Hpi hellfire ss

[obelix]

I am finally ready to order the Motor, esc for the hellfire build but I need some advise.

This is the setup I was looking at getting
Mamba Monster v3 Running 6s trackpowers 25c
NEU 1515 2.5d
std gear ratio 13t mod 1 pinion 53 spur


I do not know all the gear ratios to enter in Brian G's speed calculator so I based this on the rpm I would get from a 28 nitro engine (35000) and increased it slightly I also selected this motor because RC Monster has It in stock.
Is this a good setup or can I get better ?
Does anyone know if there are aluminium diff cases available for the hellfire if not which other make would fit.

Thanks

[Patrick]

6s with the 1515 2.5d (1650kv) is a good setup. It will have a maximum motor rpm of around 36k, but with more torque than the nitro.
With 13/53 gearing your top speed should be around 36mph which is enough for a lot of tracks and bashing spot's but it depends what your aiming for. That setup will easily handle a couple more teeth on the pinion without worrying about temps, and a couple more teeth for speed run style driving.
For 6s and gearing for low to mid 40's for normal bashing that would be the motor I would choose (I already have a 1515 2.5d), but if there is a better setup depends what your aiming for.

The calculator isn't hard to use, you already have most of the numbers you need.
First is the diff ratio, so just scroll down the list of diffs until you find the hellfire (4.2:1 ratio)
Transmission ratio is 1 since you are using a center diff.
Leave additional ratio as 1 for center diff cars. Not many cars will have to use the additional ratio.
Spur gear you already know is 53.
13 is your starting point for pinion teeth.
For voltage usually use 3.7v per cell (22.2v for 6s).
Kv is 1650 for the 1515 2.5d or scroll down the list of motors until you find what you want.
Most truggy tires are around 5.7", but there's a list of tires to choose from. I sometimes just use 6" to make up for a small amount of ballooning you get at anything over 35mph.
Once you've got your speed click on the gear symbol next to your top speed and it will show you your speed for 10-47t pinions rather than having to change pinion number in the calculator all the time.

a couple of things to remember about the Hellfire it is heavy for a truggy especially to the rear.

[obelix]

Thanks for the replies

Patrick I think what I should be aiming for is a rig that can do speed runs of 60 to 70 mph on 6s with optimal gearing and also be able to dial it down to give 35 to 40mph. From my experience with the kyosha tyre ballooning on a 4 wheel drive is more problamatic than on a 2 wheel drive, I found either more ballooning on the rear than on the front or vise versa and battled to get a even balance I eventualy ended up locking both diffs. Do you think I will have the same problem with the hellfire? The hellfire bieng heavier does this mean a bigger motor or just beef up the suspension.

Thanks for the help