Track Time at Hallet, OK and Overheating

[swaltner]

I took the Atom down to Hallett, OK this last weekend. The day was pretty hot, with ambient temps of 100 F (38 C), which led to the car over heating in the last session.

I was trying to accelerate out of one of the corners and the car missed, almost lunging me forward in the seat before power came back almost as quick. I glanced at the dash and saw "WT 227" with the WT flashing, so the water temp was much hotter than I've ever seen it before. I slowed down and came into the pits at the end of that lap. By the time I got off the track, the water temp was down to 215 and letting the car idle for a few minutes, it got down to 190 before I shutdown the engine. Driving around town this summer with ambient temps as high as 108 (42 C), I don't think I've ever seen the water temp over 210, and rarely does it get over 200.

Would the engine running hot like that cause it to miss, or was that more likely due to the fact that I had less than 3 gallons of gas in the tank? If the low fuel was the likely cause, I'll be sure to take a can or two of gas with me to the next track event. Unfortunately, I don't know if the engine was running hot like that all day, since I know I wasn't paying attention to that part of the dash at other times during the day. I'll need to keep an eye on the water temp on any future track day events.

My fastest lap for the weekend was 1:37.8, which I thought was pretty good for my second track day event. Can't wait until next time. Hopefully it will be a little cooler than this month!

[Terry Kennedy]

I was trying to accelerate out of one of the corners and the car missed, almost lunging me forward in the seat before power came back almost as quick.

Left-hand turn? The fuel pump is on the left side, so fuel sloshing over to the right side of the tank can cause the pump to grab air instead of fuel.

I glanced at the dash and saw "WT 227" with the WT flashing, so the water temp was much hotter than I've ever seen it before. I slowed down and came into the pits at the end of that lap. By the time I got off the track, the water temp was down to 215 and letting the car idle for a few minutes, it got down to 190 before I shutdown the engine. Driving around town this summer with ambient temps as high as 108 (42 C), I don't think I've ever seen the water temp over 210, and rarely does it get over 200.

The boiling point of Dex-Cool at the recommended concentration at sea level is 228 degrees. Under pressure, the boiling point will rise, but you run the risk of blowing one of the coolant hoses when the pressure increases. This happened to my car at Hallett:



Is your car a Brammo car or a TMI one? Ecotec or Honda engine?

[swaltner]

Left-hand turn? The fuel pump is on the left side, so fuel sloshing over to the right side of the tank can cause the pump to grab air instead of fuel.

Yep, it was a left turn. Looking at the video, it happened while I was tracking out from the apex of the turn, so the car was still under lateral G loading. The Traqmate showed between .75g and just over 1g lateral for about 5-6 seconds while going through the corner. I had done about 70 miles on the track at this point, so I was probably down around 2.5 gal of gas left. I'll try to fillup the tank tonight to see just how low I was on gas. The gas gauge read empty at times, but it always does that with a few gals of gas left, assuming the car does actually have a 9.7 gal gas tank. Sounds like I just let the tank run a little too dry. I'll take extra gas with me to the track in the future and top off the tank at lunch time.

Is your car a Brammo car or a TMI one? Ecotec or Honda engine?

I've got an Atom 2 built by Brammo with the "245 hp" supercharged Ecotec engine.

[swaltner]

I filled up the tank today and put 7.7 gals in. I drove a little after the track event, so I did have right at 2.5 gals in the tank at the end of the day. Is that low enough that the fuel pump would be sucking air instead of gas at the end of the track day?