Building and racing the new OS3 TFX
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jrrc
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That was another very informative video. I am expecting my OS3 TRX car tomorrow. If it arrives early enough I will do some testing right away. I will be off racing the following day. A fellow club member did get his cars a couple of days ago and was quite pleased with them. Out of the box with only oiling and pickup shoe adjustments the cars were slower than a full blown T-Jet SS car as you might expect. He checked the cars on a dyno and ran laps on his Bucktrack road course. The cars were all run without bodies. I plan on doing my own testing using both Trans-Am and Fray style bodies. The one modification that he tried was to score the bottoms of the motor brushes to keep them from spinning, that resulted in a fair improvement in the dyno readings as well as in the lap times.
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My OS3 TFX arrived today, I oiled it, adjusted the pickup shoes, snapped in the guide pin and trimmed it to the proper length. The pickup shoe tension measured 2.8g, the tires were 0.352” in diameter as advertised. The axle, armature shaft and cluster gear shaft holes were the correct diameter and the idler gear was a perfect fit on its post. The armature measured 17.1 ohms at 75°F. The total weight with a Fray Lamborghini body and screws was 18.2 grams. The downforce measured 8.6 grams on my homemade tester compared to 24.3 grams for a 2nd generation T-Dash with Killer Bee magnets. I will measure the TFX magnets when I get a chance. At 18 volts the car read 2.40 on my VRP dyno, my regular cars were already prepped and packed away for tomorrow’s race, I will run some of the pancake cars on the dyno later on.
I ran the car around my ~50 foot MaxTrax road course without a body using an OS3 All Pro Elite controller, a small amount of brakes was needed. The car ran smoothly with some humming from the gears at higher speeds. The car had good acceleration and top speed. Rear grip was a limiting factor, the car never deslotted, it would just spin out at the limit. The tires did seem to get better as they scuffed in. The best lap time was 5.745 seconds compared to a full race T-Jet SS with silicone on sponge tires at about 5.4 seconds. With an Auto World ’70 Camaro body the car did 5.985 seconds and I had to turn the brakes up a notch. With a Fray type Lamborghini body the best lap time dropped to 5.595 seconds. I intend to try different tires in the future, with more grip the car may need more weight up front, an inexpensive E-Fray type front end might do the trick.
I was very pleased with the car, it runs great with no tweaks, if we do not run them in a new class we will probably have some for IROC style racing.
I ran the car around my ~50 foot MaxTrax road course without a body using an OS3 All Pro Elite controller, a small amount of brakes was needed. The car ran smoothly with some humming from the gears at higher speeds. The car had good acceleration and top speed. Rear grip was a limiting factor, the car never deslotted, it would just spin out at the limit. The tires did seem to get better as they scuffed in. The best lap time was 5.745 seconds compared to a full race T-Jet SS with silicone on sponge tires at about 5.4 seconds. With an Auto World ’70 Camaro body the car did 5.985 seconds and I had to turn the brakes up a notch. With a Fray type Lamborghini body the best lap time dropped to 5.595 seconds. I intend to try different tires in the future, with more grip the car may need more weight up front, an inexpensive E-Fray type front end might do the trick.
I was very pleased with the car, it runs great with no tweaks, if we do not run them in a new class we will probably have some for IROC style racing.
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Thank you for the report.
Sounds like they hit the bullseye!
Sounds like they hit the bullseye!
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The nose, sides, and tail lights scream Porsche Carrera GT to me. But I know nothing (except for that little screaming voice. Very puzzling).
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I was thinking the wheels would look better painted (or molded {moulded?}) something other than bright red.
Black is better, I would suggest that silver (or grey) would be better yet.
& yes, thank you Rich for your efforts. Does Supertires have anything off the shelf for these or will they/you be developing some?
Black is better, I would suggest that silver (or grey) would be better yet.
& yes, thank you Rich for your efforts. Does Supertires have anything off the shelf for these or will they/you be developing some?
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It looks like that body is indeed a Porsche Carrera GT. I will have to change the file name for that picture!
I checked the magnets and they measured 555 and 565 gauss, that is a bit less than the most powerful Aurora T-Jet magnets, the green/orange ones that measure 600-650 gauss. In the future I may try 850 gauss magnets.
Super Tires has the 340R Pro Series tires that are 0.350" on a 0.170" wheel and 344Rs that are 0.354". I plan on getting some of both in the regular silicone formulation as well as in the Silver Edition formulation.
328Rs would be 0.352" on a 0.188" diameter wheel.
I checked the magnets and they measured 555 and 565 gauss, that is a bit less than the most powerful Aurora T-Jet magnets, the green/orange ones that measure 600-650 gauss. In the future I may try 850 gauss magnets.
Super Tires has the 340R Pro Series tires that are 0.350" on a 0.170" wheel and 344Rs that are 0.354". I plan on getting some of both in the regular silicone formulation as well as in the Silver Edition formulation.
328Rs would be 0.352" on a 0.188" diameter wheel.
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I got some tire testing with my OS3 TFX car today. I had a Vonco Porsche Carrera GT Fray style body on the chassis. The Lamborghini body that I used for my initial testing actually works better with the car.
The stock tires are perfectly satisfactory for casual running, but on my track they tend to go off very quickly. I can do a couple of quick laps before the car starts to slide a lot. Before I begin tire testing I wipe the track down with a special dusting cloth, then run a magnet car with sponge tires with a little traction compound on them for about 25 laps, then another car with slip on silicone tires until the grip does not change much as the laps pile up. I run a couple of air purifiers while the testing is going on. I used the tire cleaner that Ed Bianchi makes.
With the stock 0.352” OD tires I was able to get down to 5.783 seconds on my ~50 foot MaxTrax road course, but within five laps the car was sliding a lot. It became difficult to do a lap where the car did not slide out enough to lose time and the lap times after that were over 6 seconds. At the limit the car would spin out.
With 344RF tires (0.354” mounted OD) the best lap time was 5.642 seconds and the drop off as the laps piled up was only one or two tenths of a second. There were few spinouts those tires. With 344RSE tires the best time was 5.716 seconds, that was a surprise because they are usually good for another 0.1 to 0.2 seconds less than regular silicone slip-on tires. The car did not get loose as the laps went by, but the front end would come out of the slot at the limit. With 340RF tires (0.350” mounted diameter) the best lap time was 5.675 seconds, as with the other aftermarket tires the lap times did not fall off by much and the car was only slightly loose at the limit. With 340RSE tires the best lap time was 5.621, the times did not increase by much after 30 laps or so and there was not the front end understeer problem that I got with the 344RSE tires. I am guessing that the car has a smidge more magnetic downforce with the 0.004” smaller diameter tires. That would tend to increase cornering speeds while the top speed would go down slightly.
Note that the aftermarket tires were a little loose on the stock wheels and those wheels were a little too narrow for the tires. A fanatic would probably want to switch to the appropriate CNC machined double flange wheels.
Finally, I finished up with the stock tires, the lap times did not change from what they were at the beginning of the test session.
If the stock tires had been able to maintain their best lap time the difference would seem to be slight, but it would in fact be significant to a hardcore racer. During a 12 minute race the stock tires would do 124.5 laps and the best (at least for me) aftermarket tires would be good for 128.09 laps, a 3.5 lap advantage.
Note that my track favors cars with a lot of top speed and it has few joints to upset a car. On a twisty track, and especially if it was a little bumpy the SE tires would probably have a greater advantage.
The stock tires are perfectly satisfactory for casual running, but on my track they tend to go off very quickly. I can do a couple of quick laps before the car starts to slide a lot. Before I begin tire testing I wipe the track down with a special dusting cloth, then run a magnet car with sponge tires with a little traction compound on them for about 25 laps, then another car with slip on silicone tires until the grip does not change much as the laps pile up. I run a couple of air purifiers while the testing is going on. I used the tire cleaner that Ed Bianchi makes.
With the stock 0.352” OD tires I was able to get down to 5.783 seconds on my ~50 foot MaxTrax road course, but within five laps the car was sliding a lot. It became difficult to do a lap where the car did not slide out enough to lose time and the lap times after that were over 6 seconds. At the limit the car would spin out.
With 344RF tires (0.354” mounted OD) the best lap time was 5.642 seconds and the drop off as the laps piled up was only one or two tenths of a second. There were few spinouts those tires. With 344RSE tires the best time was 5.716 seconds, that was a surprise because they are usually good for another 0.1 to 0.2 seconds less than regular silicone slip-on tires. The car did not get loose as the laps went by, but the front end would come out of the slot at the limit. With 340RF tires (0.350” mounted diameter) the best lap time was 5.675 seconds, as with the other aftermarket tires the lap times did not fall off by much and the car was only slightly loose at the limit. With 340RSE tires the best lap time was 5.621, the times did not increase by much after 30 laps or so and there was not the front end understeer problem that I got with the 344RSE tires. I am guessing that the car has a smidge more magnetic downforce with the 0.004” smaller diameter tires. That would tend to increase cornering speeds while the top speed would go down slightly.
Note that the aftermarket tires were a little loose on the stock wheels and those wheels were a little too narrow for the tires. A fanatic would probably want to switch to the appropriate CNC machined double flange wheels.
Finally, I finished up with the stock tires, the lap times did not change from what they were at the beginning of the test session.
If the stock tires had been able to maintain their best lap time the difference would seem to be slight, but it would in fact be significant to a hardcore racer. During a 12 minute race the stock tires would do 124.5 laps and the best (at least for me) aftermarket tires would be good for 128.09 laps, a 3.5 lap advantage.
Note that my track favors cars with a lot of top speed and it has few joints to upset a car. On a twisty track, and especially if it was a little bumpy the SE tires would probably have a greater advantage.
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My track has gotten a great deal of use lately so now it is really in top shape. The track is now in its oval condition, which is not ideal for tire testing however. I ran some laps yesterday and the stock tires held up very well as the laps went by. Previously they went off quickly while the aftermarket tires that I tried lasted a lot longer. I made up a couple of rear axle assemblies using TFX axles and CNC 0.170" DF wheels, one has a 15 tooth crown gear and one has a 19 tooth crown gear. With the 19 tooth crown gear the car was just over 0.2 seconds slower around my 35 foot MaxMrax oval.
With the stock rear axle assembly and 0.352" OD tires the car was a bit faster than with the DF wheels and 0.354" OD tires. It looks like the folks at OS3 did some testing before they settled on the 0.352" diameter.
With the stock rear axle assembly and 0.352" OD tires the car was a bit faster than with the DF wheels and 0.354" OD tires. It looks like the folks at OS3 did some testing before they settled on the 0.352" diameter.
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In layman's terms. The lower the Ohms, the faster the armature spins. Low Ohm armatures are meant for faster cars and will draw more amperage.
5-Ohms = Makes cars little bullets that are hard to keep on the track for a newbie racer. Great for drag-racing with track magnets.
14-Ohms = Great for casual racing on a Sunday afternoon.
It's fun to have at least 2 of each.
5-Ohms = Makes cars little bullets that are hard to keep on the track for a newbie racer. Great for drag-racing with track magnets.
14-Ohms = Great for casual racing on a Sunday afternoon.
It's fun to have at least 2 of each.
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As someone who has patents in my name owned by my employer, I take a different perspective. I feel honored when someone takes my ideas and runs with it.
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"As someone who has patents in my name owned by my employer, I take a different perspective. I feel honored when someone takes my ideas and runs with it."--cbwho
As well you should. My comments to Model Murdering were in jest. Really, whatever I say probably should be taken with a grain of salt.
As well you should. My comments to Model Murdering were in jest. Really, whatever I say probably should be taken with a grain of salt.
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I just worked with an already existing concept. Raising axle heights to drop the ride height came shortly after fire and the wheel.
Cant take a brownie button for that.
If your up on T-jet mods of the past, the TFX is Mr Humble Mark Owang all the way. I'll bet lunch he's either involved, or his ground breaking work served to inspire others.
Cant take a brownie button for that.
If your up on T-jet mods of the past, the TFX is Mr Humble Mark Owang all the way. I'll bet lunch he's either involved, or his ground breaking work served to inspire others.
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Usually a car with a lower ohm value armature will have more power, but that is not always the case. Aurora T-Jet armatures were mostly about 16 ohms. Later A/FX cars often had 6 ohm armatures, which could sometimes be more powerful, but not always. More power is not always a plus if you end up with a car that you can't drive.
I just got a couple of tweaked Typhoon armatures from OS3, a 16.5 and a 5.5 ohm. The tweaked armatures are balanced and have had the commutators trued. I believe that Bacher, who did the tweaked Aurora Tornado arms, is doing the Typhoons. NOS Aurora armatures that were worth working up became very difficult to find, so Tornado armatures have not been available for several years.
I just got a couple of tweaked Typhoon armatures from OS3, a 16.5 and a 5.5 ohm. The tweaked armatures are balanced and have had the commutators trued. I believe that Bacher, who did the tweaked Aurora Tornado arms, is doing the Typhoons. NOS Aurora armatures that were worth working up became very difficult to find, so Tornado armatures have not been available for several years.
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Tornados and Typhoons ... Oh my!
Now we gotta be meteorologists to play slots.
Im looking forward to your comments down the road, re: the typhoons.
Now we gotta be meteorologists to play slots.
Im looking forward to your comments down the road, re: the typhoons.
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It may be a while before I get a chance to try those armatures, but I will be sure to post something when I do. Thus far I just checked the ohms, they were a tenth higher than the specified value, but I measured them at 70°F. I believe that 68°F is the standard temperature. The resistance will go down as the temperature goes down. I will have to check the balance as well.
HOCOC will be doing a demonstration race for TFX cars at our next event. Here are two cars that I prepared for that.
![Image]()
HOCOC will be doing a demonstration race for TFX cars at our next event. Here are two cars that I prepared for that.
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