Well, searching around the web, I could find several articles on tuning Fly classic cars. Most of these modify the cars to an extend where they work well, either with or without magnets. But I wanted something more. I needed to make these cars perform good on club racing conditions and compete against some faster cars. I wanted to try a put some resistance to the Slot.it (or a potential future NSR entry) classic cars. OK, a good driver driving a 312PB would still win, but I wanted to be able to give a good fight.
So I started working on these:


Our class regulations allow any FC130 motor on closed cockpit big block sports, open Can Am or older prototypes, so I usually prefer the Slot.it v12/3 25k motor. The smaller prototypes like the 312PB or the Alfa 33 may only use the 21.5k or the older v12/2 25k motor (that nobody prefers anyway). I also had to improve the drivetrain. So slot.it axles and gears are used. Bronze bushings were glued to the motor pods. The front wheels are stock, but the rears are Slot.its with the stock rear wheels trued down to fit as inserts. Slot.it P5 tires are also used at the rear, at the front I used whatever suited the ride height, coated with nail varnish. I also used the Slot.it deep guide for wood tracks, trimmed to 5.7mm in depth for the SCX track.
My main problem while initially testing on our SCX club track, was that these cars hopped and bounced around on acceleration a lot. I faced the same problem with a Lancia Beta and I managed to cure it by strengthening the chassis. So I tried the same here. I used steel nails and I glued them on the chassis with 6min epoxy. Below are the results on each one...

My 512S:


Check out the nails on the chassis:

This is a really nice car, fast and stable, still a bit tail happy, but with a change of tires, it will be better, as these are very old and abused. It has the longest guide lead than the others.

My Lola:


Lola Chassis:

This one is rigid enough, I only used two small pins at the bottom of the motor pod, to strengthen between the motor and the rear axle. The Lola has the longest wheelbase. It is the fastest of the three now, but I don't think that it will still be faster than my 512S with the same tires.

My 917:


917 chassis:


917chassis again:


This is the hardest case. The 917 is the shortest car, but with a heavy body and flexible chassis. I haven't found a way to make it perform equally well as the other two. I keep trying...

************ Update - New entry ************
Martini 917/10:


917/10 chassis:

The tube chassis design, doesn't need strengthening in the main part, but at the front end it is quite flexible.
So I added 2 nails outside both sides of the seats, up to the front body post holes:

I wasn't sure about how rigid the rear end was, so I added some extra stiffness at the bottom of the pod:



Well, testing and performance impressions and comments will follow as soon as I manage to run some decent laps on these.

I also have a pair of lightweight prototypes:


These are faster than the closed sports cars but not by much. Still those cars are not ready to fight with the 312PB or the Alfa 33 and I feel I haven't finished tuning them, but I believe they are already improved by a significant margin. Stay tuned for testing results!!


------- ********* List of updates **********----------
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Update No1:
Seems that the 917 had a problem with the front end. One wheel was firmly planted on the track while the other was about 1mm away. Some filing, trimming, straightening the chassis etc, and now both front wheels barely touch the track. Looks much better on the setup board, and runs faster now.

Update No2:
Added the Porsche 917/10 to the list of cars. Nice car, proved the fastest but not so consistent. A bit hard to drive.

Update No3:
Managed to run some decent tests on my track. This is a track that is a bit more slippery than our club track and much shorter. So a good motor doesn't really help here, and I expect a car that slides here to be better on the club. A car that grips a lot here, may have trouble with too much traction and hopping issues at the club. Still, conclusions can be drawn.

So total time for a 30lap run and best laps for each one:

1. Porsche 917/10 : 2':09".841 - best lap : 4.193s
2. Porsche 908/3 : 2':11".647 - best lap : 4.250s
3. Lola T70MkIII : 2':13".013s - best lap : 4.304
4. Chevron B19 : 2':13".183 - best lap : 4.299s
5. Porsche 917K : 2':13".434 - best lap : 4.331s
6. Ferrari 512S : 2':15".424 - best lap : 4.380s

I did more than one runs on each car, and above is the best. The 917/10 managed this impressive result, but another run was around 2.12-2.13. The 908/3 is agile but slides easily, so a fast in-careful out pays off in this case. The Lola has power but is a long car and its tail likes to swing around a bit more than it should. The Chevron is narrower than the 908 and you need to be a bit less aggressive, or else it may pop off the slot or snap its tail suddenly. The 917K has plenty of rear end grip and its motor is running in now, so I got a few more rpms for the test, but it still is very low on power, compared to the Lola and the 512S. If pushed too much, the Porsche lifts its inner rear wheel and its hops a bit under power. The 512 is still too tail happy. It is impossible to apply the power early on corner exits, the car fishtails down the straights, and in general it lacks rear end grip.