SlotsintheCity.com EXCLUSIVE First Review!
The Slot.it Audi R18 e-Tron Quattro is quite unlike any other slot car I’ve driven, for many reasons. To begin with, there’s the sound it makes – it’s not that it’s noisy, but that slight whine you hear the first time you squeeze the trigger is a dead give-away to the fact that there’s more than the usual going on under this bodyshell.
And those ‘more than usual goings on’ make themselves felt during even the first few gentle laps; immediately, I noticed how reactive this car is to throttle input – it launches forward without hesitation and seems almost to have stopped by the time I’ve finished releasing the trigger. As I gradually built up more speed with each successive lap, I found myself having to continually re-think my braking points in order to avoid slowing so much that I needed to get back onto the throttle before taking the corner! It really is very different to drive – but, to my mind, removing the magnet would be the only way to reveal just how much difference this new 4WD system was making.
…fire up the Quattro!
So, magnet out and back on track, the e-Tron Quattro feels just as urgent as it did before, but lighter and more nimble – what’s also becoming noticeable now is how the car is pulled around the bends by the 4WD system rather than just pushed by 2WD. With the throttle balanced around a corner, you get the distinct impression that those clever clutched bearings in the front hubs are starting to come into play. During a corner and at a constant speed, they create the effect of an independent front axle – helping to keep the car stable as it corners. Then, as you gradually feed in the power towards corner exit and the rear wheels begin to break traction, the bearings ‘engage’ and the car becomes truly 4WD. Get it right and the Audi practically slingshots its way out of a bend and onto the next braking point. Unfortunately, there’s a fine line between getting it right and getting it sideways; the C1-compound tyres fitted as standard are not my first choice for Carrera track, so they were swapped out for a set of Slot.it P6 to avoid any unnecessary scrabbling for grip.
Switching to the grippier tyres improved things immensely – the lap-times soon fell to the 10.53s I’d posted when the magnet had been fitted, and there was still room for improvement. At this stage, I’d normally start adjusting the front axle upwards so as to encourage as much guide into the slot as possible – the car does look to ride quite high at the front, after all. But, to raise the wheels too much would obviously negate the effect of the 4WD – so, the tricky part is achieving a balance of weight across both front wheels and the guide. And, this is trickier than you’d think, because the drive belt will always attempt to pull the axle towards the lower limit of its travel… for this reason, I found it best to keep that movement as small as possible. Those who like a lot of vertical travel in their front end might have to adapt their setup technique!
Slot.it have already taken care of any the horizontal movement with the simple addition of brass bushings to the front axle; for some time now, Slot.it chassis have been manufactured with a small groove in the front axle carriers for exactly this reason, but this is the first model to have them installed at the factory.
So, with the vertical axle movement now set to sensible limits and the guide as deep into the slot as possible without lifting the front tyres off of the track surface, I set about attacking the lap-times. The car requires a lot of concentration to hustle quickly round the circuit – with so much grip now available up front, there is a tendency for the rear end to break free – and any drifting behaviour really slows forward progress! As with the axle setup, there is a fine balance to be achieved – this time with the last 10 to 15% of throttle travel. A little too much throttle is fine, as the 4WD compensates when the rears lose grip to pull the back end into check; but a lot too much throttle is much less forgiving than with a 2WD chassis as, instead of a nice display of flamboyantly-stylish drifting, the outside tyres simply dig in and lift the guide clean out of the slot – a less-than-stylish display of the car’s underside. Still, we’re down to 10.39s now.
I decided to experiment with other areas of the car setup in order to alleviate this oversteer. Slot.it supply their e-Tron Quattro with the front pulley one tooth larger than the rear one, which ensures that the front axle spins whenever the rear one does, but always slightly slower, giving a rear-drive bias. Spare belt pulleys are included in the box, so, I tried the small one at the front, large at the rear – and was interested to find that this front-drive bias actually made the car much more steady on corner exit, unfortunately at the cost of some top speed. So, although the car was now much easier to drive and harder to de-slot, it was ultimately slower. I tried out the equal-sized pulleys next (I opted to fit the larger ones so as to tension the belt further away from the pinion…) and this, for me, proved to be the best option and I was able to consistently lap mid-10.2s – some final tweaks to loosen the motor pod screws and increase the pod movement gave me a fastest time of 10.14s.
…other unique details
The front bushings aren’t the only feature unique to this release – remove the body or motor pod screws and you’ll find interesting little ‘slotted’ washers that can be rotated to help restrict any movement you allow when you loosen the screws to the direction that you choose; front-to-back, side-to-side or anywhere inbetween.
The belt tensioner fits neatly, making efficient use of the screws already used to hold in the motor plus one of the front motor pod screws. It has splines to position a tensioner wheel in one of three different positions – but a little fettling was needed to make sure that the wheel spun freely and didn’t cause drag… and, you do need to be careful to get the belt tension right, as any looseness could result in the belt moving about and fouling the pinion.
…should I, shouldn’t I…?
Of course, there really is only one way to see what difference the 4WD system makes. In the end, I had to give in to temptation and attempt a few flying laps without the drive belt fitted – immediately, I could hear the increase in motor RPM down the straights, lapping a couple of tenths quicker as a result – but the handling was a lot more nervous, and harder to control through the curves at that speed than it was with the belt in place, 4WD system working as it should.
Belt reinstalled, I pitted the e-Tron Quattro against a 2WD CA24a Audi R18 TDi Monza which confirmed the above findings – a little slower down the straights, but more sure-footed through the twisty sections and faster out of the corners. This also afforded me the opportunity to take some side-by-side shots, showing the attention to detail that Slot.it have taken to reproduce the subtle differences between the #1 2011 and #4 2013 models, particularly at the rear of the car.
The Audi e-Tron Quattro is going a little faster each time I run it – everything seems to be loosening up, it pulls very well through the twisty bits, and the braking ability continues to amaze me. However, top speed is still a little slower than a 2WD R18 running the same motor and gear ratio – at the moment, the 4WD is running a tenth or two off the pace… but provided you concentrate on that throttle balance, it remains more predictable and easy to keep going at that pace, lap after lap.
It’s a hugely entertaining car to drive and will be fantastic on twisty circuits – only time will tell if it loosens up enough to present a real challenge to its 2WD counterparts on the more sweeping, faster ones! But, although it’s looking encouraging so far, on the large circuits I tested on at least, the benefits of the 4WD system through the corners do not yet outweigh the slight drag it causes down the straights.
This car requires a different driving style to one with a conventional chassis and, as a result, some drivers will likely be able to adjust and get results more quickly than I did. You shouldn’t buy this car expecting it to be faster than a 2WD equivalent straight out of the box; it will require testing, fettling and more testing before you get the best out of it. But that’s surely one of the most entertaining and rewarding facets of this hobby – yes, it might prove a little frustrating on occasion, but that only serves to make any positive result you achieve more satisfying. So, while it needs time and attention to bring up to speed, I’m positive that the Slot.it Audi R18 e-Tron Quattro will ultimately be one of the most entertaining and rewarding slot cars you choose to own and drive.
Available in stores: 29th April 2015
Once again, I’d like to say a big thank you to everyone at Slot.it – not only for making this model available to me so quickly, but for pushing the envelope in the first place to release such an interesting and innovative new product!
Thanks also go to my HiP clubmates at SRC-Meiderich for track-time on their fantastic brand-new Carrera club circuit in Duisburg, Germany.