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5/27/2011 4:21 pm  #1


XJ40 IRS into an Aussie falcon

and so it begins
good news is, it looks like its going to work. Got it jacked up and roughly in place

heres some pics.
Its a bit tight in the shed atm, so it hard to get many decent angles








Good news is, its tight, but i have enough room for exhausts. also, the front mounts end up in an ideal spot, i can fabricate some bolt on brackets that utilise the falcons upper control arm holes through the rails. I can utilise the falcons lower control arm mounting points for a bracket to reinforce the mounts and make it double sheer like the jags had it set up. the rear mounts are easy, remove the watts link brackets, weld in a crossmember and required brackets. Im sure im going to have a few headaches, but so far so good

 

5/27/2011 9:17 pm  #2


Re: XJ40 IRS into an Aussie falcon

NOT FAIR!!!!
you got it easy I had to fabricate up this thing to make my set up "bolt in"

I didn't see a single mounting point in your situation  that couldn't be accommodated by making a simple bracket or two.  What is the wiring harness coming of the diff??  also what is your pinion angle in relation to the plane of the LCA pivots??  on the older units there were a couple of pinion angle options and we discussed them in great detail on past threads debating the best way to get the correct pinion, trans alignment.


If it isn't broken..... modify it anyway!!!!
 

5/27/2011 10:57 pm  #3


Re: XJ40 IRS into an Aussie falcon

Daze wrote:

NOT FAIR!!!!
you got it easy I had to fabricate up this thing to make my set up "bolt in"

I didn't see a single mounting point in your situation  that couldn't be accommodated by making a simple bracket or two.  What is the wiring harness coming of the diff??  also what is your pinion angle in relation to the plane of the LCA pivots??  on the older units there were a couple of pinion angle options and we discussed them in great detail on past threads debating the best way to get the correct pinion, trans alignment.

Yeah, these IRS units look very user friendly, im suprised more people arn't using them.
the wiring is the ABS sensors, there is also a hall effect speedo sensor up near the diff on the left hand half shaft. I removed all that today.
I plan to match the pinion angle of the trans. my engine sits on my own fabricated mounts and is arund 2deg down, so ill run the irs @ 2deg up. How the lower arm anlgle will end up im not sure, but im not really concerned if the plane of the lower arms is not parallel with the ground, unless of course it end up being a ridiculous angle....ill cross that bridge when i come to it, but the great thing with this irs, pinion angle on the diff will be extremly easy too adjust by making adjustable rods for the rear mounts, the front mounts have plenty of give so theres a few degrees of flex there...

Keep in mind, mine wont be a true bolt in, i need to remove all my old watts link bracketry, so i wont be able to revert back to standard suspenson easily like your system

Last edited by KLR250 (5/27/2011 11:05 pm)

     Thread Starter
 

6/14/2011 4:19 am  #4


Re: XJ40 IRS into an Aussie falcon

Been tinkering with my IRS install lately, been able to fabricate the forward mounts, I was fortunate enough to be able to utilise the original upper control arm mounting holes
The brackets i have made from 4mm
Ill make the mounts double shear, utilising the original lower control arm mounting points

pictures (a bit crappy in quality sorry)
















A few things of interest, I havent put the angle finder on to lower arm yet to confirm, but just eyeballing the XJ40 IRS when the pinion is at 0 deg the arms appear to be angled back around 8 degrees, good or bad, Im not sure, is this an anti squat feature?
More pics soon

Last edited by KLR250 (6/14/2011 4:21 am)

     Thread Starter
 

6/14/2011 7:02 am  #5


Re: XJ40 IRS into an Aussie falcon

Aw the great debate about pinion angle.  My bet is 6º  I say that because that is the angle Jaguar used on some previous models  As far as how you should deal with it, this has been a hot topic.  Their are basically two camps, one says get the suspension traveling vertically and let the pinion angle be what it is and others say get the pinion angle correct and let the suspension travel angle be what it is.  I am of the mind that the suspension needs to travel as vertical as possible.  The pinion angle is important but because of the differential being in a fixed location you can get away with a slight mismatch between the differential and transmission.   What angle is your transmission at???


If it isn't broken..... modify it anyway!!!!
 

6/14/2011 11:47 am  #6


Re: XJ40 IRS into an Aussie falcon

Trans angle is 3deg down, which is easy enough to change, i could probably get that to 1.5 deg
I think i would be happy with a slight compromise and set the diff at 0deg, as i dont want any more angle on  my arms.

What is the reason jaguar ran an angle on the arms? There must be a good reason i would have thought, I figured it must be an anti squat feature and work a little like anti dive on the front upper arm?

     Thread Starter
 

6/14/2011 12:21 pm  #7


Re: XJ40 IRS into an Aussie falcon

they ran the suspension at 0º  the suspension traveled vertically any angles at the pinion where to correctly align it to the transmission.


If it isn't broken..... modify it anyway!!!!
 

6/14/2011 12:24 pm  #8


Re: XJ40 IRS into an Aussie falcon

BTW I got so caught up in the pinion angle stuff  forgot to mention nice fab work on the brackets!!!!!


If it isn't broken..... modify it anyway!!!!
 

6/14/2011 2:35 pm  #9


Re: XJ40 IRS into an Aussie falcon

Daze wrote:

they ran the suspension at 0º  the suspension traveled vertically any angles at the pinion where to correctly align it to the transmission.

okay, but to make sure im being clear, with the diff pinion set to 0 my arm lean down toowards the rear on at least a 6 deg angle, it looks closer to 8 or 10 though, so as the suspension moves up the hub travels rearwards a little

if i set the arms to 0 the pinion would be facing down the said amount of degrees, which obviously is not an option

so your saying setting the pinion on the older units to 0deg had the arms level?

just out of interest, heres a picture of an XJ40, now bear in mind its harder to judge because of the angle the picture is taken, but you can clealy see the angle of the lower arm pivot bolt, it angles down towards the back of the car...once i get thses brackets done ill post some more pics

Last edited by KLR250 (6/14/2011 2:39 pm)

     Thread Starter
 

6/14/2011 2:40 pm  #10


Re: XJ40 IRS into an Aussie falcon

Daze wrote:

BTW I got so caught up in the pinion angle stuff  forgot to mention nice fab work on the brackets!!!!!

Thanks Buddy! more pics soon

     Thread Starter
 

6/14/2011 3:17 pm  #11


Re: XJ40 IRS into an Aussie falcon

KLR250, the pinion needs to be parallel to your trans output shaft first off. As far as the control arm angle, exaggerate it in your minds eye, say 45 degrees. Now imagine the effects.
http://www.hotrodhotline.com/md/html/drive_shaft_harmonics.php

Last edited by Ralphy (6/14/2011 3:25 pm)

 

6/14/2011 7:12 pm  #12


Re: XJ40 IRS into an Aussie falcon

KLR250 wrote:

okay, but to make sure im being clear, with the diff pinion set to 0 my arm lean down toowards the rear on at least a 6 deg angle, it looks closer to 8 or 10 though, so as the suspension moves up the hub travels rearwards a little

if i set the arms to 0 the pinion would be facing down the said amount of degrees, which obviously is not an option

so your saying setting the pinion on the older units to 0deg had the arms level?

OH, thats is a problem... or is it??? I was picturing it going the other way  on the older jag units you have 3 pinion angle options but the suspension is always perpendicular to the road.  depending on which differential side brackets you use.  0º 3º or 6º  The XKE brackets will give you the 6º which is how my car is set up my trans hangs down at 5º so it is close enough.  The XJ6/12 and XJS cars have the pinion set at 0º and I can not remember what the other bracket is.


If it isn't broken..... modify it anyway!!!!
 

6/16/2011 5:19 am  #13


Re: XJ40 IRS into an Aussie falcon

Finished both front mounts tonight which is good

Drivers side



Passenger side



Off to a machine shop to get some mounting spigots machined up and Ill weld them onto my brackets, then i can start on the rear mounts finally.

Sorry about these crappy quality pics, my camera is broken and im using the wifes iphone

Last edited by KLR250 (6/16/2011 5:25 am)

     Thread Starter
 

6/16/2011 8:23 am  #14


Re: XJ40 IRS into an Aussie falcon

looking good!!!  what have you decided about your pinion angle??


If it isn't broken..... modify it anyway!!!!
 

6/16/2011 2:18 pm  #15


Re: XJ40 IRS into an Aussie falcon

ill set it to 1.5deg up to match my gearbox This is where i have set my brackets (gearbox can easily be shimmed up, lots of room), not to concerned about the angle of the lower arms, as this is how the XJ40 was, so i pressume the jag engineers had a good reason to do this. I need to find an XJ40 and find out where they set the pinion, but either way im not to concerned, the bush's 0n the irs are very flexable, so i can fine tune the pinion angle by making the rear mounting rods adjustable

Last edited by KLR250 (6/16/2011 2:31 pm)

     Thread Starter
 

6/17/2011 3:38 pm  #16


Re: XJ40 IRS into an Aussie falcon

well, i was a bit concerned with the possibility of the wheel travelling rearwards to much as the suspension compressed, because it seems the XJ40 ran a lot of what id only describe as +caster (not sure what else to call this angle) so i hung a string and plumb bob to the wheel arch and was happy to see a total of 1" of rearward travel on the hub from full droop to full compression, My fears have been all for nothing. Also bear in mind i will never use the full travel of this suspension, Im measuring the total travel, so the lower arm is going much lower than it is supposed to, the spring assembly would normally limit quite a bit

I put the angle finder on the mounting cradle, and when its set to 0deg the pinion is 1.5deg up, so im 99% sure this is how jag would have had it, with the lower mounting cradle set level with the rest of the car. The gearbox will easily go up to 1.5deg (plenty of room) and with this arrangment i have a 2deg angle on my tailshaft (angled down from the front) so i think im heading in a good direction

Last edited by KLR250 (6/17/2011 3:44 pm)

     Thread Starter
 

6/17/2011 6:28 pm  #17


Re: XJ40 IRS into an Aussie falcon

so are you compensating and mounting it in the center of the wheel well at ride height???  that way it will move forward as the suspension extends and back as the suspension compresses???


If it isn't broken..... modify it anyway!!!!
 

6/17/2011 9:18 pm  #18


Re: XJ40 IRS into an Aussie falcon

yeah, I have the wheel centred exactly where the original axle was at ride height. Interestingly this morning i did the plumb bob thing on the spare falcon and discovered a similar amount of rearward movement with the factory 4 link system, so it set my mind at ease

Last edited by KLR250 (6/17/2011 9:19 pm)

     Thread Starter
 

6/18/2011 7:33 pm  #19


Re: XJ40 IRS into an Aussie falcon

well, after a few hours of drilling cutting, getting covered in grinding sparks I have the watts link crap removed, what a nasty job that was









and heres whats left....good riddance to it



put the IRS back in to check how the rear mounting struts will sit





the drivers side rail opens up to the spare wheel tub, so it looks like ill need to shorten that rod 2". I think ill shorten both rods, as i want them to looks the same. Ill make the rods adjustable,
this way i can adjust my pinion angle easily



Out of interest, this pic shows just how well things line up. I used an old watts link rod to see how the lower spring mount on the jag IRS lines up with the spring tower





In this pic you will see where ive marked out this peice in the middle, its close to touching the diff, so it needs a minor trim and a bit of sheet will be welded in





and a few random pics for good measure









Last edited by KLR250 (6/18/2011 7:34 pm)

     Thread Starter
 

7/08/2011 4:10 pm  #20


Re: XJ40 IRS into an Aussie falcon

not much posting lately, been busy though! hopefully have some worth while updates next week

picked up wheel adapters from the machine shop today

been itching to get home from work to bolt the wheels up, Tucked 265's! wheels still turned with no bind at this height. Very strange to see camber on the rear of a falcon lol









     Thread Starter
 

7/21/2011 6:44 pm  #21


Re: XJ40 IRS into an Aussie falcon

looks like it is coming together.  have you made any more progress on the install??


If it isn't broken..... modify it anyway!!!!
 

8/05/2011 1:47 am  #22


Re: XJ40 IRS into an Aussie falcon

Not a lot of progress, have been to busy at work of late. Ill update the thread asap

     Thread Starter
 

8/26/2011 9:30 pm  #23


Re: XJ40 IRS into an Aussie falcon

Ive been really slack lately, like really really slack!

anyways, made my adjustable mounting rods for the rear supports omn the jag IRS. Ive ditched the factory jag rods and made some new ones utilising some XF watts link rods. I needed the rods to be shorter than the jag ones, just because of the differnt shape of the floor and how far up inside the car i have the IRS assembly. Cutting down watts link rods made a bit of sence, there thicker walled, bigger in diameter, buysh's are available in nolathane, and there free. First i cut the rods down and tapped a 14 x 1.5mm thread into them, I wanted the thread resonably fine for better adjustment, and 14 x 1.5mm was as fine as i had. Inital plan was to buy some grade 8 all thread, but it doesnt seem to exist, so i bought some long grade 8 bolts, cut the heads of and got the threads cut on the lathe, so now ill be able to easily adjust pinion angle on the diff, which makes it easy to fine tune and match the pinion angle to the transmission.






Here you can see the jag tube diamter vs the XF watts link



all done, Jag vs New rod




and this is how i plan to set them up, the RHS is just some old "I used a word I shouldn't have" i had lying around, but this is the size ill use, it will tuck up a bit higher and have the required bracketry welded on to secure the rods.









The twin exhausts will pass in between the rods and diff centre

hmmmmm camber



Currently im working on the spare lower control arms I have, Im actually shifting the hub mounting brackets forward, as im not happy with the wheel position, and i dont want to shift the whole assembly forward. as it stands i have room for the exhausts to pass over and id rather not hack the floor for room, so rather than shift the entire assembly forward im just shifting the hubs forward on the lower arms. This involves cutting of the brackets, jigging them up so the brackets sit where i want and re-welding them....not to hard, and really, if you had to do this conversion most people would move the IRS assembly forward, but i like I said, i like the room for the exhausts.

anyways, ill get some pics of that later

     Thread Starter
 

8/27/2011 8:14 am  #24


Re: XJ40 IRS into an Aussie falcon

well you make the phrase "Ive been really slack lately, like really really slack!" look like you got a lot done.  I think its all the pictures.  That is one of my favorite parts of your post there so visual that a person can really see what you are working on.  It may not seam like a lot of work but we all know that those "little" jobs take a lot of time so the more of those you can nock out the better can't weight to see more, thanks for posting.


If it isn't broken..... modify it anyway!!!!
 

8/30/2011 2:07 am  #25


Re: XJ40 IRS into an Aussie falcon

Daze wrote:

well you make the phrase "Ive been really slack lately, like really really slack!" look like you got a lot done.  I think its all the pictures.  That is one of my favorite parts of your post there so visual that a person can really see what you are working on.  It may not seam like a lot of work but we all know that those "little" jobs take a lot of time so the more of those you can nock out the better can't weight to see more, thanks for posting.

Thankyou Daze, good when someone else appreciates the effort involved, its all these little niggly jobs that take so long! Im a pretty simple person, not good at working things out on paper, I kind of have to put things together and rework where neccasary lol

     Thread Starter
 

8/30/2011 8:20 am  #26


Re: XJ40 IRS into an Aussie falcon

KLR250 wrote:

Im a pretty simple person, not good at working things out on paper, I kind of have to put things together and rework where neccasary lol

They are both excellent approaches.  There is something to be said for having a plan on paper first so you have an idea where you are going BUT in most cases the best laid plans still fall short and you have to rework on the fly. 


If it isn't broken..... modify it anyway!!!!
 

8/30/2011 8:40 am  #27


Re: XJ40 IRS into an Aussie falcon

Enough about your life Day!

Daze wrote:

KLR250 wrote:

Im a pretty simple person, not good at working things out on paper, I kind of have to put things together and rework where neccasary lol

They are both excellent approaches.  There is something to be said for having a plan on paper first so you have an idea where you are going BUT in most cases the best laid plans still fall short and you have to rework on the fly. 

Last edited by Ralphy (8/30/2011 8:40 am)

 

8/30/2011 3:09 pm  #28


Re: XJ40 IRS into an Aussie falcon

very funny!


If it isn't broken..... modify it anyway!!!!
 

10/21/2011 11:55 am  #29


Re: XJ40 IRS into an Aussie falcon

hey KLR250 how is the project going we have not gotten an update in a few months


If it isn't broken..... modify it anyway!!!!
 

11/12/2011 2:46 pm  #30


Re: XJ40 IRS into an Aussie falcon

So, there I am in the same boat as KLR250!!

All attempt to locate a first gen. Jaguar  IRS for a friends '68 Mustang failed! The only Jaguar IRS that could be located is a second gen. assembly (according a telephone call with the owner and his description). Never paid attention to these units but looks like they will work too.

How are these differentials called and what kind of locking carrier works for them? What kind of spring/shock are you going to use? How wide are these and can they be shortened or did you shorten them? These are the questions in my mind and am not able to find these on the www.

I have no way to see that part before purchase and still looking for someone who could take some pics and send them to me but would be great if KLR250 would chime in and give some info on the 2.gen. Jaguar IRS.

Thanks in advance!

Mustsed


Nothing is impossible, some just cost more!
 

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