Friday, December 14, 2012

NINCO LIGHTNING AUDI R18 e-tron quattro LMP1

By Michael Ashton

THE 1:1 CAR

Wow! Did you hear? Aunt Edna's Audi hybrid quattro won the 24 Hours of Le Mans! Well, sort of. A hybrid did win the 2012 24 Hours of Le Mans. And it was all wheel drive. And it was an Audi quattro. But it doesn't even remotely resemble anything that Aunt Edna would drive. It was the Audi R18 e-tron quattro LMP1.

The 1:1 R18 e-tron quattro represented by this NINCO model is a hybrid version of the R18 Ultra, which was just introduced in 2012. The hybrid system in the R18 quattro was designed by Williams Hybrid Power which is a division of the Williams F1 racing team enterprise. The system utilizes a flywheel accumulator system which stores energy that is subsequently delivered to the front wheels via an electric motor. Current regulations restrict the system's use to speeds above 75 mph, so the car is all wheel drive, but only above that speed. This also allows the car to operate with a relatively small (by LMP standards, 58 liter) fuel tank. That's just over 15 US gallons.

The exotic drive system is complimented by equally sophisticated management and control systems which pretty much allow the driver to steer the car and enjoy the scenery.


This is obviously remarkable technology in an automobile. However, even more remarkable, in my opinion, is the fact that two Audi R18 e-tron quattros finished 1-2 overall in the 2012 24 Hours of Le Mans.


THE MODEL

NINCO's initial release of this car includes two decorations: the R18 e-tron quattro being reviewed here, and the #2 R18 Ultra (curiously named "Sebring" although it did not run there, making its debut with the e-tron later at Spa). Personally, I am very happy that they chose to do the e-tron because it is a very impressive decoration and no other company has released it into the already crowded field of 1/32nd scale Audi R18s—at least not yet. Upon removing the model from its case and viewing it from various perspectives my initial impression of its appearance was very favorable.


Fit, finish and attention to detail are all quite good, however, not the best that I have seen from NINCO. Regardless, the overall striking appearance of the model tends to subordinate the few minor flaws that my eyes were able to detect.


One problem area of the car's appearance that is difficult to ignore is the fit of the front tires to the wheels. The front tire compound is hard, dry and relatively stiff. I assume that the intention is to minimize grip. The tires also appear to be slightly too narrow for the the front wheels. These two conditions prevent the tires from conforming properly to the wheel surface and outside flange. The yellow arrows in the following photo show the resulting gaps in tire fitment. This was visibly annoying but the tires are quite secure on the wheels so there was no discernible effect on performance.


And then there are the wheels themselves. Ah yes, once again, the wheels. They are not true reproductions of the actual R18 racing wheel. They are the NINCO ProRace V.03 17" wheels with the (aforementioned) ultra low profile tires on the front. This is the wheel that NINCO installs on all of the Lightning cars and I assume that its use here is a concession to performance over pure scale accuracy. The wheels look good to me and do not detract from the car's overall appearance. As always, this is a personal preference and I understand how this might be an issue for the scale conscious enthusiast.

A point worth noting is the use of the 17" wheels all around which is consistent with the configuration of the 1:1 car. It's likely that the inclusion of the front axle adjustment components, which allow the guide to maintain good electrical contact over a range of different conditions (track rail height, wheel/tire size, etc.), make the large wheels in front possible. The low profile stock front tires are no doubt a concession to slot car performance.


MECHANICAL

Under the body is a relatively simple chassis with a clean design. The NINCO NC-12 "Crusher+" motor, rated at 23.5K rpm and 270 gcm torque @ 14.8 volts, is mounted in a in-line configuration and rests in a three-point adjustable isolated motor pod with a spring-loaded rear suspension. The "+" designation in this motor denotes an increased level of magnetic down force when compared to its predecessor, the NC-6. The running gear is NINCO's time proven standard in-line 9 tooth brass pinion driving a 24 tooth ProRace EVO crown gear. This results in a gear ratio of 2.67:1 which is probably at the low (tall) end for in-lines, and certainly for the average home track. The guide is the ProRace standard (i.e., longer flag but not suspension) type and braids are standard, relatively stiff, copper. A quite powerful narrow, but thick, removable bar magnet is present just in front of the motor secured in the pod.


New for NINCO is front axle adjustment that allows both ride height and vertical travel to be adjusted on both sides of the chassis. This is accomplished via two sets of M2 grub screws. One set housed in blocks above the axle and the second set that extends upward through the chassis floor and are accessible underneath the chassis (see the yellow arrows in the photo below).


Here are both rear-on and head-on views of the chassis. The first photo highlights the drive train, featuring the spring-loaded adjustment screws of the rear suspension. The motor is firmly secured by two hex head Allen screws.


The second photo below provides a good view of the front axle adjustment components. The [left hand] lead wire is seen to be touching the axle. This did not prove to be a problem as the wire can be made to lie flat on the chassis floor by pressing it farther into the holder (visible just behind the axle) and routing it through the channel formed by the lower axle adjustment screw and the guide holder brace, as is the [right hand] lead wire.


I am curious as to why standard braids are fitted in a ProRace guide and the drive train features a ProRace crown but only a standard pinion. Only NINCO knows for sure. In any event, I'm glad that NINCO chose to implement an in-line drive train in this car only because that happens to be my personal preference. And even before placing the car on the track I was confident that the suspension motor pod and adjustable front axle—if only by their appearance—would be of real benefit to performance. I also found the spring-loaded suspension pod in the previously released Lightning Citroen C4 WRC Novikov to be effective, although that was an angle winder.

However, when I initially attempted to feel the movement of the pod by pressing it upward with my thumbs, I knew immediately that something was wrong. The pod moved vertically, but it was binding and scraping against something. Closer examination revealed two problems. One not so serious and shown in the first photo below: the pod was binding against the chassis opening in the area of the yellow arrow. There appeared to be some flashing or excess material that formed a seam there that would require removal. Not uncommon among virtually every slot car manufacturer.


Fortunately all that was needed was some light sanding with a medium grit emery board and the problem was eliminated.


The second problem turned out to be more serious, but not unsolvable, and was present in the area depicted by the yellow arrow below: the screws chosen for the pod's rear suspension vertical tension adjustment have relatively sharp and wide threads. This was causing the threads to catch on both the spring's coils and the holes in the pod that allow vertical movement around the screw. When moving the rear of the pod vertically the feeling of screw threads scraping was obvious. And the mechanism would frequently bind up and not move at all.


There are probably several approaches to solving this problem. In my case I did not want to risk damaging the pod. And I was not going to forgo the potential benefits of an adjustable pod by just "dogging it down" to the point where movement was eliminated. So the best solution to me, was to remove the threads on the top half of the adjustment screws. Only the threads on the lower part (less than half of the screw's length) were needed for full vertical adjustment. I turned the screw about one third of the way into its adjustment hole in the chassis without the pod in place. This functioned adequately as a tiny vice and allowed the use of a small flat edged file to carefully remove the top half threads.


This was somewhat tedious and time consuming but it worked. A two speed Dremel with a small chuck that could hold the screw would have been much faster. Regardless, the following photo shows the modified adjustment screw, which now allowed the full, smooth pod movement and adjustment that was obviously intended.


Please note that these problems do not stop the car from being run straight out of the box, but if left unchecked they effectively negate any potential benefit that the isolated motor pod can provide.


PERFORMANCE

First I wanted to run the car on an analog track but my track is normally configured for N-Digital operation, so I had to perform a quick switch. My analog configuration is simple but I feel it is adequate for the testing at hand. A Pyramid PS-26KX variable power supply provides track power through a NINCO standard power base. I connected a single NINCO 55 PLUS controller (55 ohms). When configured for analog running I do not have lap timing available so I will convey only subjective observations about speed and handling in the analog mode.


Apart from the motor pod modifications, the only things done to the car were:
  • Lubrication of all axle bushings, motor bushings, the guide post and the gears.
  • Replacement of the standard braids with ProRace (tinned) braids.
  • Removal of the magnet.
The motor pod suspension adjustment screws were backed out about one quarter of the way from their fully tight setting. I would describe this as a stiff, but movable pod. The front axle adjustment was set to allow the wheels to just touch the track surface. In this position there was very little vertical travel. Body mounting screws were loosened by one half turn from the tight position. Experimentation with all these adjustments would be performed later in digital operation when lap timing would be available. I decided to start off without the magnet so that some mild break-in could occur initially as part of the testing.

I ran the car on my 62' twisty, bumpy, technical NINCO track first at 10 and then at 12 volts, switching back and forth. This car has a level of power and handling that I normally don't experience on my track, so It took a little while to get used to it. The car was fast but surprisingly easy to control, even at the higher voltage. The effect of the increased magnetic down force and pretty good grip from the stock tires tended to minimize rear end sliding, which I think is appropriate for this car. The gear mesh was quite smooth from the very first lap, and will undoubtedly improve as the car breaks in. Braking was good, about the same as other NINCO cars with strong, long can motors that I have experienced. It also tended to stay in the slot until pushed far too hard into a turn. Coming out of turns it tolerated everything that the NINCO 55 ohm controller could deliver within reason, with no evidence of hop or chatter.

Next, I replaced the magnet, and ran the car at 12 volts. I have several LMP cars that I run exclusively with the magnet, but this car was a new experience for me. There is no doubt that I had to control the car via the throttle, however, it went trough turns at speeds that appeared to me to be absurdly fast, and I could not perceive any feedback as to where the limit of adhesion was, beyond the visual. And frankly, I wasn't all that anxious to find out. It reminded me of how HO cars with magnets appear as a blur circling the track. It was fun to run this way but quite nerve racking. Those who race with magnets should be pleased with this car—I would soon need therapy.

After about 200 or so laps of analog running to get the feel of both mag and no-mag handling, and to break the drive train in a little, it was time to install the N-Digital decoder chip. As previously stated, running in digital mode allows the recording of lap times in order to provide some objective evaluation.

The N-Digital decoder chip in its protective red plastic case will not fit in the R18 quattro. But after removing the chip from the case there were no obstacles to installation. In the position shown in the following photo the chip is secure and there is ample clearance between the chip and all other parts of the chassis and body. I left the chip in its "naked" state in order to show how small the NINCO chip is. Fear not—it will eventually be wrapped in electrical tape. This conversion to digital operation should be classified as "easy".


With the track configured for digital operation, I ran the NINCO Lightning Audi R18 e-tron quattro for a series of 25 lap sessions totaling several hundred laps. Each session included a unique combination of N-Digital throttle profile, motor pod suspension adjustment, front axle ride height/travel adjustment and body mounting screw setting. For those not familiar with N-Digital: the so called 'amateur' throttle profile is roughly analogous to 9-10 volts maximum in analog with a mild response in the lower end of the throttle curve for an adjustable (PWM) electronic controller. The 'professional' profile would be closer to 11-12 volts maximum with a steeper response in the lower region of the curve. For perspective: my track lane length is 62'. The previous fastest lap recorded was 6.12 seconds by a NINCO Sport Acura LMP2 with magnet in the 'professional' throttle profile. The previous fastest no-mag lap time was 7.40 seconds recorded by a NINCO Lightning Lamborghini Murcielago using the 'amateur' profile with the same NC-12 motor. So the Audi has effectively broken all the track lap records.

The best resulting lap times for the Audi R18 e-tron quattro from the various combinations of adjustments are shown in the following table:


Generally speaking, the best lap times were obtained with the following settings:




CONCLUSION

It is obvious (to me anyway) that this car is designed and equipped to be raced on a large track. So, one personal goal that I had in mind when performing this review was to determine whether or not this type of high performance slot car could be raced and enjoyed on a smaller, more technical home track. From my perspective, the qualified answer is yes. The car handled well in a fairly wide range of parameters including track voltage and magnetic down force. My experience tinkering with the various combinations of settings for front axle height/travel, motor pod suspension tension, amount of body float, and presence/absence of the magnet lead me to believe that there are enough effective adjustments available to optimize this car for just about any track. However, one serious reservation that I would have is racing a group of these cars, especially with the magnet, on a home digital track. The potential for severe rear end collisions would be very high, even with the most experienced drivers.


The argument could be made that another Audi R18 is not needed in an already crowded field of available slot cars. But I for one am glad that NINCO decided to forge ahead with this model. And there is no shortage of formidable competition for this model out there. 

Nevertheless, this car has a lot going for it:
  • The physical appearance is really striking. And it is the decoration of a history making winner at Le Mans.
  • On track performance seems to be in the upper tier of slot cars intended for serious racing. Of course, time will tell.
  • The model strikes a good balance between scale accuracy and performance.
  • Performance adjustments such as front axle height/travel and the motor pod with spring-loaded rear suspension provide an exceptional level of versatility.
On the down side, the problem with the pod suspension screws is significant and cannot be ignored. However, the solution was relatively simple and did not require additional expense. Beyond that, nothing really needs to be added in order to get superior performance from this car.

All conclusions in this review are derived from performance on a home plastic race course. Hopefully someone will get the opportunity to let the NINCO Audi R18 quattro stretch its legs on a large wood track with a long straightaway and some sweeping curves so that the true level of versatility of this slot racing platform can be determined.


Check out this short clip of the NINCO LIGHTNING Audi R18 e-tron quattro in action on a home N-Digital track... 
 

_Michael Ashton

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