I’ve been playing since Forza 3, however just recently have I begun to become interested in actually tuning my cars. I’ve been following the tuning guide posted and have found it wonderful, but I feel I could still do better. I know it is something that I need to practice and get better at, but right now I could desperately use some advice on how to actually pick the parts to upgrade the cars before I start tuning. Before I would just buy the race upgrade for every part, and call it quits. However, clearly that is not the best strategy. I’m open to any advice. Thanks guys 
First take the weight out.
Never use a clutch, never use a flywheel, try to not add weight unless you add a centrifugal supercharger. Probably avoid using any other aspiration upgrade.
Agreed with wormburner.
Weight is my biggest thing so I will usually put on race exhaust. Race supercharger is the other I try to add to get the biggest bang for my buck. Very rarely do I use a race trans. I try to ether go stock or street (sometimes street actually lowers your PI.) Sport trans is really good with the 1.6l motor and run a 2.40 final drive to start with.
Read the tune guide in the tuning forum.
http://forums.forza.net/turn10_postst221_Tuning-Guide.aspx
A couple of links…
http://forums.forza.net/turn10_postst6455_Universal-Tuning-System.aspx
http://forums.forza.net/turn10_postst7220_Drows--Guide--For-Beginner-Tuner.aspx
http://forums.forza.net/turn10_postst13959_Camber-Tuning-Techniques.aspx
http://forums.forza.net/turn10_postst5760_ONR-RoadRunner---Damping-Formula.aspx
http://forums.forza.net/turn10_postst13277_True-or-False---Tuning-Statements.aspx
http://forums.forza.net/turn10_postst14462_Three-Minute-Tune.aspx
Thanks for the response! I haven’t gotten a chance to look through all those links, but at this point I’m wondering when engine swaps should I be doing?
Pick the car, class and the tracks you want to race. The build is the most important part of the process. Then, you can perform the tune per the links above, and, tweak per your driving style and issues you encounter as you need. Once you have the build and 1st pass tune, you can post a new thread and get feedback from the community. There are also many open-sourced tunes that you can get some ideas as to what upgrades you might consider. Good luck!
Ok, so after reading through and following those guides I’ve come up with a tune I’m semi happy with. I’m sure there is room for improvment, but it is defiantly better than stock. I didn’t want to clog the forums with a new thread, so i’ll just post it here.
Car: 10’ Audi TT RS Coupe
Class: A-700
Upgrades:
Racing tires
Sport transmission
race differential
race brakes
race springs/ dampers
race ARB’s (F/B)
race weight reduction
sport exhaust
street cams
race pistons
race turbo
Tune:
PSI 27.5/ 27.5
final drive 4.45
camber -3.0 / -2.5
toe 0.2 / -0.5
caster 7.0
arb 14.02 / 20.61
springs 444.9 / 346.6
height 4.3 / 4.3
rebound 6.7 / 5.5
bump 1.7 / 1.0
brake 60%
brake force 110%
differential
front 30 / 0
rear 60 / 30
balance 40%
Sorry if it is hard to read. I think my differential settings need some adjustment. I had the balance favoring the rear, but I found it more stable during turns if it favored the front.
It is nearly always beneficial to add Race Forza wings to both front and rear. This not only improves handling significantly but more often than not reduces the PI allowing for a little more power or wider rims to be added.
What about the pretty signifigant decrease in speed? Its a drop from 7.5 down to 7.0 if I remember correctly off the top of my head.
Johnson gave you a pretty good answer, but also you can change just how much downforce is applied in the tune. Most of my tunes in D and C class usually have the aero settings as low as they can go. Every car is different though and you have to experiment. Downforce usually provides better handling and that can very easily offset greater top speed. I don’t look at top speed for any car unless I’m building it for LeMans. I care about how well it gets through the corners and how much momentum it will maintain. That means way more than top speed…
Speed is not important because 99% of the time u will never get close to top speed… forza aero is the way to go almost all the time until u have tuning figured out. If the game will let u install the motors do it in this order… 1.6l, 5.7l, 6.0 l v12 3.0 vvt… most of the cars u run will have those four motors. The 6.0 l v12 is a very strong motor A class and up.
Adding the Downforce on that build seems to have helped quite a bit. I am sliding a lot less through the corners, and as a result can push the car harder into and out of the turns. It brought my lap times down almost two seconds. Thanks for the tip! Has anyone got any advice on the differentials for awd vehicles? I could defiantly use some pointers on that.
35/0/70/10/70
Thank you very much.