Quote:
Originally Posted by bender
Now that there are a few of us running the SX at my local low-grip dirt track, we are finally starting to improve the car for Aussie conditions. My car was handling and jumping very well, with the rear shock mod fitted for the first time.
However, I'm still not convinced that its effect is that great, and I believe that the mods greatest grip improvement comes from the sweep of the drive shafts, rather than the ballast difference by having the shocks out the back.
I've done a few calculations and discovered that moving the shocks to the back is only moving around 2.5% of the mass back approx 6.7% and moves the wing back only 3.2%. How much this contributes to improving grip is debatable, especially as my own car was never really lacking in grip to start with.
The biggest improvement in my car has been the fitting of Tamiya shocks from the 501x, which certainly improved the cars handling over the bumps.
Next meeting I will be trying something else, running the shocks at the front of the arm again, but modifying the arms so that the wheelbase is reduced a further 2-3mm from the kit "short" position. This should result in a similar wheelbase and driveshaft sweep compared to reversing the arms, but still allows the shocks to be in their original locations.
The next step is to try and get the motor as far back as possible. I'm switching to the 80t spur for the next meeting but it would be better if Schumacher made down to a 75t spur I think, though perhaps it would be difficult to get the right ratios with some of the hotter mod motors.
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i can see were your coming from with the percentages moving the shocks behind, have you calculated the diffrence in force that loads up the rear shocks under acceleration having extra mass at the rear when the car accelerates it should create more rear load thus better rear traction assuming the shocks are setup correctly and anti squat plus every thing else that contributes to setup but as like for like test it should genarate more rear traction.
stu rand