Since you’ve added fatter rear tires, I believe you. But the original Viper posted has a heavy rearward brake bias. Don’t get me wrong, I actually like just a little rearward brake bias. Just not as much as shown in the available download.
edit to add: your front brake power is through the middle of the line. If rear brake force is above the line, it’s rearward biased. the thing (for me) to consider is: when I’m overbraking it, how do I want it to act? The answer for me is rotation, but it will vary by driver. If you’d rather just have it slide to the outside, then more brakes up front.
Edit2:Having driven the Viper posted at top, I thought the chassis was decently set up. I can’t fault the brake setup, they felt good even going deep into corners. In fact, the only oversteer I really noticed was 1) every time I shifted, and 2) every time the turbo kicked in. Whee! You could use a less aggressive shifting trans (adv auto or dsg) to help this a bit,
I tinkered a bit and came up with this, it’s a little bit faster with 30 less hp.
Viper - R1 by LPE.car (23.7 KB)
It also doesn’t get stuck in a gravel trap, hehe. I tried to keep the “feel” original, that turbo still kicks hard and it can be a little hard to modulate out of low speed corners.
I think the build is hamstrung a bit by the turbo size, which in Automation is based on bore size. As an inline engine, only one turbo is granted; in an undersquare engine it’s just not enough to feed that exotic cylinder head. Further, that long stroke is keeping you from spinning the engine high enough to take advantage of that exotic piece. Turbo motors don’t like overlap, so I backed down the cam. Ditto timing, and I bumped compression ratio. The result is a 1.8 that gets serious at 6000rpm (300+ hp), and stays rowdy to its 9300 rpm redline. Peak of 388 at 7700.
As to how you’re being beaten by the Meijer car, weight and cornering speed. That car corners at 1.2g, and carries 500 fewer lbs. And, it’s so easy to drive my grandmother could hot lap that thing.