billythekid

iTrader: (9)

billythekid

iTrader: (9)

I have an almost brand new SPX Stock Spec for sale. Just posted today.

http://www.rctech.net/forum/r-c-item...ml#post6391309

Please PM me if interested.

Thanks.

Tuner EM

Question for you guys. I run a SPX in a 2S, 17.5 spec class. The lap and run times are about the same regardless of where I gear it between 50 and 60 mmpr except around 54mmpr where I lack straight away speed compared to other cars. The speed is better if I gear higher or lower. I wonder if at that particular rollout the dynamic timing doesn't engage but does engage at a lower rollout giving me more speed. When I gear higher the motor pulls more speed so I don't need the dynamic timing (the temps are higher). At low gearing the motor sounds different like it's spinning faster.

Skiddins

I think you have it correctly.

If the gearing is quite tall (your 60mm/r) then you are using the torque of the motor to do the work, when you reduce it to 50mm/r the revs increase which means the motor's torque is not as much use, the timing now creates the higher revs instead.

We've found the same on our outdoor asphalt cars, I've gone from 4.97 on the old Sphere, to 5.29 on the SPX, now I'm on 5.8

Interestingly, almost everyone I know that does or has run an SPX uses profile 7, not 8.

Skiddins

TRF4evr

iTrader: (2)

I'm running a 416WE with a tekin 17.5-0 timing and SPX esc- profile 8. I have been playing with different gearing the last few days but can't find any sweet spot for the combo setup for my car. I started with 74/48p spur with 35 pinion.(FDR 4.34 and rollout 45.54).on a indoor track med grip. got good bottom end but no top end played with gearing allnight until the finals which i ended with 74/48p with 38 pinion(FDR4.003 and rollout 49.44) temp stayed around 40-46C. laptimes not much difference from 3qualifying to finals....should I play with the motor timing.need some advise

cyanyde

I'm not sure about the SPX but I think most esc's were designed to work with motors that have some default advanced motor timing, usually 10-15 degrees. Try advancing the motor timing a little. Your temp is a sign that there's more power to find.

Still Bill

iTrader: (16)

From the Tekin website...

· Until you are seeing temps of about 160 degrees F on the motor, you are not pulling much power and are possibly not running enough timing or are undergeared. Try advancing timing first.

Bill

fleetmaster

iTrader: (16)

Albert, I tried middle hole (10*) on my duo a fortnight ago , and it went well.
Not sure if it was faster than zero though, as the track hasn't been as grippy lately (with my worn tyres.lol).
I ran regular 11.8 -9s. That was cruising too. Trying to keep it clean, as everyone else hacked each other on turn two.

Also, try a new pack ,as voltage sag makes a big difference.

Cheers,
Fleety.

TRF4evr

iTrader: (2)

played with the motor timing on the tekin 17.5 today made difference, the motor seems to be reving higher and more punch out of corners gonna do some more testing with my other 17.5 motor .....thanks for the advise guys.

dsyed1

does any one run a speed passion 17.5r v2 motor with the spx? i am trying to figure out of this motor has physical timing on it or will i need to switch to v3 or some other motor to get the timing to advance... ( i am already using advance timing on the esc)

M-Technic

iTrader: (15)

That's what I am running currently, and no, you cannot change the timing on that motor.

billythekid

iTrader: (9)

SP 17.5T is one of the fastest, if not the fastest stock motor available. I have tested a lot of stock motors. The timing is fixed, you do not need to change it, because the timing is fixed at the optimized position. It also work perfectly well with SPX, you should be able to go really fast with this combination. You should run profile 8 with it, and all you need to do is figure out the gearing. You should gear it around 3-4 tooth (64 pitch) smaller on the pinion than with Sphere TC.

If your car is slower than cars with Sphere TC with this setup, then the problem should be with your battery packs.

Hope it helps

sidecarphil1

iTrader: (1)

it is all about the gearing and your driving with the SPX

i am slower in a straight line than the other stock speedos at the end of the straight but through the infield i have the legs on them out of the corners

i also have found the Speed Passion motors slower then the other makes

my 10.5 SP motor is with lipo was slower then my GM 13.5 with lipo

they are poop completly , LRP or GM are the best i have found

M-Technic

iTrader: (15)

Speed Passion motors just need to be geared differently from the rest. With the appropriate gearing (wildly different from what people gear their Duo2's for instance) my car is just as fast as the rest at my track.

sidecarphil1

iTrader: (1)

what gearing do you use / compaired to other racers at your track ??