Posted by dmw16

Currently on my E46 M3 I have Billstein HD shocks and Eibach springs. I bought the setup upon discovery that my factory rear spring had broken and at the time hadn't really thought about track-duty.

I am now getting my car ready for track-duty as a more primary focus (it's not my DD) and I'm wondering if I'd do well to upgrade/change-out the Eibach springs with a set of linear springs like Hypercoil or Swift?

If so, how do I go about selecting spring rates, length, etc?

Thanks.

You should contact Harold at hpashop.com..He's very knowledgeable on suspension tuning for BMWs.

He's also a vendor here on the forum

http://www.m3post.com/forums/member.php?u=20060

[M3SQRD]

Originally Posted by dmw16

Thanks. You understood what I thought I wanted to do correctly

I'm going to drive the car as-is for at least a season before upgrading the suspension and at that point I'll just get a proper coilover setup.

Depending on where you're located in MD, if you are interested, once things warm up I can take you for a ride in my e92 M3 with a JRZ RS1 setup (500/800 lbf/in spring rates)...