13 replies to this topic

[rexy]

By end to end you mean bolt up face of disc/drum side to side?

[Bigfella237]

Standard wheel-bolt-up-face to bolt-up-face diff widths (including brake drums/discs thickness) for LH / LX diffs are:

 

1456mm for L34 / A9X (with disc brakes); and

1446mm for everything else (with drum brakes).

 

Hopefully someone else has the figures for LC / LJ

 

So your diff is well short for a big Torana if the 1310 measurement includes the axles and brakes, in fact I'd guess too short even to use the standard lower trailing arm and shock mounts, so you're probably looking at a full custom coil-over setup?

 

The other thing is, what capacity motor are you looking at using? The LC / LJ factory tare weight will restrict your (legal) options somewhat more than the LH / LX.

[Bigfella237]

Hmm... speaking for the LH / LX here, if you want to keep the factory rail then there's no point doing mini tubs as the rail is just about the first thing you'll hit, as Glen's picture here illustrates...

 

I also done this to my other torana, you can see the problem with just moving the rail at the back the tyre starts hitting on everything else.

 

 

According to this drawing the rear chassis rails are at 1177mm centres...

 

 LH LX Rear Clip.jpg   133.28K   7 downloads

 

...so with your 1310mm diff I'm guessing the brakes will be lucky to clear the spring seats on full compression? It may fit (just) but you would end up with very deep dish wheels with almost no backspace, which means extra load on the axles and bearings.

 

I had hoped somebody would chime in with the LC / LJ diff width(s), or if someone has accurate rear track and factory rim offset figures I'll calculate the diff width?

Edited by Bigfella237, 29 May 2015 - 06:47 AM.

[Bigfella237]

Just quickly, I see you're in QLD which is under the NCOP for Light Vehicle Mods, so without going into all the crap on how to work it out, based on the L34/A9X rims & tyres and assuming you plan on keeping it legal (ie getting it past an engineer)...

 

The maximum size tyre you can (legally) fit to an LH or LX will be 265mm wide and 668mm diameter (so 265/50R15 or 265/40/17 or 265/35R18) on all four corners.

 

Under NCOP the rim size is not specified so long as it's suitable for the tyres fitted.

 

LC / LJ never had a 14" wheel option so although I haven't worked it out, I suspect the maximum legal size for the earlier Torana will be much smaller than that.

 

EDIT: I forgot to mention that a 10" wide rim would be suitable for a 265mm tyre

 

Wheel track will be something else again, with a shortened diff you'll have to consult an engineer about that?

Edited by Bigfella237, 29 May 2015 - 10:04 AM.

[Uncle Chop Chop]

I had hoped somebody would chime in with the LC / LJ diff width(s), or if someone has accurate rear track and factory rim offset figures I'll calculate the diff width?

 

Based on the L34/A9X rear track of 1443.2mm and an offset of -1/4" for those wheels, the LH-UC diff (BUF - BUF) must be 1430.5mm wide.

[Bigfella237]

Based on the L34/A9X rear track of 1443.2mm and an offset of -1/4" for those wheels, the LH-UC diff (BUF - BUF) must be 1430.5mm wide.

 

Here we go again...

 

That would be true *IF* the offset was MINUS ¼" but it's not, it's PLUS ¼"

 

From the GMH L34 Service Bulletin dated AUGUST 1, 1974

 

 L34 Service Bulletin - Wheels.JPG   44.02K   3 downloads

 

If you do the math on the front end it has to be +¼", it just doesn't work out any other way, I can go through all the math again here if you like?

[Uncle Chop Chop]

I'm sure I saw it listed as - 1/4" offset somewhere, but I can't find it ATM.

[Bigfella237]

Yeah it seems somebody mistook the dash in "Offset - ins.(mm)" for a minus sign but if you calculate the BUF-BUF for the front end of an L34/A9X using -¼" offset it comes out skinnier than a standard RTS front suspension, which we know is not correct.

 

Still after the figures on an LC / LJ if anyone has them?

[N/A-PWR]

Hi Andrew,
 
LC/LJ is 1370mm from wheel face to wheel face:-
 
 Drum to Drum Measurement 1370.jpg   78.97K   3 downloads
 Drum to Drum Measurement 1370.jpg   71.5K   2 downloads
 Drum to Drum Measurement 1370.jpg   95.93K   2 downloads
 
not the prettiest sight, but I guess it is a before shot for the RAT. 

Still after the figures on an LC / LJ if anyone has them?

now to answer the shortened diff question for the RAT.

I have 80mm from behind the drum to the shocky,

(in the past was normal shock with the top protection cover taken off)

so I will knock off 50mm a side =1270mm face to face for me.

Edited by NA-PWR, 09 January 2016 - 02:38 PM.

[madtoranajzedded]

Seems you have some serious grunt bud  maybe if you have clearance to the chassis rails to shorten housing more to allow you

to run a floater kit for safety reasons.would keep the authorities happy.maybe ask the engineer you will use or authorities on it.

 

just my 2 c