BMW Garage BMW Meets Register Search Today's Posts Mark Forums Read

Go Back   ZPOST > BMW Z4 Technical Talk > Suspension and Braking Chat

Post Reply
Thread Tools Search this Thread
      11-10-2019, 07:40 PM   #1

Drives: 1994 Toyota Supra
Join Date: Aug 2011
Location: NJ

iTrader: (1)

BC BR vs KW Clubsport - results

Jury is in - just completed an HPDE event on KW Clubsports, and have some interesting feedback on how they compare to my BC BR coilovers.

BC BRs were run at 30 of 32 comp/rebound front and back (basically full stiff), with 504lb front, 672lb rear springs

When swapping over the KWs, I kept the same springs. I tried a few adjustments, settled on 5fr/6rear rebound, 3fr/3rear compression (from closed).

Track was Thunderbolt NJMP:
My best time on BC BR was 1:30.0 on this track (R888R)
My best time on KW Clubsport was 1:29.2 (R888R)

For reference, many 911 GT3 Club spec cars with full slicks can run 1:24-1:26, and I've seen E46 M3 GTS2 spec running 1:24.

Yes, I have gobs more horsepower, but this track doesn't give me the opportunity to use it much. Corner speeds are where the time is made.

I tend to drive deep into the turn, set the rear, slide to the apex, and slide out on power. With the BCs, on some turns during turn-in, I would feel the car transfer load sideways without compression, and then suddenly, it would compress, settle, and car was happy. The transition felt like the shock couldn't keep up with the heavy spring and load transfer. Always some sort of delay. I got used to it...

On these KWs, I noticed even at fairly stiff, the car has slightly more body roll (very slightly), but the feeling described above is gone. During turn in and body transfer, the car has a very progressive set, and does inspire more confidence. On some bumpy sections, my teeth no longer rattle vs. the BCs.

On some areas, I can manipulate throttle/brake to set the car, and the weight moves where I want with precision. I can really feel it! On the BCs, it would sometimes have a 'dead-zone' where I would wait for the shock to 'compress'.

Were the shocks the reason for the faster times? You judge... I've had 3 years on the BCs and must say for the money, they are VERY good units for track. No issues with leaks or build quality, ever.

But, I will say, once you are at a more advanced level with car control at speed, until you've tried something else, better quality... no, not quality: better designed shocks, seem to really help in car control and confidence. None of this should be shocking to you all, but I never could understand what the big deal was between budget shocks and mid-range shocks.

Last edited by dre99gsx; 11-11-2019 at 07:03 AM..
Appreciate 0
Post Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

All times are GMT -5. The time now is 04:02 AM.

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2020, vBulletin Solutions Inc.
1Addicts.com, BIMMERPOST.com, E90Post.com, F30Post.com, M3Post.com, ZPost.com, 5Post.com, 6Post.com, 7Post.com, XBimmers.com logo and trademark are properties of BIMMERPOST