Thompson Speedway Gearing

[William I. Hollingsworth]

Straight at Thompson is 3000 ft. For comparison Watkins Glen straight is 2600 ft, Summit Point straight is 3000 ft, VIR straights are 3000 ft and 4000 ft. In looking at the most recent video of a car driving Thompson a few weeks ago the very tight turn (4), a 160 deg right hander does not look as tight, or as slow, as turns 5 and 6 at Summit Point. THOUGHTS ON GEARING?

Look at the track map on the web sight and and some videos. Have any of you driven the track?

[EACIII]

The Thompson front straight is slightly up hill and I think will effect top speed on most cars that are not running a blown 426 hemi. As for the other corners, I will be guessing.

Ed

[flat tappet]

The Thompson front straight is slightly up hill and I think will effect top speed on most cars that are not running a blown 426 hemi. As for the other corners, I will be guessing.

Ed

Anyone got a 426 hemi past tech in a fVEE? Just kidding,ED.

[Michael Rand]

Bill H, EAC, etc, guys, yes the "straight" at Thompson is indeed 3000 feet [6/10s of a mile] BUT there is a very long duration double apex right hander about 800 feet into said straight that is sure to scrub substantial speed off virtually any car.
AND the exit speed of turn 8 [at least I am calling it Turn 8, the right hand part of the left/right off the ovals backstraight] is I would estimate at 50-60 mph. It exits onto entire 3000 ft "straight" including the above referenced double apex right.
And I wonder where Bills WGI 3000' straight starts ? Exit Turn 1 ? Top of the hill at many mph already ?

A better example is Summit Point.
The facts are, from an extremely fast F2000 race winners on board data, he exits T10 at Summit at 105 mph +/- onto Summits 1/2 mile [2,700 ft] DOWNHILL straight with a terminal velocity of 140+/-.
So onto a downhill straight of maybe 10% less distance exiting at 100+mph a top F2000/FC car gains under 40 mph.
Exiting Thompson Turn 8 at QUESTIMATED 60mph onto a 10% longer straight BUT with at least an almost 2 tenths of a mile high scrub right hander, 2/10s start to finish, onto a slightly uphill straight it is not hard to imagine the same F2000 car would fall substantially short of Summit 140mph top speed, by how much ?
10MPH maybe ?
Obviously everyone's math will be different

For the doubters I have spent over 2 years consulting with the excellent owners and management of Thompson and as late as last Wednesday spent the day witnessing apex curbing of my design being built and measuring , ok, just with the Suburbans odometer but better than guessing, distances after researching Summits info from a more than reputable pro team engineer.

For what it's worth I am taking the Crossle/Fit to next weekends New England so called "Soft Opening" with Lime Rock gearing and go from there.
I suspect anyones Summit gearing would be a perfectly decent place to start as well with all the tools and boxes of gears and gear charts ready to be gotten into after upon the finish of the first session.

[Doug Fisher]

Mike....look forward to hearing about your experience at the new circuit....some real interesting corners around that place in my opinion. I, we, would love to know what shakes out about gearing there.
Doug Fisher

[EACIII]

Note to those that don't know Mike's gearing but believe he gears his box to use all 4 gears at Lime Rock. Some others use 3 gears at Lime Rock and use first for slow starts only. So your Lime Rock gearing may be different then his.

But heck, either one would be a good starting point. I think the Summit top gear will be too much but I have been wrong many times before.

Hell, I have been racing at WG for 30 years and still don't have the right first gear in my car.


Ed