[Frecklychimp]

XX4 is still a very competitive car against the modern models, last years National series results proves that one!

They will take modern 5.5T/6.5T power but i know the team were struggling with eating slipper plates quickly when running XX4's last year and they are hard to get hold of new these days.

personally i'd go for a 8.5T and run boost as needed for top end, it'll be a bit softer lower down which will help the slipper and will still be a lot quicker than a vintage brushed set up ever was.

belts also have a hard time with brushless, with expansion under power and slipping under harder braking so its best to retro fit tensioners and use Tough Racing kevlar belts where possible, i know this is the case with CAT 2000's too.

Older cars are a lot lighter so if you stick to power to weight thinking and don't go for silly tyre shredding fast in a straight line power you won't find yourself adding loads of weight to balance handling so will have less strain on transmission.

It seems these days in comparison we have a lot more downforce (which effectively adds weight) add lots of brass bits for balance and then add loads more power to compensate, back in the day we were trying to make cars as light as possible to limits.

I'm running a 10.5T with no timing in my XX and its as quick as my Vega running 7.5T and boost and keeps up well with modern cars on track, obviously the handling is not as sharp over the obstacles and jumps but XX is a lot more fun to drive, needs a few tweaks to adapt to astro grip levels better but its definitely brought more of the enjoyment factor to racing back.