....I'm using the innovate LC-1 and haven't been able to get a reliable reading out of it since day one. I'm looking for an analog alternative.
Regarding the cooler air, this car produced better speed in hot, thin air, which indicates to me that it is the aero that is more of a problem than lack of power. Speeds consistently increased as temp and adjusted altitude went up. . . .
Where is the O2 sensor for the LC-1 in relation to the end of the pipe and also the collector? We didn't always have good readings with the LM-1 but it was not that far from the end of the pipe and it was also operating in high temps. I had a heat sink on it that helped some. They don't really like temps over 1000. We bit the bullet and put the ....

http://www.innovatemotorsports.com/xcart/product.php?productid=16148&cat=250&page=2
...expensive heatsink standoffs on the new turbo motor and so far that has worked great. They are only about 9 inches from the turbo. We have a second fitting further down the exhaust we can move to if the heat gets to much but getting near the end of the pipe can cause problems also. We bought all of the new Innovate parts from Jerry at DIYautotune. He is also a landspeed racer.
I'm wondering if the air/fuel ratio you are ending up with in the afternoon makes more HP. If you could get the same ratio in the denser morning air you might make even more HP. The Difference between 4500 air and 7000 air is about the same as 1 lb. of boost. I'd hate to give that up if possible. We have almost always done better in the morning air.
Good luck,
Sum
Thanks, Sumner.
By the way - it's good seeing you active on the boards again!

The sensor is the standard issue Bosch unit that came with the gauge. It's about 8 inches from the end of the tailpipe - I don't think heat was an issue, but the erratic reading was pretty useless.
I'm running leaded fuel, but I was doing the gauge reset before each run - to no avail.
The best speed was obtained after going to 165 jets and bumping up tire pressure. We started with 180s, which is what we tuned with at 750 feet, and was adjusted after temp, humidity and barometric pressure, if I recall right, to 1,700.
It's possible I'm still too rich, or that the low air density actually put the engine into a better state of relative tune, but I can't judge from the gauge.
Either way, aero work will commence, and I'll figure out the gauge later.
And I'd prefer to run in cooler temps - it gets a tad warm in that little kipper can. But as it sat this year, it appears as though the aero advantage of less dense air proves to provide better speed than the power of denser, colder air.

Logic dictates it shouldn't look like this, but this is the data I collected on my 9 competitive runs.