2005-2009 Mustang GT. Independent Rear Suspension?
09-30-2009, 01:24 PM
#31
3rd Gear Member
Join Date: Sep 2006
Location: PA
Posts: 750
Why did you take your car in for an alignment to begin with? Was something wrong with it? This thread is confusing as anything because most of what you're saying really doesn't make sense or you're using the wrong terminology.
The solid rear axle is fixed and therefore will never need any type of alignment. The front is where an alignment is done. They'll check toe, camber, caster and adjust what is needed to align the front end. However, unless you did some suspension work, or messed something up in the front end, I can't see why you would have needed a "realignment" to begin with.
The solid rear axle is fixed and therefore will never need any type of alignment. The front is where an alignment is done. They'll check toe, camber, caster and adjust what is needed to align the front end. However, unless you did some suspension work, or messed something up in the front end, I can't see why you would have needed a "realignment" to begin with.
10-01-2009, 02:05 PM
#32
The Paranoid One
Thread Starter
Join Date: Apr 2006
Location: Texas
Posts: 5,320
Why did you take your car in for an alignment to begin with? Was something wrong with it? This thread is confusing as anything because most of what you're saying really doesn't make sense or you're using the wrong terminology.
The solid rear axle is fixed and therefore will never need any type of alignment. The front is where an alignment is done. They'll check toe, camber, caster and adjust what is needed to align the front end. However, unless you did some suspension work, or messed something up in the front end, I can't see why you would have needed a "realignment" to begin with.
The solid rear axle is fixed and therefore will never need any type of alignment. The front is where an alignment is done. They'll check toe, camber, caster and adjust what is needed to align the front end. However, unless you did some suspension work, or messed something up in the front end, I can't see why you would have needed a "realignment" to begin with.
Actually I took it in to have a front wheel replaced.
The shop guy showed me how the tire was worn unevenly with more wear on the inside and and along with that he showed me that if you looked at the front tires they were actually angled in compared to the back ones which where straight up and down.
He asked me if I wanted to have the alignment checked.
I said sure and turns out the alignment was off.
No wrecks in the car ... nothing.
One time I did have a wheel replaced because of my girl hitting the curb with it. Not sure if that, bigger wheels, tires, and time all did it or what.
I understand the solid rear axle is fixed. But what happened is that when they originally put my car in the computer they put FORD GT instead of Ford Mustang GT, therefore IRS came up.
After looking under the car and seeing it was solid rear they used the specs to align it with Mustang Coupe entered in the computer because they said they could not find a Mustang GT in the computer..... therefore I wanted to make sure the specs for the GT and the V6 were the same so that I would have the right alignment specs.
I am wondering now if like 157db said.. .it was a waste of money.
The car feels exactly the same and the front wheels look the same to me.
I wonder if the reason the car came up as being off on the alignment was in fact because they had entered it in as a FORD GT when they had it up at first
Last edited by Blacksmoke; 10-01-2009 at 02:07 PM.
10-01-2009, 02:28 PM
#33
Gentleman's Relish
Join Date: Feb 2005
Location: AZ
Posts: 13,090
If you hit a curb hard enough or hit a big enough pot hole it WILL require an alignment. The wheel acts as a lever and can take out both your camber and caster adjustments on that side of the car if the right amount of force is applied. Bigger wheels (like 20's and other G-dog size rims) provide leverage to knock things out of alignment and put more stress on your hubs and other steering components.
Older cars had all this stuff adjustable from the factory which made an alignment every year necessary because nuts and bolts will shift over time. Newer cars including the mustang have everything machined into to place meaning they set it at the factory and weld everything or tack everything into place so movement is not possible. There still leave some adjustment for age or wear but sometimes it's not enough.
You'll find camber/caster strut mounting plates for the 94-04 mustangs for just that reason. As a car ages the metal will fatigue in certain areas and affect your adjustments. If you have a car that is essentially machined to spec then you need to add the plates that allow the movement you need.
Those caster/camber plates can also be used in situations where you need to make greater adjustments to the alignment to get it back into spec like with extreme lowering. There are other parts out there that can hep (bump-steer kits) but that's just one type.
Older cars had all this stuff adjustable from the factory which made an alignment every year necessary because nuts and bolts will shift over time. Newer cars including the mustang have everything machined into to place meaning they set it at the factory and weld everything or tack everything into place so movement is not possible. There still leave some adjustment for age or wear but sometimes it's not enough.
You'll find camber/caster strut mounting plates for the 94-04 mustangs for just that reason. As a car ages the metal will fatigue in certain areas and affect your adjustments. If you have a car that is essentially machined to spec then you need to add the plates that allow the movement you need.
Those caster/camber plates can also be used in situations where you need to make greater adjustments to the alignment to get it back into spec like with extreme lowering. There are other parts out there that can hep (bump-steer kits) but that's just one type.
10-02-2009, 02:12 PM
#34
4th Gear Member
Join Date: Mar 2005
Location: California
Posts: 1,471
Let's look at just these two items that *nominally* favor IRS.
The first is true once the pavement has deteriorated beyond some point, but it's not necessarily the case otherwise. The point is that a well done stick axle is more predictable to drive than an indifferently done (read: done to a relatively inexpensive price point) IRS. A suspension that the driver has more confidence in is one that he will be more comfortable driving hard. It's worse than pointless to make a big deal over any theoretical performance advantages of IRS in general if the specific IRS in question discourages you from driving it very hard. At that point, it simply rides better. I hate to trot out "magazine tech", but the various handling comparisons are not favoring the IRS-equipped ponycars at this point.
You aren't going to get a 5% shift in weight distribution by swapping out the 8.8 axle for IRS. Even if the IRS and all of its additional structure weighs 200 lb more than the live axle and it all sits right over the rear wheels, that only buys you about a 3% change (to 52/48, using 55/45 as a starting point). Of course, now your 3500 lb car weighs 3700 lb with a relatively higher polar moment of inertia . . . and don't forget that you're still working with the same motor and wheel/tire sizes.
It's not that I'm specifically against IRS (I'm not, and I'd like to see Chip's project turn out well). But unless IRS is going to really provide better performance AND be neither clumsier (think "2010 Camaro/Challenger" here) nor trickier to drive up toward those limits (a little rear end "twitch" due to rear wheel compliance toe at only 0.7 lateral g will definitely get your attention, and not in a good way), it isn't buying you any headway.
Norm
The first is true once the pavement has deteriorated beyond some point, but it's not necessarily the case otherwise. The point is that a well done stick axle is more predictable to drive than an indifferently done (read: done to a relatively inexpensive price point) IRS. A suspension that the driver has more confidence in is one that he will be more comfortable driving hard. It's worse than pointless to make a big deal over any theoretical performance advantages of IRS in general if the specific IRS in question discourages you from driving it very hard. At that point, it simply rides better. I hate to trot out "magazine tech", but the various handling comparisons are not favoring the IRS-equipped ponycars at this point.
You aren't going to get a 5% shift in weight distribution by swapping out the 8.8 axle for IRS. Even if the IRS and all of its additional structure weighs 200 lb more than the live axle and it all sits right over the rear wheels, that only buys you about a 3% change (to 52/48, using 55/45 as a starting point). Of course, now your 3500 lb car weighs 3700 lb with a relatively higher polar moment of inertia . . . and don't forget that you're still working with the same motor and wheel/tire sizes.
It's not that I'm specifically against IRS (I'm not, and I'd like to see Chip's project turn out well). But unless IRS is going to really provide better performance AND be neither clumsier (think "2010 Camaro/Challenger" here) nor trickier to drive up toward those limits (a little rear end "twitch" due to rear wheel compliance toe at only 0.7 lateral g will definitely get your attention, and not in a good way), it isn't buying you any headway.
Norm
It's not my car I'm pretty happy with my car as it sits (once I work out a few more details). LOL! This is a friend's HLG '08 Bullit, he has the IRS and a shop with the fab skills to pull it off and I'm just along to see it actually works once it's in.
I can't say I've been discouraging him to do it but if it's going to happen I'd like to help them build it right and maximize the potential for handling and ride improvement if they are there to be found in this setup. But not being an optimized IRS I can't see it making a big improvement in the handling department. I've driven 03/04 Cobras and have never been a big fan even with the improved bushings and adjustable bits installed and tweaked. Of course it could have been the rest of the suspension in that 700+rwhp car I was playing with causing the problems I had with the handling but it had some significant upgrades installed.
Cheers/Chip
10-04-2009, 02:54 PM
#37
S197 Section Modder-ator
Join Date: Sep 2007
Location: Orlando FL
Posts: 13,373
Not the first time there is confusion between the Mustang GT and the Ford GT.
In any case though, I'd run away from that shop for sure.
10-07-2009, 10:15 AM
#38
Not to bump this thread, but in digging around on the net to find out what the stock components are for a S197 Gt - I found this, and while I'd already figured out most of this by way of inference and context, and having read-outs of my own car explained to me by a friend, this was still helpful for visualization purposes:
http://www.americanmuscle.com/suspen...ide-part1.html
http://www.americanmuscle.com/suspen...ide-part1.html
10-09-2009, 10:54 PM
#40
Multi-Tasking Moderator!
Join Date: Nov 2006
Location: Detroit Rock City!
Posts: 15,618
Called someone to verify solid rear axle.
How bout crawling underneith and looking.
Its not rocket science.
Whats this 'alignment kit'?
I call BS on that one.
Hope they dont'charge you' for the 'kit'. Thats a new one.
Gotta love the double posts...
How bout crawling underneith and looking.
Its not rocket science.
Whats this 'alignment kit'?
I call BS on that one.
Hope they dont'charge you' for the 'kit'. Thats a new one.
Gotta love the double posts...
