Also it would be a good idea to add on how to tune pack for a race.

Pack is adjusted by changing out shock pistons. There are different pistons that give different hole sizes. A larger holed piston will give less pack, a smaller holed piston will give more pack.

So how do I know what piston to use? Well, it depends on the track of course. Obviously, you will need more pack if you are having huge jumps with no landing slope. This means your truck is just landing on the ground hard. Use smaller holed pistons here. If the track is for the most part, smooth and good jumps where you are landing on a slope, no real chassis slapping anywhere, use larger holed pistons.

So basically if you are using large holed pistons with 35Wt oil but find out you need more pack. Try using smaller holed pistons and 30-32.5 wt oil. Or lets say you are using small holed pistons and 30 wt oil, but you are racing at a smooth race track, go up in piston hole size and drop oil weight a bit.

And remember to tune your pack to the majority of the track. If you have just one awful jump but 95% of the track is smooth, use larger holed pistons. If the entire track is crappy jumps, use smaller holed pistons.

More pack can be detrimental to the handling of your truck. High pack can cause your truck to skate around on the straights or through washboard/hazards. This is because the truck tires are never allowed to fully rebound to get the best grip.