10 replies to this topic

[MarkH]

I know you need to add some teeth on the pinion for a H6 compared to a H7. It seems the RPM of the H6 is not as high as the H7. Do any of you know the RPM limit of the H6?

Do most of you add 2-3 teeth from a H7 setup for the same track?

 

Also, we had a club race the other night and the power is a 30 amp unit with a 2 farad cap. The starts were ok but during the race when on or more of the 4 cars would come off there was a power surge. Logic makes me think these H6 motors must be pulling somewhere around 6-8 amps under acceleration maxing or close maxing the power supply while the starts were ok because of the cap. Does this sound correct that 4 H6s could be maxing out the smaller power supply?

 

We rarely run these motors on this smaller track but have not had any power issues running H7 and F7 motors. So the owner is looking at splitting the power and adding another 30 amp and 2 farad cap.

[DOCinCanton]

On the hillclimbs in Florida, I usually run 12T pinion on a 35T or 36T gear.

[Les Boyd]

The JK web site states that both motors turn 48,000 rpm.

[MarkH]

I wonder why if they are supposed to turn the same max RPM the H6 runs out of RPM way quicker than H7. Other club members have told me the same thing. Maybe we, as a group, just have some under performing pieces. The guys who have made them work have added extra teeth to the pinion and I just wanted to see if this is normal. 

[zipper]

Different mags - Hawk 6  can run a bigger pinion. Into my ear the rpm is pretty similar on 10V.

[Matt Sheldon]

I run 12/35 with .760 tires on a Hillclimb @ 13 Volts.

[MarkH]

I appreciate everyones help. However, what I am really looking for is if you were to race a H6 and a H7 on the same track, how many teeth do you add to the pinion of the H6 compared to the H7? Perhaps you run the same ratio. Either way, I am interested.

 

What about the amp draw of the H6? it does appear to be more than the H7. Anyone know for sure? I know it will very depending on the gear ration and track conditions. We are just trying to figure out the power supply issue.

Thanks

[Matt Sheldon]

I run the same pinion on my H6 and H7. The spur gear on my H7 cars is typically 2 teeth larger with the same size tire. Obviously track length can change that .

 

Cannot help on amp draw

[Chris Dadds]

It seems to me that testing this could best be done by paralleling a car battery onto the power supply and see what happens. What do you think?

[Michael Rigsby]

Mark, most everyone here in Florida on our hillclimbs starts out both at 12/34, then go to 12/35 or 12/36 as needed.  I raced a Hawk 6 in Group F wing car at 12/34 for a couple of years and had no problem keeping up with most Hawk 7's.  The Hawk 7 does turn up a little faster, gets to its max RPM quicker (less magnet cog...stronger magnets in the Hawk 6), and since it's a few grams lighter than a Hawk 6, a Hawk 7 powered car does have a slight weight advantage.

 

The Hawk 6 will draw about 1.5 amps at 6 volts if setup correctly, and under initial acceleration you may see a spike to 3 amps, so yeah, if you are running eight lanes and a car comes off, you may have a power surge with only a 30 amp supply,

[MarkH]

Chris, I will let the track owner know. This is a good idea.

 

Michael, thanks for the good info, makes sense to me. We are only running 4 lanes and still experienced power surges when cars came off. Perhaps there is another problem. The track owner told me last night about 2 months ago he had a lightning strike and it burned something on the trackmate board. I am wondering now if the power supply also was damaged. Hmmm……………...