Category: Information

MegaG+ Traction Magnet Measurements and Maximum Downforce Limits for Lites and Modified Classes

I took some measurements of a set of MG+ 1.7 IROC cars with Modified paper bodies, but other than that, stock out of the box cars with rear tire upgrades, including various sizes of Super Tires and a couple with Viper low-pro MG+ tires.

The average change in downforce when flipping a traction magnet is roughly .7 grams of downforce, which is reasonably significant. The measurements of the orange car are a bit suspect, but the others are fairly consistent. The Yellow lane car measurements were a bit of a surprise, but we’ve seen up to 6.3 in tech recently, which would definitely indicate a high-downforce orientation of N30 magnets in a Modified chassis.

MegaG+ 1.7 “Modified” IROC Set (stock rear axles, super tires, low-pro VSR tires)
Yellow Blue Orange Green White Red
VRP Meter (grams) 5.8 5.2 5.8 5.1 4.7 4.5
Flipped 6.6 6.1 5.7 5.9 5.4 5.4
Change 0.8 0.9 -0.1 0.8 0.7 0.9
Average Change (grams) 0.7
Gauss Readings Gs Range VRP Meter before/after flip (grams) Change
N30 (Stock) 2700 – 2800 5.5 6.8 1.3
N42 3200 – 3290 7.5 8.8 1.3
N52 3400 – 3600 9.7 10.8 1.1

The above N30 measurements were from one of my Modified platforms with N30 mags and a VSR replacement rear axle assembly with double-flange (.250) hubs and VSR PST Silicone soft Rear Tires (.432).  Some run the Lo-Pro VSR tires in both the Lites and Modified classes, which are slightly taller (.445). Aftermarket parts are only allowed on the Modified version of this car, so we shouldn’t see “Lite” cars with downforce much greater than 6 grams on the VRP meter and “Modified” cars with downforce not much greater than 7 grams on the VRP meter.

Of course, different VRP magnet meters can vary by up to +/- 5%. So, the maximum downforce for each class is as follows:

      • MegaG+ 1.7 Lites: 6.30 grams
      • MegaG+ 1.7 Modified: 7.35 grams

If a car’s downforce measurements exceed the above before racing, resolve the excessive downforce by using larger tires/hubs, or flipping a traction magnet. If a car has downforce greater than the above after a race, the car is disqualified from any races completed.

Note: If you're looking to get more downforce out a chassis, reduce the size of the rear tires (lower rear of chassis) to get more downforce. Lowering the chassis too much will result in slower top speed and usually slower lap times. It's a trade-off between speed and handling, find what works best for your driving style.

We may encounter modified-rules cars exceeding this maximum downforce limit due to unforeseen tire and/or hub sizes, or other factors. We’ll address that if/when it arises.

Please feel free to comment or discuss this addition to our MG+ rules here on the site or at our next event. Keep in mind, any rule can be changed if a majority of drivers/teams support it.

MG+ “Lite” Rules
MG+ “Modified” Rules

MegaG+ “Modified” Class Review

This simple class has proven to be a great success. Its rules are simple, the paper body transforms the car’s handling, it has faster lap times, and it is generally an enjoyable car to drive.

I know the paper body is only available from Stewart Raceway, but I’m sure others could figure out how to make one. In fact, Webster Motosports makes a slightly different style of body, which seems to work pretty well, too.

Our current MG+ Modified class is not all that “modified,” which begs the question: should we allow more mods in this class?

There are quite a few additional modifications that could be made:

      • Independent Front Ends from Viper
      • Aftermarket Rear Axle Assembly from Viper
      • Aftermarket Front and Rear Tires from Viper
      • 22T Crown Gears and Gear Bosses from Viper
      • Aftermarket Replacement FF-N20 Motor and/or Shoe Hanger Assembly from Jag Hobbies
      • Neodymium 45 or 52 Traction Magnets from Harden Creek

I’m sure there are other hop-up parts out there, but the point is that this car could be much more “modified” than we’re currently running it.

I recently tested the replacement motor assembly from Jag Hobbies and found it pretty slick, easy to install, and a nice upgrade to the stock motor. The chassis I used to test it was doing laps in the 5.8 range with its factory motor. After replacing it with the new Jag motor and hanger assembly, lap times dropped into the 5.4 range. It’s not a tremendous upgrade, but knowing there are alternatives is nice. There are also “hotter” motors out there that could be allowed.

To be clear, I am not pushing changes to our current rules for this car. I think a heavier and independent front end would be a simple but effective performance upgrade. Another modification we could allow is the high-downforce configuration using the stock N30 traction magnets. This rapid mod involves flipping one traction magnet to go from low to high downforce, which results in an additional 2 to 4 grams of downforce.

Again, I’m not advocating changes; I’m happy with the current rules. However, if enough teams/drivers want to change the rules, it isn’t out of the question.

Feel free to chime in via a comment below.

Operations Updates

SlotTrak Fuel Management Features Update

Many of you have suffered from the SlotTrak bug that can occur during a yellow flag situation. As power is cut to the lanes, the software does not detect or register that you have entered the pits. When the track goes green, your car doesn’t refuel. This is very frustrating, of course.

I haven’t fully tested the latest version of SlotTrak because the Fuel Management feature didn’t work with those versions. However, their update documentation indicates they may have fixed this problem in one of the latest versions. We tried to run the latest on SR2 and SR3 several times, but the software did not detect pit entries, rendering the feature useless.

We’re currently running version 16.24. I plan to upgrade both SR2 and SR3 to version 17.34, which is currently the latest version available.

Kevin and I figured out after the racing last Saturday that this issue was caused by the latest version install, which seems to corrupt the TrackConfig file by removing the Pit Detection setup. Once we realized this was happening, we updated the TrackConfig file, and Boom! All was good!

So, the bottom line is that we’ll test the fuel management features during a future racing event and see if the latest version solves that pesky refueling problem most of us have experienced in the past. Let’s hope so!

StewartRaceway.org Web Site Unsecure or Not Secure Notices

I didn’t realize this was causing people to stop using our site or become concerned that the site was somehow potentially harmful.

All this means is that keystroke data going to/from the site is not encrypted via SSL [SSL (Secure Sockets Layer) and its successor, TLS (Transport Layer Security), are protocols for establishing secure links between networked computers.]

StewartRaceway.org is not an eCommerce site. To utilize it, you do not enter private or sensitive financial or other information anywhere on the site, and it does not collect or store that sort of information.

Unless you’re concerned about a remote possibility that somebody out there may be able to capture the keystrokes your computer sends to the site when leaving a comment on the site, for example, there is no threat to you or your computer/network. This is no different than any other site you use that doesn’t utilize expensive SSL/TLS technology.

StewartRaceway.org can conduct eCommerce activities, but we don’t sell or buy anything on the site today. No financial or personal/private information is collected. If that changes, of course we’d employ SSL/TLS technology to make sure those transactions and associated data was secure and protected.

So, please don’t fret about this message. I don’t think Russians, government agents, or other bad guys are snooping around StewartRaceway.org. And if they were, all they’d find out is that we’re having a lot of fun racing little cars for no money!

Okay, shut up and drive!

 

2024 Open Wheel Series, Round 3: A Record Setting Day

Yep, Round 3 of the 2024 Open Wheel Series was a speed fest.

The big story is George Peters (GP Sports). George is a consummate builder, master tuner, and gifted artistic talent when painting and detailing car bodies.

George put down the fastest lap with a “SPEC STOCK” Viper V-SPEC platform, clicking off a 4.270-second lap in the SR3 Orange lane during Round 3 of the 2024 Open Wheel Series.

Sportsman driver Jerry Pearson clicked off a new lap record with a MegaG+ 1.7 Modified car in the IROC race in the White lane. Jerry won the individual MegaG+ Modified race, so he has some special skills with this platform, which suits his driving style well.

Aaron Castro continues to build his legacy at Stewart Raceway, setting numerous lap records in our individual classes. In our current premier Viper class, Aaron was just .139 seconds off George’s blistering record time and in the Blue lane!

Class Lane Time Driver
Viper V-SPEC SPEC STOCK Lexan 2 4.432 George Peters
Viper V-SPEC SPEC STOCK Lexan 3 4.320 George Peters
Viper V-SPEC SPEC STOCK Lexan 4 4.270 George Peters
Viper V-SPEC SPEC STOCK Lexan 5 4.409 Aaron Castro
MegaG+ 1.7 Modified 2 5.347 Steve Stewart
MegaG+ 1.7 Modified 3 5.233 Aaron Castro
MegaG+ 1.7 Modified 4 5.146 Aaron Castro
MegaG+ 1.7 Modified 5 5.328 Steve Stewart
Viper V-SPEC F1/Indy 1.7 (i) Lexan 3 4.826 Steve Stewart
Viper V-SPEC F1/Indy 1.7 (i) Lexan 5 4.668 Steve Stewart
MegaG+ 1.7 Modified (i) 2 5.921 Jerry Pearson
MegaG+ 1.7 Modified (i) 3 5.553 Aaron Castro
MegaG+ 1.7 Modified (i) 4 5.552 Aaron Castro
MegaG+ 1.7 Modified (i) 5 6.017 Steve Stewart
MegaG+ 1.7 (Scooby Doo) Vans (i) 2 7.680 Steve Stewart
MegaG+ 1.7 (Scooby Doo) Vans (i) 3 7.339 Steve Stewart
MegaG+ 1.7 (Scooby Doo) Vans (i) 4 7.530 Steve Stewart
MegaG+ 1.7 (Scooby Doo) Vans (i) 5 7.459 Steve Stewart

These drivers are crazy fast!

Track Day Report, February 17, 2024

Aaron and Kevin working on little cars.

What to do on a rainy day? Play with slot cars, of course!

We had no Junior drivers in the mix for the first time in a long time.

Eric “Fast” Lane was the first driver to show up and the first to leave but not without testing out some tweaks to his IROC fleet of “Scooby Doo” vans. Eric and I did one race with those and the tweaks appear to have improved these already fun-to-drive cars. It was just the two of us but we did a full rotation with all six cars to flush them out.

Shortly after Eric departed, Webster Motorsports and then Aaron Castro of Team Forza, showed up. Kevin and Aaron worked on a few MegaG+ cars before racing broke out. The three of us ended up doing about five fuel and tire wear races, running well into the night.

Aaron’s 1965 Shelby GT350 Mustang on a MegaG+ chassis, very cool new AFX/Racemasters offering.

The highlight of the day was adding Tire Wear to the racing formats. This is a feature of SlotTrak that we hadn’t used before. Similar to Fuel Allocation in the Race Management settings, Tire Wear is an additional factor that can be injected in addition to fuel stops. We found out that it works pretty much like the fuel allocation, when you wear out a tire, power is cycled just like running out of fuel. Fuel races make things more interesting, for sure, but adding tire wear into the equation and things get even more interesting and challenging.

New Lexan F1/Indy bodies for the Open Wheel Series fitted to the Viper V-SPEC “SPEC STOCK” chassis in the standard wheel base configuration.
Top: Lexan Sprint Car bodies for a, hopefully, Round 2 Tyco 440-X2 IROC set being prepared by George. Bottom: New Lexan for our “SPEC STOCK” Vipers. Hopefully, we’ll have enough to go around and debut them in Round 2.

We started with 25-lap heats and then upped it to 50-lap heats with a 25-lap fuel allocation and a 75-lap tire allocation, with each driver starting the race having one tire 25% worn. Made for some interesting but exciting pit strategies and seemed like more competitive racing. We’ll try this out in Round 2 and see how everyone likes it. Might be a bit too much for the Junior drivers, we’ll see.

New Lexan Sprint Car body on a Tyco 440-X2 narrow chassis.

Okay, Round 2 is currently set for next Saturday, February 24. Stay tuned for more details but this round will be on the SR3 Oval.

Okay, shut up and drive!