Scalextric Ford Sierra tuning experiments

[Vinno]

Being a big fan of Group A Touring Cars I enjoy getting these cars to run as well as I can non magnet. The Ford Sierra RS500 Cosworth was a favourite of mine and they can be a bit of a challenge getting the best out of them compared to others. 

I have been playing around with a few different configurations and thought I would see how they all compare.

My track is about 15 metres of Policar and Fleischmann plastic track. It has a couple of R1 corners which test how planted a car is and a flip flop across the top that needs a planted car to negotiate smoothly. I allowed myself 50 laps per car after multiple cleans of the tyres with a damp cloth. 

The first car is a standard B&H Sierra with weight and F22 tyres only. The weight of the car is 85 grams with some lead placed low and anywhere it will fit. The F22 tyres aren’t glued which is fine as I am only running 10 volts. I didn’t try truing the tyres down on this one.
 

My best lap was 5.619 seconds with comfortable lap times of 5.75 seconds. The car was tricky on the inside of the R1 radius corner and it was easy to go that bit too deep and tip over. I think I spent more laps lifting the inside wheels through this corner than anything else. 

The second car is the DJR Shell Sierra. Being my favourite driver from this era I spent quite a bit of time trying to get the most out of this car without changing major parts. The main change I did with this one was to add a Slot.it guide to get the front down a low as possible. I also trued down the standard tyres by 1.5mm to get the most out of the ride height while making sure the tyres still touch the track. 
 

I trued the rear tyres down a bit but they aren’t that conducive to the tyre truer. I did get them down by about 1mm which helped get the chassis a little lower to help the centre of gravity. The weight of the car is 86 grams with the same weight placement as the B&H. After running for 50 laps with a few tyre cleans thrown in I got the car down to a 5.54 second lap but it would do consistent 5.6 second laps with no offs at all. Easy to driving and a nice drift through the R1 corner. 

The last car is the Allan Moffat Sierra but with about as much as I could do using the standard engine. This one has a 3D printed chassis from the Slot.it print shop from Shapeways and an Olifer Pod using the standard motor. The Olifer pod allows the engine to sit lower than a standard Scalextric chassis and I used an offset crown as the motor shaft sits lower than the axle. I have 15.8 x 8.2 Slot.it air rims on the rear and 15.8 x 8.2 Slot.it  plastic rims. The front tyres are the standard Scalextric tyres trued down and the same Slot.it R22 tyres on the rear with a little bit of truing to get the diameter down a little. The weight of the car ended up at 80 grams as there wasn’t a lot of places to add weight. I used the standard Scalextric motor but had to cut down the shaft and grind down part of the knurling on the shaft as the motor sits closer than in a standard Scalextric setup. I still have to add wheel inserts which will happen after my lathe turns up. 

After the obligatory 50 laps I was able to get the lap times down to a best of 5.352 seconds and a consistent 5.38 was easy to achieve. The car had a better launch out of corners as the chassis is very flexible and made for plastic track. It was very smooth and fun to drive. This would be the perfect race car. 

The last two photos show the difference in the cars ride height. The DJR car has a rake to it which I could fix by turning down the tyres a bit more but considering how easy it is to drive I think I should leave it alone. The chassis under the ANZ Sierra is very flexible and I had to sit it in near boiling water on a flat surface to fix the twist in it. It still isn’t 100% as the rear just isn’t easy to fix but it is a weapon on the track. I bought another and also two for the Scalextric M3. The M3 will be another work in progress when I get to that. 

I also found some of the Scalextric Sierra and M3 Slot.it Chassis on line for my next comparison. The plan is to try and get a Sierra to run as well as a Slot.it Nissan GTR. I have a Slot.it V12 engine ready so I can see how I go.

[rosco01]

Great write up, Vinno...... I have two of these old Scalextric Sierra's..... given me some thoughts.

 

frats,

Rosco

[gazza]

Nice one Vince, the ANZ one looks the part

[munter]

I have templates for lightweight (vac form) windows for both old and new models.

Could probably do light weight interiors too if I had a donor.

 

 

[munter]

Oh and nice work Vinno.... an icon of a car made just that bit more iconic by your hands.

[charlesx]

Good write-up VINNO. I have the red one entered in Bathurst Proxy but late build has run into trouble. Standard Scaly but re-powered with Thunderslot 21400rpm motor. Went OK at home but only did 3-4 laps before posting so only have myself to blame. Regards Charles Le Breton (charlesx)

[Kieran]

I don't know much about Scalextric.  I bought a couple of Sierras second hand for about $30 each for an entry-level car to race at Mr Slot Car's Saturday morning races.  They seem to have independent front axles because there is a lot of vertical movement in the front wheels.  So they don't seem to like corners much.  Is there an easy fix to stop this movement?  Cheers.

[mtpanorama]

6 hours ago, Kieran said:

I don't know much about Scalextric.  I bought a couple of Sierras second hand for about $30 each for an entry-level car to race at Mr Slot Car's Saturday morning races.  They seem to have independent front axles because there is a lot of vertical movement in the front wheels.  So they don't seem to like corners much.  Is there an easy fix to stop this movement?  Cheers.

I think you have the Sierras from the 1990's, the above Sierras are a completely new and different car released in the last 2 to 3 years.  There is no easy fix for the older Sierras but it is possible to put in a solid axle but you will need to make something to hold the axle in place.

[Vinno]

8 hours ago, Kieran said:

I don't know much about Scalextric.  I bought a couple of Sierras second hand for about $30 each for an entry-level car to race at Mr Slot Car's Saturday morning races.  They seem to have independent front axles because there is a lot of vertical movement in the front wheels.  So they don't seem to like corners much.  Is there an easy fix to stop this movement?  Cheers.

Hi Kieran

As mentioned above the old Sierras are completely different. I have two versions of the old car, one with the floppy front end and one with a straight through axle. The chassis are different on both but it would be possible to modify the front end if you have some model building skills. But realistically they won’t compete with the modern versions. Below are both versions with the one on the right with the independent front axles. There is a screw in one side as the little clip had broken that holds the plate on place. The left version is the later one with some differences in the front end including the first guide setup that had prongs on the underside making contact with the braid in the guide. This was eventually replaced with the current setup on the Scalextric cars.

The second picture shows you under the plate. While the axle points are in the same place you will also find the wheels would probably struggle to fit onto an axle in any sort of straight fashion. Try one of the new cars if you want to have a decent race but they are expensive to make run well once you start adding in parts to even them up with a Slot.it or similar.

 

[Kieran]

So it appears that I have bought some donor cars to build up some printed chassis cars!

[Kevan]

On 8/22/2023 at 10:39 AM, Vinno said:

and aren't they just 'orrid!

[ShawnK]

On 8/22/2023 at 12:39 PM, Vinno said:

Hi Kieran

As mentioned above the old Sierras are completely different. I have two versions of the old car, one with the floppy front end and one with a straight through axle. The chassis are different on both but it would be possible to modify the front end if you have some model building skills. But realistically they won’t compete with the modern versions. Below are both versions with the one on the right with the independent front axles. There is a screw in one side as the little clip had broken that holds the plate on place. The left version is the later one with some differences in the front end including the first guide setup that had prongs on the underside making contact with the braid in the guide. This was eventually replaced with the current setup on the Scalextric cars.

The second picture shows you under the plate. While the axle points are in the same place you will also find the wheels would probably struggle to fit onto an axle in any sort of straight fashion. Try one of the new cars if you want to have a decent race but they are expensive to make run well once you start adding in parts to even them up with a Slot.it or similar.

 

I thought nobody had any old slot cars left. But to have a race on them is very unusual.
You're right to point out that for a decent race, new slot cars should be used. It's just that the new ones are of better quality.
But the old models were new at some point And modern models will become obsolete one day. I hope to see the development of slot cars in 20 years.

[Shaynus]

This is my Sierra that I entered into the 2023 Bathurst proxy. While it didn't win (came in 6th), it did, I believe hold it's own against a pretty tough field of XB/C Falcons and Camaros. It's performance outweighed it's appearance sort of thing.  It weighed in at 86.6g. MJK rear wheels and tyres and a wood guide. Also I designed and printed a rear brace to stiffen the rear end. No idea if it made any difference, but it was a fun little project to do. 

[Kevan]

I'd put some tape over the slot in the top of the motor to keep all that crud out of the motor.