Home » Posts tagged 'Summit Point'

Tag Archives: Summit Point

Archives

Experiments in Coaching

I have the opportunity this month to have two events on the same track. At the beginning of June I instructed with PCA at the Shenandoah Circuit, Summit Point Motorsports Park, and at the end of June I return with BMW. I’ve always wanted to see if I could gather data to answer two common questions: How much faster will I be on track tires? And, how effective is coaching an experienced driver?

So the answer to the first one is fairly straight forward, but since this track can have several different layouts, let’s establish some controls. We will not use the banked Karussel, but instead take the inside apron. We will run the Old Ram cut-off instead of running through the hot grid, and we will drive the Range Straight instead of the Range Esses.

I have 75+ days on this track and data on several hundred laps, that until now, were always on max performance summer tires (treadler 200 or greater.) My best recorded time was 1:44.73. At the start of this first weekend in June, I did a few sessions on Falken 615Ks (treadwear 200) and then switched to Toyo RRs (treadwear 40.) The best on the Falkens was 1:44.87 (so 0.14 sec off of my best). The best on the Toyos was 1:42.96, an improvement of 1.77 sec over my best, and 1.91 sec better than the Falkens on the same day. Average the two together and that’s a 1.84 sec improvement or just about 1.75%. So, just by spending money on better tires, I was faster, but that doesn’t mean I was better.

Armed with my new faster tires, I then asked one of my fellow instructors, Paul Bylis to ride along and coach me. I listened to his advice for a session, and then went out on my own again. This time, my best lap was a 1:41.97. A further improvement of 0.99 sec. So now I have a rough comparison of the value of coaching (which for me is free since I just have to ask for it) vs. spending money on more expensive tires.

The Catalyst tells me I’m still leaving a three fourths of a second on the table.

M3 at the Jeff

After a long break, we finally got back to the track in September. The weekend of 11-13 September saw the National Capital Chapter of BMW CCA back on the extended Jefferson Circuit at Summit Point. The format was a bit different with all lead-follow instruction, but the instructor run group was still a blast.

I’m still getting used to the M3 and have to remember three key differences from the MINI:

  1. It’s wider.
  2. You have to actually steer OUT of corners as you get back on the power.
  3. When the back steps out, MORE GAS is not the answer.

I also need to get used the pedals to improve my heal-toe downshifts. If I can remember that I don’t have to square every corner, I think I’ll get to be pretty quick in this car. My best lap was already 3 seconds faster on the same tires.

Remember that bit about the car being wider? Here’s a small clip from my second track session in the car and I was finally getting up to speed.

There are a few lessons to be learned here. I’m driving an unfamiliar car that’s about a foot wider than what I’m used to driving. I finally got the apex right at the previous corner and as a result, arrive at the braking zone here about 2 MPH faster than usual. I come off the brakes too soon, and as a result don’t get far enough around T13 when I have to brake again. I run out of track at the entry to turn 14. I come off the brakes as I leave the track, but still have enough brake force on the front left that I spin around the front left when 3 wheels are off. I straighten the wheel and almost pull off the 360 before heading into Pit-In. So next time, be more aware when making a step increase in speed. Adjust the brake point so I apex T13 at the same speed. And keep the last 18 inches of apron as a buffer. Oh, and know how wide your car is.

Vibra-Technics Motor Mount

After destroying two upper motor mounts and two exhaust flex joints in successive track weekends, I decided to try a more robust motor mount to see if I could reduce some engine movement. Vibra Technics makes two versions of this mount for Gen 1 MINI and this is the track (harder) version.

My first thought when it arrived was that it belonged in a museum. It was beautiful.

Installation is actually fairly simple. Get the car up on jack stands in the front. Remove the right road wheel and fender liner. Support the engine from below with a jack to relieve pressure on the mount. Remove the grounding strap from the mount carrier and the vapor return line which is in the way. Loosen but do not remove the nut at the top of the mount. Remove the four bolts holding the mount support to the top of the engine. Remove the nut at the top of the mount and carefully remove the upper mount support. Remove the stock Torx bolt from the bottom of the mount. Remove the side bolt and the stock mount should pull free. Installation is the reverse of removal.

I also replaced the lower dog-bone mount earlier with a semi-solid mount from Torque Solutions.

So what was the net result? I accomplished my first goal, completing over 200 track miles without breaking anything. An interesting side effect was to lower lap time by almost a second. To be fair, I made two changes to the car for this weekend: I replaced the motor mounts and I ADDED 50 lbs to the rear end of the car. I think the combination of better balance and less wheel hop gave me higher apex speeds. Here’s a lap.

How is it on the street? It’s probably not a combination you want to use on your daily driver. NVH is definitely increased. Depending on your RPM, the vibration through the steering wheel could make your fingers go numb. On the track, or any time you are constantly working through the revs, I can’t say I noticed. But cruising at steady speed — brutal.

Since the upper mount can be changed in about 30 minutes once you figure it out, I swapped back to a new OEM top mount and left the lower mount. That does have some increased NVH over stock, but it’s a good compromise. And next time I have a track weekend, I’ll drop the Vibra-Technics back in before heading out.

Summit Point in the Rain

Track season is just starting to get into full swing so I thought I’d share a lap of Summit Point in the rain.  Newly repaved for 2018, the surface as fairly good grip and no more of the inconsistencies from water on seam sealer. The surface is less crowned than before.  Water run-off is mostly good, but there are some areas where small streams of water cut across the full width of the track, especially in the exits of turn 2 and 9, both heavy acceleration zones.

Track Analysis: Summit Point, Jefferson Circuit Extension


Last weekend I had the chance to drive and instruct on the extended Jefferson Circuit at Summit Point. Below is my analysis of the changes and a description of my line around the track. This works for me in a FWD MINI on summer street tires. Your results may vary. No wagering. (In-car video by ReplayXD.)

Jefferson Circuit Extension
The extension (turns 4 – 10) adds about a half a mile to the old track and doubles the number of corners. I think most old-timers would have preferred if they had just renumbered the new section as corners 4a to 4g instead of renumbering all of the corners, but we’ll use the new numbering scheme. The old track could be run in both directions. The new layout only works in a counter-clockwise direction (though you can still use the old course in the other direction.)

Google Earth hasn’t yet uploaded a new image of the circuit so the plot shows the path through open fields, but it is actually paved, just not well (more on that in a minute.) How to read this chart: Turn numbers are in circles. The color on the path of the car shows acceleration (green) or deceleration (red). Note that deceleration might just be lifting as in between 2 and 3 or the apex of 4 or 8. Green speed readings on the track show max speed before deceleration and red shows apex speed. The bars in each corner show relative lateral G load. Green bars are .4 to .8 Gs. Yellow bars are .8 to 1.1 Gs. Notice the lateral load where the new track rejoins the old track and in the middle of the back straight. There the car is going straight and the lateral load is from the unevenness of the surface. You see some of that on the front straight from 14 to 1 as you drive across the crown to set up for turn 1. Red arrows show apex visuals. If you already know the old Jeff, then jump down to Turn 4.

entry to turn 1
When you enter the track from pit-out, stay to the right all of the way to the apex of turn 1, otherwise, when at speed cross-over from right to left on the front straight and look down the track to the flagger’s bucket. RWD cars set up to the left for turn-in. The road is crowned so FWD will want to be more in the middle of the left half of the track or you’ll never get over the crown to the apex.

turn 1 apex
The apex is very late and almost at the end of the curbing. You can ride the middle part of the curbing, but stay off of the end as it will unsettle the car. Stay to the right upon exit and let the car settle before turning-in to turn 2.

apex turn 2
Turn 2 and 3 should flow. If you’re early for 2, you’ll also be early for 3 so wait to turn in and make 2 a very late apex. Lift or tap the brakes to turn-in to 3.

apex turn 3
Turn 3 is one of the few corners where you can ride up on the curbs without unsettling the car. Apex is very late and carry as much speed as you can. Don’t worry about track position on track-out as the entry to the next corner is rough and you’ll probably have to lift anyway to get back to the apex.

apex turn 4
Turn 4 is also a late apex. Ride the rumble strips and try to straighten 4 and 5 as much as possible.

apex turn 5
The exit to turn 5 is the roughest spot on the track. Point the car straight after the apex and brake in a straight line. Wait for the second bump before turning-in to turn 6.

apex turn 6
Set the car about a car-width from the curbing and late-apex turn 6 at the top of the hill. Open the wheel and let the car track out to set up for turn 7.

apex turn 7
Turn 7 is the most difficult corner on the track. You must be patient, especially when your tires are cold. It is a decreasing radius corner. Look for the path of the patch. Set your entry squarely in the middle of the patch and then pinch-off the apex. Trail-braking helps. If you don’t sufficiently load the front-end, expect to under-steer through the apex and off the other side of the track. Track out to mid-track.

apex turn 8
Treat turns 8 and 9 as one double-apex corner. Do not track too far out in the middle as the pavement drop off is pretty severe.

apex turn 9
Ride the curbing on curves 8, 9, and 10.

apex turn 10
Late apex 10 but get on the power early to increase the length of the straight. The point where the new track joins the old is quite bumpy so stay away from the track edge.

apex turn 11
Stay 3 feed from the edge in the braking zone to 11 to avoid more bumps. Turn 11 will really hook up when done right. Release the brakes as soon as the car starts to turn-in and power through the exit using the full track width. Cross over from right to left to set up 12.

entry to turn 12
Staying as far left as possible, turn in for 12 as soon as 12 and 13 line up and straight-line 12.

apex turn 13
Stay off of the curbing on 12 as it will really unsettle the car. Downshift and brake for 13 in a straight line. Some people are able to carry enough speed to brake once through 13 to set up turn 14. In the FWD MINI I have to release the brakes in 13 to get the car to rotate and can actually accelerate a little up the hill before turning-in for 14.

entry to turn 14
RWD set up 14 by going as deep as possible for the entry. FWD don’t go too deep or you won’t be able to cross the crown to get back to the apex of 14.

apex turn 14
The apex of 14 is very late. Stay off of the curbing. If you are tracking out to the edge of the track before the pit-in lane, then your apex was early. Cross over from right to left and do it all again.

Larger photos here.