The rule of thumb on unsprung weight vs. sprung weight is one pound off the unsprung weight is worth ten pounds off sprung weight. Works the same for bicycles, as I'm sure Les knows. A pound off the bike itself is worth the rider losing ten. The BBS RC's in 16x7.5 weigh 15.5 pounds, WAY lighter than anything else available in the same size back in '95. The two piece BBS 15" wheels which came stock on '92 GTI 16V's were extremely light. I only went with the RC's was to fit 312mm two piece front rotors and Wilwood four piston calipers. Being able to run 225/40-16 tires was a bonus. All this is making wish I had the resources to go back to Mexico and retrieve my beloved 16V. The story of how it ended up there is way too long to type on a phone, and I'm sure no one cares anyway...
~Holland On Jan 14, 2016 14:06, "Les Noriel" <[email protected]> wrote: > I remember an article in the old European Car magazine that dealt with the > topic of wheel mass and its effect on acceleration and deceleration. One > other observation was that suspension control improved because of the lower > unsprung weight at each corner > > There was another article which used a dyno to measure benefits of a > lightweight flywheel. At certain rpms, the engine actually created more > measurable horsepower in certain gears. > > Wheel weights are difficult to obtain unless you measure them yourself. I > remember 15" VW wheels at around 19lbs while a tire added another 10- > 15lbs. I was shocked to see some aftermarket wheels tilted the scale at > 30+ lbs! > > Today's modern vehicles have wheel and tire combinations that tip the > scale at over 150 lbs each! > On Jan 14, 2016 10:33 AM, "Holland Phillips" <[email protected]> > wrote: > >> I think to put it in a nutshell, as far as acceleration is concerned, >> it's wheel RPM where the benefits of less rotating mass are manifested... >> >> ~Holland >> On Jan 14, 2016 10:24, "Chad Rebuck" <[email protected]> wrote: >> >>> I don't know if you would say the impact of the tire weight varies based >>> on gear. The acceleration benefits with lighter weight wheels/tires are >>> greater the faster they are accelerating. In the same way, a lower weight >>> flywheel, pulley,or other rotating piece would provide more benefit when >>> the engine rpm is changing quickly, so lower gears are where the benefits >>> would be most noticeable. >>> >>> Maybe we are saying the same thing? I spent too much time thinking >>> about this already :) >>> >>> On Thu, Jan 14, 2016 at 12:04 PM, Larry Velez <[email protected]> wrote: >>> >>>> Seems like each gear would have different gains on wheel weight >>>> reduction so it would depend on what your end goal is but generally less >>>> unspring weight seems to be “better” (and more expensive per size) >>>> >>>> >>>> >>>> Rotational Inertia - Equivalent Mass >>>> >>>> https://www.youtube.com/watch?v=SR3nVx1aaTo >>>> >>>> >>>> >>>> -Larry >>>> >>>> >>>> >>>> *From:* [email protected] [mailto:[email protected]] *On >>>> Behalf Of *Holland Phillips >>>> *Sent:* Thursday, January 14, 2016 11:43 AM >>>> *To:* [email protected] >>>> *Subject:* Re: [mk2-16v] Impact of wheel weight on acceleration >>>> >>>> >>>> >>>> Back when I was building my '92 GTI 16V, I chose BBS RC 16x7.5 wheels >>>> because they were the lightest wheels available at the time. I understood >>>> the physics involved, as in the benefits of lower unsprung weight, less >>>> rotational weight, etc. All these aspects greatly benefit handling, >>>> braking, and acceleration. Not to mention I always loved the look of that >>>> style of wheel. They are reminiscent of the BBS 3 piece wheels that were >>>> used on the old Porsche RSR race cars from the early seventies, and >>>> continued to be used by Porsche and BMW for years on their race cars. >>>> >>>> ~Holland >>>> >>>> On Jan 13, 2016 19:53, "Chad Rebuck" <[email protected]> wrote: >>>> >>>> I had never really seen a test like this done. The impact on >>>> acceleration is more than I would expect. >>>> >>>> -- >>>> You received this message because you are subscribed to the Google >>>> Groups "MK2-16v" group. >>>> To unsubscribe from this group and stop receiving emails from it, send >>>> an email to [email protected]. >>>> To post to this group, send email to [email protected]. >>>> Visit this group at https://groups.google.com/group/mk2-16v. >>>> To view this discussion on the web visit >>>> https://groups.google.com/d/msgid/mk2-16v/CA%2BV5SC_oP8WwXMCVn6RzJLcc9-Vca8WYjzgBOGkQ7G3c_YZeXA%40mail.gmail.com >>>> <https://groups.google.com/d/msgid/mk2-16v/CA%2BV5SC_oP8WwXMCVn6RzJLcc9-Vca8WYjzgBOGkQ7G3c_YZeXA%40mail.gmail.com?utm_medium=email&utm_source=footer> >>>> . >>>> For more options, visit https://groups.google.com/d/optout. >>>> >>>> -- >>>> You received this message because you are subscribed to the Google >>>> Groups "MK2-16v" group. >>>> To unsubscribe from this group and stop receiving emails from it, send >>>> an email to [email protected]. >>>> To post to this group, send email to [email protected]. >>>> Visit this group at https://groups.google.com/group/mk2-16v. >>>> To view this discussion on the web visit >>>> https://groups.google.com/d/msgid/mk2-16v/CABrbKB%3Dns%3Dj5yd%3DqWPcUCqE8p6YQonkeM1B33z4tybj54pO9hw%40mail.gmail.com >>>> <https://groups.google.com/d/msgid/mk2-16v/CABrbKB%3Dns%3Dj5yd%3DqWPcUCqE8p6YQonkeM1B33z4tybj54pO9hw%40mail.gmail.com?utm_medium=email&utm_source=footer> >>>> . >>>> For more options, visit https://groups.google.com/d/optout. >>>> >>>> -- >>>> You received this message because you are subscribed to the Google >>>> Groups "MK2-16v" group. >>>> To unsubscribe from this group and stop receiving emails from it, send >>>> an email to [email protected]. >>>> To post to this group, send email to [email protected]. >>>> Visit this group at https://groups.google.com/group/mk2-16v. >>>> To view this discussion on the web visit >>>> https://groups.google.com/d/msgid/mk2-16v/c20bd37fda574a79a2b36cc8f10b73d6%40MBX082-E1-VA-2.EXCH082.SERVERPOD.NET >>>> <https://groups.google.com/d/msgid/mk2-16v/c20bd37fda574a79a2b36cc8f10b73d6%40MBX082-E1-VA-2.EXCH082.SERVERPOD.NET?utm_medium=email&utm_source=footer> >>>> . >>>> >>>> For more options, visit https://groups.google.com/d/optout. >>>> >>> >>> -- >>> You received this message because you are subscribed to the Google >>> Groups "MK2-16v" group. >>> To unsubscribe from this group and stop receiving emails from it, send >>> an email to [email protected]. >>> To post to this group, send email to [email protected]. >>> Visit this group at https://groups.google.com/group/mk2-16v. >>> To view this discussion on the web visit >>> https://groups.google.com/d/msgid/mk2-16v/CA%2BV5SC8VnLdcBU_JMwmES8P0MFkQ9%2BMHmoL5ZYeNa0USE3vdBg%40mail.gmail.com >>> <https://groups.google.com/d/msgid/mk2-16v/CA%2BV5SC8VnLdcBU_JMwmES8P0MFkQ9%2BMHmoL5ZYeNa0USE3vdBg%40mail.gmail.com?utm_medium=email&utm_source=footer> >>> . >>> For more options, visit https://groups.google.com/d/optout. >>> >> -- >> You received this message because you are subscribed to the Google Groups >> "MK2-16v" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> To post to this group, send email to [email protected]. >> Visit this group at https://groups.google.com/group/mk2-16v. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/mk2-16v/CABrbKB%3DggD-7NQqBHFmRmMHxvozpvwRVHcZ29%2BzvPM%2B%3D8hXSvg%40mail.gmail.com >> <https://groups.google.com/d/msgid/mk2-16v/CABrbKB%3DggD-7NQqBHFmRmMHxvozpvwRVHcZ29%2BzvPM%2B%3D8hXSvg%40mail.gmail.com?utm_medium=email&utm_source=footer> >> . >> For more options, visit https://groups.google.com/d/optout. >> > -- > You received this message because you are subscribed to the Google Groups > "MK2-16v" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To post to this group, send email to [email protected]. > Visit this group at https://groups.google.com/group/mk2-16v. > To view this discussion on the web visit > https://groups.google.com/d/msgid/mk2-16v/CAEpuu2PpPuiS3o9hnJs7igQyLqJ3O%2BXUEE2LhDe8hKAei2KYTA%40mail.gmail.com > <https://groups.google.com/d/msgid/mk2-16v/CAEpuu2PpPuiS3o9hnJs7igQyLqJ3O%2BXUEE2LhDe8hKAei2KYTA%40mail.gmail.com?utm_medium=email&utm_source=footer> > . > For more options, visit https://groups.google.com/d/optout. > -- You received this message because you are subscribed to the Google Groups "MK2-16v" group. 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