on September 22, 2010, 7:37 am, vernlee wrote:

Hello, After seeing you guys tackle this project I have decided to go for it, I bought a T-bird IRS and I'm going to attempt to put it in my 66 mustang coupe,I think I can figure most of it out except, ride height,when the car is setting are the axels level or at an angle ? how will I know how much the car will settle with the full weight on it ? I'm aiming for factory ride height,right now I'm in the process of narrowing the unit to get my width,I'll keep updating, and asking plenty of questions
Vern

on September 22, 2010, 9:09 am, Daze wrote:

Welcome to the forum!!!! Nice to see another IRS unit other than JAG

yes we have a few other non jag guys here but are heavily Jag and I want this board to grow in diversity. Here is a couple of things to think of when first figuring ride height. first of all most car suspensions want the LCA to be parallel or near parallel with the road, so I would be willing to be that the T-bird is the same and that when it is sitting where Ford wanted it the LCA was parallel to the road. With that said the second thing to consider is the position of your live axle differential. If you take measurements and position the 8.8 differential in approximately the same location under the car that the original diff occupied than your ride height should in theory be the same as original and your LCAs should be parallel to the road. The only issue you may run in to is spring rate differences due to weight differences, but that can be modified many ways like changing springs, moving the upper mounting location and so on.

Once you have a general idea of where it needs to be, there is no substitute for mocking it up under the car. yes it is a lot more work however it shows you so much that it is well worth the effort.

So how are you narrowing the t-bird unit?? also I recommend getting an idea of the T-bird's original camber curve, either by measuring it or having some one put your suspension dimensions in a computer that way you can see how narrowing it will effect camber. IF it has a drastic effect on camber you may want to take off a little more or a little less from either the upper or lower control arms to get a better camber curve.

Once again welcome the forum!!! we would love to see some pictures of your project.

on September 22, 2010, 9:25 am, vernlee wrote:

Thanks for the info,I'm planing on useing coil over shocks which will allow me some up and down adjustment,My car is on a rotisserie right now so I can hang the IRS unit upside down from a cherry picker and position it.I plan on making new upper and lower control arms out of some 11/8" D.O.M. tubing I have on hand.As far as camber, I'll need to get some help.I figure I have to take 2.125'' from each side to get the correct width.
Vern

on September 22, 2010, 9:40 am, Daze wrote:

If you haven't taken any thing apart you should be able to...

get the camber measurements from the assembly. All you have to do is level up the assembly, move the suspension so that the LCAs are parallel with the ground and then use an angle finder to get the angle of the face of the hub. should be around 90º meaning 0º of caster. then take the suspension through it full range of motion starting with fully extended and get angle measurements at the face of the hub with every .25" of vertical hub travel until you have gotten the suspension to fully compressed. This data can be graphed and will give us an idea as to what type of camber curve the suspension has. With that info you can make a better decision as to exactly how the unit should be narrowed.

I am not as familiar with the t-bird units do you know how camber is adjusted on them when the car is aligned???

on September 22, 2010, 10:06 am, vernlee wrote:

No I have no idea how its adjusted, But you can bet before I'm thru, I'll know everything there is to know about it-whether I want to or not !

Vern

on September 22, 2010, 10:40 am, Daze wrote:

I will see what I can find let us know how the camber measurements...

come out

on September 22, 2010, 11:14 am, vernlee wrote:

After looking this unit over I don't see any adjustment for camber what so ever,could this be possible ? If I knew how to send pictures I would

Vern

on September 22, 2010, 11:31 am, Daze wrote:

there is instructions for posting pix...

if you click the forum info link at the top of the page. if you can not get that to work, click the envelope next to my user name and email the pix to me and I will post them.

on September 22, 2010, 11:05 am, Daze wrote:

I did a net search and couldn't find any thing then...

I went to the best source on line I remembered that a member here had posted some pictures of a Mark 8 IRS (basically the same as yours)

http://members.boardhost.com/IRS/msg/1272663882.html

I looked through the pictures and found the camber adjustment which I highlited in the picture below I would assume there are 4 of them total, 2 per side, each side having one toward the front of the car and one toward the rear.


If you are making all new arms you can use heim joints at the pivots and increase your adjustability. It's still a good idea to get the camber curve measurements first.

on September 22, 2010, 11:21 am, vernlee wrote:

Yep, your right, Now that I know where to look sure enough there it is,I guess a picture is worth a thousand words.

Vern

on September 22, 2010, 11:32 am, Daze wrote:

are there 4 of them, one front and rear per side, or only two...

one per side???

on on September 22, 2010, 12:17 pm, vernlee wrote:

on October 1, 2010, 11:42 am, Vernlee wrote:

Well I have been so busy I haven't had time to work on my project but, I did find out there is adjustment on both upper and lower c/a at all pivot points. Also I have a open diff. that will not do. Thought I would buy a trac lok 8.8 cheap and be o.k. not so, the IRS unit is different then a standard 8.8 I'm starting to see a hugh money pit here,But I won't give up, I'll see it thru. I will post again when I have maid more progress,
Vern

on October 1, 2010, 5:37 pm, Daze wrote:

Thanks for the update!!
I want to learn all I can about that IRS unit, can you start a new thread and post some pictures of the upper adjustments.