Seam Welding

First things first. I know seam welding is not legal for IT. I am (slowly) building a 00 Civic Si with the final target being STL/HC where the rules are a little friendlier to the suspension. The car is almost stripped in prep for the cage, so it is at a point where it would be easier to do the seam welding if it is to be done. That brings me to the question.

What are the benefits of seam welding and what is the magnitude of the performance gain? At the heart of the question is whether the performance to be gained in STL/HC is worth not being able to run IT or double dip while the car is (slowly) being built and otherwise meets both rule sets?

My gut tells me the performance gain is minimal, especially compared to things like proper ($$$$$) shocks, but I'd love to hear other opinions.

Rory

It is going to help stiffness wise; no doubt about it.

What do you give up? Repairability for one and corrosion resistance for another.

If it did not have a benefit, no teams would do it where permitted.