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Well, I got the bit between my teeth with the BMW320, so I figured I would carry right on into this group 5 to run with it.

Unfortunately the chassis would be the single most diabolical creation I have ever encountered in a slot chassis.

For anyone unfamiliar with these, the motor is placed according to Fly tradition, - in the same location as the original car.
Here's the Rusty French 935 K3 photographed at Phillip Island a few years back.

These were a beast of a car


Sooooo.... it is BEHIND the rear axle.

The chassis also rises up from the line of the rear axle, so it is mounted high, which apart from having oval wheels, makes it like driving a porsche in ice with bald tyres.
And it had more sway back than a 25 year old horse, the chassis has no longitudinal bracing at all.


So I started by trying to make a sidewinder ssetup in front of the axle, but that required serious dremel work on the interior to make it fit. it was also going to take up the full width of the chassis, making it had to insert lengthwise bracing. So I abandoned that idea.

So I decided to fit a Slot.it sidewinder pod and mount the motor in that, but that fit was tight, and the sidewinder pod just didn't allow enough width for a decent tyre outside the axle bush strut.

So I went the final step and mounted a Slot.it INLINE pod which is narrower. That also allowed me to generously treat the chassis with my good buddy Mr J.B. Weld, and a couple of 2.5mm diameter brass rods cut to fit.
I first worked out where the pod had to sit for left to right balance, and wheelbase, then drilled the chassis and temporarily screwed through the raised rear end of the chassis into the two rear pod mounts to stop it moving about.
Then I set the chassis on a steel plate with just that tail overhanging so the screws didn't touch the plate and cause it to distort upwards.
Then I added lots of magnets to force it flat, and put JB Weld under the edges of the pod, then forced it flat, added magnets to the pod. The weld squirted out the edges of the pod and I then mounted one pre-cut rod to each side, hard against the edge of the pod, and added more weld to immerse the brass. I would have used piano wire which has higher tensile strangth than brass, but the rod is pretty thick and stiff, and it isn't magnetic. I had to many other magnetic bits about, to try and deal with everything sticking to the rod as well.
This bracing is never going to move.
As JB Weld contains a lot of ferrous metal, it has a tendancy to try and run off with a magnet, so I had to apply it carefully, and wiped off any "stretch" with cotton buds, so the magnets didn't all get glued to the chassis.
Sorry, I forgot to take shots of this step.

Now it looks like this. A bit rough visually, but straight and strong - and I trimmed the edges of the chasis including around the exhaust pipes to give it body float.




The pan has been shaved all round. It looks tight just in front of the rear wheel arch, but that's just me squeezing it as I hold it up for the pic.It actually floats very freely around with about 1.5 turns off from tight on the body screws.


Still to do, replace the stiff braids, replace the temporary wheels with some wider alloys, inserts, and 13mm rubber.
I'd like to get it lower, but as there is no depression underneath the chassis for the "flat" of the guide to sit into, the guide plate thickness and braid thickness determines the front ride height. I could rebuild the entire guide area to create one, but that seems a lot of work.
Anyone any ideas?

Make a flat pan interior and fit a driver. - Thanks Ken (mmoose) for a great idea on SCI to photograph and print interiors, then glue a driver on top....
It is currently running almost identical times to the BMW I just built, and 1/10th a lap off our racing Capris, and is very stable and easy to pilot consistent laps.
With final mods it should come pretty close to a match. As it has the same motor and gearing as we run for the Capris at club, a fat set of feet with taller final ratio should make it feel almost the same to drive.

Next stop, a Fly BMW 3.5 CSL Group 5, ala 10th place at Le Mans 1976

Here's some of the group 5 cars, and some sports racing at Spa last year
Actual racing starts 4 minutes in.
 

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hy slot crazy, i,m so glad your into group 5s. i,ve got one sitting here and a 3.5 csl waiting to be done, your making my life to easy. where did you get the wheel inserts for this car or any grp5 type inserts. i just spent £450[in my dreams] on all the sideways group 5s coming out, 10-12 different cars. keep it up wonderfull for me. on the front i,d dremmel a half circle out of the chassis and glue plasticard on top, to drop the guide up into the chassis. john
 

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I know of 2 people who have set these up for wood & neither did anything like what you did. The one who runs his 935's the most did nothing but add a little weight & true up a set of urethane tires & the car is an absolute demon; the other replaced gears & machined the wheels.
I personally find the car ugly as sin, so I've never bought one. I do have a Racer 935J which run pretty darn good, but that's an equine quadruped of an alternate hue.
 

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Discussion Starter · #4 ·
Ah Martini, mine would barely go around the track, the wheels were so off centre. The chassis was so buckled it was pulling longitudinally on the body, and it didn't complete a lap before a motor fixing tag snapped from the shuddering.

I hadn't really intended to get so radical, but the sad state of the chassis meant I had to brace, and the COG was so high with that motor up on the backside anyway. After the motor mount broke, I thought I'd just do a switch to sidewinder in front of the axle, and remove the rear tray of the interior and put a plat part in that . . but that wasn't going to work . . . and so on. It was more a case of one thing leading to another, and the deeper I got, the more I dremeled, the more I funneled myself to the end choices.

Plus, I had pondered mmoose's setup of his Revel BMW320 on my other Group 5 thread a few days back (on that other forum), and decided I'd give the same principles a crack, just to see how close it ends up to the Capris.

And yeah, they get my vote for the ugliest porsches ever - the only worse is the moby dick variant of these

Urethane tyres tells me the grip levels you are working at, and the forces involved are a lot lower. That does mean it is possible to do less, and get a half way decent running car, but the more you ramp up the grip, the more work you have to do with any plastic chassised car to make it go right - that's not a put down in any way, it's just a matter of the physics of what increased grip does to stress, stretch and bend anything that can stretch, bend or break.

Stoner - I don't have a suitable insert set yet. The original wheels on this are way too big to turn down for inserts, but I'll figure or find something. But as I happen to know what Racer are using for wheels on their cars, and the insert size of those . . . . . I can eventually use their inserts in the Slot.it wheels.

But if you message me your email addy, I'll remember to let you know what I come up with - amongst my "things" are casting inserts and some scenery items in resin. So I just need one set of Porsche Group 5 inserts of some kind, and I can turn them into ones to fit Slot.it large hub, the Racer wide classic hub [R03] and the big NSR hubs for Vanquish MG cars, which is what we use on our Capris.
- for those I just use Slot.it BBS inserts at present, with a black "shim" of about 0.5mm all round on the outside edge.
 
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