Fox T-Bird/Cougar Forums

Technical => Suspension/Steering => Topic started by: booksix on August 21, 2006, 04:07:57 PM

Title: 88 TC, 13" brakes: 89 mustang a-arms?
Post by: booksix on August 21, 2006, 04:07:57 PM
I have an 88 TC that i put 13" cobra brakes on a few months ago...  The cobra brakes widened my front track by about 1" per side.  Can I swap in the shorter 87-93 mustang a-arms to make up for this?  My main concern is changing the geometry of the strut cause it is already only about 1/2" from my tire (17x9 R's).  Also, would this cause any alignment issues?

Just for additional info, my other option was having my wheels machined on the back to bring them in which I'm willing to do...  Would this be better?
Title: 88 TC, 13" brakes: 89 mustang a-arms?
Post by: Beau on August 21, 2006, 06:09:44 PM
I can tell you that using the Stang A-arms will cause you to have a camber problem.
Basically, on the 87-88 Bird/Cougars, we have an SN95 Mustang front suspension.
The 86-88 Tbird/Coug k member is narrower than the Mustang, but has longer A-arms to keep a similar track width.
There's more info to this in the k-member section in here, pretty good read.
As far as changing strut geometry, someone else will have to chime in...i'm still learning about that :flame:
Title: 88 TC, 13" brakes: 89 mustang a-arms?
Post by: Tbird232ci on August 21, 2006, 09:46:04 PM
What year spindles did you use up front?
Title: 88 TC, 13" brakes: 89 mustang a-arms?
Post by: booksix on August 21, 2006, 10:52:42 PM
94
Title: 88 TC, 13" brakes: 89 mustang a-arms?
Post by: booksix on December 21, 2006, 03:40:48 PM
Resurecting this one...  Still looking for a solution (short of maching my wheels to change the offset)...
Title: 88 TC, 13" brakes: 89 mustang a-arms?
Post by: JeremyB on December 21, 2006, 04:19:21 PM
Someone correct me if I'm wrong, but...

Changing the LCA shouldn't change the interface between the strut and the tire. It will change the tire's location in the wheel-well though.
Shaving off metal from the inside of the wheel will change the strut-tire interface. If you have 1/2" of space, and shave off 1/2"...you now have no space and interference issues.

Going to the shorter LCA will increase camber (obviously), but a set of CC plates should be able to correct that deficiency.
Title: 88 TC, 13" brakes: 89 mustang a-arms?
Post by: Chuck W on December 21, 2006, 05:15:02 PM
The shorter arms aren't going to change the strut-to-tire distance...that's fixed.  There is no geometry to change there.

You can swap the arms and that will narrow the track.  You may or may not need CC plates to be able to get the camber back in spec.  It depends.  Lowering the car will increase the negative camber, but shortening the arms will increase positive camber....so who knows, you may have enough adjustment with the stock upper strut mounts.
Title: 88 TC, 13" brakes: 89 mustang a-arms?
Post by: 1BadBird on December 22, 2006, 10:20:38 AM
If the stang x-member is narrower than our birds x-member, then why do Griggs, Maximum Motorsports, AKE and a few others sell the same x-member for either car???
Title: 88 TC, 13" brakes: 89 mustang a-arms?
Post by: Chuck W on December 22, 2006, 10:42:16 AM
Quote from: 1BadBird;119678
If the stang x-member is narrower than our birds x-member, then why do Griggs, Maximum Motorsports, AKE and a few others sell the same x-member for either car???


The Mustang K-member isn't narrower...the arms are shorter (Fox).  The SN-95 are the same length.

Anyway, why do they sell the same one?  Because they don't want to mess with new jigs and fixtures and engineering costs for something like that.  The Mustang stuff can be made to work....
Title: 88 TC, 13" brakes: 89 mustang a-arms?
Post by: 1BadBird on December 25, 2006, 06:17:49 PM
When I installed the 90' Lincoln LSC spindles and rotors on my car. I had to use sn-95 arms to make it work as the stock T-bird arms were too short. I installed c/c plates to help, they didn't, not with stock arms anyway.
So, going by what you're saying, I shouldn't have had to use the sn-95 arms when I changed those parts and that the stock t-bird arms should've worked. The camber was soo bad, it looked like the back of a VW bug that was jacked up.

Ford Truck Freeek said;
Quote
I can tell you that using the Stang A-arms will cause you to have a camber problem.
Basically, on the 87-88 Bird/Cougars, we have an SN95 Mustang front suspension.


Yes, after I had installed the 90' Lincoln spindles/rotors with the stock arms, I went back and got the lincoln arms, removed everything and compared them, I then saw a 11/2" difference with the stock arms being shorter. I then bought the 94' (sn-95) tubular control arms. They worked. That moved the bottom of the spindles out to correct the awful camber. It just seems that there are 2 different things being said here. The quote above and the 2 below.

Ford Truck Freeek also said;
Quote
"The 86-88 Tbird/Coug k member is narrower than the Mustang, but has longer A-arms to keep a similar track width."


and Chuck W, you said
Quote
The Mustang K-member isn't narrower...the arms are shorter (Fox). The SN-95 are the same length.


I don't mean to stir things up, but things just don't add up. I am planning on upgrading my front brakes also with 13" rotors/97' spindles.
Title: 88 TC, 13" brakes: 89 mustang a-arms?
Post by: Chuck W on December 25, 2006, 06:39:58 PM
No one is talking Lincoln stuff here....just you.

Yes the Lincoln (and SVO) front control arms are longer than the FOX Mustang arms and the 80-86 Tbird ones as well as the 87-88Tbird and 94+ Mustang arms.

The 87-88 Tbird arms are the same length as the SN-95 (94-98) Mustangs.

The front track on the 83-88 Tbirds is the same. 

On the 87-88 Tbirds (not 86), the control arm mounting points are moved inboard to compensate (I have an 87-88 Kmember I can measure the mounting points on), thus keeping the 58.1"-ish front track.  The '94+ Mustangs have a 60" front track.  We know that some of the increase comes from the spindles, but since it is a given fact that the front arms are the same as the 87-88TBird...where do you think the extra width comes from?

In his case, using the shorter Fox Mustang arms will help with what he needs (and it has been done by others).

I've used the Lincoln/SVO spindles w/o issue myself...with the stock short 83-86 Tbird arms.

When you swap to the SN-95 brakes, you will probably find that the SN-95 arms you have on there now will be too long.  Especially with the 96-04 spindles
Title: 88 TC, 13" brakes: 89 mustang a-arms?
Post by: 1BadBird on December 25, 2006, 07:46:14 PM
Thanks Chuck for clarifying that :)
I had heard that certain mounting points had been moved inboard but I wasn't sure if I was told correctly.
When I change my brakes, I had thought about also changing the k-member. Any recommendations??

Thanks again Chuck
John


P.S. By the way, I like those NACA ducs you put in your car. Are they functional??
Title: 88 TC, 13" brakes: 89 mustang a-arms?
Post by: Chuck W on December 25, 2006, 08:18:44 PM
Recommendations as to what brand K-member?  Personally I would lean towards MM if I was buying one.

The reason I mention swapping arms back is that if you look at my '83.  With the stock arms, 95 spindles, Cobra wheels with 245/45's...I am right at the fender.  Your 97 spindles will push things out just a touch more.

The ducts are meant to be functional at some point in the future.  For what I haven't decided.  I was originally going to put and IRS in it and use them for diff cooler, etc...but that plan has washed up at the moment.  I may use them for brake cooling ducts, who knows.  Right now they are just something different.
Title: 88 TC, 13" brakes: 89 mustang a-arms?
Post by: booksix on December 26, 2006, 03:03:43 PM
Ok, one more thing I should clear up now that I've realized my error...  The 1/2" clearance I had was BEFORE the 13" brakes and 94 spindles.  So there is probably more now...

But anyway, I'm still kind of confused.  I've been also looking into 83-86 t-bird arms.  How do they compare to the fox arms?
Title: 88 TC, 13" brakes: 89 mustang a-arms?
Post by: Chuck W on December 26, 2006, 03:13:54 PM
Quote from: booksix;120126


But anyway, I'm still kind of confused.  I've been also looking into 83-86 t-bird arms.  How do they compare to the fox arms?


You're not confused...you're just not reading.......

The 83-86 Tbird are are the SAME as the Fox Mustang arms.....
Title: 88 TC, 13" brakes: 89 mustang a-arms?
Post by: booksix on December 26, 2006, 03:59:53 PM
Yeah, I did actually miss part of the thread before posting, my bad.  I guess I'm going to try and get my hands on some fox a-arms and probably some MM CC Plates to adjust camber problems
Title: 88 TC, 13" brakes: 89 mustang a-arms?
Post by: cougarman on December 27, 2006, 12:45:41 PM
heres a shot of a 87 with stang arms and a qa1 k-member with camber plates
Title: 88 TC, 13" brakes: 89 mustang a-arms?
Post by: booksix on December 31, 2006, 01:18:03 AM
Thanks cougarman!  So that bird has sn spindles up front, right?  Would you mind shooting a shot of your bay with the cc plates?  Did you have to put them in negative orientation?

EDIT:
Just noticed by your wording it may not be your ride...  but if so more info would be cool!
Title: 88 TC, 13" brakes: 89 mustang a-arms?
Post by: Ether947 on December 31, 2006, 10:02:01 AM
it's his car... he doesn't have it anymore.

The wheels are 18x9s, he has Cobra brakes all around and I'm not sure on the plates. But you can play with that yourself.