This is an article I have been working on. It is
extremely lengthy. Remember it is my approach and not meant as an do all, end
all. Especially since I get my doors blown off on that Freaky Bonzai at
Renton! Man, I have to figure that sucker out!
I am not the most successful Super Stock racer but I’m
decent at writing and observing those who are successful. I like finding out
what works and passing it on. So I hope this humble article may help you with
your G3 and G3-R Super Stock racing.
First here is a list of the parts I use in my G3-R which has at times led the
Arizona Racing Association’s championship against some very, very tough
competition. My setup, procedures, processes and logistics also allow me to do
much better than I expected at various out of state national caliber events.
It is my personal opinion that the G3-R is the highest quality, best handling
and easiest to build HO slot car I have ever raced. You can go from G-Jet to
Neo and use a lot of common parts. For reference I use a DiFalco 15 band
controller and will give my settings later in the article. I reference
everything viewing from the rear of the chassis topside up. Here are the
parts:
Part# Description
962 G3-R Flexi chassis w/new timing plate
HT161 Aluminum body posts
HT164 Aluminum body pins
HT141 Guide pin
149 Gold power, dynamic balanced armature
828 Zapped and matched motor magnets
HT092 Gold plated tweaked endbell
HT082 Gary Beedle “blue” plastic endbell bushing
HT158 Gold plated pickup shoe holders
249 Pickup shoes
222G Medium tension .009” gold plated pickup springs
982 Full width ceramic traction magnets
HT201 Delrin front end
HT220 Splined rear axle
422 22t delrin rear gear
417 7t delrin pinion
HT083 Gary Beedle “blue” rear bushing
HT330N-.xxx” AST rear tires
Before assembling the chassis drill out the rear for axle retainers using
Scale Auto’s #HT378 fixture. I use .021” straight pins. I use to drill all the
way to the magnet but now I stop and do not drill into the traction magnet
area. So the pin is only on the rear part of the chassis. Thanks BSRT1! Put
the guide pin in at the most rearward position and the front axle in the most
rearward holes (swb) insuring that the axle rotates easily. If tight start
with a .050” reamer and go bigger if needed. Super polish the front axle using
Semichrome by spinning it in a Dremel. Clean the Semichrome off afterwards. I
use the front tires provided ~.350” as they are a very good starting point and
are somewhat soft. I and others have found that the soft front tire grips a
little better allowing the chassis to rotate at the apex of a corner versus
the harder front tire which I use for the higher downforce classes. Using a
2-56 tap thread the body post holes about halfway. I found that using the body
posts to finish the tapping provides a tighter and more secure fit. The new
body post installation tool, #926 is a great tool to have for this. You can
use Loctite or Blackmax to ease your mind of potential problems
Clip the pickup shoe holders on. I don’t do any tricks with them. I found the
standard holder is just fine as it with maybe a slight tweak down of the part
that goes over the spring to insure it is flat once installed. Some work on
the hanger tightening it up but I have found stock profile is fine for me.
Once installed put a flat tipped screwdriver with the blade the width of the
holder and push down from the bottom to open the shoe retainer window a little
bit to prevent hanging the shoe up. Do both sides. Insure that hinge area is
as far forward in the chassis fully touching the built in stops.
I am not the best at tweaking an endbell so I purchase the HT093. I take an
old armature, one that is epoxied, tied and lightly crosshatch the comm with
an X-Acto blade. Use a battery powered Dremel, chuck the arm up into the
endbell. Spin just for a few seconds. Remove battery and place into Dremel so
you can run in reverse. This may require breaking the tab in the Dremel that
only allows the battery to be put in one position. Spin a few seconds. This
break-ins the brushes and takes the sharp edges off. The brushes should be
adjusted so that when you move one off the other the freed brush should go to
the outer edge of the bushing at a 10 degree angle off center. Take a small
screwdriver and push the electrical parts together on the sides of the endbell.
The gold plated endbell kinda “fuses” the parts together. Bend the front
contact tab to the holders so that the contact area is increased on the
holder. I use a small wire, push it into the bent portion of the tab and then
flatten the contact tab. This gives it a nice U shape. Super polish the
armature shafts with Semichrome with the Dremel like the front axle. Clean the
Semichrome off. For stock Tomy bushings ream to at least .060”, chamfer the
side away from the armature, and if worried about bushing rotation lightly
score the outside flange part. If into max setup polish the side facing the
armature to a mirror finish. I usually put one large red plastic spacer
(.010”) and a .005” steel spacer in front of the comm. Assemble the motor
using the endbell, bracket, armature, rear bushing, pinion and motor magnets.
Slightly oil the comm end of the armature shaft. Using BSRT’s endbell tool
HT394 put the arm into the endbell. I have found the 828 motor magnets are
usually matched well and high in strength as opposed to stock out of the
package ones. Space the rear of the armature for minimum spacing but insure
there is slop. BSRT’s HT393 armature spacer tool is excellent for judging this
out of the chassis. Put motor assembly into chassis slightly pushing the
holders forward while snapping the timing bracket into the chassis. Insure the
rear bushing is aligned with the chassis while snapping downward. Check the
armature clearance at this time before installing the traction magnet clip to
insure the armature is not too tight and or too free. Oil the rear bushing at
this point.
Install gauss and matched traction magnets in the downforce mode. This is the
bottom of the right side traction magnet is attracted to the back of the right
side motor magnet and same for left side. I marked the magnets so I put them
in the same way every time. Gently bend the tab of the traction magnet clip in
where it clips onto the bottom of the magnet. Clip on.
Turn the chassis upside down. Install pickup springs and shoes. Some file the
bottom notch on the shoes to allow more travel and ever so slightly bend the
rear retention tab to insure the shoe travels evenly from the front to the
rear on the rails. Check and make sure the shoes travel smoothly up and down.
Check that spacing of the hook you opened so that the pickup shoe does not
hang up. Put the 7 tooth pinion on the armature shaft. Assemble the rear axle
using BSRT’s HT385 crown gear press. This makes putting gears on the splined
axle much easier. Put the proper amount of spacers behind the gear to achieve
good spacing that isn’t too tight. A .015” is a good starting point. Put your
best guess at rear tires on (~.440”) and remember you have brand new traction
magnets with no groves. So this is a very preliminary starting point.
It is my opinion that if you have a substandard armature you will run into
major handling difficulties let alone lack of straight speed. My experience is
that a very good armature will “push through” a chassis, its internal friction
and free it up. The #149 Gold Power and #148 Hot Stock are excellent starting
points. If you have a superb armature and the chassis feels bound up you may
have assembly problems, parts too tight, gearing is unsuited for that chassis,
running way too low, endbell tension too high, you driving style is not suited
to a freed up chassis, etc. To determine a superb armature on the bench take a
9 volt battery with clips, insuring it is quiet and go through your armatures.
Do this without the rear axle. What I am looking for is high rpm with no
vibrations. You can hear the rpm and I place my fingers on the side of the
chassis to feel the vibration. A smooth armature does a lot of positive things
but it also plays a large part in the handling. It is my experience that a
smooth armature makes corner entry and exit much easier. Be patient going
through the arms and make notes on what they are doing. You will be pleasantly
surprised at the difference between the arms. On a side bar, those who race
against me know very well I am one of the few pros taking extensive notes.
Knowing which arms are good and especially chassis setup notes makes life
easier at the races.
A Hudy comm truer with the diamond bit converted for HO arms is a nice thing
to have to insure your comm is clean and true. Some of us swear by them. I
know several pro Super Stock racers who even retrue their comms between heats!
That may be a little excessive but at a Nats level race you want every edge
you can get.
I don’t have a huge selection of motor magnets. So I focus more on matching
them. There is an ongoing discussion about maximum strength versus rpm
acceleration ramp time. My advice is to gauss your magnets and match them as
carefully as possible. Then try them on your current setup and observe the
results. I currently do not have a setup to get the maximum downforce from
motor magnets other than gaussing the edges and putting the strongest side
down towards the rails. There is some thought that the outside “notch” area
dimensions differs and that it should be measured to maximize that area for
downforce. The smaller the notch the more downforce. A procedure for this is
to place the motor magnet on a steel flat sheet and use feeler gauges to check
the dimension. I have used a set of dial calipers in the depth mode to
determine the dimensions. It appears if you have similar sets of magnets and
one set has a shallower cut you should use it to increase magnetic downforce.
Once you have selected your race motor put it on a power supply and break it
in noting the startup and idle current draw. The lower the current draw the
better. Break the motor in for at least 15 minutes. Afterwards I break in the
gear mesh observing the current draw. I compare current draw with and without
the rear axle. A properly setup rear axle will cause no additional current
draw. You can use a variety of compounds to help the mesh. Semichrome polish,
toothpaste, gear lube, etc. Some don’t use anything. Others prep the gears by
taking a Dremel with the plastic wheel and gently polishing the teeth face to
knock off edges. I placed small drops of Semichrome on the teeth of the spur
gear and power up the motor very slowly so as not to fling the paste. I take
my finger and gently push on the outside of the gear forcing the Semichrome
into the teeth. After a period of time carefully clean off all traces of the
Semichrome. Turn down the power to see the arm turn over slowly. Turn power up
and the motor should respond instantly and smoothly. You want everything to
look and feel smooth. The arm should begin to rotate without any hesitation or
jerking. Transitions between power settings should also be smooth. Take the
other good motors and have them available as backups or for practice.
I am a firm believer in that body style can affect handling. Although I have
been frequently beaten by others using bodies that do not work for me! Yeah
you David Banta! In fact I just finished behind a Rothwell Porsche 962 in a
recent race that had a large portion hanging behind the chassis. Currently the
BSRT Nissan NPT90 is my favorite but if I run into handling issues I sometime
try to run bodies that are as short as possible like the Thunderbolt Ford C100
to avoid oversteer. I mount my bodies insuring that nothing is touching the
chassis or track other than the mounting points. Especially the pickup shoes!
A body hitting the chassis and pickup shoes usually handles erratically. It is
interesting that if you have a chassis that is understeering you can help
rotation in the corner with a longer body. I am a big fan of test sessions and
you can learn a lot without having to deal with the hectic pace of a race.
Whip up a couple of your favorite bodies and try them out in a back to back
comparison. Hopefully you have a good lap timing system that can help you in
tuning your car into one that will be more successful. Be aware that testing
and racing are 2 different things. The test session only gives you a baseline
setup to begin the fine tuning at the race practice sessions. Although I know
a lot of pros who test without a body. Usually once I put the body on I
experience at least a .1 second increase in lap time, usually .2 to .3 seconds
slower. Can be very frustrating to do a ton of tuning without the body and
find out in practice right before qualifying you cannot get close to your
previous lap times. Some clubs will not allow you to put a car on the track
without a body.
The items you can change include the following. Pickup shoe springs. Pretty
much I stay in the .008” light (#221) and .009” medium (#222) area. If you
have a superb armature you can “detune” with softer springs to get the
handling you want. Try to get the gold plated ones also. In essence gold
plating provides a slightly stiffer spring. So the sequence can go .008”,
.008”G, .009” .009”G. Try different Scale Auto pickup shoes. They have
different characteristics and may help your driving style. Insure the pickup
is level by eyeballing on a test track and carefully check the wear pattern.
You should have a good wear pattern from the front all the way to the rear.
Tweak with pliers to get it level. If it will not wear properly try another
shoe. Riding on the rear portion not only causes a lot of performance problems
but leads to excessive wear.
I always run a 7 tooth pinion. I have tried 8 tooth but they free wheel too
much for my taste. Rear gearing can run from 20 to 24. Be careful running the
bigger gears as they may contact the track and rails with smaller tires. From
my personal experience the 20 gives you more roll, less brakes, smoother accel
and higher top end. But you can run into problems with these characteristic
behaving in an excessive manner. The 21 is usually what I run as it provides a
little of everything although it can with a good motor give you too much
“overrun” at the end of a straight. The 22 seems to be like downshifting in
the corner and puts the motor into a kind of slow mode. It works if the
chassis feels edgy to calm it down some. The 23 seems to do this more but with
some punch exiting. It is interesting that a 21 can do the same thing. You can
roll more into the corner maybe have a faster apex speed so when you pick-up
the throttle the limited ceramic downforce cannot handle it. So think about
how you are tuning your car and the consequences. Still, try different gears
to get your optimum setup.
If after all this the motor feels slightly slow you may want to retweak the
endbell. I have observed some excellent tuners and looked at their endbells
coming off some very fast cars. It appears in many cases that light tension is
a good way to go. Some of the fastest Super Stocks have brushes that are not
even touching. So check your brush alignment for timing as mentioned above.
Typically the top brush is about 50% “ahead” of the bottom brush. Look at the
sides carefully to see both are flat to each other and hopefully the comm.
Take a Scale Auto endbell tool #HT394 that has had one pin removed and feel
the tension of one brush arm alone. This is now a “feel” thing. If you do this
carefully you can feel the tension and adjust accordingly. My personal
preference is no tension at all. I don’t want to feel any pressure resisting
my moving the brush arm. I want it to move freely and easily up and down.
I have a suspicion that too light tension does not allow proper current flow
but with Super Stocks the magnetic downforce is less thus the current flow may
not be as critical as say a Drop in Neo. Although you still want effective
current flow with all your cars. But excessive brush tension can drag the
motor down at the lower rpm such as at the apex of a corner. When you pick up
the throttle to accelerate out the brushes drag, drag and then snap free the
armature. This happens in a very short period of time but can result in
deslots. You can tune around this with gearing, pickups, pickup springs but
you may also encounter a heat issue. In discussions with many winning pros the
characteristics of the G3 is it is a car that rewards smoothness. Easy in,
easy out, not as much brake, lots of roll, very, very smooth. Eliminating
friction which includes brush tension aids those characteristics.
Front tires. I’m usually in the .338” to .357” front tire area. This is
somewhat different from what I hear around the country. It’s my preference and
every time I try to go lower I run into too many issues and the car just feels
uncomfortable. Bear in mind that as you lower the front you preload the pickup
springs and if you are running very small front tires may want to go softer.
If you’re an older racer who stock piles parts from the cars you ever have own
you might want to drag out some old AFX or Tomy pickup springs and try them
out. Currently I think I have over 20 different options for pickup springs so
keep that in mind when lowering or raising the front tires. I am not a big fan
of crushing or spreading the springs. But in some cases it needs to be done.
Rear tire size. You want to mark the front bracket and traction magnets with a
silver Sharpie pen. This will tell you your ride height in relation to the
rails. I have seen mechanics spray the bottom of 1:1 race cars to note if the
car is bottoming on the track. This is the same thing. Note the marks and
correlate to how the car feels to you. Be aware that track conditions play a
big part. There is a reason the F1 teams let the slower cars clean the track
before cutting a fast lap. Once the lane, the car, you feel ready and warmed
up start serious tuning. Noting the marks try a different set of rear tires
and note lap times, number of deslots, how comfortable the car feels to you.
Correlate the marks with how the car feels to you. Put your observations into
your notes making only one adjustment at a time and carefully observe which
way you are progressing. A race car is like a Rubik’s Cube and you can make
things worse real quick. If an adjustment doesn’t work return to your previous
setting. If you get really lost get back to your baseline and start over maybe
going in a different direction. Some chassis will not get similar markings on
both sides so you may have to resort to staggering the rear tires. I have at
time run rear tires that are .006” different in diameter. I don’t like doing
it but if the car feels better it’s okay with me.
I feel racing is one of the most honest endeavors I do. The results pretty
much state the truth of that moment. That guy on this day is faster than me.
So be honest with yourself during practice. If you cannot focus on every part
of the track you probably are not up to speed. For me it takes quite a while
to get up to speed and I will make some adjustments to the car if they are way
off. But once the car starts to feel comfortable I focus on learning the track
as best as I can before micro tuning. You will find that the early learning,
major setup changes yield several tenths even a half a second. But once you
learn the track you will be striving to get a tenth or two improvement. An
example is my Super Stock at the Big Buck Shootout. Even though I did a ton a
laps I still hadn’t gotten Walt’s excellent Scorpion down. I was struggling
down in the 2.8 bracket and many were in the low 2.7s. I began focusing on
each corner and found to my delight that I could punch the controller on the
sweeper onto the main straight before the entry into it! This moved me
immediately into the mid 2.7s. I then focus on my exit onto the back straight
and I went into the low 2.7s. I was relying on pure rhythm for some points of
the track further away from me so I focused on the end of the main straight
and the entry into the s turns afterwards. I did a mid 2.6 which caught the
attention of some other pros. All of this happened in a short period of time
of just focusing on my driving and areas to improve on. I have a personal
technique I do when in this mode of figuring out the track, car, controller,
in that I visualize the car “flat”. That is it is flat, level, upon exit of
the turn. Squared up for the next straight. This helps me in that the car
doesn’t feel as edgy yet I get good times. Once back in the pits I consulted
my notes to insure I knew the track as best I can and to also begin focusing
on setting up the car to be comfortable to drive in the 2.7 bracket.
I really enjoy the Scorpion which some myself included consider the “Blue
King” standard of the HO racing community. It provides an excellent track to
do testing on and you can compare times with others around the country that
have one also. I usually prefer to test on the outside red lane. It has the
longest straight to see fully how the motors perform. One thing I have
experienced is that if I can get my car to handle the hairpin turn before the
main straight sweeper my car will pretty much handle all the other lanes. You
also get an excellent viewpoint of your car coming into the hairpin on the
middle section. I don’t know for sure but I think it is also the longest lane
on the track so your times there will at least be better on the other lanes.
I’ll jump to yellow lane and once again concentrate on the hairpin onto the
main straight. I set my Difalco DD530 15 band pretty much the same for all my
cars. I have the choke either all the way on (slow) 7 o’clock looking at the
knob or maybe a quarter turn, 9 o’clock. I use brakes, just can’t seem to get
the coast thing down other than with PloyMods and it is set at the 3 o’clock
position. Sensitivity is also at the 3 o’clock position. If the motor drags a
little I may crank the choke in a clockwise manner to increase power but
usually for me it is a fine tuning. Turning up the sensitivity has a sharper
affect but can really upset the chassis if turned up too much. Brake is
adjusted to get the right amount of roll to compensate for maybe underbraking
at times in the heat of battle. I use the middle hairpin for setting the
brakes properly. As always these are my personal settings. If you watch pros
racing HO cars you may see different speeds on the wiper as it goes across the
bands. Watch their hands and out of the corner of your eye their car. Very
interesting to see how they enter, exit corners and react to the short
straights. But best to adjust the controller for you individual driving style.
A good test if your technique is dialed in is to practice, by yourself a heat
of 2 to 3 minutes. See if you can do it without coming out. If you can, doing
this is more difficult than you think, note the number of laps, fast lap and
average lap time. If you can get your average lap time to within .3 seconds of
your fastest lap and have your total laps with a couple of laps of the track
record you’re looking very, very good. Be patient as you will find that it is
difficult at first to go past 20 laps without deslotting.
Usually the race winning pace is .4 to .5 seconds slower than the top
qualifying time. The Big Buck Shootout Pro Main had a fast lap of 2.582 with a
race lap total of 230 laps. That is a 3.130 average or .548 off fastest lap. A
similar car that had a fast lap of 2.638 also did 230 laps so many aspects
come into play such as traffic, amount of crashing, etc but a comfortable car
can handle these well. So if you are within .2 seconds of TQ and have a
comfortable and well handling car you have a good shot at the win. Comfortable
is the key word. I have sacrificed a tenth to get a more comfortable car. If
you just have to be on the edge go ahead and use the fast setup for qualifying
and the comfortable one for the race. But this is my approach. The pace of the
pros has gotten quicker with little room for mistakes. It is almost like
MotoGP where if you lose 20 feet to Rossi in a corner you will not get it
back.
Currently the top 3 in points here in Arizona are using the G3. 2 are the G3-R
flexy and 1 is a G3 with a G3-R flexy bulkhead. You can use a medium chassis
if you have a track with outstanding grip or can drive a “freer” car. The
medium chassis really wakes up the motor at the cost of grip. This is very
apparent with slip on tires but with sized coated foam not as huge a
difference. I had trouble deciding at the Western States which chassis I
should use and ended up with a medium. I logged identical times with both
chassis but there were some handling differences. I was comfortable enough
with the medium to go ahead and put a little more focus on speed. I would
suggest you build 2 cars to compare the chassis as if one motor is doggy you
can change and make a good evaluation. I have run a flexy with a med bulkhead
and vice a versa. Once again I will select the car that is most comfortable.
I hope you enjoyed this.
Have Fun and Good Luck.
Greg Williams