Originally Posted by masterhit
Yes, I ran into the same problem. By the end of the day I ended up at -10 timing (4 dot) with an FDR of 5.57 with 2/7/1/1 on my SPX. It was about 160 at the end of the run with one high speed 25mm fan. This set-up stayed strong for the full run.
I know your not supposed to use profile 7 or 8..... But I'm a sucker for it.
It was slightly faster than another competitive driver running a ballistic (I believe) and Tekin with Vegas 200, and good out of the turns. There is also the caveat that I was running a shaftie (Evo V MS).
I still don't feel this is the "best" set-up, but it should be a good start. This was rubber tire TC on carpet.
Originally Posted by LOW ET
maybe try -5 on the motor and profile 6 on the esc???
Has anyone found the G spot yet for this combo (SPX and X-12 17.5) ? I've played around with a ton of variations as I too have the problem of fast initial laps and a significant drop in speed. I'm running a Cyclone TC, rubber tires on asphalt. The best so far has been per Mike's recommendation above ... 2-7-1-1, 4 dot, and a 5.56 FDR. Though the drop off is less I still feel this motor and ESC should be capable of more top end and be able to keep it through the run. I've tried the below and every one of them suffers from the drop off (temps never exceeded 170F even the few times on profile 8).
2-7-1-1, 2 dot, FDR 5.56 through 6.02
2-6-1-1, 2 dot, FDR 5.56 through 6.02 (no real drop, just slow)
2-7-1-1, 3 dot, FDR 5.56 through 6.02
2-7-1-1, 4 dot, FDR 5.56 through 6.19
Throughout testing, I also tried profile 8 a few times with the 3 and 4 dot but never really saw any improvement to speed or the drop off issue.
I suppose I could try the 3 dot and profile 6 as mentioned above, but I just don't see how this will be any faster. May be more consistent I guess but there has to be a sweet spot that I'm missing. Am I way off on the FDR range this motor should like ?
Prior to the X-12 I was using a Novak SS 17.5 (stock timing) at 2-8-2-3 and a FDR of 3.7. I swear this combo was faster and did not suffer the drop off. Does anyone know why this drop is occuring ? Can it be related to batteries ? I'm using Orion 3800 30C's.
Any help to this mystery is greatly appreciated !