197 replies to this topic

[Dangerous]

Yep double checked it 75mm.

Thanks Peter - another part of the jigsaw puzzle

[StephenSLR]

2.  Yep all the Lower Control Arms have the same geometry.

I notice on the upper control arms of the UC there is a 'R' stamped into it, is this the driver or passenger side?

On the lower arms there are no stamps indicating right or left.

s

Edited by StephenSLR, 15 January 2007 - 11:56 AM.

[arrimar]

the r is for the drivers side.

[StephenSLR]

A few questions:

I notice in the pic of the A9X Xmember jigsaw new looking studs, bolts and nuts, where can these be obtained?

I plan on putting a UC front xmember into my LX and a few here recommend drilling lower holes for the UCA's. How far lower should I drill these holes?

I have the xmember in pieces at the moment and plan to have it painted soon, can anyone recommend someone in Sydney to install it for me?

Any recommendations for a painter?

s

[Dangerous]

Stephen, those nuts and bolts were all the original ones that I had cadmium and/or zinc plated. It's pretty cheap, and there's usually a minimum charge, so grab all the spare nuts and bolts you have as well as the ones you need plated, and get them done as a batch. There's not a lot of places around that still do cadmium plating, but a few that do zinc plating. The silver finish is 'non passivated' and the gold is 'passivated'. The silver finish does tend to dull off a bit, especially if handled a lot.

If you can't find a plater to do zinc/cadmium, try asking around at your nearest light aircraft airport - it's still used quite a bit in the aero industry.

The hole location depends on how aggressive you drive - you could leave the UC top holes and use them, but while the front end is out, I'd suggest drilling holes around 25mm lower might be a good compromise. Toranamat is the most up to date with optimum setings, thanks to what seems like an incredible amount of research and measuring/testing. If you post wheel/tyre/ride height and driving style that you expect to use, I'm sure between us all here on the forum we can suggest a hole location to suit.

Sorry, can't help about Sydney mechanics.

[Toranamat69]

Here is the best pic I could get of the front end in my car showing the UCA mounting position - I pulled this front end out of a '77 LX RTS hatch many moons ago (1993 infact - bloody hell)



Definately mounted as low as you can go and notice there is only the 1 set of holes.

M@

[StephenSLR]

> all the original ones that I had cadmium and/or zinc plated

Why did you choose to have some cad plated and others zinc plated?

> The hole location depends on how aggressive you drive

I just drive on the streets and highways, nothing too radical.

> wheel/tyre/ride height

the car is lowered with Kmac springs (LX and UC are the same right?)

I plan on going to 15" rims and to keep it as legal as possible so the track width will be an inch or so more than standard and I will try to keep the wheel/tyre diameter to be close to standard if possible.

I was thinking to have the holes drilled for future use if applicable.

s

[Dangerous]

Stephen, I'd go pretty much straight for the hole locations as per Toranamats photo and use them, ie as low as you can get on the vertical part of the crossmember upright without fouling anything. We don't really know why the UC upper mount holes were made so high, but Holden obviously had its reasons, and the UC was a far superior handling car to the LX - and left the LH for dead. Having said all that, simple logic points towards the lower location being better for increased camber on cornering. If you have both drilled, at least you can experiment if you're keen, and have a direct comparison between the two.


Re the cadmium/zinc, originally I was trying to replicate the original finish, so if it was cad plated, it got cad plated again. Passivated zinc looks just like passivated cad (as far as I know - I don't think I can tell them apart) and the finish varies, depending on the plating settings and times for each batch, so there is always some colour variation.

LH to UC springs are interchangeable.
Going to 15" rims will improve handling, and there are still plenty of good tyres available for reasonably narrow rims - I wish I could say the same for 10" rims

As a final point, I've had much beter results with the UC rear sway bars than the LX ones, so I'd recommend tossing the stock LX sway bar over the back fence and either fiting a UC rear sway bar by cutting a UC floorpan to get the slightly different mounts, and welding these bits onto your floorpan and diff housing (involved), or buying and aftermarket rear sway bar that mounts to the diff axle tubes and the floor pan (much easier), not just the trailing arms like the stock one does.

[StephenSLR]

> as low as you can get on the vertical part of the crossmember upright without fouling anything

What would that be in mm - about 25mm?

Also, aren't the studs a press fit? The tolerances would have to be very accurate right?

How big should the holes be? I wouldn't want the studs loose in there if they are not supposed to be.

> so if it was cad plated, it got cad plated again

To save on fiddling would it be better to get them all plated the same and which plating would be best?

> I'd recommend tossing the stock LX sway bar fitting a UC rear sway bar

I have a K-Mac anti-sway bar and it has different mounting points to the LX one.

From memory it is secured to the diff housing with U bolts and also has pins at each end that go into the floorpan.

s

[slr5640]

I do have drawings of the bump stop with measurements somewhere.

Gooday Dangerous, Just curious if you have come across these drawings or measurements yet.
Or any closer pics.
Let me know if you want to e mail them I will send details.
Thanks in advance.

[Toranamat69]

Also, aren't the studs a press fit? The tolerances would have to be very accurate right?

How big should the holes be? I wouldn't want the studs loose in there if they are not supposed to be.

Drill the holes to 7/16" - the bolts are splined like a wheel stud so you don't have to hold the head with a spanner to stop them turning when you are doing/undoing the nuts.

You can either give the bolts a tap on the head with a hammer and drift or just tighten them up and they will bite and pull through - I would still give them a tap on the head once done up just to make sure they are all the way in and don't loosen off at a later stage.

If I keep hooking in this arvo I should be able to update my cardomain site a bit later on and best of all I will actually have all of my baseline measurements done and I can get on with the PS conversion.

In case you all haven't reallised, it sucks doing repeat mesurements for every combo of front end parts for bumpsteer etc - hence why I keep putting them off - Oh well nearly there.
I am going to skip a few combo's but I am going to do the HQ stubs with LX and UC steering arms as that is renound for being a nasty setup (that is what I am currently doing when I get off the net and out of the aircon )

I have just done the Std A9X bumpsteer and it is the best of the standard Torana setups - only just slightly better than the UC bumpsteer but bugger all in it.

M@

[dattoman]

We've got some tarmac rally cars to build...... could you get on with this PS setup please
Were on abit of a tight time schedule

[Toranamat69]

Here are the camber curves for the UC (top mounting spot) and the A9X and RTS LX setup (bottom mounting holes). You can choose where ever you want between the dark blue and red curves by drilling somewhere in between.

Notice the purple curve using the spindle extender make approx 2 times the difference in redrilling the UCA mounting holes lower as these extenders are approx 2"high so roughly double the change.



M@

[A9X]

Thanks Mat, great work.
Regarding this and the other graph in the other post.

What is the optimum line ?

Or is there such a thing, is the line bad in itself and optimum is no movement.?

Sorry if these are silly questions, but you lost me a while back.

Welby

[Toranamat69]

It really depends on the tires you are running as well as how stiff your springs/swaybars are. The more body roll, the more significant the camber curve becomes.

The old crossplies didn't respond as well to camber gain as radials do and low profile large rim wheels like mine need a stronger camber curve to keep the tire flatter on the ground compared with a smaller rim and larger side wall.

I reckon the optimum will lie somewhere between the A9x and the one with the spindle extender - real life testing will tell for sure what is the best from that point.

If only I could get some adjustment in that range as at the moment I can only go to either of those extremes.

If I can work out how to fit the moog adjustable balljoints (thanks 82911) top and bottom and clear my rim, I can then get full adjustment between these curves.

M@

[StephenSLR]

A quick question,

Are LX and UC stub axles identical?

s

[Toranamat69]

Yep

[Toranamat69]

G'day Marko,

First Q' - A 7 degree KPI stub axle will still have 7 degree KPI with the stub extenders fitted, it does not change that, only the overall height of the stub.

Second Q' - The guy at TSS used to sell these stub extenders and he claimed these were exactly what the Torana front end needed - it seems to me that he is correct but I have not had a chace to verify it yet. The curve I have plotted above with the extender is with the UCA(upper control arm) in the to (UC) position.
If you run the spindle extenders with a 7 degree KPI stub you will be in trouble with adjustment.
To run the spindle extenders you need to have a wedge shaped spacer on the top balljoint (approx 12 degree wedge) - if you also run the upper control arm in the lower holes you will need about an 18 degree wedge or the upper balljoint will run out of travel and almost definately fail. You would also have an even more agressive camber curve than those above - probably taking things a little too far.

3rd Q' - Yes - especially if lowering tha front more than 1.5 to 2".

4th Q' - If your front end has bent badly I suppose you could run into problems with adjustment using 9 degree stubs but that would be pretty severe bending of the subframe.
On my test jig, the 7 degree stubs can be adjusted to proper alignment specs if the springs are standard height (this will still drop the front ride height by 30mm) If I lower the front approximately 20mm further in the spring then I run into trouble and cannot align the camber to anything less than 1 degree negative and it gets worst the lower it goes.
Putting the extenders on makes this worse (you need to remove more shims) as well because the UCA angles over more and 'shortens' in the horizontal direction.

It is worth noting that TSS no longer make these spindle extenders so you would have to make your own or buy these ones I did from the US. These US ones use the Chev upper balljoint taper and need machining to fit the Torana - I don't have the correct reamer to do that at the moment but I may be getting one in the next few months, not sure yet.

M@

[dattoman]

KPI is same on both A9X and H series so no help there by eye
Whats the casting #?
They are the same as HX 1 ton as far as casting # is concerned

Welby might be able to help he has a brand new pair he can get numbers off for you

[REDA9X]

Stub axle is the same A9X to HZ, same part number from memory. I'll have a look for sure.