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Difference between the Mazda MX5 roadster and cup car?

Discussion in 'iRacing' started by Bram, May 14, 2011.

  1. Bram

    Administrator Staff Member Premium Member

    I am driving in the Grand Touring Cup today with a mixed field of MX5 and Jetta's. Both versions of the MX5 are able to be selected. I choose the Mazda MX5 Cup version.

    What is difference between the two cars in performance? I noticed that the roadster has five instead of six gears and less setup options. However in terms of speed I was outpaced by two roadsters in the last race (can be lack of skills of course :D)
  2. Roadsters seemed to be the class of the field much of the time in the MX-5 league we did. I think the gearing just works better on most tracks with it being a momentum car (real MX-5's are the same to me, I much prefer the 5 speed gearbox in my '94 to the 6 speed in my turbo '05)
  3. Stolen from last year's release notes:

    The cars are more than just mirror images of each other. The Cup car is left hand drive, and uses the 6-speed transmission available in the production car. The Roadster is based more closely on the Japanese-spec NR-A version, with it’s 5-speed transmission and slightly smaller tires.

    This may seem like a mis-match, but it’s closer than you may think. With the different gearing, the Roadster loses a little bit in straight line acceleration, due to the bigger RPM drops between shifts, but partly makes up for it with a better top (5th) gear ratio compared to 6th in the Cup car. That’s not even mentioning the right hand weight bias that can prove beneficial on the predominantly clockwise-run road racing tracks. However, the Cup car does have a potentially higher top speed (in the draft) on the longer tracks.

    - Gearing and setups are the big difference between the two. Gearsets are below:
    Cup Roadster
    1st: 3.82 3.136
    2nd: 2.26 1.888
    3rd: 1.64 1.330
    4th: 1.18 1.000
    5th: 1.00 0.814
    6th: 0.79
    Final Drive: 4.10

    - Both cars are going to be fixed setup for Novice level races, so that takes a lot of the “tinkering” out of the equation. Advanced level events in both cars will allow standard adjustment of alignments (Caster, Camber and Toe) along with tire pressures. The Cup car will allow shock damping adjustments as well as limited ride height variation.

    - Roadster has Bilstein (non-adjustable) dampers and stiffer springs than standard production, but not too stiff for daily use. (A good number of the racers that run the car at Tsukuba Raceway drive the cars to and from the track, and even commute in them.)

    - Cup car has Sachs 2-way adjustable dampers (Bump and Rebound) and are quite similar to the Mustang shocks in their damping adjustment method. Bump is adjusted in “clicks” while rebound is modified by 45° “sweeps.”

    - Tires are BFGoodrich G-Force R-1s on the Cup car. The Roadster is going to run the same tires on it, for consistency of performance between the two cars. The mandated tires for the NR-A car are a Bridgestone RE-11 tire, but they aren’t a DOT-R compound, so to minimize any competitive disadvantage it was decided to be consistent, even if not 100% correct in this particular case.
  4. The wheel is on the correct side in the roadster :p
  5. Bram

    Administrator Staff Member Premium Member

    You're wrong Mike :)

    @Eric: thanks for that explanation :thumb:
  6. I've noticed that the Roadster's right-hand-drive layout results in a more suitable crossweight for clockwise circuits (eg. Lime Rock, Okayama, etc.) - and vice versa for the Cup. I've found more people using the Roadster at clockwise circuits and more using the Cup at anti-clockwise circuits.
  7. Abdul Al-Amry

    Abdul Al-Amry
    2011 RD Indy 500 Winner

    And since when have u been iRacing young man?

    RileyDP @ Sebring at night tonight Rhys. Join up m8.
  8. Certainly around Lime Rock and Okayama, the roadster is quicker, by about 1 second because of the more friendly and flexible gearing that the 5 speed gives, there are more definite gears around these circuits than in the cup whic i suspect you're sometimes in a decision whether to change down or not.

    and ps the steering wheel is on the correct side in the roadster.
  9. Since January. :)

    I'd join the RD iRacing events, but they're out of my time zone so they're currently a no-go... :frown: