for the USGT "Spec" tires, what are guys doing to enhance the traction?

I've heard simple green, wd40, brake clean and other...

We stuck three Trackstar motors on the Motolyser (sp). At the + sign they were between 44 and 53 degrees of timing. Those are really where the motor produces at about max efficiency. So with that said, adding more timing is probably not beneficial. There lower speed is from a high resistance stator (compared to other motors in the wind). I had a interesting back to back last weekend. I ran one TS 21.5 for 6 minutes and it was 125 deg. I switched to another that showed 4 degrees more timing. After a 6 minute run it was 165 and actually ran slower. I ran the same gearing with each. Next step will be to check the resistance of the stators. The rotors feel similar but I will check them also.

Mine (13.5T) maxes out at 33 degrees, as measured on a GForce motor checker. That's much lower than most other motors. It's nearly identical to an old Novak SS Pro I have (34 degrees), and the KV of these two motors is also very close (3030 vs 3150 RPM/V). Maybe the 21.5T versions have been changed for more timing?

A higher stator resistance (within reason) has little effect on the KV constant of the motor. Rotor size and strength has more effect.

I modified my trackstar motors to get an extra 10 degrees timing out of them. They were definitely much faster with the extra timing. On the dyno, they made 10% more torque than my D4 short stack, but had 10% lower KV, so I had to run a pinion that was 2-3 teeth larger with the trackstar motor. Interestingly enough, I'm consistently faster on my small local track using the trackstar over the D4. Both motors come off at 157-160 degrees.

Howard: I haven't measured it but how do they compare in air gap?
One of those motors was a 17.5 it is the one that was 44.

If the rules set by RobK state Roar motors, how does modifying the motor to get more timing work?

See posts 4075-4078 on the previous page.

Doesn't roar approval mean no modifying the motor? If not then can one cut a turn off the windings since it's not adding a part and is leveling the playing field with the short stack motors?

I think you're opening up a can of worms...

That's an excellent point! I haven't measured the air gap.

Agreed. I'm a mechanical engineer with access to machine shop equipment. It's good to know that as long as I don't add parts, I can freely modify my motors and not be illegal.

:batman:

Mark

Then let a computer engineer remind you that... you're racing toy cars :p

Life's too short to grind on $30 motors in (what should be) a fun hobby.

It stuff like this that makes me hate racing sometimes.....

I agree with you 100%. I'm trying to make a point. :nod:

I've been racing "rulebooks" for over 35 years. SCCA, NASCAR, and now RC cars. It's what is said 'between' the lines that is often more important. And anytime two guys get together and race, someone will look for an advantage. Toy cars are not exempt from that. ;)

Personally, I just use off-the-shelf stuff and go racing. But if I'm given carte blanche to have at it, it might be fun. Penske is my hero. :batman:

Mark

P.S. RobK's left eye is probably starting to twitch right about now...lol.

Yes, because he gave permission to increase the timing range on the Trackstar 21.5 motor so that it will have the same range as other brands, and this now seems to be interpreted by some as "I can modify any motor in any way that I want".

Keep in mind that if any ROAR-approved spec motor is modified like this, then it won't be legal for use in ROAR-sanctioned races. But I haven't seen too many 21.5 classes at ROAR events.

It seems there are those who interpreted my post as I will modify the motor any way I want. Far from it. My point is if you allow one thing others will see it as not following the set rule and they can do other motor mods. Thus my saying "you are opening a can of worms". Those that buy a specific motor should run it as is. If you don't like any part of a motor then don't buy it..

Well you can see how this stuff always goes. Then again, I have watched people grind other brand motor's timing rings because the initial production had less timing than subsequent production runs. I didn't think it was a big deal or cheating, but of course no one can use any common sense to think critically about this stuff. I just hear "I'm gonna take 5 winds off the stator and put in a mod rotor HEEEEEEEHAAAAWWWWWWWWWWWWWWWWWW":D

Because that is the exact same thing as getting the extra 5 or 10* of timing that every other motor has.

This is not really directed at you sydewynder, it's just what everybody does when you open the door even a crack. It's why we can't have nice things around here.

Fair enough.

Keep in mind that the rule set is determined by only one person, RobK, and if anyone has a question as to what is or isn't allowed, he will usually respond within a short time right here on RCTech. (EDIT: Which he just did!)

I don't always like all of the rules either. But I do like being able to get an official answer nearly instantaneously, without waiting for a committee to vote on something. Benevolent dictatorships or monarchies can be very efficient!

Rules are always divided into "letter of the rules" and "intent of the rules". Races can only go by the letter, because we rarely have any insight into intent when the rules are written.

Just add "timing rings may be modified to increase timing adjustment available".

Done.

Or don't allow ANY modifications to a stock ROAR approved motor. Then each motor will have to stand on its own merit, warts and all.

Thanks for putting up with us, RobK.

:sneaky:

Mark

My experience has been that when I spend more time making my car's setup better, my lap times improve more than when I worry about a better battery or motor.

While I like to challenge for the podium every time I race, over the years I've learned that I'm really racing against the clock and myself. Even if I'm running an "inferior" motor, "old" battery, or "obsolete" chassis, I can still try to get the most out of the equipment I've got. On those rare days that I do get everything right, it is one of the most rewarding feelings I can get racing.

With all the rain we've been having lately, I'll be running a 4 blade 22 degree prop, anybody have a problem with that ? :lol:

Is that a detongued prop? You know that's a mod..

Box Stock or Sharpened and Balanced???

Im telling....

This is very well said and I think describes the spirit of RC racing better than anything else. It's a thought angle that I often forget myself. It's easy to throw money at the latest and greatest (says the guy who runs a T4 2015 with top of the line electronics in a 25.5 VTA-ish class), but in the end you have to remember to have fun. It's not only about winning and many things go into making a good race day/night.

I feel the pain whenever I see people modifying motors internally in spec classes.

Show me in the ROAR Rules where it states you cannot alter the timing range of a motor, because I cannot find it.

Grinding the timing ring does not alter any base dimensions or specifications of an approved motor. I've never had to max the available timing on any other motor, so trying to get more out of those would only melt it into a puddle.



edit: If ROAR cared about timing range they would set a max internal+adjustable percent I would think.

Just to make things clear, I run TSR's because they are awesome but I feel the Trackstar is good for the longevity and affordability of the sport.

Ron, it pains me to see people dropping $170 on a motor for spec classes.

Show me in the ROAR rules where it says you are ALLOWED to alter the timing range. I cannot find that either.

:sneaky:

Mark

Does ROAR measure the available timing of a motor as part of it's approval process?

If they don't....

The guys that do this are the ones who destroy spec class racing. It usually the ones who aren't the best drivers, knowing they couldn't be competitive in a mod class and can't stand loosing. They killed the stock Slash off-road class by me and I hope they stay away from our on-road. This class is the most competitive and fun class I have raced alongside 17.5 buggy.

Onroad or offroad, spec classes are always the most expensive to run. Limited hp means having to get the most out of everything else (tires, batteries, vehicle drivetrain, etc), which all costs money. Mod is always cheaper to run. But onroad mod is too fast for most drivers. Offroad, grip is more limited so you can't put down all the hp you have anyway.

Any MODIFICATION of a motor is Illegal by All Sanctioning Rules - thus if you have to Modifiy the motor for additional timing adjustment - it makes the motor Illegal by Sanctioning Rules -

This happened several years ago with the Original NOVAK SS motors - (which is what helped create a motor w/ Adjustable timing)

Our two fastest guys (who are fast in any class they run) did have stellar, certified motors. Weekly the battle for first and second was between those two and the real action was third through eighth. LOL :lol:

But luckily for us, those two guys realized that they are top runners and have decided to take a break from this class to try to revive 1/12 scale pan cars and beef up the 17.5 class. One of them even put his USGT motor up for sale locally to give others a shot and not have any excuses.

I've never been one to blame my equipment for a lousy performance. I might blame setup, but that again falls back to me. I normally blame my lack of consistency and making dumb mistakes. I know the way to improve is to work on my setup and get more trigger time.:nod:

Anything I should do to wear in the tires other than sauce them up with SXT 3.0 and run them?

Running a tight carpet track...

Gravity tires. Take the bead/ridge out of the middle with a Dremel and do a few laps on the asphalt or use gravity tire sanding tool. Both work equally well. Biggest thing is that center ridge.

In what direction would I mount the rubber on the wheel for these USGT Specs? Tread in the same direction on all sides or opposite tread on left vs right?

It will look better if they all face the same direction, but I have never found any difference in performance no matter which way they face.

There was some very good USGT racing at Lake in the Hills Hobbytown today. Thanks to Shawn and the Hobbytown crew.

Don't know how well he mirrors will hold up, but they are secured by small body clips on the inside of the body so the mirrors can be easily removed if you are worried. For show I'm going to leave the mirrors on; for racing they will be safe in my pit box. My 1/8th scale buddies have the same body and it really looks sharp on the track. Coolest detailed body I've seen in a long time and I'm told one of the fastest too. OK so my Ferrari and Audi will has to sit for awhile! All I have to do now is mount a TC wing and wait for the rain to stop here in TX. I'll so some lap times with the various bodies and report if this Corvette is as good as is claimed.

I remember a sign at the first race track my son and I went to: "Speed is measured in cubic dollars; how fast can you afford go to?" After doing this hobby/addiction for 30+ years I'm not sure I agree with you. If you think the world class mod drivers don't obsess over the same details (tires, batteries, vehicle drive train, etc.) as the guys that run the spec classes you simply haven't known a world class racer. Believe me they obsess about those details even more so than us guys who now just run the spec classes. IMO what makes spec classes costly or more costly than it needs to be is lack of quality control of the spec controlled parts (motors, batteries etc.). Take for example Street Spec, a old attempt to control the cost of racing. Good idea - IMO poor implementation. Take the Street Spec motor for example. You had to buy 5 or 10 to find that one that was awesome. Then we (me too) cut the rotor so small that it lasted only a few runs. (OH but you say, those weren't rebuildable motors how can you cut the coms? - my secret and it involve REVTEC com drops). Some realized the foolishness of all of this and pushed for rebuildable hand-wound high quality 19T motors, so instead of buying 10 $50 dollar motors we only had to buy 1 $80 good motor and replaced only that $19 armature instead of buying another 10 $50 dollar motors when the armature got too small.