alecladanga

iTrader: (5)

SalvadoriRacing

Hope you don't mind my question.

What would be the effect of moving the timing of the LRP x11? Either moving it up 2mm to moving it down 2mm? Does it effect torque or rpm?

I have a LRP X11 13.5t with a sintered rotor, i'm very much interested in playing with the timing. Just want to know what's the theory behind it so that i would know what to look for when i run the car.

Thanks and apologies to all in advance for not sticking to the subject of this thread.

SalvadoriRacing

more advance = less eficiency, more rpm and peak power at higher rpm..........it's needed to run shorter ratio to take some advantage and to not fry the motor........

Murphy's Law

Hi Bill

Thanks for your reply and request for more clarity - my question was more generic, but I run an X-Ray T2'007 on rubber tyres (Sorex 24), using a Losi Xceorin 10.5 BL with the Losi ESC. My son runs the identical car but with a Novak 10.5SS / GTB on profile 1.

We both run Trakpower 3600 mAh 30C batteries. The track is indoor, low grip carpet, about 75' x 30' and generally set up with a 75' straight, with a fast sweep at the end, and a twisty infield. The GTB is frustrating due to the lack of ability to fine-tune the throttle / brake profiles whereas the Xcelorin is pretty good in the ability to setup via the PC link.

Controlling exit wheelspin with the GTB is proving to be quite difficult, even using the radio throttle EXP function and turning down the throttle EPA. The GTB seems to come in with a "bang" even with the "min drive" set to its lowest. Obviously tuned fingers and thumbs helps !

So I have decided to try the spx, frankly more based on the "softer" profiles 1-6 and generally good reports about it, rather than aiming to use the 7 & 8 profiles (but will certainly try !! ).

Having said all that, it seems from this thread that the spx rates very well on longer, more sweeping tracks, but I am interested in other racer's experiences on tight, low-grip ones.

alecladanga

iTrader: (5)

thanks

syndr0me

iTrader: (32)

profile 8 + 13.5 @ 6.04 = oh my goodness!

sidecarphil1

iTrader: (1)

well after a week of timing and changing gearing ang profiles we have finally found the "sweet spot" on the speedo

and WOW it's quick

i use program 8 with 4.479:1 gearing

10.5 lrp and 5 cells

the only thing i have noticed is that after a few laps when the cells have lost that initial "punch" the speedo changes slightly and it doesn't seem the change into high speed mode in the same place ywice in a row

still very happy with it and i think i can now keep up with the GM powered cars and i am over half a second a lap quicker

Still Bill

iTrader: (16)

In the vicinity for a short track.

Now, if you just get the right motor...and that motor's optimum timing...

gruman28

iTrader: (18)

I posted a couple weeks ago about my SPX. I ran about 6 laps and it just stopped. I didnt have another brushless motor, so I tried a brushed motor I had laying around. Still nothing. All the lights on the esc light up correctly when I pull the trigger, but the motor doesnt turn. I can change all of the settings, but cannot get the motor to turn. Before I give up and send it back to LRP, I was looking for any help you can give.

Thanks
Chris

Still Bill

iTrader: (16)

Is it known that the bl motor is good? If not, I would borrow another brushless motor to try with the SPX before to confirm it is the ESC.

If it is bad, it should go back to LRP via Associated in SoCal.

Bill

gruman28

iTrader: (18)

The brushed motor I tried is good. Guess its back to LRP....

sidecarphil1

iTrader: (1)

from what i have heard if they get too hot inside they do cook

what sort of gearing did you use ??

Still Bill

iTrader: (16)

Excellent question!

What make of BL motor too? 17.5, 13.5, 10.5, other? What timing? All three factors would make for different gearing.

I have already heard of two locals cooking their SPX's after only a few laps on NorCal's asphalt track with too high of gearing (low FD numbers) while on setting 8. For 13.5 TC at NorCal, I am now in the high-fives (5.7 FD)with the SPX; whereas with a TC ESC I was in the mid-fours (4.5 FD). Locals can see my brand of motor and its timing...

Bill

Timmie

iTrader: (3)

Yeah I would go ahead and send it back. Looks like you checked everything else. I had basically the same thing happen to my 2 week old SPX. As a update to my experience with the SPX, I have run the replacement now for 4 races and no problems since. My first one must have just been bad luck.Yesterday it was really hot here, track temps were 140f and It worked flawlessly for me. My local asphalt track is pretty big and with a Express/Trinity duo 17.5 with middle hole timing and profile 7, after 6 min my motor temp was 161F. FDR was 4.77. Another local asphalt track has a small very technical layout and there I run same motor but first hole timing, profile 7 and FDR 5.19 with similar motor temps. Like the others have said motor type and gearing has a lot of variables. When I go to a new track I have never been to or try a new brand of motor, I just gear to a FDR like 5.5- 6.0 and go out and practice to memorize the track. Check the temp after a few min and then just start going up on pinion till i get to the motor temp I am comfortable with.

Still Bill

iTrader: (16)

Excellent logic Timmie. You'll go far in r/c...

Tell us when you get to profile 8? It's da bong!

Bill

gruman28

iTrader: (18)

I had it in my Xray T2 set up for USVTA. I used a Novak 21.5 motor. I believe 4.29 was my gear ratio. We actually raised it right before we took it out, but I cant rememeber to what. I didnt change the timing on the motor and I kept the esc on the default settings except I did change to profile 7.

I took the car around six laps, then it stopped. Nothing Crazy. I was just trying to get everything set up. Maybe 1 or 2 were hot laps. I took the car, the motor and ESC were hot, but nothing crazy. I forgot the exact temp. I was in a fuss to find out what was wrong.

Thanks for all the help.