197 replies to this topic

[antelopeslr5000]

What are the physical differences between LX RTS and the UC RTS setup?

Would there really be much of an advantage "upgrading" to a UC front end? Or does anyone know if there are any disadvantages in changing to UC front end?

If anyone could supply pictures of both a LX and an UC setup that would be greatly appreciated.

Thanks in advance!

[enderwigginau]

The UC RTS front end needs the upper control arms dropped ~1" I believe to take them back to A9X position.
Other than that, the RTS front is a great idea.

Grant..

[Toranamat69]

Also the UC's have a different pair of upper control arms with the balljoint offset rearward to allow almost 3 degrees more positive castor.

The maximum Castor setting on the LX type upper control arm is 3.6 degrees whereas with the UC type arms I can get 6.5 degrees.

You can achieve factory alignment specs with either arm.

It is better to run the UC upper control arm if you are going to have more than +2.5 to +3 degrees castor as you have a better range of camber adjustment.
for normal road use in a V8 LX Torana there is no real advantage as you can't steer them with more than 3 degrees castor anyway.

The UC also has the steering rack solid mounted which is easy to do to LX.

If you are using UC castor alignment specs (which I would), UC steering arms are better than the LX ones.



M@

[Toranavista]

What was the advantage for the UC going back to the top mounting position for the upper control arms?

[REDA9X]

You don't lower them to the lower position on a road car, and the reason for the offset arms was to help stop the wheel from rolling under when turning. Look at some of the old test pictures of LH's given a hard time and turning, Scarey.

[Toranavista]

I understand that LH/LX pre RTS and UC use the top mounting position, but thought LX RTS shared the lower position with A9X. Is this not the case? If it is then my question is why did the UC change to the top mounting position after it had been changed to lower on LX RTS and A9X?

[Toranamat69]

I think the jury is still out on that one Toranavista.

The only things I can suggest is they wanted to design more understeer back into the front end.

Either that or they considered the additional Castor they ran in the UC was sufficient for cornering and they didn't need the steeper camber curve.

We need one of the buggers who designed it to chip in with their reasons about now

I can't see a prob drilling the UC one lower and tearing around like that on the street - I actually plan to make twice that change on mine.

In fact I have been doing it for 3 1/2 years and I am one of the only ones I know with 255 tires up front that don't wear too badly on the inner and outer edges.

M@

[A9X]

So with Tarmac Rally in mind, would one stay with a standard LX front end and realign to suit, or bolt in the UC front end or mix and match?
Keeping in mind Tramac Rally rules will only allow a maximum rim of 16 x 9.

Welby

[hatchssv8]

Makes for interesting reading gents. Now I am totally confused. Anyway, thought I would post up some pics to show visually the differences between some parts. Hope this helps.

LH/X non RTS engine x member
Upper control arm holes in lower position and absense of control arm stop.

UC RTS engine xmember
Upper control arm mounting holes in the lower position and the addition of a upper control arm stop.

LH/X v UC upper control arms
Offset position of the UC control arm (balljoint position further rearward)

LH/X v UC lower control arms
Steering arm stop added

LH/X v LX/UC RTS steering arms
UC longer and slight angle difference at tierod end hole.

LH/X v HQ/Z stub axles
Obvious axle position sits higher on HQ and not visible, the KPI differences (2 degrees)

I have tried to capture all the differences, if there are others, please enlighten us all.
Cheers, Max

[Toranamat69]

These are great pics. I have been wanting someone to post some at this angle for a non RTS LX front as I only have UC ones here to play with.

My first query though, those pictures of both the LX & UC X-memebers above have the holes in the upper position, not lower as you state.

I have thought a few times that what we refer to as the 'upper mounting position' is slightly different bewteen UC and the LH/early LX and that is exacty what that looks like in your pics there, the UC one looks 2 or 3mm higher.

You refer to an 'Upper control arm stop' I actually took some pics of this piece on the weekend on my UC front and I was going to post a question as to what they are actually for. you saved me the trouble of posting my pics
Can you explain to me what these do?

M@

Edited by Toranamat69, 25 October 2006 - 06:17 PM.

[355LX]

On this subject, can someone remind me, but I was always of the understanding that HQ etc had 7degree KPI, and the torana has 9 degree. The stub axles I recieved from CRS are supposed to be std torana kpi, and have 9 degree's stamped on them, as I expected, but I have since seen posts that contradicted this.

Dave

[355LX]

Sweet, I thought that was the case, but have seen it posted otherwise so many times now started doubting myself.

Dave

Edited by 355LX, 25 October 2006 - 10:38 PM.

[hatchssv8]

Toranamat,

The measurements of the holes to the mounting surface (above) is approximately-
UC xmember (painted) 28mm, LH/X RTS(dirty) 40mm. I also have a confirmed early non RTS LX at app. 32mm. So I stand corrected, I didnt think to take measurements as I always believed what I heard/read was distinguished visually.

Does this mean that I should have prepared the dirty xmember to fit to my Torana??? I am getting confused too. What I can confirm is that the 'set' I got painted was removed by me from a virgin UC RTS 6cyl sedan.

The stop I refer to can only be a stop for the upper control arm. I presume that after ccompressing the rubber bump stop, it would then 'bottom out' on the metal stop welded to the xmember.

Can someone also quote the parts manual for me. We constantly see posts that say 'check the manual and you will see'. The manual I have only provides part numbers and can also refer to footnotes i.e. use with RTS. In this example, xmembers dont seem to have a part number stamped on them.

Please note that this is not a dig at anyone.

Cheers, Max

PS: Thanks toranamat for the pic comment

[hatchssv8]

OK.curiosity got the better of me. Just back from the shed at this time of night!

Checked the disc stub axles I have....Both pairs look identical visually. One pair has matching part number as listed in my parts manual. The other pair I cannot make out the numbers.will do a more thorough look tomorrow.

I also checked the drum stubs I have and again the part numbers match those listed in the parts manual. Furthermore, both stubs have the single number '9' cast on the outer surface of the stub, about 20mm below the upper arm mounting hole. Could this be indicating the 9 degree KPI (or is it a cavity/die number)

Lastly, the parts manual lists two types of disc stubs (each with their own part number). One is for use without ADR31 and the other with ADR31. Who can enlighten me about ADR31

Thanks, Max

[Toranavista]

Great work guys! I dont mind being confused when i know there is an answer on the way. ADR 31/00 Hydraulic Brakes Passenger Car

[A9X]

I have 2 stubs sitting here witha tag that reads part no # 9943696

I think they are hq one tonner stubbs but they are out of my torana 'don't sell' box.

No 9 cast on them though, while someone has got their head in the books, can you clarify these stubbs for me?

But as Aqua says

Can someone tell me/us how to put the ultimate front end together using all the available pieces from the various models.......................I am confused now..

Thanks

Welby

[hatchssv8]

Welby,

The 9943696 is the RH Stub as used in PO A9X. 95 is the LH Stub.

Those numbers are as listed in the literature I have. Can someone confirm if the same numbers are used in HQ/Z

Where is the 9 cast?

[Toranamat69]

All very interresting, I suspected the UC ones were higher as some guys have the upper control arms hitting on their chassis when they put the UC front ends in the LX's.

The nice painted one above is definately UC - my 2 in the shed are the same.

I have redrilled my UC one on the test bed to the same as what is in my car and that front end is an RTS LX front end. The bolts for the Upper control arm are about 50mm down from the flange - you could probably have drilled this one about 3 or 4mm lower if you were after every skeric but I was trying to simulate the setup in my car.

Anyway this is the best spot to run any of the Torana front ends in my view.



I am going to plot out the camber curve for this arrangment on the weekend. I don't know if I could be bothered with yet another whole set of measurements now I know there are a few mounting spots for the control arms, I have just measured the top and am about to do the bottom so I know the adjustable range.


With those 'control arm stops' - I scratched my head about those for ages, because as you point out, only the UC's have them and I want to grind them off.

They are there so you can hook the top of the stub axle on them if you have the top ball joint separated and the lower control arm still connected to the stub as it all wants to fall down.

I was just interrested if anyone else noticed this point.


M@