Nitro 4-Tec conversion

[lincpimp]

So I acquired a Nitro 4-Tec for a guy who had tried to convert it...

All I can say is that it is not pretty. Needs belts, he mangled most of the uper deck parts trying to make room for the battery, and his wiring must be seen to be believed...

So I tore most of it apart, replaced the steering servo, and had a look at what I could do. The car came with a mm/5700 combo, and he was running it with a maxamps 6300, 3s lipo, 9 2100 cells in a 3s3p config. With the stock gearing of 1st gear 15/45, and 2nd gear 19/41, it was good for over 100mph on paper... It could not pull the gearing, and stay cool, needless to say.

You have to admire someone who takes a 5" fan and mounts it to the body to keep temps down. The only cool thing he did was have the local machinist make some adapters to screww the stock pinions on, and mount directly to the cc 5700 1/8 shaft. Pitty that I will not be using that adapter.

I did some measurement, and found that the tekno motor mount will fit great with only minor mods to the chassis. I am talking about this mount. This will give me room to run the electric clutch adapter and use the stock 4 tec clutch bell and 2 speed. I am going to run the clutch, mainly due to the very high gearing. No tranny reduction to speak of. It has a 1.7 diff ratio, and the mentioned 1st and 2nd primary gearing. So the spool up the clutch offers will allow the vehicle to start better than it currently does. Hoping it will keep some of the heat down...

Now the maxamps lipo has a bad cell, so I plan to make a 6300 2s lipo. That will give me a little over 42k rpm with the 5700kv motor. Gearing is high but I hope it will work!

I will use the mech brakes, so no reverse. I just plan to drift and so some speed runs with the car, so that is ok with me.

Heres both ratios plugged into BG's calc:

1st

Differential Ratio: 1.7
Transmission Ratio: 1
Other Ratio: 1
Spur Tooth Count: 45
Pinion Tooth Count: 15
Total Voltage: 7.4
Motor KV: 5700
Tire Diameter (inches): 2.5
Tire Ballooning (inches): 0
Motor Current Draw: 0
Motor coil Ω: 0
Spur/Pinion Ratio: 3 : 1
Total Ratio: 5.1 : 1
Tire Circumference (inches): 7.85 inches (199.49 mm)
Total Motor Speed: 42180 RPM
Vehicle Speed: 61.51 mph (98.81 km/h)
Estimated Adjusted Speed: 56 mph (91 km/h) - 8% loss


2nd

Differential Ratio: 1.7
Transmission Ratio: 1
Other Ratio: 1
Spur Tooth Count: 41
Pinion Tooth Count: 19
Total Voltage: 7.4
Motor KV: 5700
Tire Diameter (inches): 2.5
Tire Ballooning (inches): 0
Motor Current Draw: 0
Motor coil Ω: 0
Spur/Pinion Ratio: 2.16 : 1
Total Ratio: 3.66842 : 1
Tire Circumference (inches): 7.85 inches (199.49 mm)
Total Motor Speed: 42180 RPM
Vehicle Speed: 85.52 mph (137.37 km/h)
Estimated Adjusted Speed: 75 mph (121 km/h) - 12% loss

I should have all the parts together at the end of the week. I got a ton of spares from this guy for a great price, so no comlaints from me.