Originally Posted by
80'sracer
Hi Guys, looking for advice.
I'm new to the mini class, I have the M05 (stock), it was already built so I can't confirm build quality. I drove it yesterday for the first time and found the following.
The diff is REALLY stiff, even after a days running.
On and off power it wants to wander. On power, to the right, off power to the left, can't hold a straight line. Cornering, it's always tail happy, and spins out.
It has the silver can motor, lrp speedo, 'S' grip tires... fronts with firm to hard inserts.. and rear with no inserts. I changed the shocks to oil filled, front shock 60wt ( one hole) with blue spring, rear 40wt (two hole) with yellow spring. Ride height, lower arms level. I also shimmed out the streering rack to try and get rid of the slop, this didn't work.
Went from 2deg toe out, to 0/.5deg out.
Wheelbase is 225mm.
Track was carpet.
Finally, what hop-ups should I get as a minimum?
Thanks in advance.
Sounds like the biggest problem is the diff. OUt of the box, the M-05 diff will be very free, so the previous owner either deliberately tried to lock it up, or built it wrong. Rebuild the car with a medium-tension diff and it should be a lot more consistent to drive - easiest solution is a Tamiya TA03 diff (built as standard to start with), or you could try the 3Racing gear diff (which needs a lot of running in, once run in I prefer 30k oil).
Your basic setup sounds fine, I would run it with more toe-out rather than less toe-out (I use a 1mm spacer on the links). The only hop-ups you need from a standard M-05 are bearings, oil shocks (which you have), a steering upgrade (just the Tamiya steering posts and high-torque servo saver is enough) and a diff (as mentioned above). The alternative front shock tower that stands the shocks up works well also.
Another thing to watch is droop - set your shock length so you have the absolute minimum, measured at the shock shaft. Lots of droop will make the car roll, pre-loaded springs will make the car roll too.