2019 CanAm Proxy Round 4 - PMCC, SoCal

[gascarnut]

Welcome Race Fans to the Pebblestone Model Car Circuit, for Round 4 of the 2019 HRW CanAm proxy series.

We intend to run this round on Saturday August 3rd, but that is subject to confirmation. Failing that date, the next available slot will be Saturday August 17.

For those new to Proxy racing or to HRW, a word about PMCC:

119 Under lights 02.jpg

PMCC is a three-lane wood track of 60 feet and 3 inches per lap. Each lane is equally long, but not equally fast, with the "outer" red lane being about 0.2 seconds faster than the center blue lane, and it in turn another 0.2 seconds faster than the "inner" yellow lane. Most of this is due to the combination of tight and wide turns and where they are situated around the lap.

We have hosted many Proxy events here over the last 9 years or so, and our drivers enjoy them enormously. Most of the drivers will be regular racers from either the 1/24 scale Retro racing scene at Buena Park Raceway, or racers who run at the Los Angeles area Farr-Out club, or both. All the drivers will be familiar not only with the PMCC track but with the processes used for Proxy races. They all run here often and all have their own 1/32 cars so they know how these cars work.

The track surface is MDF, painted with UMA (urethane modified acrylic), a paint that provides very good grip for many types of tire. We will however run lots of laps on rubber tires to prepare the track for this proxy. Since the track stands on a covered patio rather than in a garage or a basement, the local temperature and humidity does affect the traction somewhat. Normally at elevated temperatures the grip can go off a little, so we hope that our current heat wave has abated some by the time we race. Contact is by non-magnetic braid, recessed .005" below the surface.

Power is via a Pyramid PX26 adjustable power supply that will be set to 11 volts for the race. Much experimentation has established that voltage as the optimum for the cars and tires we are using in this event. Controllers are up to the individual drivers, but most everyone uses the track controllers, which are Professor Motor Diode units with adjustable brakes.

Racing will take place as follows

- I will pre-qualify the cars before the event, by running each car for 1 minute on the center lane and recording the fastest lap.
- Come race day we will use 6 drivers, and divide the field into two groups based on qualifying. Group 1 will be run for two minutes on each lane by three drivers, then again for two minute per lane with the other 3 drivers. Then Group 2 will run two minutes per lane with the first set of drivers and again with the second set of drivers. This way, each car gets 12 minutes of racing with 6 drivers each. Drivers will run on one lane only with the cars rotating through the lanes. This process allows the drivers to relax a little and not have to run 25 heats in a row.
- All the results will be combined to get the cars with the highest lap totals, regardless of the Group in which they raced.

I trust this is helpful to all. Please check back for updates in the following days.

[gascarnut]

Update #1: Car Inspection

I have unpacked Allan's very sturdy box and performed a quick inspection on all the cars. Aside from deranged braids from the packing and shipping, and what is obviously some race damage from earlier rounds there is not much to report.

I have re-attached the mirror on the #25 McKee as this was in a baggie taped to the inside of the box.

I also reattached one fender strake on the #70 McLaren. I managed this without getting any superglue in the motor or rear axle bearings, although I must admit it was a struggle.....

[Smokeio]

[Brumos RSR]

Thank you for the explanation of the race format and details of the track and it's surface. Good luck to all the builders in qualifying.

[Doubl-B]

Gascarnut:
That is awesome that each car is getting 12 minutes of driving with 2 different drivers in each lane!
Should be an exciting race! Can't wait for race day. Good luck to all - especially us back-runners...
BB

[Audi1]

Thanks for the update, Dennis. Looking forward to the Round at PMCC!

Allan

[gascarnut]

As we move toward the weekend and Round 4, we can report that Qualifying took place here yesterday.

Under perfect conditions (warm but not too hot), I ran the cars first in number order to check that they were all running without issues. I'm pleased to report that they were.

Then I ran each car in a random order for 1 minute on the center blue lane of the track. Before each run I cleaned the braids of each car, and cleaned the tires on a sticky pad. If I de-slotted during a run, I hit the pause on the TrackMate timer and re-slotted the car before continuing. Each car's best lap time was recorded, and the results look like this:

Quali times and comments.JPG

I have attached the original Excel sheet as well for those who can open it.

Some general comments on the cars:

It has to be said that there are some super-fast cars in this field. I think the times shown represent the fastest total field of Proxy cars we have ever seen here. The TQ time is the fastest ever seen in a Proxy, beating out my own 2016/7 Gp5 car that clocked a 5.452. Also, there are more cars under the 6 second mark than ever before.

For comparison purposes, I ran a few of my tuned-up Thunderslots and Slot.it cars. These all use the stock chassis and have N22 tires on the rear. Generally they carry little to no extra weight. My TS McLaren M6 ran 5.581, My Lola T70 ran 5.755, a Slot.it McLaren M8D clocked in at 5.582, and my Chaparral 2E at 5.913 with its wing mounted.

For those at the blunt end of the qualifying, some advice:

First off, glued and trued tires, front and rear are a MUST. Also, as good as the Slot.it stock tires have become, they do not cut it at this level of competition. The compounds to use here are Slot.it N22, the stock Thunderslot compound, and NSR Ultragrips. Super grips are OK, but can't quite hang with the others.

Secondly, many of these cars, while fast, have the feel of swinging a hammer on the end of a rope. There's just way too much rear end drifting to be really fast, and that all comes from excess rear weight. The way to get grip at the rear is NOT by adding weight at the rear, it is by using grippier tires or taping the frame or using a spring suspension. This is one of the reasons no-one uses a long can motor in Proxies, too much rear weight (along with too much low end torque).

Thirdly, pay more attention to the way the guide moves and how the braids are set up. Some cars have very sloppy guide movement, some have the guides so tight they won't self-center. Super-long, or super-short braids are not the way to go. The braids should be as long as the flat base of the guide for support. Anything more than that and you run the risk of them getting tangled and twisted during racing. Anything shorter and the contact may be impacted.

Once the race has been run there will be more comments. Some of the cars are good in a 1-minute qualifier, but may not translate that into a 2-minute race as their grip goes away quite fast after the tape cleaning. Others will do better as they maintain good traction all the way through a run.

This track in the past has often provided results that differ a lot from others in the series, so expect some surprises!

I hope this helps.

[wanabgts]

Thanks for the qual Dennis. Interesting my car now chatter, hopefully a tire isnt coming unglued. It has been reported as being exceptionally smooth up until now, and I never had a lick of chatter in my testing. Never the less the pace does seem to be on par with my results!

Zack

[FC47]

Thanks Dennis for the efforts,

Tires were glued here..non stock rears

Regards

[gascarnut]

[gascarnut]

[FC47]

Thanks for your insight to the builds Dennis, it’s worth a lot. Fronts are glazed stocks, rears are P’s or C1? I didn’t super clean them before using hard as nails in their centers..didn’t work I guess, sorry it’s a slug, you guys may feel free to leave it aside, save some time for y’all.

Thank you for the help man,

[Brumos RSR]

Sir Gascarnut, thanks for the notes, added advise and qualifying of the cars. I knew the 70 would show up, it was just a matter of time. Congratulations Smokieo on your pole position, DRW21 that car is sooo consistent and I'm not surprised by the 76 rounding out the top 3. It looks tight throughout the field which will add to the fun and excitement. Good luck to all the builders on raceday.

[bov]

Hello Dennis - greetings from tomorrow and the other side of the world....

Happy to see my #12 Zep-Mobile up towards the font end of the field - maybe this is a track that the Sideways rear tires half get along with......

Appreciate your general thoughts, and I agree that I have too much rear weight bias in the car, things to learn from going forward....

And fully agree with your thoughts that rule compliance should not be optional...

[Fast Co.]

Great report Dennis. I do not have a dog in this fight, but I hosted Round 3 and am following this proxy. Gleaning ideas for my entry in the GT3 proxy this fall.