high temps in the summer time
The C5 and the Z06 have the same cooling system (if you are referring to a C5 Z06). 232 does sound a bit hotter than I see in similar conditions, but it's nothing to be terribly concerned about. Fan #1 doesn't come on until around 226 degrees F and fan #2 doesn't come on until 235 degrees F. So even GM is saying that anything shy of 235 is fine.
Still, when was the last time you had your radiator/condensor cleaned of debris? It's quite possible you either have a single large object sucked up in there (plastic shopping bags tend to find their way inside more frequently than you'd think) or maybe you just have enough dirt, leaves, and road crap that your cooling performance has been inhibited a bit. The front of the C5 literally acts as a Hoover sometimes and does suck up a lot of random stuff floating around the streets.
If all that is good and nothing is mechanically wrong (e.g., fans are turning at full speed, nothing wrong with water pump, etc.) I would start with a simple thermostat swap and fan settings reprogram (only if you can get this done cheaply somewhere, some shops have to burn a license in their software and try to charge you quite a bit for this). My guess is if you get your rad/condensor cleaned, get a fan reprogram, and a 160 therm, you'll see your temps drop quite a bit.
Hope this helps,
Tony
Get your fans reprogrammed to come on at 180 and 190 or if you want you engine to run hotter try 200 and 210. That way she won't get any warmer then 210*'s or so. Good luck on cooling her off, because I know heat robs horsepower, and no one wants to drive their car when it feels like a dog.

