Mopar Muscle Association UK

Spoiler going back on this afternoon !

Goodwood tomorrow with the AC Owners' Club. Bad weather forecast - oh well.


Andy - Yes I'm intending to do a full season next year
CSCC have just released their Dates. I'm intending to do as many races as poss with Bernie's as well - hopefully there won't be too many clashes.

A bit of finishing to do.

The car needed some specially shaped ducts behind the front spoiler to direct cool air to the front brakes.

Here's a pic of one of the original cars
I had a bit of a go at building something from sheet ally, but the shape of the duct is quite awkward.


I asked my mates James and Adrian (who did the vinyl printing for the stickers) if they could make me a pair of ducts on their 3-d printer, but the print time was going to be around 3 days !

Fortunately this week they took delivery of a new printer, which is one of the largest and fastest available.

I made a pattern so that I could plot the positions of the inlet and outlet, and the angles and distances between them.


And it took 28 minutes to print these. The next job the printer's doing is a life-size Wallace & Gromit.
The plastic itself is not particularly strong, but after it's set you can coat it in a self-levelling resin that fills in the print marks and adds structural strength

I wanted to get them on the car quickly though for the show this weekend , so just a quick coat of grey primer and some angle brackets for now. I'll install them properly later.

Loving it !!!

Going to do a few winter jobs on the car over the next weeks.

I've got a Track Day at Silverstone GP on 7th Feb, and one at Goodwood on 26 Feb - which will be good opportunities to test any alterations before the season starts t end of March.

In rough order of importance:

1) Cut out and raise the transmission tunnel to give more propshaft clearance, so that I can lower the rear ride height. At the same time, cut and alter the torsion bar crossmember so that I can get the Tremec gearbox mounted higher up, and hence get the header collectors up against the floorpan and further away from the ground.

2) Fabricate and add a Panhard rod to the rear axle (this will involve relocating the shocks to in front of the axle)

3) Fit green bearings to rear axle for:
a) Improved oil sealing at axle ends
b) Easier diff changes
c) Elimination of axle endplay. I suspect the small amount of endplay has potential to knock the rear disc brake pads back slightly at times.
d)The axle is making a really weird groaning noise, only under very hard cornering, and I'm pretty sure it's not the LSD. This is one thing to try, as part of a process of elimination.

The new style Green Bearings are apparently quite happy with side loading, unlike the first design which gave many reports of trouble.

4) Fit smaller diameter brake master cylinders. The pedal force required to brake hard is too high at the moment. Reducing the master cylinder diameters by 1/8" will give me approx 30% more line pressure for the same pedal effort. The tradeoff is 30% more pedal travel, but I think I can live with that.


On the longer list are:

1) Traction bars / Anti tramp bars for rear axle. Will have to design carefully to avoid binding the suspension or changing effective spring rates during travel.
2) Magnumforce 2" drop spindles for the front end, so I can get some suspension travel back at the existing ride height, and maybe then lower it some more.
3) A new fuel tank to sit *under* the boot floor - getting the weight of the fuel as low in the car as possible.

Plenty to do there Matt. I ran the Green bearings on the Superbee, never had an issue. Fitted plenty to road cars as well over the years.

Started on the Panhard rod today

Geometrically, the rod needs to be as long as possible - and horizontal at ride height.

I want to attach the rod directly to the axle rather than the spring shackle plate, as the axle is where the load originates. If the car can generate corner forces of , say, 1.2 G - then there's going to be around 850 Kg sideways force on the linkage and brackets - and I'd rather not transfer this load through the shackle plate, U-bolts etc just to get it from the axle to the rod.


Initially, it looks like the shocks will be in the way, and will have to be relocated to in front of the axle. It looks like there will be room for them there.
Axle brackets mocked up from thin plywood. The bolt through the rose joint eye will eventually be M16 , and there will be gussets.
And in position.
Other side - this bracket will be triangulated over to the other chassis rail eventually
And the whole thing



At this point, I notice that the RH shock will actually reattach with the panhard rod in place, although the LH presents more of a problem.

Mock up a larger bracket, with the rod spaced about an inch further away from the axle tube.






And fit.

I'm not entirely happy with the leverages involved with this larger bracket - even with added gussets round the relieved part , but will sleep on it. There is also currrently very little clearance between the shock and the panhard rod.

But if I can get around relocating the shocks, it will save a ton of work.

that axle bracket is more than strong enough, especially if you 'box' as much as you can between the 2 halves. i'd be more concerned about the chassis bracket length but you already said you're bracing that so you have it covered .
neil.

Loving the Threshold - I am sure that will be great in Compression....

Loving the work as ever!

Class act Matt, your a clever fella, braced enough it will be fine remember it will not take all the force some will still get taken care of from the leaf spring mnts etc

good work,you never stop, did you think of using a watts linkage or was that going to be too much work ?

Thanks Neil and Dunc

Andy I thought about a Watts Linkage , and would probably look at it a bit harder if doing the same job again.

The Panhard does the job well enough though, and is simple. THe trick of course is to keep the bar long, and horizontal. In 6" of suspension travel (3 up, 3 down) , a 40" bar gives only about 3mm of side movement.

I couldn't be bothered to calculate it, so I drew it out.

If I adjust the bar with about 1.5mm preload at the mid point , then the leaf springs will be only pushed 1.5mm off-centre in each direction during the travel. Roughly.

the Mk IV axle bracket is good to go. I'm fairly happy with the clearances now.




And at last ...

Those wheels look rather nice, genuine Minilites I assume?

Hi Matt, yes genuine Minilites.

Slight delay now in fitting the wheels as the centre holes in the fronts aren't large enough to fit over the disc hubs. Minilite are going to enlarge the holes for me.

Also the outer beads on the new Hoosier tyres are very hard to seat on the rims. THe solution apparently is to use fairy liquid rather than tyre soap, and to increase seating pressures beyond recommended.


So onwards with the panhard rod.

Wooden patterns dismantled and used as templates for plasma cutting

Not happy about adding weight to the car, but it's for a good reason.

finished plates

Axle mount. This has changed sides, since I read that cars that usually turn right are done this way. Something about wheel loading on corner exit, according to Carroll Smith.
and part-way through boxing in
and the chassis mount
My next-door neighbour made me some nice tapped bushes to mount the rod ends


And while the U-bolt plates were off I added brackets for the anti-tramp bars




the anti-tramp bars will eventually look something like this.


finished !

and then some testing yesterday at Silverstone