Honest opinions on my chassis-work please...

[db]

P, can you re-bracket the panhard to the inside of the frame section rather than underside?

I guess, i spent ages makin it and welding it in tho so i'd have to leave it a few days before i could bear to hack it off...
I'd also have to extend the axle bracket by quite a bit so there might be leverage issues there.
AND... i've fully welded the rod ends on and i'd have to shorten it
No, good suggestion Ian but really can't see me doing all that

[db]

Great work, Just noticed your Portamig! These were made by my old fella in York:thumbright:

Tell him he's a bloody genius
I struggled for years with a poxy little Clarke one and i got this a year or so ago. Not cheap but i bet i'll get 20 years out of it and it's improved my welding by a mile

[Anonymous]

DO NOT BEND THE PANHARD ROD!

The straight link can only transmit force along it's axis. If you bend it it will create a moment allowing the bar to bend, which is bad.

Personally I prefer the Watts Linkage design but the Panhard works well enough.

The diagonal bar I was describing was infact a diagonal chassis member to reduce chassis twist (measured in Nm/deg). Stiffening the chassis in this way will reduce the amount the chassis twists on a hard launch and also improve the roll stiffness in a corner (if that is important to you). Bu like I said the extra chassis strength you have already built in will have improved things over the original.

[db]

Thanks James, that sounds like a convincing argument.
I only need about 3/4" more clearance so i'll redrill the frame end higher up and extend the axle end, possibly with an extra gusset.

I agree the Watts is a far better method, the Panhard is a compromise of cost, space & simplicity. With the tyre differentials etc, i doubt the handling improvements of the Watts would be noticeable.

Where would you suggest locationg the diagonal member James? Have you an example pic?

[Anonymous]

Send me your email address and I will send some info over.

[db]

Right, fix underway

[TrevD]

looks like a good solution, nice bit of fabrication work, better than some of the profesional do

[db]

I see a lot of 'professional' work Trev and i can't believe what some folk can charge good money for.
Fabriction is my favourite bit of car building and the angle grinder is always my weapon of choice

[TrevD]

a true craftsman, its a shame some of the people selling this sort of stuff dont have your skill with an angle grinder, i know i dont thats why i trust a CNC machine to do all mine for me

[Anonymous]

And then you go and mangle it with a welder

[db]

too true James!

Thanks Trev, to be honest i never had the mathematical brain to learn technical engineering so i had to learn to do it by eye.

While i've have your attention you two, any opinions on whether i actually need my anti-roll bar?
It's shown in the S&W catalog as being for use with their 4-link but i just can't see how it will do anything

[Anonymous]

I would put one on, but bear in mind you want the front roll stiffness of the car to be higher than the rear, so make sure the ARB at the rear is of a smaller diameter than the front (in laymans terms). In actual fact diameter is only a rough guide of the torsional stiffness.

This is if you want to tune out body roll at the rear of the car. If you want to play around with the rear handling setup make the mounts and make a bunch of bars of different diameters and try each one out.

Under heavy loading the ladder bars are going to be fighting to hold the car level, they will bend and they will bend at the weakest point, usually the rod ends. Having seen the state of Terry's rods ends after he took them off the Demon I would suggest a device for taking roll loading away from the ladder bars is a good idea.

Personally I am not a fan of the ladder bar system because it constrains the axle rotation during roll thus stressing itself. A four link system works well in this way.



EDIT: After writing this I looked back at the first pictures you posted and noticed you infact have a 4 link system and not ladder bars.

I would still use the ARB since the sperical bearings allow the axle to rotate freely. I had an FD Victor (parallel 4 link rear) with no ARB and I could almost get the door handles to scrape the floor under hard cornering!

[db]

Ta Bratfink.
The Belve had ladder bars when i got it, i could see they would be a bit agricultural on the road!

It's only now i've fitted the 4-link and can move it around that i'm getting a feel for how it operates.
If i lift one end of the axle case, the other end lifts simultaneously, is this just because the rod ends are new and tight? (they're Chromoly so super-strong!)
I don't quite see how the case can rotate (about the prop axis) without the links changing length or the case itself twisting Maybe if i chock one end and gently jack the other and see what happens

The ARB is on the left in this pic: there is limited adjustment in using different holes in the arms but thats it really. The torsion bar sits inside the tube and is splined & machined Chromoly so i doubt i'll be making a choice of those to try (The drop arms can be set at unequal lengths to counter twisting under a hard launch).

[db]

As yet, i haven't begun to think about a design for my front ARB...

[db]

Right, well.... here's a funny thing....

Me ARB won't fit.

Not a chance.

There's no room for the torsion bar to fit underneath the chassis rails where it's supposed to go as mine don't arch as high over the axle as a proper 'back-half' would.
The torsion bar is too long to fit inbetween the rails and being Chromoly with splined ends it ain't very shortenable.
Can't go under the axle due to ground clearance.

Dammitall