Road to the 2024 Snowbird Nationals

[Iowa crawler]

Yup
This is off the rule sheet.

Motor:

Must use Dynamite 20T brushed motor. Motors can not be opened from original factory state. You can solder direct. No fans allowed on the motor during racing. No 'freezing' motor with the intent of motor to be below ambient temperature at the start of the race. Clip-on heat sinks allowed.



Winners or TQs motor can be claimed for $20 by any other racer in that class (end of event)(first come first serve)(must be in the A- main).

 

[Mtbmatty]

I wonder if someone has gone so far as to buy another dudes motor. Seems odd, I would think at that point in the game it would be fair to ask a judge to inspect the motor with the owner and the whiner

 

[Iowa crawler]

I wish I could kick someone’s ass so bad they bought me a new motor.

 

[Iowa crawler]

Just an update. Everyone is back from the 2023 Snowbird nationals. They had a great time and are pumped for next year .
It’s great to race with these guys and get an idea what I’m up against.

So I want to run two classes. Busch pro and 21.5 super truck. That’s enough to have fun without sitting around to much or having to much to keep track of. Both cars use a similar chassis.
Here is the rub. Currently I am racing Busch lite. Not Busch pro. If I run Busch pro I can never run Busch lite again. ( track rules) and there are a lot of people in Busch lite. So I’m not ready to change.
For the 21.5 super truck it’s a pretty popular class and I’d be competing with pros.
So for the time being or until I get a 3.6 second lap in Busch lite or win two races I’ll stick with Busch lite.
Now I need to build a 21.5 truck. So this is it
Avenger chassis
Hyperdrive front suspension.
Foam tires
The motor I have to use is a spec 21.5 Gravity RC motor
Tekin RS ESC set to 1 s
One cell battery
And a pickup truck body.
So far I have the chassis and the front end together

So this is the new chassis. It will be a couple weeks before I can get any electronics. I put in the tekin motor just to test it out .

 

[Iowa crawler]

As I am sitting here looking at the photo of the truck body and starting to go through all the color choice BS AGAIN. I got lucky. It’s done and I can do this .
The box art is actually pretty cool. The stripes on the side look like the ICE or the white semicircle at each end of the track. This is a slippery area that you don’t want to touch and define the inside edge of the corner. I’m going to paint the front purple. Like plum crazy Mopar purple with white on the back and a black stripe that changes thickness to give a 3-D look of the white corner of the oval and a white stripe to look like a lane . Basically the box art for the Protoform but purple instead of blue. And more paint on the back bed.
The color is tricky. Its PS45 translucent purple backed with silver and black. But you got to put on a bunch of really, really thin coats. If the coverage of the purple is not perfect and very thick the silver shows through like dust. And if you try to get too much paint on at one time it will fisheye and you’re done. So that’s the only trick.

 

[Iowa crawler]

I got a couple small parts today.
I have found a couple boutique shops that specialize in oval racing. I did not realize oval racing was so popular in the Midwest. There are a number of shops that specialize in carpet and dirt oval racing.
The first car I bought with the Superbird body is called an avenger and is designed and built at my local track .I bought the first one as a complete car. This 21.5 truck I bought as a slider and am putting together the suspension using my many weeks worth of experience.
So I found these parts made of stuff called Turcite. Super strong and slippery. The pivot balls have oil groves. And the spring keeper hold the spring in center so they can’t rub the king pin. The oil will act as a damper so thicker oil on the king pin will smooth out the suspension action somewhat. And I got some shims to adjust ride height.
Little pieces of a big puzzle.

 

[Iowa crawler]

Well that was just two hours of BS I did not want. I picked up my 21.5 USGT motor. These things are super hard to get. I intended to pair it with a Tekin RSPro ESC and run a 1 cell lipo.

So I soldered the new motor in and it would not work. I played around with different setting and nothing. I switched it to a 2 cell and it worked great. So I started reading the VERY good instructions that come with the ESC and it has troubleshooting. The code I’m getting is wrong motor. And I checked everything twice. Then I read it says to try a different motor. And another thing is a possible bad solder joint. Now I pride myself on my solder, brazing and welding. But I’m also humble enough to know my junk don’t work. So I solder in a 21.5 Tekin motor and plug in the sensor wire and switch it back to 1 cell and it worked. Yaaa. Then I just swap the Tekin 21.5 for the new USGT 21.5, say a prayer and IT WORKED. Must have been a cold solder joint. So now I have the suspension and electronics together. A few more details and the body and it should be ready to race. Watching the pros today at the track the 21.5 Super Trucks are turning 3.2-3.5 second laps.

 

[Doom!]

Well that was just two hours of BS I did not want. I picked up my 21.5 USGT motor. These things are super hard to get. I intended to pair it with a Tekin RSPro ESC and run a 1 cell lipo.

So I soldered the new motor in and it would not work. I played around with different setting and nothing. I switched it to a 2 cell and it worked great. So I started reading the VERY good instructions that come with the ESC and it has troubleshooting. The code I’m getting is wrong motor. And I checked everything twice. Then I read it says to try a different motor. And another thing is a possible bad solder joint. Now I pride myself on my solder, brazing and welding. But I’m also humble enough to know my junk don’t work. So I solder in a 21.5 Tekin motor and plug in the sensor wire and switch it back to 1 cell and it worked. Yaaa. Then I just swap the Tekin 21.5 for the new USGT 21.5, say a prayer and IT WORKED. Must have been a cold solder joint. So now I have the suspension and electronics together. A few more details and the body and it should be ready to race. Watching the pros today at the track the 21.5 Super Trucks are turning 3.2-3.5 second laps.

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Sometimes things just go that way, if for no other reason than to test your sanity.

 

[Iowa crawler]

I got the chassis finished on my 21.5 super truck class pan car. The body is ordered but now I can start testing and tuning. The rear wheels spin at over 6000 rpm with that giant pinion. It’s at 58 tooth.
Buy comparison my Busch light has a 23 tooth and the tires spin at 4000 rpm.

 

[Iowa crawler]

I finally got out on the track. Still no body or cut tires but just to drive it around.
First of all the Tekin RS pro has one cell lipo capability. But I tried a lot of different things and I cannot get the brakes to work on 1S. Works on 2S and I can get brakes to work with a Tekin RSX but not the pro. And the RSX is too large to fit the chassis. I need the pro for my buggy so I now need a 1s speed control. And the Hobbywing is perfectly suited.

Next thing is my driving impressions.
The rear tires freewheel to 6000 rpm. And I am running a 58/84 gear set. The motor is 21.5 brushless with a 1S battery. So it has no torque at all. But once it gets moving. It is very very fast. The object of this game is momentum and picking the proper gear set to keep the rpm constant around the oval. A small pinion might be good for accelerating out of the turn but not getting to top speed. A big pinion might be fast in the straight but coming out of the turn it won’t accelerate well. The balance is the driver The track conditions and the gearing. 3.5 second laps will be interesting. Hopefully I get the truck ready for the summer season.

 

[Iowa crawler]

I finally got the chassis and all the electronics sorted out.
Ended up with a hobbywing XR10 pro heavy duty 1S Edition. It has 120 amps and can handle the load. And now I have breaks. Don’t really use them for racing it’s more for lining up and pulling off the track.

Next is the body and then tuning.

 

[Iowa crawler]

Finally got the body and paint done. This is my most adventurous paint job yet. I made few mistakes but I think the next body will be better.
The white curve is meant to look like the white center or the “ice” swooping around. The black is the carpet and the purple is the color of the chassis maker. It’s an Avenger chassis.
Now I have to tune it Friday night and race it for the first time Sunday.

 

[Iowa crawler]

I competed in my first pro race this weekend. It did not go as planned that’s for sure.
I entered the 21.5 super truck class and was all set.
The truck was brand new and I only drive it a couple laps.
I did not have brakes or reverse so I needed to buy the Hobbywing digital interface to program the ESC.
Well I apparently pushed the button changing the mode. Went from mode 1 blinky to mode 5 . Mode five is for dragsters . So I go out and test the brakes never really use reverse but it’s nice to have in practice. So my first race the motor thermals out at 59 laps. The motor was 220 deg.
Now I tested the rear tire rpm and noticed it was spinning over 14000 rpm and was dropping fast. So I changed the gear from 58 to a 52 tooth pinion.
Second heat the motor thermals out at lap 65.
Now I’m curious, panicking and frustrated. So I ask for help. Everyone was so nice and super helpful. After the second thermal someone said it must be in the ESC try a reset. Before I had a chance someone said it is supposed to be in blinky mode. That’s when we figured it out. Now the back tires spin 6000 rpm with the 58 tooth pinion.
But I forgot to put traction compound on my tires. So in the B Main I finished last. But I finished a five minute race and the motor was 125 deg and my fast lap time in the qualifying heats was fast enough to be competitive. So over all I’ll call finishing last a win.
BUT now that I entered that race I can no longer run in the sportsman classes.
Now I have to convert my Busch light car to a Busch Pro car. That means I have to change body's.
Then go from 4 cell nickel metal battery to 2 cell lipo. And I can range from 21~26 pinion.

The car are now 3.5 second laps for the 21.5 truck and the Busch pro can go 3.0 second laps and about fifty miles per hour.
The wall are kinda unforgiving at those speeds.

 

[Iowa crawler]

I spent four hours practicing and tuning today. The new Busch Pro car ran a 3.2 second lap with a professional driver. I was able to get 3.4 ( a personal best) and a consistent 3.5 second lap times.

Still a lot more to do. I bought new front tires for the Busch pro. That helped me get a couple tenths. It’s really about as fast as I think I want to go. It really is flying.

The 21.5 Super truck feels like it is stuck to the track with magnets or something and turns 3.7 laps.

 

[WickedFog]

I spent four hours practicing and tuning today. The new Busch Pro car ran a 3.2 second lap with a professional driver. I was able to get 3.4 ( a personal best) and a consistent 3.5 second lap times.

Still a lot more to do. I bought new front tires for the Busch pro. That helped me get a couple tenths. It’s really about as fast as I think I want to go. It really is flying.

The 21.5 Super truck feels like it is stuck to the track with magnets or something and turns 3.7 laps.

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Love that paintjob! You gotta post some vids!