[Formulajones]

The biggest chassis header we run on our stuff is 2". Worked well on Dad's 571. They are just out of the box hooker super comps and used them on the dyno with an exhaust system and made 724ho 764 tq with them. They fit the car nicely, don't hang low. Exhaust is a custom 3 1/2" from headers into a dr gas X that changes to 3" from there.

My 598 also uses 2" hooker super comps and made 786hp 772 tq. Again just out of the box chassis headers that fit really well. Same exhaust system..

When you get into bigger header tubes, at least on our cars, they all seem to wrap one tube around the frame and the inner fender needs to be cut. No thanks. So we stick to 2" headers. They are just street cars and don't need anything fancier.

We run electric cutouts on everything including these 2 examples. Not for performance but mainly for fun. In fact my 598 on back to back passes ran exactly identical passes through the exhaust vs cutouts open. So the system seems to be working well enough on that setup.