So it's been a few weeks since I've posted any meeting feedback, and I've had a coupe of good weeks learning the car more, so here we go again...
Last weekend was a club race at the Bayside track, where we had our recent State titles. Started out with the same setup as at the state titles with the exception of 450wt oil in the shocks all round, and 1 groove rear hub plates. The main things I wanted to work on, were to try and reduce how quickly the car rotated, particularly in the slower corners, and also trying to improve the mid-corner steering in higher speed, particularly on exit. With time to think over the previous weeks, and having talked to a few other drivers about how my car looked on track, I had a developed a feeling that the car was pushing, particularly on-power out of the turns, whilst at the same time rotating too quickly in the centre. This was making it hard to flow the car well. This was less of an issue at Bayside, but at Logan this was a real issue.
Anyway, with this in mind, my line of thought was that the rotation issue was mostly related to the rear end setup. I had been using the Hoffer outdoor setup, with 1mm under the rear suspension balls, and also both braces fitted. With the 1mm shims raising the roll centre, and the braces stiffening up the rear of the car, this was pretty much a double whammy of increasing rear rotation. So it was in this part of the setup I wanted to focus on.
First run of the night, I kept the car as before, mainly to get a baseline laptime, and just see what the other changes had done. It felt good, with decent (but not great laptimes), but the aforementioned issues were still there.
So, first change, due to ease, was to just pull the braces off the rear end, but leaving 1mm under the balls.. Straight away, this was a big improvement. fast lap improved by 3/10ths, and was much easier to flow, as the rotation in the middle of the turn was much more predictable. Interestingly, didn't feel that the on-power steering suffered.
For the next run, I wanted to try a different method to achieving a similar thing, by lowering the roll-centre shims to 0.5mm, and putting the braces back on. Interestingly, car felt very very similar to the 1mm/no-braces setup, with almost identical laptimes, and only a very slightly different feel. In some respects it felt like that the car rotated a little harder with the braces, but no where near as much when running the higher roll-centres.
Given that the feel of the car was, to me, better without them (and also for ease of setup!) I went back to not having the braces, and the higher roll-centre shims for the rest of the night.
Next on the list, was to try the modified rear wishbone plastics, moving the rear lower shock mounting position outwards by 1mm. Straight away, this improved the on-power, with meaning I could get on the gas earlier out of the tighter turns.. but, it did also cause one slight issue, with the stiffer rear end springing now causing a problem with the front lifting over a particularly sevre bump on the main straight.. at one point I managed a full back flip over another car! A change of bodyshell to another LTC, and lowering the front down helped to stop this for the rest of the night.
So with the car balance better, the next change I wanted to try out was a 1.3mm front roll bar to gain steering, and also try different springs, mainly to try and make the car a little smoother over the bumps. The front bar pretty much did as expected, loosing a smidge of initial steering, but gaining from the middle out. Spring wise, I tried a few variants, switching between Ride and Schumacher Greens. The Ride's are a softer spring, and felt good over the bumps, but laptimes were similar. It'll be something I'll come back and test out next time I'm there, and will also give the Ride and Schuey Blues a try as well.
Now, during that meeting, Scott G from Action RC handed over a 2mm stiff chassis, which is something I've been keen to try since it was announced. The plate itself is certainly stiffer than the stock part, and being thinner as well helps to lower the whole CoG of the car by 0.5mm, by being thinner. Given that pretty much all the UK driver setups have been using this for a while, during the week pulled the stock plate off the car, and put the 2mm on. Also gave the car a little bit of a fettle, and had a bit of an inspection on the diffs, as I had been having issues with the outdrives leaking oil. Looking closely at the outdrives, and the o-ring, there was a bit of float, so I spaced the o-ring up by putting 0.3mm of shims, which now (lightly) pushes the o-ring up to the outdrive.
So with the 2mm chassis on, first run out was yesterday at Logan. Different track, with much higher speed turns, and getting a good flow with the car is vital for a fast times. Putting the car on the track (with only changes from previous week were less droop, spool, and lower ride-height), straight away the car felt more reactive, all the way through the turn. Really liked the feel, and was very close to hitting 19s laps even on the green track. Main order of business was to firstly check the previous rear end changes (trying the 1mm/no-braces vs 0.5mm/braces) tested out at Bayside, with the new chassis plate. Interestingly, I now found the 0.5mm/braces combo to be faster, and feel better... quite possibly the stiffer plate has altered the balance a little, and now favours that combination.
Actually spent quite a bit of the night trying out changes I've made before, more in terms of checking to see what they did with the new chassis. Tried out changing rear hub plates (zero groove vs 1 groove), camber plates (3groove vs 4), and also re-testing out the previous roll bar change.
All told, I preferred the 3groove camber plates, the 4groove feeling like it rolled a little too much, and had lower corner speed. Hubs plates, not sure on this one... ended up going with the zero (kit) plates, but I think by the end of the night the one-groove would have been the better option, as the rear of the car was starting to step sideways on a couple of corners on exit.
In terms of the roll bars, 1.4mm gave more intital turn-in, but seemed to give up mid-exit, and ultimately, was a little slower, although not much in it.
Overall though, had my best night at Logan, setting a new PB, and only being a hare (0.02s!) off of 16lap pace. Over the last time I was there, gained over 0.4s of laptime, and was able to do these times all night. Yes the track was in a good state, but a lot of that was down to the behaviour of the car, which I strongly put down to the new chassis plate... a very worthwhile upgrade IMO.
Interestingly, I wasn't the only one having a good time with his Mi5 at Logan, as Scott G also had his car whipping round, also posting some really quick times too, with pretty similar settings.
As for next time out, couple of things on the list to try, such as the hub plates (again), springs, and also bodyshells, as I gave a Speed6 a try out after racing, and it felt nice vs the LTC-R... but with no times available b y then to check, will give it a proper run next time out.
But overall, rather happy with the car at the moment... feels really good on track, and getting good comments, and I am competitive on times... win-win
Setups attached!