over gear

iTrader: (18)

OK, I'm officially confused. at a simple touch of a button, the magical profile #8 up the gearing from 3.6 to 5.0 ??

sometimes, i don't think i belong to pro stock class.

Skiddins

The cars were geared down, and the motors being used had fixed timing

Hmm, don't advance the timing...check
Gear down....check.
You've said ignore temps unless it's a very hot day etc...check

So the only thing that has beeen mentioned by the others was the use of advance timing in the motors when the ESC was on the higher profiles. However, as the motors used had fixed timing this shouldn't have been an issue.

So what's left, forgetting to use voodoo before turning the car on.

Skiddins

Is there a visual check that can be perofmed to see if the timing has a lot of advance?
How close to the edge of the 'coils' (with regards to their circular position on the sensor board) should the sensors be to be at 0 timing?

Is 0 degree's timing when the sensors are in the dead centre of each coil?

Example, what timing do you think this might be;


Skiddins

burito

Your understanding is correct, if the sensor sits exactly center of the stack (e.g. centerline with the winding coil) that is the zero timing position. But with any wye wound motor, it would run like a dog at that position...
The timing on the motor in your picture is ~30°, which is what many (racers & manufactuers) consider as zero...

If the sensors outer edge lines up with the edge/end of the stack, that is roughly 40° of timing.

Looking into the motor from the front like you do, is indeed the best and only way to check for true timing!

Just to make the confusion complete, on delta wound motors (which are hardly ever seen tough) the timing is an entirely different thing, there you should have the sensors at real zero mechanical timing (e.g. center of stack) or advance it by a maximum of 10°.

Skiddins

Thanks once again Burito, great information

If we run the SPX on setting 7 or 8, we know to gear down a lot, but should the timing be retarded or should it still be safe when used on 30deg timing in the motor?

Thanks
Skiddins

Tpg racer

One of the best question for SPX users....

burito

Having the sensor at 30° should be safe.

Skiddins

Thanks

If the motors and speed controllers are not getting very hot (50 degC for example), is there anything else we should keep an eye on?

Skiddins

SlowerOne

First class questions, Skiddins (he said, patronisingly!) that's how we do homework! As you can see, it's just the same as the questions we asked of BR, and the answers give the details you need.

As to your question, the main thing to keep an eye on is the pick-up off the turns. As you get to 7 and 8, my experience is that when the gearing is too high, the car is a slug out of the turns. Get the gearing down to where the car picks up like it does on 5 and 6 (like it did before LRP came out with this 'Stock Spec' profile) and then let the LRP magic do its stuff to get the speed up.

I find that when the pick up is sluggish, you're simply converting battery energy into heat, and hence the problems you have seen. When you get it right, the rip down a reasonable straight is quite impressive!!

Remember that this is all a balance, and what works on one track won't work on another. I've had equal success with a high ratio on profile 6 as I have with a low ratio on profile 7 on different tracks.

At West London, it's debatable whether the rip down the straight is adequate compensation for the lack of speed between corners on a low ratio. Try both, and let the clock be your guide, whatever your head says is fast! HTH

HTH

GerwinGood

Hello All,

Im running also a LRP spx Stock spec version since a week. But im searching for the right gearing for my engine. Using Profile 8 of the spx. But now the problem i dont really know what timing i should use.

FDR 4.0 or maybe more to 6.5, Any one has an idea what kind of FDR would be good for my setup?

Xray t2 009
LRP SPX Stock spec
Corally 25c 5000 mah lipo
Speed passion 10.5T brushless

Thanks already

TheCoolCanFanMan

Ask the Slowone, he seems to have all the answers,

AARON YOUNG

iTrader: (15)

Here is how i determined a good gearing ..I dropped 3 teeht from the start on my 13.5.THe car jumped off the corners and seemed dead till the last ten feet of the straight so i dropped one more tooth.The changed moved where the car advanced the timing back about 5 feet each time i dropped a tooth.I settled at 5.7 gearing on a long straight and the motor was coming off at 160 degrees.Has anyone noticed that it seems to kill rotors faster even without abusing them with heat.I also had one spx start to stutter like cogging under load but doesnt affect steering like a glitch.

TheCoolCanFanMan

Be very careful when you feel/hear the motor cogging, as this is what I felt just as I put my car down and drove it round to the start line, then the car would go no further, took the car back to the pits and not only had the motor blown, but the Nosram esc had gone pop
Cheers TCCFM

LoonyRacing

iTrader: (11)

Cool

mark williams

ok easy question..

with lrp X11 10.5t on my sphere tc spec on a large track (cotswolds) my timing was on full and my FDR was 4.65 and punch setting 6

i now have my SPX comp what FDR should i use for the same large track? as from what ive read the timing will stay on 0 (30 degs)

what is a safe max temp for SPX?
vector X11 10.5t?

thanks in advance
mark