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Topic Review (Newest First)

  • 08-01-2006, 01:58 PM
    Wldeyefoto

    No rush. Thanks!

    Grease Monkey
  • 08-01-2006, 01:00 PM
    dwz8

    Re: Z8 coil-over kits

    I am still working on getting the details. The Head of the Engineering group is in the US right now, and his notes are on his desk in Germany.
    Once he will be back he promised to send me the details.
  • 07-15-2006, 12:35 PM
    Grease Monkey

    Re: Z8 coil-over kits

    Apparently the Pirelli P Zero Corsa tires, which are DOT legal competition tires, were intended primarily for track use. Their slick with shallow grooves tread pattern works extremely well on dry pavement but is not intended to handle significant water on the road. In order to make them more practical for use on the street as well as at the track, Pirelli came up with the P Zero Corsa "System" tires which are also DOT legal competiton tires. The primary difference is that the System tires come in 2 versions, one with a tread pattern designed to increase water dispersion for use in front and a second which has the normal Corsa tread pattern for use in the rear. The front tires are called Direzionale and their tread pattern is supposed to allow them to penetrate through standing water and disperse it to the sides, thereby clearing a path for the rear tires, called Asimmetrico, which can then handle the reduced water on the road. This "System" of Corsa tires was originally developed for use on the Ferrari 360 Challenge and Porsche GT3 cars. The important thing to note here is that these are mid and rear engined cars which in general dynamic terms have a tendency towards oversteer. Because the Direzionale front tires have a tread pattern which is better able to deal with standing water on the road, their dry handling capabilities are somewhat compromised when compared to the rear Asimmetricos. This reduced front grip will increase a car's tendency to understeer which fortuitously counterbalances the oversteer tendency of mid and rear engined cars. As a result, Pirelli does not recommend their use on front engined cars which have an inherent trendency towards understeer which would be exacerbated by the System approach. Instead, they recommend the use of Asimmetrico style tires and or regular Corsas on all four wheels. Unfortunately, Pirelli only makes a very limited selection of Corsa and Corsa System Asimmetrico tires making their use on front engined cars somewhat problematic. However, BMW worked with Pirelli to come up with a set of Corsa System tires, Direzionale and Asimmetrico, which could be used on their new M6, which is, of course, a front engined car. Either Pirelli's recommendations are extremely conservative or BMW did some suspension tuning to adapt to the System's behavioural tendencies. Since these tires are only available opn European M6s and are not offered on US models, any special tuning done by BMW must have been subtle since they had to accomodate the other tire brands fitted to the M6 which no doubt behave differently from the Corsas. Still, the fact remains that an M6 fitted with Pirelli Corsa System tires in sizes 255/40-19 up front and 285/35-19 in back generates well over 1g on the skid pad whereas an M6 with Continental Sport Contact 2s (same size) is limited to .88g, so the advantages of the Corsa System certainly outweigh any drawbacks. Now, given the fact that the Pirelli System Corsas should fit on a Z8 with 19" wheels (although, apparently not when coil overs have been installed), and the availability of adjustable anti-roll bars which can be used to counteract understeer tendencies, fitting these tires is an intriguing possibility. I have ordered a set (not yet available in US) and will report my findings once they are installed and the chassis is properly dialed in. If they work, this will be the first time a DOT legal competition tire has been available that would fit on a Z8 and if the System approach makes them somewhat practical for street use, this could be an exciting option for performance oriented owners.




  • 07-13-2006, 02:31 PM
    dwz8

    Re: Z8 coil-over kits

    Interesting question, but I don't know the answer.

    For the PZero Rosso there is a Direzionale for front usage as well as an Asimetrico. The first set I had was Direzionale front and Asimetricos rear, from then on - after consulting with Pirelli - I changed to Asimetricos front and rear.

    I don't know whether they make the same difference with the Corsas.
  • 07-13-2006, 01:41 PM
    Grease Monkey

    Re: Z8 coil-over kits

    Were the front Corsas (255/40-19) the Directionale tread pattern while the rears (285/35-19) the Asimetrico tread design? If so, is that the way they are used on the M6? In the past, Pirelli only recommended using the Directionales on the front if the car was rear or mid-engined, preferring to use Asimetricos on all 4 wheels for front engined cars. Perhaps they have changed their thinking on this since they don't appear to offer any Asimetricos that would fit the front wheels of the M6.
  • 07-13-2006, 02:12 AM
    dwz8

    Re: Z8 coil-over kits

    The Pirellis are excellent. I am using the third set now. Superior compared to the S03's with regard to grip and especially turn-in exactness.

    I am running 245/40-19 and 275/35-19. The coilovers and my brakes unfortunately prohibit the usage of 255 / 285, at least on 19" wheels.

    Unfortunately, the "M6" Corsas have that width, we installed them but it didn't work. The tires would touch the spring while no space was left on the outside to add additional spacers. I would have loved to use the Corsas, they are magnificent, as I was allowed to learn on the Estoril race track running M6s.

    Cheers,
    Dieter
  • 07-12-2006, 05:48 PM
    Grease Monkey

    Re: Z8 coil-over kits

    Very generous offer! I may well take you up on it. Curious about your experiences with the Pirellis. Satisfied? Any thoughts compared to Michelin or Bridgestone? Are you running 245/40-19 and 275/35-19 or were you able to fit something wider? Any info on the "Corsas" fitted to the new M6?
  • 07-12-2006, 10:41 AM
    dwz8

    Re: Z8 coil-over kits

    Anything you want to buy here in Germany may be shipped to the US.

    So - within reasonable boundaries - if I can be of help I would offer to get the parts here and ship them to you.

    Cheers,
    Dieter
  • 07-12-2006, 10:39 AM
    Grease Monkey

    Re: Z8 coil-over kits

    Thanks for your comprehensive reply. You are fortunate to have so many options to choose from in Germany since availability in the US is virtually nil. Any spring rate specs you come up with would be of great interest. Sounds like you've got an outstanding set up on your Z8!
  • 07-12-2006, 10:36 AM
    Grease Monkey

    Re: Z8 coil-over kits

    The problem with coil overs on Z8s is they won't clear the stock wheels so you have to use at least a 19" wheel and even then spacers may be required to provide adequate clearance. I don't know if Shadowman installed the Hamann kit but I will follow up and see. Thanks for your input.
  • 07-11-2006, 09:50 AM
    dwz8

    Re: Z8 coil-over kits

    Spring rates:
    I'll investigate and will get back to you once I'll have an answer.

    Weight:
    I didn't weigh the components, perhaps the KW weight is somewhere in their documentation, then we could compare to the OEM setup.

    Difference between V2 and V3:
    The main difference is the double adjustable dampers on V3 versus adjustable rebound on V2. However, the Variant 3 is not really on their list, it was specifically developed for and on my car, and this did include stiffer springs. Again, I am waiting for a response here.

    Adjustment:
    You don't have to remove the coilovers for adjustment, everything is done in place. The process is described here
    The rebound adjustment is straightforward for the front, for the rear you simply remove the two grills and the carpet underneath the softtop, then you can see the top of the dampers.

    Street vs. Track:
    This clearly depends on the spring rate you choose and the setting of the dampers. My springs are stiff enough for track usage, however, I had my wife with me on our trip to Como (1,500 mls or so), and she didn't complain. I didn't even change the damper setting for the long trip.
    The range you can control the dampers is wide enough to accomplish both, and it takes you about 10 min. to change it.

    Compared to the ACS setup:
    - stiffer springs keep the body from rolling to much
    - stiffer bound setting does the same, and it increases mechanical grip a lot
    - stiffer rebound setting stops the body from rolling and shaking

    All in all, it keeps the car much better to the ground than ACS, however, you loose a bit of comfort.
    Mechanical grip is now - together with Dinan rollbars (unchanged setting that we all prefered on these) and 19" PZero Rosso - a LOT better than before. I must say that I hardly disable DSC right now because the grip is so good that it takes quite brute force to get into the range where DSC comes into play. Of course, I am driving the Quaife, which helps a lot as well.

    Variant 2 is all in all comparable to the ACS setup, however, you can adjust the height.
    Again: Coilovers need more room, so you may need spacers depending on which wheels you have.

    Cheers,
    Dieter
  • 07-08-2006, 09:45 PM
    Michael

    Re: Z8 coil-over kits

    I was under the impression the Hamann coilovers cleared the huge 20x10 and 20x11 inch wheels they also produce.

    Any knowledge of that? Dosen't shadowman have this set up?
  • 07-07-2006, 11:13 AM
    Grease Monkey

    Re: Z8 coil-over kits

    Thanks for the information. Any idea what the spring rates are, front and rear, for the KW coil overs? Did KW take any steps to reduce weight of the components? Is the difference between Variant 2 and Variant 3 just the double adjustable dampers or is there a spring rate difference also? Do you have to remove the coil overs to adjust damping rates? Would you characterize the KW suspension as firm but street oriented or more track oriented? Thanks for your help in this matter!
  • 07-05-2006, 06:23 PM
    dwz8

    Re: Z8 coil-over kits

    KW is another source for coilovers. A variant 2 is listed on their website, I use a variant 3 with adjustable bound and rebound.
    Very good experiences so far.

    Be aware that coilovers take more space towards the wheel, so you can use 19" wheels, however, you have to stick with the original widths.

    Cheers,
    Dieter
  • 07-05-2006, 12:15 PM
    Grease Monkey

    Z8 coil-over kits

    I'm looking for input from anyone who has had experience with a coil-over kit on their Z8. Hamann makes one and I believe H&R may offer one in Europe. Anyone used either one of these or know of another coil-over kit that will fit a Z8? Thanks.

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