Runoffs Trap Speeds

[Dave Gomberg]

Runoffs trap speeds are now posted with the results at http://www.scca.com/eventresults.aspx?event=13506&hub=1

Dave

[Doug Carter]

Here's a direct link to the FV PDF.


Notice the runaway leader, Mike Varacins' trap speed—27th fastest out of 41 cars. Almost 6 mph slower than the fastest trap speed. Tell ya' anything?

Even more impressive, Michael. Well done.

[CSatterley]

Can someone give me their thoughts on the differences at the start/finish? gearing, tourque curve, carb, draft, I find it hard to believe a 7mph difference through the whole straight.

[Doug Carter]

Keep in mind, those are trap speeds (not top speeds), through a 120' chunk of track around the S/F line. Michael was running alone almost the entire race with no draft to aid in straight-line speeds, versus the guys in the pack all running in big bunches. If they had stayed in line, they might have been able to hang a little longer. Or not.

It's even more amazing how much of a gap he pulled on everyone running by himself. I'd love to see his data and exit + apex speeds. Mike's mid-corner and exit speeds have to be astonishing compared to the rest of the field.

[cendiv37]

The difference in trap speeds near FS is almost all due to the draft. The draft is already well in play by then. It would be interesting to see trap speeds near pit out...

It's fascinating to look at the speed data from my car. The trap speeds listed by SCCA match up pretty well. I don't know exactly where the AIM beacon was, but it was pretty close to SF as best I can tell. At about 125 ft. past SF, my best recorded speed during the race was 99.8. on lap 3 with the slowest speed 94. I was at about 96 there in Q3 with better lap times...

Defining exit speed as the speed at which the lateral G's go approx. to zero, my exit speeds at 14 during the race vary by about 3 mph. By comparison, my exit speeds on the last three laps of Q3 were within 1 mph at the top of that range.

Things that stand out when looking at the graphs: the brake point variations into turn 5, minimum speeds in the middle of turn 1 and top speeds heading into 12.

At the same point on the track, just before braking at turn 5, on one lap I'm going 114. 2 laps later I'm going 105 and essentially coasting trying to find a spot to fit into line.

Similarly at a point near the apex at 1, my speed varied by 10 mph, using 3rd gear when it got that slow.

The other nexus of chaos was into and through 12. My top speeds heading towards 12 varied by more that 10 mph during the race. On one lap you can see some of this speed differential from Charlie Hearn's on board camera. Exit speeds varied 6 mph during the race (vs. 2 mph at/above the top of that range in Q3...).

In summary, during the race we in the pack did a corner (or 2) right once every couple laps.
But it was exciting!

[Dave Gomberg]

...
I don't know exactly where the AIM beacon was, but it was pretty close to SF as best I can tell. At about 125 ft. past SF, ...

The data was captured using the timing loops at S/F and 120 feet after S/F. The results are very accurate because they use the on board transponders.

At RA, there are a bunch of timing loops scattered around the track. Next year, we hope to use more of them to generate other trap speeds and sector times (a la F1).

Dave

[cendiv37]

I was commenting on how and where my AIM data compared relative to the more accurate timing loop data. Since the numbers were close, I compared my speeds at 125 ft past the beacon at the start of a new lap to the timing loop data. Maybe I should have take it at 60 ft past the AIM beacon as being closer to the average between the loops. But since I didn't place the beacon myself, I can only estimate it's location. There is also certainly error in my data from wheel circumference, etc.

[Speedsport]

I guess I have some work to do this winter.

[cendiv37]

I guess I have some work to do this winter.

We that know you well, also know you will.

We who feign to compete with you, however, have even more work to do!

[37 CREW]

Bruce, Seeing how you have more work than others have you started yet? You realize next season is only about six months away!!!

[Fos]

Guys--

I'm extremely happy to hear that the speedtrap info shows a large delta!

Cudos of course to the winner!

Seems like grip still matters over overall speed!

Does this help with the intake discussions?

TTFN
Fos