Tuner looking for advanced 'proper' tuning tips

So, I’ve basically mastered top speed builds by fidgeting with bits and pieces of tuning and slightly understand most of the settings now.
What I don’t understand is 100% how to adjust what and how much. I can pretty much make a car go really fast and not go all over the road.

Example. I made a GTR build that hits 0-60 in less than 70 ft, and just now I’m messing around with a 2015 Mustang GT TT build.

The mustang build, tops out about 244.5mph (if you hold it that long) but I’m mainly interested in making tunes for circuit racing, as well as drifting.

So, what i’m saying is that I understand most parts of tuning, but I was wondering if someone could help me learn the ‘ins and outs’ of tuning a car for drifting/circuit racing.

Appreciate the help!

P.S. I have read a few tips and tricks type guides on the forums and none of them really explain what i’m looking for in enough detail.
(why you change certain settings and what it causes).
I know that’s also partially in the game, but I need a little more guidance so i can properly tune my cars for circuit/drag/drifting races and not just my random ‘go fast’ tunes’

http://forums.forza.net/turn10_postst221_Tuning-Guide.aspx

I’ve had and thoroughly played every Forza games since and including FM2. I’ve been tuning cars since I can remember and I know almost all of the technical stuff. I mainly specialize in circuit tunes but can do drift tunes, drag and top speed too. I can give you tips on tuning or even make a tune for you if you have a certain car or catogory you would like to tune. You can email me at EvanMulcahy@outlook.ie if you want or just post a reply. Emailing me would be better because it’s hard to find posts you’ve done on this website. If you have any questions just ask.

For the Xbox One games, I suggest looking at the Tuner’s Lounge subforums for Horza 2 and Motorsport 5. You can also google the various settings and how they affect real world performance to get an idea of what to adjust and how in-game.

Great link SatNiteEduardo. I’ve seen similar in text form on this forum, but that really sets it out in a manner that’s easy to use. I like it.