6° hubs and Anti-dive theory...

Been a reasonably quiet Christmas, with no racing on, so time to sit back and chill... that was until this week, and then got the chance to race twice in a few days, both at the Logan track.

Wednesday night, wanted to work through a few things from before, more than anything to check previous changes, and get reatuned with the Logan track. Last time out at this track, car was good, but a little taily on power out of the tighter turns. Also seemed to lack a little corner speed, but I think I had resolved that by upping the shock oil last time out at Wynnum, but still needed to check this change was suitable at Logan.

The track wasn't overly grippy to start out, and pretty much getting on power was proving difficult whilst using the 3K rear diff. Switching to 2K helped make the car much easier to drive, and also going to hole 4 on the shock tower (one in from the outside) helped with the lower grip level, and improve the consistency. With the car more settled, I wanted to try out a setting I've some other cars utilise a little, using 6deg Castor blocks in combination with anti-dive.

In theory, the extra castor should give the car more mid-exit steering, but at the expense of initial. So to compensate, adding anti-dive will take away a little castor, whilst also giving the added benefit of more stability on the brakes. So the two settings go hand in hand really

It was a little difficult to tell with the track being lower grip, but I liked the feel of this change, although times were similar. Decided to then try it again on the saturday when I would have a better read of the track times.

Having been happy with how the car was working on Wed in the lower grip, I switched back to the 4deg hubs/flat arms to start out with on Sat. Car worked straight off the bat, putting in mid-high 19s laps without issue, even on three meeting old tyres. Only change needed was to lay the shocks down to the middle hole to help with the freeing up the rear end. The thicker shock oil (see above) really helped out as well, really helping the car to carry speed round the turns, but also remaining stable and driveable... 500wt F&R is now my starting oil!

First qualifier, and finally managed to break the 16 lap barrier... and comfortably so as well. Previous best for a perfect run had been 15 in 5:00.2, and this was a far from perfect run with a roll and a few more errors. Pretty stunned, as I improved my best lap by over half a second to a 19.1.
In the second qualifier, switched the front end to the 6deg/anti-dive setup. Fastest lap was a little slower, but still improved on overall by a 1s, even with a few mistakes again. Deffiently felt like the car was holding the middle of the corners better, whilst also allowing to be braked harder into the turns. Initial reaction wasn't quite the same, but car was still pretty good on the tighter sections. Ended up qualifying third on the grid, albeit a lot closer to the two front guys than in recent times.
First final, made a small adjustment to the bump steer spacers, going from a 2mm to 1.5mm shim, flattening the steering links a little. Again, added a little mid-corner, and helped to sharpen the front a bit more. Also tried out a different additive which I liked... will need to try that out again next time out. Managed to hang with the front two for a few minutes, and then was forced off line by a back marker and lost my rhythm.. ended up holding onto third, but overall happy with the changes made.
Last final, having had a discussion on the Aussie Mi5 Racers Whatsapp group (yes, we have one ), decided to give softer front oil a try to see if I could gain any more steering. Thankfully my second car has shocks with 450 in them, so just popped them off and away I went. Honestly have to say, didn't really like this change. Seemed to make the car a little inconsistent on the front, and also outside observers mentioned that it looked like the car was taking two bites to get to the apex. Maybe going to 550 rear would have been a better option, but something to try later on.

After the finals, had one more quick run to make sure my batts were at storage voltage (obviously ), and went back to the 500 front oil, and changed the front outer camberlink spacer to 1.5mm from 1mm, trying to give the front tyres a bit more camber change... Straight away double bite issue was gone, and the car felt really good all over. One section of the track I had been really struggling with in recent times was getting enough rotation through a tight hairpin onto the back straight. I'd normally end up with the rear stepping out, or the front washing wide... not this time, was point and go.

Pretty much a very pleasing evening, can honestly say that was the best I've had my car go at this track, and now feel like I've got the car working really well at both local tracks in the area, with a solid base setting, and knowing what to alter to get what I want from the car.

Cheers Ed