I did a pretty thorough suspension refresh on my 110k mile car including Bilstein Sports but stayed with the stock springs. I got new fluid and brake lines in, and will likely go with EBC red stuff pads for a little more resiliency from the brakes - happy to shorten on-track sessions by a few laps if brakes are getting hot. 2 questions:

1) For better or worse, I didn't do coilovers with the refresh. Would the TMS (or similar) sway bar kit (front + rear) be a good upgrade that would make the car a good bit better on track? It seems like for $400 or whatever the bars cost would be a great value for my application, but wanted to see what others think.

2) Are there any known weak spots with the engine that are likely to be an issue after a few on-track sessions?

Thanks.