XRAY - Model racing cars

Sounds like the traction was more on the medium side and the cars rear was too soft. With a rear downstop of 2, the inside rear tire was probably lifting off the ground on corner entry as the car rolled over too far on the outside rear tire. The stiffer springs should take away the sluggishness in the corners and make the car more reactive.

You might want to stay with 30w oil and test the car with it as is and then with two and then three holes closed all the way around (I believe you're currently running with 1 hole closed on all four). If it works better with three holes closed all the way around, then 35w oil with 0 or 1 holes closed all the way around should work.

I'd suggest trying the stiffer springs first and then the piston holes and oil weight before you change the wheelbase.