Rear sway bar for CR

[Rob. Smith]

Originally Posted by cobbindale

Hi All,

Is anyone running a rear sway bar on their CR or should the question be is it worth running a rear bar?
I only ask as it seems there are no mounting points on the chassis for one. Best weld then on before final paint to chassis (I've said that 3 times now).
They may have been missed when building my chassis. I'm also short so rear bracing supports from the seat belt mounting frame the the chassis.

Thanks,
Dale.

I read somewhere that you should paint your chassis in a light colour, so that cracks or fluid leaks would show up easily as apposed to black that hides everything....I painted mine silver and it looks great !

[Beejay]

Hello Ian,

Can you confirm all of the differences with a race chassis as opposed for a street car?

Not sure about everyone else, but I do not mind if my car is impractical on the street, I am building for the occasional rush of adrenaline!

Ben

[cobbindale]

Pedders in Geelong have given me the measurements of Phils bar which they have on record at the factory.
I've asked them to look at a slightly different design which is 100 wider and has 3 adjustment holes. Making the bar wider should make the bar work with less effort and the adjustment holes give 3 stiffness settings. The rear measurement is 400mm as this will allow the bar to be mounted directly to the 2 square sections under the diff housing. The pedders 4204 links could be used to attach to the lower arm, they are only 60mm long between centers at about $55 each


Should hear back later this week

Cheers,
Dale.

[cobbindale]

Heard back from Pedders today, the same bar as Phil is $225ish with saddles and bushes. This bar is 615mm between lower arm mounting points and can use a cut down link like the 4208 jobbie from Pedders with the balls at 180 degrees to each other and 500mm across were the saddles mount.
The stighly different bar than Phils is $242 which comes with saddles and bushes and 3 adjustment positions. This bar is 100mm wider which should sit even with the mounting holes in the lower arms and use the 4204 link and is 400mm across were the saddles sit, (noticed I said should).

I'm happy to buy the wider bar and take some pics if you like. Discounts on multiple orders were breifly discussed and only a few bucks mentioned as a saving. He estimated $15 - $20 for shipping to Sydney.

If you wish to have a chat to the guy, his name is Scott at Pedders Geelong Ph. 03 52213233.

Cheers.

[pneall]

Dale,

I fitted my rear bar yesterday and agree that it should be wider . There could be two sets of specs on Pedders data base. The first one I got made is the one Phil M is running. He suggsted the arms should be longer. The second bar I got made has arms 40mm longer than the first but I think this is about 15mm to long.

I'll let you know hat it feels like on the track.

Regards,

Phil

[400TT]

What thickness bars are you guys running front & back on your CR's.

[cobbindale]

Placed order this morning for wider bar. Should have it in a week or so and will take some pictures when installed. Looks like there will be 3 rear bars for the CR.

Craig,
The front bars are 22mm and the rear is 16mm. Not yet tested on any cars to see the difference.
Was thinking of going to 14mm bar but Scott at Pedders Geelong said there is either 70 time or 70% difference in the strength between 16mm and 14mm, can't remember what was said 5 hours ago.

Cheers.
Dale.

[NASSTY]

I'm no expert at suspension settings but I have a question for those have dabbled in the black art.

Given that Cobra's usually have a even weight distribution or slight rear weight bias, what would be the effect if you used the same diameter bar front and rear? Or to put it another way, do street cars have a larger front bar because of the front weight bias?

Any thoughts?

[400TT]

Thanks cobbindale for the sizes.

Originally Posted by cobbindale

Was thinking of going to 14mm bar but Scott at Pedders Geelong said there is either 70 time or 70% difference in the strength between 16mm and 14mm

Check out this whiteline page for difference in torsion between bar sizes: http://www.whiteline.com.au/docs/bulletins/010barup.pdf

[400TT]

Originally Posted by NASSTY

what would be the effect if you used the same diameter bar front and rear?

(I really have no idea, but here is my take. )

Too much turn-in oversteer. So that's why you run a heavier bar on the front, lighter bar on the rear. You can dial the turn-in oversteer out to some degree by winding the front shocks up stiffer, but this causes other problems e.g. braking problems on bumpy tracks.

Unfortunately different Cobra makes vary so much in design & suspension setup, so we have no magic formula for all Cobras.

CR guys are working towards a better solution and there is a fair bit of knowledge around for suspension tuning Harrisons as well.

Put it this way, I am surprised by how light a front bar the CR's run. On a Harrison you would be thinking something like minimum 28mm front, matched with 16mm rear. Use adjustable bars. But there are so many variables.

[NASSTY]

Thanks 400TT