To my surprise, the traction was not increasing that quickly, and some drivers were struggling with a loose rear off-power, specially in modified. As usual, I tried to help as many XRAY drivers as possible, but there were still many which I had no time time to help directly, and also for those who were not at the event, and who are facing similar traction issues at their races, I would like to share some set-up tips that I have done to improve the car's performance. Hopefully you will find it useful!

As I expected, the event started off with low traction, and thus, I started with my set-up which I normally use at one-day events where traction does not exceed a medium level: https://setup.teamxray.com/sheet/view?userSheetId=22600&search=martin+hudy
 

The balance of the car was OK, but the main problem was off-power traction. Simply when I left the throttle, the rear wanted to swing around immediately. I did not want to make any big changes, since I knew that when traction increased, I should have way more rear traction - but to my surprise, after the 3rd round of practice, the traction was improving only very little, and the problem of the loose rear end was still there. The car felt like the rear was flexing and rolling way too much, and that the oversteering came from the rear and not the front. In normal conditions, I would eliminate some initial steering by increasing bump steer shimming, raising the front upper arm, switching from the C2.5-2.8 front springs to the softer C2.4-2.7, or just by raising the front hub to 1.0mm instead of 0.5mm - but the problem was, that this time I did not feel that I had a too agressive or reactive car. In fact, the initial steering was good, and I did not want to loose any of this initial steering. Therefore, I had to make the rear more stable.

The first change what I did was to reduce droop in the rear to make the rear more flat. I changed the downstop setting from 4.6 to 5.0, and this helped a bit. The next change was to go harder with the rear springs to make the rear stiffer, so I went from C2.6 to C2.7. Once again, the car was slightly better, but still too loose. The next step was to change the 1.6 rear top deck to a 2.0mm. As the front grip felt OK, I did not go stiffer with the front top deck, just with the rear one. I also added the T-brace to my 1.5mm chassis. The 1.5mm chassis is great benefit for me for low to medium traction conditions for modified. It gives more overall side bite and steering. But it is not necessary for the stock class. The optional T-brace helped a lot, but I still felt that car was loose, and tht I could not push that hard.

Until that moment I was using the HUDY Red additive which is always my preferred choice, as it provides super good overall traction and steering. As always, my car started very good; however this time, the additive was causing the problem that as soon as I left the ideal driving line which was super narrow, the tires collected dirt from outside of the line, and thus, I started to slide all over the place. Therefore I had to decide to change the additive to a more oily one which should be better for these kinds of issues. Therefore, I tried CS High Grip. The tires were clean after the run, and picked up a lot less dirt, but the problem was that I had way less overall traction than with the HUDY Red additive. Therefore, I had to increase the additive timing from 8 minutes, which I usually use with HUDY Red additive, to 15 minutes. This helped a bit, but still,  was lacking a lot of side bite. Therefore I had to make few more set-up changes.

First of all, I switched from the Twister body to the Twister Speciale. This body is known to have more side traction, but generates a bit more on-power understeer. My car had more side traction, and I improved the performance of the car by raising the body from 62 to 65mm in the rear, to generate more downforce, and thus more traction. I also added the HUDY side wing plates #293311 to reduce off-power rotation even more.

At this point, I felt that the car drove way better, and I could start to drive more aggressively without worrying about loosing the rear as much. The last two set-up changes that I made to fine tune the set-up was to move 20g of weight from the rear to the front of the car, to have exactly a 50/50 weight balance, and I used the optional extra low alu diff eccentric bearing holders (part number 302064), which helped to generate more rear traction as well as stability.

The set-up changes that I did which did NOT help me was to go harder with the diff, from 7K to 8K. Normally, the harder diff makes the rear more stable and improves more on-power steering, which I lacked a bit after changing the bodyshell type. But this time, I felt that my car only lost low speed steering, and that it did not help me much with the rear stability. I also tried increasing the rear caster from 2.5 to 3.5 degrees, which usually helps to lock the rear more and reduces rotation - but this time I felt that the car only became more edgy and less round in the long sweeping corners.

Overall, I was very happy with the car's performance, and for a few laps, with my driving as well! I was able to qualify and finish 6th overall in a pretty competitive field.

My final set-up sheet is posted here: https://setup.teamxray.com/sheet/view?userSheetId=23088&search=martin+hudy

I hope that you will find this information useful, and that if you have any questions, do not hesitate to contact me.

Now it's time for me to pack and fly to Bangkok for the famous TITC event. I'm looking forward to meeting all our XRAY drivers from Asia once again this year!