fbekholden.com

Sounds a bit like caltrac setup


FB ute fixer upper, EK van on rotisserie

Not sure if Mick's setup is Caltrac (which uses a pivot to bear down on the top of the spring leaf), or TractionMaster (which is a radius rod setup that does not bear on the spring or spring eye).

I managed to get hold of VPW, but sadly they do not have any of the Lakewood GM X- and F- body units in stock to measure for me. From some HAMB help, I've managed to get the rough dimensions of the shock absorber plate for these vehicles - assume the Lakewood units are similar. Using this and a bunch of published info gives the dimensions below:


From what I can see, both the Universal and the GM units will come close to working on an FB/EK. They are a smidge long (the snubber would need to run on the shortest of the three holes provided), but OK to either live with the length or trim to suit. The GM unit mounting holes (that use the original u-bolts) may be problematic. The 3 1/8" distance is fine, but the 3 7/8" distance is painful. It requires the u-bolts to be moved out along the diff tube (no drama... the banjo diff does not locate the u-bolts), but you can afford to go to about 3 5/8" before the u-bolts will hit the rear brake hose bracket.

For the GM unit, the issues stack up for me - risk of hitting the brake hose bracket, overly long, only one of the three shock mounts will get used, and pricey (about $370 for the basic bar, and then another $180 if you want J-bolts ). Given these issues, I'm not going to pursue the GM unit any further.

Plan for now is to take a look at the Universal unit, and then detail out what an FB/EK specific unit looks like (using either the Universal unit as a starting point, or some RHS and fittings).

Cheers,
Harv

55-56 chev type wouldnt work harv? Length of bar may need “adjustment” but otherwise should be bolt on?


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In place


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They probably would come close to fitting, but those look to be a Caltrac setup (I think the forward pivot is sitting on top of the leaf spring in the photo?)

Cheers,
Harv

Yes they are called Caltrac type - the forward pivot does look to be sitting on the leaf yes and rear pivot is connected to spring pivot - is that an issue?
I would have thought this type set up would be more effective than the unconnected rear pivot type.

Harv wrote: Fri Mar 05, 2021 7:08 am They probably would come close to fitting, but those look to be a Caltrac setup (I think the forward pivot is sitting on top of the leaf spring in the photo?)

Cheers,
Harv

Caltracs are more effective... but are a little too modern for what I am looking for. Mid-90's technology from Calvert Racing.

Cheers,
Harv

These look like those you were looking at but have the addition of the drop down controllers - lakewood style


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Thats spot-on what I want to build, including the oh-my-gosh-thats-yellow paint and Traction... Action decals

Cheers,
Harv

You're gonna need wheelie bars next

FB ute driver, EK van project

While I wait for the Lakewood Universal bar to show up, I’ll dig into the rules around installing traction bars. The guidance around traction bars is captured in NCOP Section LS Tyres, Rims, Suspension and Steering… but is not particularly clear. Section 1.1 indicates that "track rod" installation is a basic modification not requiring certification, with Section 4.6 clarifying that track rods may be fitted to control rear spring wind-up provided that they meet the minimum ground clearance requirements. This would indicate that I can bolt up some traction bars without an engineer… provided a “track rod” is a traction bar. Sadly, NCOP is silent on what a “track rod” is though, and the term has a lot of different meanings – for example, it can mean a panhard rod or a front suspension tie-rod depending on the author. The National Guidelines for the Construction and Modification of Street Rods in Australia (section 6.12) notes a difference between track rods (which it allows, subject to clearance as above) and traction/slapper bars (which it prohibits due to the traction bar nosing under brakes and limiting suspension movement under cornering). I suspect from the above that NCOP is referring to a radius rod, but cannot be confident.

So a bit uncertain whether traction bars can be installed on an FB/EK without certification (but pretty clear they cannot be installed on a street rod).

However, NCOP Rear Suspension Modification (Design) Code LS5 Section 3 allows for “Traction aids attached to a live rear axle near the spring mountings”, provided they are compatible with the geometry of the spring, do not cause any binding with suspension movement, and that under body clearances and ground clearance must be maintained and continue to meet regulation requirements. This sounds like I can install traction bars, though need certification. The regulation requirements mean that I need at least 100mm at any point within 1 metre of the axle (NCOP Section LS Section 2 General Requirements Section 2.1.4) and that the traction bars must hang no lower than the wheel rim (NCOP Section LS Section 2.1.6 Tyre Deflation). For my FB/EK, this gives the following:


The traction bar can be 64mm deep, limited by the 100mm road clearance requirement. Note that this is using Sampson Magnum 13” rims (same rim diameter as standard FB/EK), but 205 tyres (different tyre profile will alter the above).

The Moroso traction bars are 2.5” (63.5mm) and thus would comply, but not sure about the Lakewood ones (suspect they are the same, but will see when they arrive). If you are making bars at home, 65mm RHS would probably be close enough to the 64mm to be compliant (you can probably squeak another 1mm by smooshing the diff u-bolt rubber mounting pad or inflating the tyres a little more).

Cheers,
Harv

this was on facebook and is pretty much what i had described

Old ad from the Eddie Thomas Speed Shop for various Holdens. Note that these are Traction Master type rods.


Cheers,
Harv

Slowly working on the traction bars in the background. Got most of the fittings, but had to wait a while for the steel (the Postie looks at me funny when he delivers stuff like that).

Rough mockup:


Should look closer to this (final dimensions to be checked to make sure the snubber hits the spring eye):


Need to get the FB's front wheels back on the ground for fit and fiddle. Its been up on stands for a while with one wheel off, waiting OK from the engineer to grind back the control arms (so the whopper stopper brakes will fit). Got the OK this morning, so this weekend is brakes back on, then fiddle with traction bars.

Naturally, no self-respecting mug lair can make slapper bars without the period correct decals. Just need the canary yellow paint.


Cheers,
Harv

Bogantastic !!!