SlotForum banner
1 - 20 of 25 Posts

·
Circuit Owner
Joined
·
5,913 Posts
We have another new class for 2013 at our fledgling digital club - it is diametrically opposite to the balls out Le Mans techy rocket class I am asking about in another thread.

In a nutshell we can upgrade the Johnson to the 18k Mabuchi but the motor spindle must remain exactly where the original was designed to sit in the chassis.

The chassis can be cut and adjusted e.g. the Porsche 935 can have its nose dropped so the wheels can sit in the wheel arches as opposed to underneath them!

No magnets.

We can add weight but not slung under the chassis.

We can replace the wheels and tyres but the diameter must not vary by more than 10% from the original.

Free choice of tyres (no silicones) and plastic wheels, braids, bearings, axles.

Pinion and gears to remain same number of teeth as original.

Front wheels must touch the track and rotate when the car is pushed gently forward on a straight.

Width must remain standard as must wheelbase and track.

The track is a 20 metre Sport track with 2 R1 hairpins, one long R4 90 degree turn at the end of a 4m straight. The rest is R2 and short straights.

Current track record held by a magged up Scaley Porsche 997 at 5.7 seconds. Magless Scaley Taurus takes 9 seconds.

We can run:
Audi Quattro
BMW 3.0 CSL
Datsun 260Z
Ford Capri 3L
Ford Escort Mexico
Ford Escort XR3i
Ford Fiesta XR2i
Lancia L037
MG Maestro
MG Metro
Mini Clubman
Mini Cooper
Pontiac Firebird
Porsche 911/935
Rover 3500
TR7
Sierra Cosworth

So what would you run?

I already own the following:
BMW 3.0 CSL
Datsun 260Z
Ford Escort Mexico
Mini Clubman
Mini Cooper
Porsche 911/935

I have tried a couple of cars so far - the C125 Porsche 911/935 whale tail, I have one with a mabuchi, I have cut the chassis ahead of the guide and dropped it 5mm which centres the front wheels nicely in the arches and brings the nose into a pleasantly aggressive stance. I have replaces the awful Large superslix front and rear with GT40 wheels shod in hard rubber fronts and urethane rears. The front axle has been tubed very accurately and the standard guide has been shod in copper braids folded back double and the guide has been converted to a sprung guide. Weight has been added (two brass rivets and blu tack) in the nose, nothing in the tail yet.

The other car I have tried is the C128 BMW 3.0 CSL. This has the standard unsprung guide with copper braids. I have tubed the front axle. I have kept the original wheels - large superslix rear and small superslix front. Hard rubber fronts and very soft urethanes at the rear. I have added weight front and rear on this (2 brass rivets and blu tack front and 3 brass rivets and blu tack back). The Johnson has been replaced with a brand new 18k Mabuchi with spacer.

The Porsche is a bit quicker at the moment but I think it's because the BMW is more prone to deslotting (this was before I added weight to either car but I need to do my sprung guide mod on it I think).

The BMW has a longer wheelbase but is 2mm narrower front and rear. The Porsche is about 3mm lower than the beemer (because of my chassis mod).

Neither have been chipped yet - I want to pick the right car before I use a chip.

The minis are probably too short.

Should I have a go at an Escort and/or Datsun before I decide?

Should I buy a Rover 3500 or Capri or something else?

Have you any experience racing any of these? Advice and experience gratefully received.
 

·
Registered
Joined
·
2,885 Posts
I'd go with an Audi Quatro but not for any scientific reason


 

·
Premium Member
Joined
·
892 Posts
A Porsche is currently quickest in our running of a Johnson powered class using this type of body but there is a pack of BMW M1s snapping at its heels.
I've done the split the chassis thing and added a mounting post into the body just in front of the windscreen.


Allan
 

·
Registered
Joined
·
3,748 Posts
The BMW 3.0 CSL, you can drop the front end if you cut the front of the chassis off (you can hold the body on the chassis using blu tack or velcro) and then grind down the guide mount.

The BMW was the best car I had when I was young so I might be biased.
 

·
Registered
Joined
·
612 Posts
I agree with Julien, the BMW with the front cut so you can lower the guide is a good way to go, although I've tried blu-tacking and it wasn't really successful so I added a body post up front as well as 5 grams of weight, admittadly we run with the original Johnson motors so they would be a little less punchy.

If we were allowed I'd run a Lancia 037 though as the body isn't as high
 

·
Circuit Owner
Joined
·
5,913 Posts
Discussion Starter · #6 ·
Thanks for your replies - interesting stuff.

We don't allow the M1 because it is too low and would have too much of an advantage over other cars and we wanted variety on the grid (at least to start with!)

We do allow the Lancia 037 although these are going for silly money on the bay.

When I split the Porsche chassis I kept the original fixing method so I dropped the front part of the chassis and fixed it with a styrene subframe which was glued and screwed for maximum strength. I had to cut away some of the cockpit to allow the Mabuchi to fit - the driver platform is now wafer thin in the middle!

I haven't tried lowering the BMW 3.0 CSL yet - I think I will give that a go. Mind you there's only about 2mm of play unless I bring the front wheels inboard. I think I will recess the guide and raise the axle tubing rather than cut the chassis.

No fans of the Escort Mexico or Datsun 260Z then?!?
 

·
Circuit Owner
Joined
·
5,913 Posts
Discussion Starter · #8 ·
I'm looking at one now and yes - raising the guide means the half circle of clearance at the front needs cutting out - and that is the only bit of chassis between the front bit and the rest!!!

It would need a major bit of work to put in new chassis members to hold it all in place. Maybe I should change the rules to allow me to fit a modern quick-change Scaley guide - that would work without cutting the chassis and allow me to drop the nose. I would probably have to move the guide pivot point forward about 4mm-5mm but there is room. Some chassis reinforcement would also be possible by filling in the cut outs for the old guide wires.

The class rules are currently a work in progress so maybe I should suggest free guides (but keeping them shallow to protect the digital sensors).
 

·
Registered
Joined
·
3,748 Posts
I cut the front off and then held the chassis on with a blob of blu-tack each side just behind the front wheels, the way the chassis and body are made means the blu-tack squeezes niceley between them.
 

·
Registered
Joined
·
612 Posts
QUOTE (Mr Modifier @ 28 Sep 2012, 13:18) <{POST_SNAPBACK}>No fans of the Escort Mexico or Datsun 260Z then?!?

I might be wrong but as the escort, datsun, mini etc are narrower i think they won't be as stable (although I'm prepping a datsun to scale model rules and will give it a try out in a few weeks
)

Here's what I've done with mine for the Scale Models championship, probably not too irrelevant to what you are doing but i thought it might give you a bit of inspiration


With both BMW 3.0's (only one pictured) I cut the front end off the chassis, trimmed it and stuck it back in place with super glue, then removed any excess plastic off from around the guide hole that wasn't needed. I then found an old body, removed the body post, and mounted it just behind the guide area.
I then lowered the motor and glued it in place and added a bit of weight near the front





I mounted the TR7 on an MRC Competition chassis so I guess this is pretty irrelevant to your class if they have to be the original chassis. Handles pretty well for what it is though




This i started today so is a bit of a mock up at the moment, as we are allowed free wheel and tyre choice I'm going to try F1's, hoping the extra width tyre will make up for it being a narrower chassis.
next job is to fit a body post to the front, maybe lower the motor a bit more and then do the thing i hate most, a re-paint







Here's what a similar class is like run with Johnson motors


http://www.youtube-nocookie.com/embed/IU9DH6v8-Ws?rel=0
 

·
Circuit Owner
Joined
·
5,913 Posts
Discussion Starter · #11 ·
Thanks for the piccies. I have seen the video before - it reinforced what fun we think these cars could be.

Nice Datsun. Interesting guide wire!

Thanks for the chassis shots - very useful.
 

·
Alfie Noakes
Joined
·
2,655 Posts
I'm going to suggest an MG Maestro, mainly because I'd like to see someone make one competitive...
 

·
Premium Member
Joined
·
892 Posts
All that lead Paul ! The poor old Johnson has enough to haul round without extra weight


Allan
 

·
Circuit Owner
Joined
·
5,913 Posts
Discussion Starter · #14 ·
QUOTE (richardtheforth @ 28 Sep 2012, 15:35) <{POST_SNAPBACK}>I'm going to suggest an MG Maestro, mainly because I'd like to see someone make one competitive...

Hi Richard

I would love one but they are rarer than hen's teeth. It would be fun trying to make one competitive.
 

·
Registered
Joined
·
612 Posts
QUOTE (AllanI @ 28 Sep 2012, 14:35) <{POST_SNAPBACK}>All that lead Paul ! The poor old Johnson has enough to haul round without extra weight


Allan

I don't normally use that much, I tend to just use about 2.5g up front when on wood but on my home track they easily deslot with not much weight in
 

·
Registered
Joined
·
6 Posts
Sorry, off topic, but I got to watching the four guys at the end's trigger fingers, since the distance of visible track was so short at the time, and was listening to the music. Well, I just got to laughing something fierce for some reason. It was like they were a four man band ~ if they would have had instruments...

Again, sorry, but when coffee comes out my nose I have to comment!

Best,
TB
 

·
Registered
Joined
·
1,688 Posts
I Would very welcome some pictures of Scaley classic Porsches with lowered fronts. I have several of them and it's a lovely model. We too like to race them now and then, in a scaley classics race. The way these Porsches negotiate corners at times, brilliant and great fun at the same time. Only the high ride up front... It just doesn't look right.


I managed to make the old Datsun look better, by simply fitting bigger wheels. What a difference that made.


I never found a satisfying way to solve that problem on the classic Porsches. See them in the background behind the Fleischmann Lotus cars.I've always wondered how to make the front wheels nicely fill the front wheel arches.


I haven't dared to chop up the chassis of the Porsche to solve things. I mainly tried to lower the guide itself.


Tips, tricks and pictures greatly appreciated to find a way to lower the front of my old Porsches. They are so much fun to race!

Merc
 

·
Premium Member
Joined
·
892 Posts
Cut the chassis in front of the guide mount. Cut out a semicircle to clear the guide in what is now the front apron. Glue the front apron to the main body. Sand of the guide mount to raise the guide relative to the chassis. Use brass tube to make an axle carrier. Make a hole in the main chassis behind the front axle and attach a mounting post. Trial fit the main chassis into the body and trim the mounting post height until you achieve the desired ride height. Glue the mounting post to the body and the axle tube to the chassis. Given the amount of free movement in the "number plate" rear body mount you'll now have some body rock as well to help the handling. Hope this explanation is clear.

Allan
 

·
Registered
Joined
·
913 Posts
I would use the rover 3500

It's nice and wide, you can fit decent wheels and tyres easily as the arches are big, tube the front axle, chop down the guide holder to lower it in the slot, lower the rear by repositioning the axle bearings higher up or if rules allow use a slot-it motor mount cut into the chassis.

You can dremel the inside of the body and trim the interior to save weight and you should be half way to a decent runner
 
1 - 20 of 25 Posts
Top