wstar's Journal

wstar

That was kind of my gut feeling at the track, too. What's particularly strange with those two runs is that my second run with the better ET had a slightly lower trap speed . I'm starting to wonder if maybe I'm misjudging where the official end of the 1/4 is and getting off the car too quick at the end heh.

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7AT Track Car!
Journal thread / Car setup details

tranceformer

Losing MPH when you lower tire pressure is normal.

How does the car feel towards the end? Did it feel 'slow' at the top of the last gear or two towards the end? What was your oil temps when you made those runs? I usually let my car cool off MINIMUM 30 minutes between each run. Ideally 45 min to 1 hour, or as long as it takes to get the oil temps back down to 150 160 degree range. Any hotter than that and I can feel the car lag at the top of 3rd gear (6MT). Can you tell I'm a track junkie?

IIRC they calculate trap speed by measuring how long it takes to cover a measured distance (which starts from the end of the 1/4 mile mark). Just because of that I stay on it until about 115-120 just in case.

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Ray
2009 370Z Base Sport 6MT / 12.860 @ 109.09mph / 1.921 60ft / street tires
official 1/4 mile track times

wstar

Ah I didn't think of that, makes sense.

Beats me, it all happens so fast it's hard to remember. I know on both runs I smoked my random competitor for the first half of the race, and then first one caught up by quite a bit near the end, and the second one ended up overtaking me.

I had a good hour between runs, but about half of that was idling in line (I did shut down during a couple long waits for other car classes to try to prevent heat soak buildup). My oil temp was 180 at the start of each run (in the evening the car tends to stabilize there at idle with my thermo'd oil cooler + oil pan spacer), and the coolant around 188-190. At the end of the run the oil would be closer to 200-210 when I looked while turning off the track.

I could get it down to 160 if I tried (harder) to avoid prolonged idling after my cooldown/off period, but I figured I didn't want the oil too cold, but I guess I'm just being paranoid about ideal temps there. I'm running 5W30 anyways, I'm thinking I should start switching to 10W30 in the hot summers here.

Yeah I definitely didn't stay on it past the 1/4 mark, and I might even be letting off early, I guess next trip in a few months I'll try to stay on it way past where I think the mark is and see what happens.

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7AT Track Car!
Journal thread / Car setup details

wstar

Oh another random thing that's probably important, ~84mph is almost exactly where I redline in 3rd and switch to 4th. Could be I'm too late or too early on that shift, too.

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7AT Track Car!
Journal thread / Car setup details