Originally Posted by markiemark
Im running 1s 17.5 blink with a stock rotor and timing on center mark with 101mm roll out .
I seem not to have low end rip like the guys with the 12.3mm rotor.
if i install the 12.3 rotor would that add more lowend or would it add to much lowend and will i need to up my timing or roll out?
Is the center mark on timing to high and i just need to turn it down more?
Well the stock rotor is the 12.3mm Broad Powerband... Unless you got one of those Revtechs from 3-4 months ago that came with the 12.5mm High Torque rotors. Have you taken the motor apart and measured the motor/looked at the colored ring?
The 12.3 rotors tend to produce more rpm and top end, but less torque and acceleration than the 12.5s.
I dont know your track size and layout, but if I had to guess... I would say your rollout is a little high for the 12.3mm rotor. I found that it doesn't like to pull all that much gear. In order to take advantage of its high rpm, it seemed to like mid 90s rollout. Again, this is just what I found through testing at my track.
If you move to the 12.5mm rotor, any of them should have a bit more low-mid range rip than the 12.3s. I tested the 12.5 High Rpm and 12.5 High Torque rotors in blinky 17.5 12th, and was able to get identical laps out of both rotors. And both 12.5s were .1-.2s a lap faster than the 12.3s on our track/layout. The 12.5 H-RPM seemed like it would be better for a more open layout, while the 12.5 HT seemed better for tight layouts with lots of slow corners that required more acceleration.
Ive also found that the 12.5 rotors aren't anywhere near as sensitive to gearing as the 12.3s. With the 12.3s, it seemed like they had a 2mm range of rollout where they were the happiest. Any higher or lower and you would suffer with noticeably slower laps, sluggishness out of the corners, and/or much quicker fade.
The 12.5s had more like a 3.5-4mm range of rollout where they could turn identical fast lap times. The only difference I saw with the rollout changes was how soon the motor starting fading... So I gear for fastest average lap over a 4-5min period.
Ive generally been pretty liberal with timing too... I usually dont run any lower than the 2nd to last hash mark.
What are you calling the "center mark"? In terms of # of hash marks?
Edit: FWIW, I was finally able to match my fastest 12.5mm laps with the stock 12.3 rotor after much trying, but it required A LOT of timing. Maybe that is how the 12.3 likes to be run, but I felt nervous running the timing a little past the "+" mark. And in order to turn those fast laps, I needed pretty clear track to build and maintain as much momentum as possible. During qualifying/race, with traffic everywhere, I suspect it would be easier to drive a 12.5 to fast laps than 12.3.