When should you upgrade torsion bars?

The bolt-in style subframe connectors should really be welded in. They’ve improved the design some from the way they used to bolt in, but there’s enough twist in the chassis to require them to be welded in for a truly permanent solution. You can bolt them in yourself and then take the car somewhere to have them welded in. Doing it that way may open up more options for welders just because there isn’t any fabrication or fitting that has to be done by the welder, just welding.

The US Cartool connectors are nice, but they require 10x or more the amount of welded as any other kind of subframe connector. And really the car needs to be fully stripped to install them, preferably on a lift or rotisserie too. You can get just as much chassis stiffening out of tubular connectors with significantly less welding required. I’ve done both the US Cartool connectors and made my own connectors from rectangular tubing. It was far less work to make my own and install them than it was to just install the US Cartool connectors. I like how they look more factory than the tubular kind, but I wouldn’t use them again.