Tek-Tips is the largest IT community on the Internet today!

Members share and learn making Tek-Tips Forums the best source of peer-reviewed technical information on the Internet!

Register Log in
  • Congratulations TugboatEng on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

Recent content by pmwltd

  1. pmwltd

    Using Mcpherson Spindle in SLA setup

    With the front drive setup we had to minimize scrub radius, so we ended up with a KPI of just under 12 deg. With rear drive, you caould design in more scrub radius and less KPI. We ran caster in the 4 to 6 deg. range, which was adjustable by moving the upper AArm, for and aft. The camber...
  2. pmwltd

    MacP strut design

    I built a setup for an Audie 4000 a number of years ago that used a Bilstein cartridge that uses the outside diameter of the cartridge body as a bearing surface. We honed the ID of the strut housing and installed bronze bushings. A hole was drilled in the bottom of the strut housing and the...
  3. pmwltd

    Using Mcpherson Spindle in SLA setup

    I have converted two different cars with strut front suspension to SLA. Both of them happento be front wheel drive, however the principle is the same with rear wheel drive and a little less crowded. The CRX we did had an upper mount welded onto the upright, the VW Rabbit had a bolt on upper...
  4. pmwltd

    Rod Ends and Spherical Bearings

    Aurora Bearing is an excellent company to do business with. Although I buy in small quantities for the most part, they give me an OEM discount. I have been using their bearings in my suspension products for 14 years and have never had a failure. Their racing performance line of bearings are...
  5. pmwltd

    Force-based roll centres vs geometrical roll centres

    As a point of interest, Bill Mitchell's software rolls the car around a point at ground level, rather than the indicated geometric roll center indicated in the graphic. Dave
  6. pmwltd

    Strut tower brace/tie-bar

    A larger issue than the strength of the bar in most cases is the method of attachment to the towers. Many times the attachment is with undersized bolts in single shear, plus the attachment location in relation to the bar induces bending moments. Many of the aftermarket bars sacrifice...
  7. pmwltd

    I thought I understood Milliken!

    Chuck Hallum was killed in an automobile accident a few months back. He was driving his "Viper", that is the only information that I have. Dave
  8. pmwltd

    I thought I understood Milliken!

    Another interesting slant on the question of tires and traction is put forth by the late Chuck Hallum in a couple of SAE papers and an article in the July, 2003 issue of Racecar Engineering. He spends time on the single particle behavior in the CP, and the short term changes in avilable...
  9. pmwltd

    Important suspension parameters

    Greg: A couple of others that might fit into the list would be ride frequency, including front to rear percentages and lateral weight transfer percentage distribution front to rear. Another piece of the geometry would be steering axis angle. I am sure there are others Dave
  10. pmwltd

    Suspension design priorities

    Going back to roll centers. There is more focus as of late on FVSA location and length than on RC alone. As you shorten the FVSA you increase camber gain and visa versa. Also as the FVSA gets closer to horizontal the lateral movement of the RC increases. Also as you raise the roll center you...
  11. pmwltd

    Suspension design priorities

    What I have done in initiating a suspension design in the past is go through Milliken's ride and roll calculations, the simplified version on Pg 601. I have put that on a spread sheet and play around with different inputs until I get some numbers I feel comfortable with. Milliken has some...
  12. pmwltd

    Suspension design priorities

    Some other items you need to factor in. tire data design ride frequecies front and rear maximum design roll angle pakaging contraints Compromise between ideal camber curve and stable RC, can be a challenge. Usually based on FVSA. What gives you the maximum contact patch at the critical places on...
  13. pmwltd

    shock friction

    Most race shocks come with spherical bearings mounted in upper and lower eyes. Although the claim is that it is to reduce compliance, which is present in rubber or urethane bushings. Even with strut suspension we convert the upper pickup point to a sperical bearing. Dave
  14. pmwltd

    Racing Damper Optimization

    Appreciate the comments on FWD. the car in question is a GT4/5 running in SCCA. Runs a Mugon LSD, is converted to SLA in front and a 4 link solid rear axle, with Mumforf link in the rear. Runs adjustable anti-roll bars front and rear. Tires are Goodyear cantilever slicks. Won't increasing...
  15. pmwltd

    Camber Change Curve

    the VW rabbit is a much easier conversion as far as the upright is concerned. It has a verticle pinch clamp at the bottom which makes for much better geometry than those that have the stock lower PU point on the upright at an angle. The top of the strut can be easily modified to allow a bolt...
See more

Part and Inventory Search

Back
Top