Well I have been thinking about this competition a lot since it was announced and despite me making my mind up early on that I would not be competing I still had several thoughts as to what I would build.
Now most people are going to go after the 2S class simply because most people have chassis and power systems that will put them there. I do think lots of people will want to run in the unlimited class but most will not officially enter as it takes a unbelievable amount of power to push a car to 150+ mph and the bigger and heavier it is the more you need . So I really feel those that actually enter the Unlimited class will primarily be made up of people who really have experience in this and already have a purpose built high speed car.I can say I could be completely wrong though . So if you have plans to run in the unlimited class more power to you but don't get your hopes too high.
If you need inspiration on the power needed the current high speed champ is Nick Case . He used a NEU 1521 motor with a 1577kv rating running on 12S or roughly 50 volts .
Now I would like to point out http://scriptasylum.com/rc_speed/solver.html Has a lot of calculators that will greatly help a person with there fighures if they want to do speed runs .
So what would I build for the unlimited class. well so far I decided I would need a chassis that is cheap and has the flexibility to be geared really high and that could be set up with lots of room for a high voltage system . At this point i think I would be looking at the Sakura D3 CS drift. In stock form it would need lots of modifications just like any other chassis but I feel the front mounted motor provides a lot of advantages . Since its mounted in front of the front wheels it opens up the center of the chassis to allow more space for batteries. The fact that with a simple front diff gear and center gear swap using essentially stock parts will give it a 1.36 diff ratio makes it look even better. Basically that means you could have up to a 4.77 rollout with common parts and that equals a lot of wheel speed.
So what would be my main fear with this chassis?
The belts .They have several advantages over a shaft drive chassis but can they handle the load that would be put on them powering a car at triple digit speeds? I have no Idea .
Wait what about 2S? Well thats pretty simple You want a mixture of the minimum and maximum you can get. You want the minimum chassis in other words you want it light weight and the most powerful motor you can get your hands on a small front profile helps also. Since this is so much simpler I actually have a parts list containing most of what would be nice for someone on a budget to buy .
1: RJ Speed 24" dragster Kit $99.99
2: Turnigy Trackstar 4.0T motor 8240KV $32.63
5: Turnigy TGY-4409MD metal gear servo $12.84
6: Bearings (4) 1/8 x 5/16 flanged and (2) 1/4 x 3/8 flanger (Avid brand: standard $6.00)
7: Transmitter and receiver of your choice .
6: Bearings (4) 1/8 x 5/16 flanged and (2) 1/4 x 3/8 flanger (Avid brand: standard $6.00)
7: Transmitter and receiver of your choice .
Theoretically using the included 20 tooth pinion and spur gear and the motor listed above the car should theoretically top out over 100 mph . Another option if you can wait would be the Turnigy Trackstar SCT 4T 550 motor as its rated at 960 watts and it has a theoretical top speed of 140 mph with proper gearing. Of course these speed are not actually as far as things could be pushed as this is going off of motor specs for a one shot run they could be pushed much further. The main problems at these speeds would be maintaining control and finding a proper area to run .
