V8 LS based cooling questions
 

Last week my LS based V8 Miata actually got an aftermarket coolant temperature gauge installed in addition to the worthless factory temperature gauge.
Now that there is a gauge which actually shows real temperature readings it brings up a couple of questions.

For background information my car has an LS1 engine with factory ECU and uses the Flyin Miata aluminum radiator with dual electric fans and an aluminum plate to shroud the radiator flow thru the fans.
It appears to be a workable and well designed system.

The ECU is programmed to have both fans start at 190 degrees F.
Is this reasonable or should they be set to start turning at two different temperatures?
If so, what temperatures are recommended?

Last week while driving in stop and go traffic the temperature gauge climbed to 220 degrees F. with local weather conditions indicating low 80's.
Is that temperature reading anything to worry about or should I wait and see what the temperature reading does when the weather conditions get over 100 degrees?
What temperature should be the maximum before pulling over and letting the car cool down if it happens again?

Several build threads mention adding hood vents to aid in air flow across the radiator.
My car seems to run at a steady temperature of right at 190 degrees F. at steady cruising on the highway so far but the air temperature has only been in the 80's since installing the gauge so it might run hotter during the heat of the Summer.
What indicators do I need to watch for to see if hood vents will help?
The car is a sleeper that was kept visually as close to stock as possible so I don't care to add vents unless there is an actual need.

Thanks for any information or insight.

Bruce

LS motors were designed to run a bit hotter than others. The fan switch temps for my LS2 are Fan 1 at 199 degrees and Fan 2 at 207 degrees. I don't use the FM rad. It's a two row design and I live and race in the southern Arizona desert where air temps in the middle of the season often reach 115 and temps out on the track are about 140. I use a Griffin 4 row 26 x 16 rad and it will still see 220 if I flog it really hard. If you duct the air into the rad and the fans are shrouded you should not have any problems but I would use the stock temp settings for your fans. I think they are the same as the LS2. I also think hood vents are just cosmetic.