Inboard suspension

[Pavel]

I'm trying to get the roadster chassis into solidworks at the moment to have a play around with packaging inboard suspension if possible. The only problem appears to be the steering rack at the moment..
Initially I was just hoping to do it at the front, but am now looking at the possibility of mounting the rear shocks into a central node above the rear diff. Will also be modifying the rear suspension frame slightly (not dimensions wise) as the lack of triangulation bothers me slightly.

Has anybody managed to use pushrod suspension on a haynes roadster?

[flyerncle]

3GE made one that is on the website if you look very carefully at the pic and John/Keith may be able to help.

[3GE Components]

It's true, we did, it looked like this....


http://i991.photobucket.com/albums/af35/3GEComponents/HaynesInboard.jpg


Kind regards

John

[twinturbo]

And somone on here bought it a few months back and then I think they were selling it.

TT

[twinturbo]

http://www.haynes.co.uk/forums/showthread.php?t=4245&highlight=inboard

[Pavel]

It's true, we did, it looked like this....


http://i991.photobucket.com/albums/af35/3GEComponents/HaynesInboard.jpg


Kind regards

John


Hi John,

Thanks for that image, much clearer than the photo of the chassis on your website. Your rocker pivot points are lower than where I was hopnig to have mine, but it's a very interesting setup.

Is the node for the lower damper mounts behind the steering rack mount, or have you integrated the shock mount with the steering rack mount by fitting a horizontal tube at the peak?

That does seem like the best way in terms of packaging, but if your rocker pivot points are in the same cross-plane as a conventional shock top mount, presumably your rockers are pivoting on an angle?
How much of an angle is this, is it about 8-10 degrees?

My initial hesitation of using this kind of setup was that gettnig the pivots to a precise angle to avoid bending/binding would be a nightmare.


Thanks again for the help.

Pavel

[3GE Components]

Hi Pavel,

What we did was to cross brace the chassis in the area formed by FF1, BR1, BR2 & BR7, this provided a node for the shock bracket to weld to. Further stiffening was provided by a bolt on sub frame that tied these & the rear upper suspension brackets together.

The pivot points are in line with the centre line of the car and the shock mount on the wishbone, so standard Haynes Roadster parts could be used. They also provide a rising rate to the front end. The layout, I felt, was the easiest way to package the shocks in the nose of the car. It also allowed for a front ARB to be fitted should it be needed.

The shocks in the diagram are about 30 degrees off vertical, they are shown at ride height, so obviously at full length and full comression this would change. It's important when designing the rockers to end up with either a straight or rising rate, it would be easy to design it with a falling rate which would result in suspension that bottoms out easily.

Kind regards

John

[Pavel]

Thanks again John,

that seems like a good setup. I'm going to try and put it all into cad and get some dimensions for the extra tubes needed. If it all appears to fit together, I'll share it on here!

[Coozer]

I'd be interested in a rear inboard design. Anyone considered that or have a design?

Steve

[Pavel]

Coozer, I'm looking at various packaging options at the rear at the moment, but they all will take a bit of work.. I'm struggling to package 13" dampers above the diff.

I will post up my sketches once I finish. CADing takes a while for me!

Pavs

[Davey]

Perhaps of some interest (or not) I saw a 1970s race car at the weekend with inboard rear suspension consisting of Hydrolastic suspension units, probably off an Austin 1800 from the look of them, it was called an MG liquid suspension system but from what I could see they were standard hydrolastic units but instead of being hydraulicly (sp?) connected they were independent with a simple schrader valve on each rear unit so you could alter the hydraulic pressure and therefore the spring rate. I'll see if I can find a photo.

D.

[Davey]

Found it! Here it is:

D.

[Pavel]

Very interesting! and would certainly help from a packaging perspective. However, don't they still need damping? Then where do you put the long dampers?