Scalextric Escort Xr3 tune up

Squeezing out those last few tenths

Scalextric Escort Xr3 tune up

Postby wixwacing » Sat 19 Jul, 2008 12:06 am

Scalextric have been guilty of some heinous slot cars during the wilderness years. None probably more heinous that the Sierra Turbo cars. These cars took great delight in being totally undrivable out of the box! Many a schoolboy must have been turned off slotcars for life by these and their peers. So what to do if you’ve been sucked into buying a really cheap replica of your favourite car from ebay!!

I actually know someone who came into slotcars several years ago now and purchased a good few models in the early days. A noticeable few (mostly Scalextric) did not come up to expectations and after a few frustrating hours they were consigned to the bin. Yep! stripped out the useful bits like gears, guide and motor and the rest went to the local landfill!!!

An extreme case, but a genuine venting of frustration on what were (and sometimes still are) substandard products which were unable to live up to reasonable expectations. But for those with limited modelling skills and a basic understanding of engineering and a vivid imagination, it shouldn’t be too hard to get these mothers to perform respectably!!



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My Waterloo was going to be the Scalextric Ford Escort XR3i. This model was probably fractionally better than the Sierra but the traits were there to aggravate all who entered! The two problems these models have are firstly, an unrealistically high centre of gravity compared to the axle width and secondly, a very unstable front end also compared to the rear axle width.

52 m.m. seems to be very close to the crucial axle width of a lot of non/low traction magnet sedan/saloon slot cars. Models with less than this perform all sorts of antics and gyrations in cornering. Some with low C of G’s will get away with it providing the tyres don’t show too much grip. But they are still potential problems. The cures are twofold. One is to add enough ballast in the RIGHT! place so the model isn’t carrying excess weight which will effect its acceleration and braking. The other is to stiffen up the front end enough to allow the front wheels to brace the model in a potential ‘tipping’ deslot situation, much like an outrigger.



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Back to the XR3i and the first problem, tipping because of high C of G was to be addressed. The Escort has a very small wheel diameter and weight added to the model ABOVE the axle centre line was not the best option. With no were else to go, the weight was going to have to go UNDER the model! No choice! I would have to double the amount inside to achieve the same effect and lose a bit of acceleration and increase my braking distance!! So I cut and weighed two strips. For a total weight of ten grams, I superglued the strips of lead to the cleaned underside of the chassis. These were later painted to reduce their visual effect. The model was retested and the initial improvement was very good. Using the original unsanded tyres, the model was smarter off the line and providing you didn’t hit the corners too hard, was smoother round the corners which allowed a higher exit speed and consequent higher terminal straight line speed.

There was still the bug of the model tipping up on the guide and one back wheel if the corners were hit too hard. And the risk of a ‘jack out’ deslot. The tilted model will jack the guide from the slot and go straight on.

A little bit of history:

For many years, leading slotcar manufacturers from Europe decided that the sloppy front axle was the way to go in slot car design. Not sure of the logic but the trend was for cars to run on the braids and the rear tyres. Probably a way of reducing the need for modelling accuracy ie to get all four wheels on the ground together!!?? But we all went along with it and the pundits extolled its virtues and we were all sucked in!! During this time, companies like Revell, Monogram, Atlas, Russkit, AMT and the ilk were making off the shelf, scale RTR kits which p****d all over the local product! And their wheels were all firmly on the track!! I remember as a very small boy driving my models to the max and while my cars were up on one wheel and the guide, my mates Cobras and DB4’s, Lotus 33’s and Ferrari 158’s were driving round the outside of me with pure ease!!

The moral to this story is enforced by the current range of models available from all the majors. Their products have rigid front axles firmly planted on the track and a precision guide which has just enough clearance not to be a drag, literally! The drag presented by this set up in corners is minimal and with a bit of skill can be overcome but unless the model is as flat as a pancake, to remove front tyre contact with the track invariably ends in tears.



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So, a rigid front end for the Escort ? Hmmmmmmmm…..? Got it! An idea used amongst the 24th brigade a few years back! Add suspension to the front of the model which is simple but rigid enough to contribute to its stability. Anyone driven the Proshock Ninco cars!?

The solution is simpler than falling down stairs with a full tea tray!
I had some spare 1.0 mm music wire which was used for another project. This wire demonstrated a reasonable spring resilience over a 50mm length so I decided to make a couple of ‘leaf springs’ to fit to the front. This consisted of cutting and shaping the wire so it fitted the internal moulding of the chassis and front ends just passed over the front axle. The rear ends had a ninety degree bend put in them. This was to stop any torsional tendency turning the wire inside the resin when in place. The rear ends were epoxied in place making sure the epoxy came the same distance forward on both springs. This was to minimise unequal spring rates.

Once set, the model was reassembled and placed back on the track. The transformation was complete. The model drove well and hit the corners well and when pushed hard through the bends, exited crisply! The tyres were still the originals and hadn’t been sanded. Extra grip at the back may well require a little more ballast underneath and either heavier gauge wire or shorter movement on the existing gauge.


Another mod would be to sand the front tyre tead into a slight radius so there is only the centre of the tyre touching the track and therefore reducing drag in turns. Another would be to install the independently rotating ‘Wixle’ system but there isn’t enough room in this model


I have to add that this model is never going to be a hot open field competitor! But even with a Johnson 111 it will be quick and manageable and a stable of similar models modified like this will add another dimension to the slotracing hobby,

If you have some of these, give it a go! Or send them to me!!
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When I'm not racing slotcars,
I'm out in the back yard, burning food!!

When I win, it's because of my talent, not my car or my controller!
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