Would a smaller spur also affect acceleration?

Not really, if its geared correctly it shouldn't be any different from any other spur gears.:nod: :nod:

Thanks for the input guys.

I have a new L4 that has been sitting on the shelf since last fall. It is my first pan car and it hasn't seen a track yet. With warmer weather approaching, I'm finally going to get a chance to run it. We race on an outdoor asphalt track.

I'm told that the L4 diff also acts as a slipper. Seems to me that the diff shouldn't be allowed to slip. What is your understanding on how tight the diff should be?

Smaller Spur/Pinion does affect efficiency - larger = better efficiency which is why we don't use 20 tooth spur gears! :D

my diff doesn't slip hardly at all - I tighten it until it doesn't. The way I check it is to hold both wheels and take my thumb and try and slip the spur - it should slip slightly and only with pressure. This guarantees that it isn't binding and putting overmuch pressure on the balls but is tight enough to not slip under acceleration.

New to 12th scale.

Do you figure rollout from the front or rear tire?

Thanks

Rollout is calculated from the rear tire diameter.

My .02

i slip mine as track/traction conditions dictate

i have run carpet were i set my diff as "boomer" states above. however depending on your track conditions the diff adjustment can be a useful tuning tool, especially on slick asphalt tracks.

example or local Hobbytown asphalt track is a banked ovalroadcourse combo with a offroad track nearby. the driverstand separates the two. they blow it (no sugar waters, soda spray, VHT) off prior to the race that's it. in fact both are raced on the sameday.

on this track we haven't been able to run mod motors even 19T's
have problems. the rear ends won't stay planted, no matter what set-up you use on the car. after a lot of testing, we ended up running stock. most of us run 88T/31P spurs (gearing is to bogg the motor down and smooth out the cars acceleration), PU frts, PK or GY rears. and 90% of us adjust our diffs to slip (both an old school thing). my set-up has about a 2-3ft slip before it takes. after one or two laps it heats up and slips less. the cars make 8min no problem in this config.

i use carbide diff balls and change the plates about every two weeks. running outdoors you would probably have to do this anyway.

5 different racers have asked me to try their cars. after just running the first ten feet i bring back, check it, readjust their diffs to my style setting, i don't even do a lap, hand them the controller and say now try it. they look puzzled and after one lap ask what did you do. i tell them and they say " I was told the diff shouldn't be allowed to slip" ;)

what alway's really gets me though is with the modern day radios and the adjustments. you should be able to set the radio/car acceleration rates/EXPs/curves/delays so you wouldn't have to do the above things.

after asking people what their settings, etc. i am always amazed...they don't know and sometimes are vague on how to work/set the controller. once they have it basically set-up to RUN they don't want to mess with it. (sort like the VCR thing:D ) 90% of the people i have helped in 12th have never really read, used, or understand all the options on their radios. in the last 2 years of 12th racing here we have lost more racers due to this, i beleive than anything else. i couldn't drive their cars with steering at 150% and who knows what else settings. move the wheel an 1/8" and they car does a near u-turn. they will work the set-up to death. or blame it on something else..... but not touch that radio.

i currnetly use a 1989 KO EX-1 AM radio and have a new KO EX10 Helios on order. i will see if there still will be a need to slip at our slick track.

Old Newbie
 

I was into R/C for years and am returning after a 10 year break. I have an old 80's vintage 1/12 Schumacher C-Car.
I am trying to restore it and need some 1/12 scale donuts.
Does anyone know where I can get them.
Does anyone have ant bits lying around for these??
Smooth roads dudes..

Wire diameter is a little hard to measure since most wire isn't quite round, but the measurements I come up with are: Castle Creations 16ga- 2.4mm and the 16ga I get from Cheap Battery Packs .com is 3.2mm.

BTW, I've stripped and compared them both, and they have the same amount of wire under the jacket. The CC wire is 259 count which is very good, the CBP wire looks about the same, but I couldn't find specs on it.

I counted...they are both 258 strands :) jk.

Not 259??!!? You bin robbed!!

I find that you can get away using 18gauge wire in your 12th scales. It's all I use in mine. I was just using 18gauge wire in my T-FOURCE with a 19 turn, and didn't notice any lose of power.

Lazyeh,

you are getting into serious voltage drop territory there, 16ga has twice the drop of 12ga (yes I measured it) 18ga is really small, maybe 2.5 times more drop than 12ga. As I recall over 2.5 inches 16ga lost 0.14v 12ga was only 0.07v. This was measured at 30A.

Chris.

Thanks for the info. I rarely run 19 turn, maybe only a couple times a year as a filler class at a trophy race. I know I was getting close and probably wouldn't run a hotter turn motor without changing the wire.

OD,

Thanks for the info. Would there be a problem using 16g for running 8 and 9 turn motors? Thanks.