sway bar size is very much dependent on the spring rate. If you are not increasing the spring rate by any amount, then adding the largest sway bar is not necessary. Unless of course you are greatly increasing the amount of lateral grip (better/larger tires).

Do spring rates and bar rates work together to compliment one another? Yes

Must they be changed together to see any positive benefit? NO

Additionally, just because the Hotckis bar is the largest available "off the shelf" bar does not make it the "largest bar". Various race teams have produced custom bars that are even larger.

In conjunction with stiffer spring rates.

I didn't say the need to be done together, but going larger than necessary without the use of a spring change isn't the best balancing solution.

And most custom bars will most likely include an adjustable blade type arm with significantly greater range of stiffness, unlike a fixed arm with different positioning holes. I don't think i've ever seen a race team use stock coilovers with a large custom ASB. It would defeat the purpose and just cause wheel jacking through every turn.

What would you say is the proper spring rate with the Hotchkis front bar, assuming for a stock sport pkg 370z?

That's rather vague without clarifying height change, camber and tire type.

But considering the hotchkis bar is estimated at about 230% stiffer than stock, you can guesstimate the spring rate increase should be a third of this at the least over stock spring rates.

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