This Shelby starts in S1 class at around 820 PI points or so. I don’t have one yet (I want one badly, actually, but keep buying other cars, haha). Try keeping it in S1 class at 900 PI and spend your points on mostly engine upgrades. Go for 7.6 to 7.8 handling stat, could be even less.
A few notes:
- AWD is a must.
- Since you’re playing online and the GT350R is a very modern car, don’t bother with rollcage as it just adds weight and the grip increase is minimal.
- This car already has 6 gears so the race transmission might be a good buy since it shouldn’t increase PI too much.
- Don’t be afraid of using sport brakes if necessary. Not adjustable, but good stopping power and costs less PI.
- Get forced induction if you can. Turbo makes bigger power and weighs less but has lag. Supercharger is the opposite. Centrifugal supercharger can be used if necessary to keep it in S1 class but requires short gears since it steals a lot of torque at lower revs.
- Flywheel, driveline, clutch should be purchased only if the car is already at the top of its class and they don’t increase PI, or when you need them to bring it to the top. If not, don’t bother with them. I recommend learning to use manual transmission with manual clutch as well, you can shift faster this way. If you have a big thumb like I do, it’s not too hard to learn!
- Never buy oil cooling. Intercooler only if the car comes with it stock (the GT350R doesn’t). These add weight to the engine, which is undesirable in a front-engined car. Oil cooling rarely increases PI, in fact the car might lose PI because of the weight penalty. Intercooler could be useful if you need the oomph but it’ll hurt handling.
Basically what you’ll want to do is to max out the engine with forced induction (or have as many power upgrades as possible at the very least), buy the highest possible weight reduction upgrade, buy race sway bars and springs, race differential, and also race transmission if PI cost is low. Race brakes are nice but if you need more power use sport.
When upgrading engine, use the upgrades that give you the best numbers. Try to get race exhaust if possible, this one reduces weight a lot. Don’t upgrade cams unless you really need it, as cams increase power by increasing engine revs, so the amount of torque they increase is almost negligible. However, more horsepower helps on high speed tracks.
As for tires, use the best ones that still keep you in the better class for the car as well as allowing you to max the engine out. The GT350R is already a modern car with modern rubber so the gain from tires is not as significant as with older cars. If you can fill in the remaining PI with tire width instead of compound, do it, as width usually costs less. If the car understeers, make the front tires wider, but never wider than the rear ones unless running FWD (which you never should when playing online). With AWD it could be good to use as close to square setup (same width front and rear) as possible, but I haven’t really messed around with it.
Rim size won’t help too much with modern cars but if you feel the car too floaty you can try using lower profile tires (bigger rim size) to make it more responsive.
Engine swap is highly dependent on the car, I usually don’t buy it unless it’s required to reach the top of the class. The problem with a swap is that the new engine may have completely different characteristics. I don’t know which options the GT350R has but I believe it’s got the 8.4L V10 as an option, which is a much different engine from stock. New engines might be heavier as well, this penalizes handling a lot in a front-engined car like the Shelby.
You could try buying aero but for S1 class I believe it’s not necessary, it’ll also hurt speed a lot unless you run very low downforce. Pay attention to the car’s behavior at high speed to see whether you need aero or not.
I’m no expert but this is an amalgamation of my experience and the tips the pros tend to give, I hope you find it useful. 