Saturday, 2 February 2008

HOW-TO: Tune a Fly Classic

HOW-TO: Setting up a FlySlot Classic
Fly's Porsche 917K and LH

The FlySlot classic range is one of the most desirable and collectible slot cars ranges released over the last decade. The detail and appearance of these slot cars is second to none. The only problem with these beautiful slots is they can be a little tricky to get performing well on the track.

There are a few how-to's on the web but most of them recommend using expensive after market parts. Let's face it, you have already spent some considerable money on a FlySlot classic so the last thing you want to do is spend another fifty dollars plus getting it up to speed.

This how-to starts by showing you the things you can do without spending a cent, basically the only thing you'll be spending is your time. Then shows you the things you can do on the cheap followed by some of the more expensive upgrades.

One of the main benefits in setting up your classic well is the pleasure you will receive when you drive it. You're classic will be transformed from a taily, noisy, un predicable beast into a smooth, quite, pleasure you will want to drive till the wheels fall off!

NOTE: For the purposes of this how-to I have chosen a FlySlot Porsche 917K but you can apply these techniques to any FlySlot classic, actually to just about any of their models.


One of the first problems with Fly slot cars is the guide braids. They are too thin and not wide enough to guarantee excellent electrical connectivity, the goal here is to ensure steady power to the motor 100% of the time.

Straight from the box, my Porsche was not running smoothly as it went around the track, the car ran as if it was stammering. In fact I actually struggled to get the slot to complete a lap without stopping at some point. This was because power to the motor was not being consistently achieved.

The first thing I do with any Fly is to increase the width of the guide braid in order to achieve better electrical connectivity with the tracks rails. In the below photo you can see how I have used a pair of needle nose pliers to spread the ends of the braids to almost double the width. Hold one side of the braid in the pliers and use your finger nails to spread the braid apart. This process takes 2 minutes but you will be amazed at how much better your classic will run. It's also a good idea to give the motor and gears a light oil, I use machine oil as it is very fine - Don't apply too much however as you'll end up with it all over your track.

After getting the braid issue sorted out, I ran the slot for approximately 50 laps to get a feel for other issues. The best laps time I achieved during these 50 laps was 7:67 seconds which I consider to be the benchmark time for the slot from the box.

FTB Lap Time: 7.67 seconds


One of the first things I noticed about the car was that it had a small vertical rear-end shake. The rear end of the car was moving up and down which means the slot has either a bent rear axle, the rear wheels aren't correctly placed on the axle or that the wheels are very badly out of true. A quick examination of the rear rubbers profile showed that the tires were VERY badly out of true.

Truing a wheel, is the process of making a wheel completely circular.

When truing a tire on a plastic wheel, the first thing to do is firstly check that the wheel itself is true and has no mold flashings. Remove the tires and closely examine the wheels for any mold flashings. In the below photo, you can see extensive plastic flashing from the wheel mold process. The rubber tires sit on top of these flashings and cause the wheels to be non circular.

To remove the flashings, place some sand paper (say 200+ grit) on the surface of the track and with the guide in the slot, carefully lower the rear of the car onto the sand paper while applying a medium amount of power. This process takes two hands and a little care. Any inconsistency in the wheel will quickly sand off. Apart from obvious flashings, you may also find that the profile of the plastic wheels is not flat, so you may want to completely true the rear wheels before progressing.

Once you have trued the rear wheels, replace the tires and go through the truing process again on the rear rubber. Fly motors are not very powerful and don't like heavy loading so only true for a few minutes at a time and don't apply any downwards pressure on the car while truing. Once the tire is correctly trued, its profile should be completely flat when you rotate the wheel. As you can see in the below photo, tires will have high spots in some areas that will require extensive sanding. Note how much tread was removed from the left-hand side of the tire.

The performance of the car was considerably improved by truing the rear wheels, after running the slot for another 25 laps, a 0.7 second improvement was recorded. Apart from the obvious performance improvements, the car was much smoother to drive and the hop in the rear end had been totally removed.

Step 2 Lap Time: 6.98 seconds

STEP 3: FRONT AXEL - $3.50

For some reason, Fly classics have plastic stubs as front axels. If these stubs aren't completely tight, the front wheels can sag vertically digging into the track going through a corner or they can rub on the body work acting like a brake and impeding the performance of the slot. Remove the front plastic stub axels and replace them with a 54mm solid axel, I used a solid steel axel, (SIPA01 - $3.50) with this car but whatever you have or can get. Whenever you are using a new axel, roll it on something flat to check that it is completely straight.

Make sure that there is a small, (less than a 1mm) amount of lateral 'play' in the front wheels. If you put them on too tightly, the front wheels will not be able to spin freely and will act as a brake when the front wheels touch the track.


Depending on your car, there will be a degree of sideways movement in the rear axel. This makes the car noisy, is not good for the gears and more importantly means that the entire slot can move from side to side on the rear wheels as the car goes through corners. This makes the car unstable but the good news is that it's easy to fix.

In the below photo you can see I have placed two thin spacers on the rear axel to remove the rear sideways movement. In this case I used two brass 1/8" flat washers produced by Zenith but any washer will do the trick. I chose to install 2 thin washers, (one on each side) instead of a single thick one to ensure the wheels have the same offset to the outer body of the car.

I was able to purchase a packet of 50 brass washers for a few dollars from my local hardware, a worth while investment of around 20 cents to seriously improve a slot. Make sure the rear wheels do not rub on the body and that the rear axle is not too tight. You don't want the motor to have to work too hard to turn the rear axel. Another simple improvement can be made by loosening the rear 3 screws half a turn so that there is some roll movement in the chassis.

There was no visible improvement in the car although it felt faster through the corners, the obvious improvement was the reduced noise coming from the car. After another 25 laps the slot was consistently lapping between the 6.6 to 6.7 second mark.

Step 3 and 4 Lap Time: 6.63 seconds


Now this is an optional improvement that I like to perform on any slot I'm serious about driving. We have already improved the electrical connectivity of the guide pick-ups but the guide itself was left standard. I have tried a few after market guides from and Ninco and although I like the screw guide, (SICH10) at around $10 I find them a little expensive to use on mass. The Ninco ProRace guide, (with spring) is around a third of the price, ($3 each) and an excellent choice.

Ninco ProRace braid is also supplied with the guides and is a very good upgrade on the standard Fly braid. Unfortunately the ProRace guide post diameter is a little larger than the Fly guide so you will have to use a 5/32 drill bit to increase the guide post hole a little. Using a battery drill with a slow setting, carefully drill the guide post hole on the slot chassis. Insert the Ninco ProRace guide and be sure it freely moves up and down and can easily rotate.

With the Porsche 917K, the nose of the car slopes down dramatically not allowing much room for the Ninco ProRace guide to move up and down. Trim the top 2mm off the guide and when reassembling the slot, do not tighten the front screws, rather leave them half a turn loose to allow the guide more vertical travel.

The performance improvement this guide upgrade makes will come as no surprise. The slot can hold more speed through corners and desloting the car becomes quite hard to do. I have vertical elevation sections on my Carrera track which can deslot a standard Fly classic under speed but the ProRace guide with spring really helps to keep the car from desloting through these sections. In the below photo, the Ninco ProRace guide can be seen on the right and the standard Fly guide on the left.

Once the guide had been fitted, I ran the slot for another 25 laps and was achieving laps times around the 6.3 second mark. That makes for another 0.3 second improvement which is impressive considering the degree of performance improvement to date. It was easy to get large time improvements early on when the slot was doing 7.7 second laps, now that it's doing 6.3 second laps, large performance improvements are harder to achieve.

Step 5 Lap Time: 6.31 seconds


Okay, so I said this would be cheap and a $22 upgrade isn't exactly cheap especially if you want to perform it on a dozen slots. So this finally step is optional, you will only get an additional 0.2 second performance increase so you need to weigh it up.

The final modification I like to perform on some of my slots is to replace the rear wheels and upgrade the rear rubber. Truth be known, if I was to replace the standard rear Fly rubber with MJK4215 to suit Fly Panoz, (that's correct, don't use the MJK for Fly classics) I would get nine tenths of the improvement I'm going to achieve by replacing the entire rear wheels. For the majority of your Fly classics, just stick with upgrading the rear rubber with MJK, ($12) and forget the wheel upgrade.

However, in this instance I used BPW EURO, (from Patto's Place) rear wheels as they are the perfect replacement for most Fly slots and are only $10 a pair. I then put rubber on the rears, (SIPT09 P3, 20mm x 12mm). Once again, check to see that the wheels are not rubbing on the body as this will cause performance issues.

Call me crazy but I believe that slots with plastic wheels feel completely different to drive than slots with aluminum or steel wheels. Anyway, my 917K felt much smoother and surer to drive and could really be pushed through the corners. It was still possible to get the tail out but it was more controlled. Noise levels also seemed to be getting lower but perhaps that had more to do with the 200+ laps the slot now had run.

Step 6 Lap Time: 6.09 seconds

You can see the BWP EURO wheels in the above photo on the right. You can either purchase some inserts for them and paint them black or use the Fly rear wheels as inserts. This requires a little work but the results are worth it. You can see a set or BWP EUROs with Fly 917 rear wheels sanded down for inserts on the 917LH on the left.


In addition to the above suggestions you could also replace the spur and pinion gear with gears or similar for around $15. This would improve noise levels and perhaps make the car even smoother to drive. Another performance upgrade would be to upgrade the 18K standard Fly motor with an after market performance motor, something around the 22K or 25K mark for approximately $30. Personally I like how fast my classics go and fell no need to upgrade these parts. Let's face it, the $45 you'd spend doing it would be better served going towards another Fly classic. ;)

If you have any other tips on improving the performance of Fly classics, drop me an email and I'll include them in this how-to.

Find this useful?  Check-out ManicSlot's How-to page by clicking the below link for more useful slotting and scenery tips and tricks.

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The Pedwells said...

Great article Manic - keep up the good work mate.
cheers DM

Anonymous said...

Very helpful indeed! Thanks for posting this information, I have a bunch of Fly's and I was wondering how to make them run well on my new routed track.

Thanks for this great resource!

Paul Komnacki said...

You can also try gluing the pod and setting up the chassis so it is slightly loose. My 12 year old Porsche 908 is still a top contender in our Wednesday night races against NSR's and's. It needs lead under the chassis as well to make it handle good enough to race these newer cars.