Since the track was recently sealed/painted, the grip level was higher than at previous events at this track. I started practicing with my modified setup that I had run at the large track in Coimbra the previous week, but it was simply too aggressive. After fine tuning the setup a bit, I was very happy with the handling. The car started out a bit too "on the nose", with the rear sometimes wanting to step out mid corner. A few key changes are mentioned below:
1.2 front anti-roll bar instead of 1.1, to keep the front end flatter on corner entry, and to maintain better cornering speeds.
More front droop (lower downstop number) to slow down the initial reaction, and to reduce the drastic weight transfer to the front wheels off-power. I came back to my usualy 0.2mm stagger between front and rear, which smoothed out the car a lot.
Shorter wheelbase, which was achieved by more rear caster (2.5 instead of 1.5) together with my preferred front caster setting for the stock class (5 degrees). The shorter wheelbase, and more rear caster, helped to lock in the rear more in certain sections, which meant that I could go on throttle harder out of turns.
Bodyshell - I've received a lot of questions about my bodyshell choice. I opted for the LensBodies Ghibli. This bodyshell has the most initial steering out of any shells on the market right now. I prefer it over the Twister and Speciale, on tracks where those bodies are usually the first choice. It also has more overall downforce than the Wolverine. I used the L version, mounted at 65mm, and with a Twister wing (important). If the Twister wing isn't allowed (for example, in BRCA rules) then a Speciale wing is my 2nd choice for this bodyshell. LensBodies are working on an optional wing. This is how I mounted it height wise:
- Front, 7th hole, 0 holder + o-ring
- Rear, 7th hole, +1 holder
- Horizontal: 64mm to the upper corner edge of the rear bumper (very similar to Twister/Speciale height).
Battery choice. I decided to use the Nosram 8100 pack, since the 7400 had a bit too much fade now because of the higher grip levels! The 8100 is an excellent pack for the 13.5T class outdoors for most track types and conditions.
My Hobbywing Technology motor & ESC combo worked perfectly even in the immensly hot air temps. I ran the exact same settings that I used at the previous two PTS rounds. 3.9 gear, 50 endbell and 8K drive frequency for the G4 motor (standard rotor).
Important! For hot air & track temps, I strongly advise to go up in shock oil (25 to 50 cSt heavier than you would normally use). Keep in mind that all shock oils (regardless of brand) do thin out in hot weather. The car felt too "springy" when I ran anything below 425 cSt with the kit pistons.
Tire prep. We did use the new batch of the Matrix 36 tires, which have a higher natural rubber content. These tires benefit from being warmed longer, and from a 2nd application of the additive (oilier additives are advised). In this case, 15 minutes of treatment (2x application) and with the warmers set at 70 deg C. I used tissues in the warmers. I cleaned the tires with brake cleaner, since this was the best way to perfectly clean out the old rubber and dirt from the tires (a more extensive cleaning job than with the "traditional style" more synthetic tires). They need to be cleaned really well before applying additive again!
On another note, I continue to use the optional -1.5mm upper clamps (in both stock and modified) with good results. They simply free up the car a bit, without sacrificing too much side bite. They have part number 301574.
Roll centers. I did use the same "experimental" roll center positions that I was testing with in Coimbra. It may look like a really low RC because of the low arm height, but keep in mind that the distance between the upper and lower arms is shorter than usual (less shims on top of hubs and upper clamps) - so the RC is in fact not that low. This RC configuration seem to use the tires very efficiently.
