Originally Posted by Benzaah
Ed, thanks or the thorough explanation. The 2 quotes above sum up my confusion. My car struggles in 1 section of the track which is an S section that leads onto the back sweeper then straight and the car will often traction roll near the end of a run coming onto the sweeper. Going 4/5 often fixes this. .
If it works to help stop traction roll, then it's all good
Anyway, spent almost two days solid testing the new car this weekend. Saturday was on a tight twisty indoor track. Traction was ok, and due to the tight nature (and running mod) steering and quick reaction was needed.
Anyway, during practise I managed to work through a lot of spring changes and shock position changes, comparing the yokomo Pink/Blue combo to various Ride set's. Whilst the Pink/Blues felt good initially, I did find that going to hole 5 on the rear tower was needed to get good on power steering.
For the rides, I tested the following (spot the odd ball);
F / R - Green / White - Way too soft, car had no reaction, and lacked steering all over, like it was losing all it's speed. Tried moving rear shocks to hole 5 as well from 4, but no real improvement.
Blue / Yellow - Better than above, but still lacking overall steering.
HPI Silver / Green - Better still, improved a lot the on power, but washing in the middle
Blue / Green - Best balance, really liked this combo, and set my fastest laps of the night on it.
So having found a nice Ride combo... I then changed it and switched back to the Yok springs, seeing if I could get them to work. Didn't make too much of a gain, although going to 4mm on the bumpsteer spacer worked really to gain mid-corner steering. Reducing the camber link spacers 1mm F&R helped with overall reaction and corner speed, but nothing really helped to gain the steering needed on the very tight end of the track.
I did get a bit funky for the last run of the night, moving the camber links to the outer holes on the camber links. This did work out pretty well, car staying very flat and having very good corner speed, but just still not getting into the very tight stuff. With hindsight, really should have thrown a front gear diff in the car, as everyone ahead was running one.
Overall though, a good session with the car, and cleared up a few things in terms of springs.
And onto today... onto an outdoor track with much more flow too it. Rain played a bit of havoc this morning, so rather than a race meet, had a test and tune day. I actually took the opportunity to go back a few settings that I threw at the car for the last run last night, reverting to inner camber link positions, keeping the Yok Springs, and back off the bump steer and ackerman spacers.
Car was much better on this layout, really good corner speed, steering and stability. Main things altered today were;
Standard V2 motor mount - gave the car more stability, reducing (but not eliminating) a tendancy to over-rotate in the middle of the corner
4mm bumpsteer and 2mm ackerman shims - flat out more steering, and really liked the feel of the steering in this configuration.
2k rear diff oil - interestingly, earlier in the day I had an issue with the car wanting to step out on initial throttle, but only intermittently. Going up on the diff oil pretty much resolved that issue, so I can only assume that the diff had been diffing out and then biting.. with the thicker oil tightening up the diff, it was easier to be smoother on the throttle. Also gained forward traction, and made the car a little more predictable into the corners. Based on that, will give 3k a try out next time
I also tried playing with the static wheelbase, by moving both front and rear arms backwards. The idea for that was to put more weight over the front of the car, to gain a bit more initial, and reduce rotation. It did feel pretty nice on track, but unfortunately, the timing software was off during that run, so wasn't able to compare times. Just something else I'll add to the list to try again next time out.
One thing I do really want to work on is to try wider front blocks... still waiting on split 1.5/0.5 blocks to arrive before I can do that. I think a 2.0/1.5 combination on the front will work really well.
Still overall very positive day, posting good time on that layout given condition of the track... driver needs more work than the car does in reality!