Ask center gravity a question

Remember the teacher saying, ‘don’t be shy, somebody else may want to ask the same question as you’.

This section is provided to allow anybody with a suspension or handling related question in public view and for the cg team to provide a honest and clear answer. We also allow people with ideas to chime in on questions and provide their own answers. center gravity will monitor these to ensure a balanced and correct answer is given. Sometimes we may not know the answer, which in may require us to go investigate. Some of the old chestnuts that have been asked are in our FAQ so do have a look.

So why are you not asking questions, you are on this website because you want answers 😉






  1. I have heard so much about your services, I just wanted to know your contact telephone number to speak to a real person.

  2. I too have heard much of CG and would like your opinion on upgrading the suspension on my 968CS (which is standard at the moment). I am in the process of upgrading some of the bushes to Powerflex (purple) and replacing the rear drop links.
    But which “package/kit” should I choose for fast road/trackday use?

    • Hi tom,
      Many thanks for your comment. Best late than never we have had to wade through hours of deleting spam from the wordpress site and you comment was buried in sunglasses, Vuitton, drugs….

      Good question. Track day cars generally get a hard workout, more so than race cars. Most of the race cars we work with have oem rubber bushes but updated I.e. M030 castor say. So long as the rubber bush is in good condition then noise, vibration and harshness is minimised. Moving to slicks or toyo r888, or Michelin cups, then the game moves up but rubber normally still performs. Problem is old rubber allows too much compliance say in toe or camber thus interfering with stability say when you want the car steady state turning. Too replace rubber with polyurethane for track cars is acceptable, even for road use. The major consideration are which hardness (rubber is between 60 and 70 shore) so Powerflex purple is more related to rubber, Powerflex black is harder. The Powerflex or Superpro bush converts the rubber bush (isolator, bearing, damper) into a bearing. Bearings run free without bind so long as they lubricated. This allows the car to take a set quicker without rubber fighting back (car wobble in pitch or roll or both). Problem is that bearings need maintenance with frequent inspection, cleaning and lubrication. Quality of the mix of urethane is sometimes faulty and bushes collapse with squeaky and odd handling consequences.

      I use urethane bushes on my sprint car which is my daily driver. I also use monoball bearings in some applications. So long as you are prepared to monitor and maintain the polyurethane then good option, otherwise stick to good health rubber.

      I find that there are lots of comments re harshness of polyurethane bushes. This is subjective, related to age of complainant and the mode of use of the car. For track don’t worry!

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