AdsoYo

iTrader: (1)

I've been lusting after Strano's hollow sway bars for years. I was real gung ho about building a top notch corner carver about 10 years ago but nowadays I live where the fun roads are farther away so I'm more interested in the weight savings. How will the car handle if I keep the stock front sway bar and upgrade the rear to Strano's hollow bar? The rest of the suspension looks like this:

UMI tubular k member, UMI tubular lower a arms, UMI weld-in 3 point SFC's, UMI tubular LCA's, UMI single adjustable panhard bar, KONI shocks, all other components are stock.

LLLosingit

iTrader: (4)

That's not an easy answer, It depends of the rate of the bar/tire compound/air pressure/shock/spring and the surface you're driving on and so on, Basically you tune to the surface you're running on and you have a lot more to consider than just the sway bar.
If you're looking for weight saving and still want the car to handle close to the way it does with the solid bar then you just need to get a hollow bar with a similar rate.

JD_AMG

Simply put, adding more rear bar will make the car oversteer more. Also there shouldnt be any weight savings going from a hollow 19mm rear bar to a hollow 22mm rear bar, and even if there was it would be so small you wouldn't notice from the drivers seat.
If you want to upgrade just one side then do the front 35mm hollow bar. It will be more prone to understeer (safer) but you will get a large amount of more turn-in and response from the car.

stp001

If you are considering putting just the rear bar on due to cost, skip the bar and get poly bushings front and rear. Not as good as bars, but balanced handling. If it is not about the money, buy the pair of bars and call it a day. If you have wider tires on the rear than the front, the 22 hollow would be about perfect. If you just believe "loose is fast" and enjoy that sensation, go for it. A 22 hollow isn't that much bar anyway.