GC, KW, or Dinan HAS (coilover conversion kits)

[Bimmer Freak]

Hey guys, I am interested in buying a has kit. I am in between the GC, KW, and Dinan.

KW seems to have fitment issues with 10 inch wheels up front, which I am planning to do in the future.

GC, not sure about 10 inch fitment, but the kit that comes with the CP's seem interesting.

Dinan is quite more expensive and wondering if its worth the extra cash (car is out of warranty).

Car is my daily, sees the track frequent enough in the summer, and sees the harsh cold winters of Quebec in Canada.

I want something that will give better performance at the track, I dont mind a rougher ride, but something that is drivable in the winter.

I have oem EDC suspension.

What would you recommend?

Thx!

[Maitre_Absolut]

None of the above.

MP HAS.

Shop installing is almost as important as what you are installing too.

[5thscaleracer]

GC would be ideal they use a traditional coil over spring 2.5" or 60mm that has a smaller OD than the original BMW spring design including the MP HAS version.

So if clearance is a concern the GC kit would be the way to go.

Overall the construction of all the HAS kits currently on the market are very good quality there really isn't one better than the other. The differences would be the selected spring rate by manufacturer. BMW MP HAS is probably the most daily driver street compliant kit vs the rest. MP HAS kit uses components to isolate and reduce NVH (Noise, Vibration, Harshness) to live up to the rock solid luxury car band feel.

The only thing I do not like are the limited choices for front spring rates.

The factory front spring has a tapered shape where it's a larger 4 or 5"OD that reduces down to a smaller size. All of the HAS kits aside form GC use a taper spring design since the top OE strut hat needs to be reused.

HAS Rear spring rates are easy to obtain since it's a standard coil over spring that can be sourced from any mfg of your choice. All you would need is to get a spring length of about 8-9" depending on height and the rate of choice.

I recently sold my KW HAS kit because of the following..

1. KW HAS kit spring rates are a little soft to my liking for road/track duties. The factory M3CS spring rates feel stiffer in comparison to the KW HAS spring rates.

2. I run a 18X10 ET25 square setup, clearance with the V2 KW HAS kit is too close for comfort for me.

3. Front spring rate for the KW HAS spring is a bit soft for my type of usage? The rear is standard 12K which is a decent rate but a bit on the soft side.

I thought about keeping the KW HAS kit and buying the GC camber plates to use a 2.5" OD coil over spring but the cost of the camber kit plus new springs didn't make any sense to me so i sold the KW HAS kit.

At the moment I am patiently waiting for the GC sale later this year before I buy the kit.


***All HAS kits currently offered have are a compromise of daily driver and light track autoX events. But when you push hard you will quickly realize you still have "Street" oriented spring rates.***

FYI Megan racing has a decent kit that goes for about $650.00 new, same design as everything else minus the Ricer name.

some key features of the Megan Racing kit that other HAS kits do not have are.
1. Spring shims which help reduce coil bind noise as the springs load and unload (BMW MP HAS kit has something similar to this and that kit will not have coil binding issues)
2. They use Swift springs which is a very reputable spring manufacturer, Swift makes a very consistent spring and typically is lighter than the competition.
3. The included bump stop is a little better than the traditional cushy foam.

[Bimmer Freak]

Thanks for all the very detailed info 5thscaleracer, very helpful!

I think I am leaning towards the GC Kit. A bit off topic from my original topic, but what do you run for tired on the track with your M3CS?

The sidewalls of my mpss are shot, and upon unmounting to flip the tire inside out we noticed the inside is riping apart lol. I am leaning into:
- Toyo AD08R (heard very good things about them, long lasting, grip, heat resistance
- The new bridgestone S007A marked as Extreme Performance, however lack of online reviews
- Federal RS-RR, hard to find, but dirt cheap, and good reviews, plus Apex sells them (only with rims) so I am thinking the must be good

These are the 3 I came down to as they would seem drivable for dd and ok in the rain. Re71r looks good too, but they wear like crazy!

[knightarmor]

I think you mean Advan AD08R.

[5thscaleracer]

Well my track setup is 18x10 275/35/18

At the moment I’m running on eagle f1 supercar 3r.

I have not tried any other tire on the M. But I might downsize a little so I can try the Advan a052.

My daily are the stock cs wheels with MPSS ties

[5thscaleracer]

Originally Posted by Bimmer Freak

Thanks for all the very detailed info 5thscaleracer, very helpful!

I think I am leaning towards the GC Kit. A bit off topic from my original topic, but what do you run for tired on the track with your M3CS?

The sidewalls of my mpss are shot, and upon unmounting to flip the tire inside out we noticed the inside is riping apart lol. I am leaning into:
- Toyo AD08R (heard very good things about them, long lasting, grip, heat resistance
- The new bridgestone S007A marked as Extreme Performance, however lack of online reviews
- Federal RS-RR, hard to find, but dirt cheap, and good reviews, plus Apex sells them (only with rims) so I am thinking the must be good

These are the 3 I came down to as they would seem drivable for dd and ok in the rain. Re71r looks good too, but they wear like crazy!

Yoke ad08r are good tires but run a little wider than normal. The sizes are inconsistent some have a wide contact patch some are rounded like MPSS so it depends. Good tire but never bought a second set due to the questionable sizes.

I want to try the Bridgestone s007a I think this would be a good street track tire.

[Bimmer Freak]

Oops, yes Yoko Advan 08R lol.