Few mod questions

[Baxter]

How can i change the size of the hog wheels?
Is it possible to change gravity for MC?
How can i change the color of the sniper tracer from grey to pink or something bright?

Thats some of the things im trying to do but without luck. I'v seen the option for hog wheel size but it didnt do anything. Tried many different ways for mc grav. Dont have a clue how to change tracers.

Any help would be great!
peace