The SCX Audi R8 Pro
by
Daniel J. Dyke

SCX is one of my favorite car makers even with all the warts and lumps that one usually finds on their products.  Their cars are durable and recently the word attractive is not out of place. But let's face it their motors are dogs and the gear train sounds like a blender with the spoon left in.  In spite of all this I love to run them.  When SCX announced a high performance version of the Audi R8, I started counting the days for the kit to appear, but always had that nagging question of whether or not it would be worth the wait.  The answer is a qualified yes.

The packaging of the car is first rate and is the type of thing that will attract the collector, but as for my tastes I think this type of car should have had an extra set of gears and not a pretty box. I guess that is enough of the negative criticism for the moment.

When opened, the box the contents of the box were neatly and securely packaged in foam.  On closer inspection I found that underneath the foam was a users/tuners manual. I have not read it yet as it is not the manly thing to do.
 

A.    Lightweight Audi R8 body with the Champion ADT livery B.    10" length of replacement steel braid. C.    Extra Guide Blade D.    Fully Assembled Chassis. E.    Screws and Allen Wrench F.    Extra Brake Shoe G.    Extra Motor Pod BTW, there is a manual hidden under the foam rubber.

THE CHASSIS

What I first wanted to inspect was the chassis which was supposed to be revolutionary by early reports.  The term evolutionary is a better term except for one thing, the brake.  Yes, the car has a brake!  It is that little white thing at the back.  The chassis, unlike other kit cars, is fully assembled and lubed.  We will first take a tour of the chassis and carefully examine each part.

The Guide Blade & Lead Wires

Starting at the front we find that the traditional SCX arrangement of flat copper strips carrying the current from a sprung guide blade to the motor has been scrapped in favor of a more traditional Ninco/Fly type guide blade and lead wires.  The blade is the same depth as the old one, but that is about the only carry over.  The guide blade is a non-sprung guide attached to the chassis by a set screw.  In the bag of screws there is even an extra screw specifically for the blade in case you lose your original.   The lead wires are attached to the motor with eyelets that fit into a crimped pocket on the motor.  Between the eyelets is a little resistor which is probably there to cut down on TV interference, but I could be wrong on what it is.  This resistor was removed and its absence caused no problems to the B&W TV attached to the same circuit in my shop.

As I was dissecting this part of the car I was wondering what could be changed.  I am a firm believer in deep slot guides and so the new grey Slot It guide was tried.  It fit the hole nicely, but was a hair too short for the flanged top to spring out and hold it in place.  Probably with a little effort one could get it to work.  Another thing would be to solder the wires to the motor instead of using those little eyelets.  I pulled the eyelets out and my old hands had a devil of a time getting them back in and so on my car they are soldered in place.  If you want, the resistor on the motor can be clipped and again this caused no problems to my little TV.

GEARS AND BRAKE

At the back of the car is a shock waiting for you.  There is a gear set that looks like it was made by Slot It.  The  pinion has nine teeth and the crown has twenty seven for a 3:1 ratio.  The pinion is new also and meshes well with the crown gear. One question that must pop into your mind is whether or not Slot It gears will fit the axle and the answer is yes.

"What is the white thing behind the crown gear?" I asked myself when I pulled the chassis out of the box. It is a brake and it is a clever little gizmo.  How much braking force it adds is another question, but conceptually it is clever, very clever!  How it works is that the motor pod slides back and forth just a little bit.  When the car accelerates the pod moves forward about a sixteenth of an inch and the brake disengages. When the power is shut off, the motor pod moves back because of the natural braking effect we are all familiar with. The result is that when the pod moves back the crown gear rubs the brake shoe. I am going to do a whole article on brakes and this is going to be my first test case.  No matter what the results are, I give SCX five stars for the idea.  If it does not work, I am sure development will improve it over the years.

WHEELS & AXLES

The plastic blobs that adorn many SCX cars are gone and in their place are setscrew aluminum wheels.  The axles are comparable to Slot It axles.  In the extras bag a wrench was provided so you can adjust the wheels.  Do you remember the frustration of your first Slot It and not having one of those micro Allen wrenches when you had a loose wheel?  I could not run my first car until a wrench came in a week later.  The wrench also works with the crown gear.

Now I have to go back to complaining. In the following picture the rim on the right is from the standard Audi R8 Crocodile Dundee car, but the one on the left is significantly narrower and has a smaller diameter and of course is from the new car. This may not have an effect on performance, but it is something that will eventually get changed to a set Slot Its in testing.  These new rims would get a rating of four stars out of five, but a Slot It or BWA set would get a five.

The front wheels are a different matter.  They are too small for the wheel well.  Notice how the rim and tire on the original car fill the well but the new wheel tire combo make the car look like it is running on a tiny spare off my Honda Civic.

TIRES/TYRES/TARS

Tires are one of the most important factors in a slot car's performance. The tire on the right is the stock one.  The one in the middle is an NSR UltraGrip for GT cars that happens to fit the SCX rim.  The one on the far left is from the standard Audi R8.  No question about it the stock tire is the worst part on the car.  The SCX tire feels hard and dry.  I am going to soak it in WD40 to see if that changes hardness.

The solution that worked was to put a set of NSR UltraGrip tires for GT cars on the rim.  They fit snuggly and needed no sanding.  Almost immediately I took two seconds off my times. The rear track had to be narrowed as these are fatter tires, but because the originals are so narrow there was plenty of space.

MOTOR

The motor is billed as a ProSpeed.  It has different characteristics from any SCX motor I have run.  It is smooth and relatively fast for a SCX.  It runs well on both short and long tracks.  It is the motor to use if you run in a group that says any SCX motor in any SCX car.  On my home track it never runs out of steam, but is also very good in the infield.  I am going to test it on the long tracks next week and will post an update.  In a preliminary test it went pretty well with the bad SCX tires, but was coming off the turn so slowly that it was hard to judge.

On the "dyno" we are developing it gave great results. It was10% faster than my best SCX Pro Turbo Plus under load.  The Pro Turbo plus gives a reading of 8.9 and the new motor gave a reading of 10.1.  The dyno we use gives relative, but accurate values and the difference translates to about 1500-2000 RPMs.

THE MOTOR PODS

The car comes with a new variation of the SCX motor pod.  It was redesigned slightly to allow float and to make the brake work. This is just a pragmatic change. The change was great enough that the old pods will not work in the car.

Will a Slot-It adapter fit the pod so I can get an even hotter motor in the thing? Yes it will, but the real question is whether or not a Slot-It (Mabuchi) motor will clear the body work enough to allow the floating motor pod to float.  Who cares? This is a way of saying that there is another new feature to the car. It has a second motor pod, but it is not for SCX motors. It will accept either the FA-130 motors like the Falcon/TSRF/Fly Racing Motor or the FF-180 type motor like the Slot It Boxer or the NC-2/5/6.  If you use the shorter motor you have to use set screws to hold them in.  Is this feature too cool or what? Too cool is the correct answer!

 What they should have thrown in here was at least three sets of gears, a FF-180 motor, an extra set of bearings and an axle. I would have paid $100 for that car. Minimally I want the bearings included as they are the only things that I can't get locally and if I drop one I know it will descend to some crack in the cement.  On the plus side they are the same spherical bearings that are in the older cars with the floating pod.

MAGNETS

 It came with no magnets, but there is space in the motor pod back by the axle where a bar magnet can be glued.  There is also a lot of real estate in the front of the car to put one anywhere you want in the nose.

BODY

Now to the body!  This is a breakthrough in construction.  It appears to be two layers of plastic.  There appears to be a clear inner body and detailed outer body bonded together into one. How it is done I do not know. Jesfour (James E. Simpson IV) and I looked at it and could not decide but agreed it seems to be two layers. What is important is that it is strong and light.  The interior is minimal to save weight and the driver is made shorter.  This is not just a reuse of the old molds/patterns with a new technique of construction, but a revised design to fit the differences of bodywork that existed between the ADT Champion car and other Audis.

LIGHTS

Unlike many SCX cars there are no lights, but the headlights lens are clear.  If you want lights they can be added very easily.  Get one of Philippe Marchand's kits to light up your life and brighten your nights.

DRIVING IMPRESSIONS

Once the tire were changed it must be said that this car is an enjoyable car.  It has a great baseline setup to start with and should respond well to tuning.  On a regular SCX Audi weight had to be added to the front, but on this car it does not seem as crucial.  Will it set lap records? On along course it is quite possible as this is a long car that begs for high speed turns. With the motor pod option horsepower and RPMs are not an issue. On a short course a Sloter or Slot It Ferrari 312PB will beat it in the twisty sections.

Would I buy the car again?  Yes, but I would also buy some tires and gears with it.  They should have at least included the gears instead of the pretty box.  I think that was said before. I love the car already and see great potential in it. If SCX keeps this type of innovation up they we will cease to be the poor cousin of Scalextric and will rival Slot It and NSR as the innovation king.
 

Dan

SPEI MELIORUM TEMPORUM
(In hope of better times!)

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Thanks to CincySlots for the great deal on the car.