Originally Posted by
mark williams
SLOWERONE:
it sounds like you are getting to grips with the spx comp, i will run mine for the first time on saturday at cotwolds (large track)..my FDR ratio with sphere tc was 4.65, full timing,profile 6..last time there, what would you suggest for ratio for the spx comp?
4.65 was 96 spur with 43 pinion..
why do you feel profile 6 with a little motor timing works well, rather than putting it on profile 8 with no timing on motor?
Please remember I am running 12th, not TC. I can't help you with TC ratios, and would defer to Skiddins, who has run TC with the SPX. As regards, the timing question, I prefer the situation where the timing is fixed, and I can predict what the motor can do. I find that a bit of motor timing helps the (12th!) car off the turn, and then the profile 6 seems to add a bit more timing. On the Sphere, where no timing is added by the profile, we used to run all the timing on the motor.
It seems that the dynamic timing works with the TC cars, but not 12th. The biggest difference is weight, so I conclude that if you put some load on the motor (weight of the car) the dynamic timing works OK, but if you don't...
Originally Posted by
billythekid
If you are using profile 6 with SPX Stock Spec, then you are not taking advantage of its dynamic timing feature. Profile 6 on SPX is equivalent to profile 8 on Sphere TC.
See my point above - do you have a setting that always makes the dynamic timing work well? I'd love to take advantage of it, but can't find a way of doing that in 12th.
Originally Posted by
Obsidian
Greetings all,
The spx is an interesting device, but is still troubling me. I recently ran it with a
Duo 13.5 - 0 deg timing
smc 5200 40c
FDR of 5.0
1,7,2,4 settings
motor temp after 6min: 185 F.
spx temp after 6min 140 F.
track temp about 135 f 140 f.
at speedworld this past weekend ( home of the RROC -09). Unfortunately, I was getting motored down the extremely long straight and the car felt soft coming off of the turns. I talked to a few people who also run the same combo but to my dismay they all had very different power settings and FDR's. At this point I'm not sure what to do exactly.
Correct me if i'm wrong, but I think I'm not accessing the dynamic timing everyone is talking about. I think I might be geared too low. I'm thinking of going from a 5.o FDR to a 5.6ish FDR.
any input would be appreciated.
Cheerz
I think you are overheating the motor. Brakes on a BL are operated by firing the coils in the motor, so they consume power. You are taking energy out of the car (kinetic energy) when you brake, and it has to go somewhere. In a road car when you brake, you turn the kinetic energy into heat energy. Same in the RC car, but the only place you can generate the heat is in the motor. Take all the drag brake off, stop using the brakes, and I think your motor will perform better through the whole race. HTH
