Making the Mustang daily driverable after modifying

[Hawaii50]

You'll have to run a level up against the tire and measure between that and the fender with a small scale. If both tires are outside the fenders, you've got a wheel offset or possibly a width issue that needs to be fixed in addition to the axle centering.

If only one tire is outside and the other tire is inside, add the inside amount to the outside amount and divide that by two. Ex., left tire 1" inside with right tire 1/2" outside means the axle needs to move 3/4" to the left (lengthen the PHB by that amount and recheck).


Norm

I attempted to adjust my panhard bar but it's seized. I got a good deal on a steeda Watts link kit and lightweight radiator support.

I'm guessing I can choose one of these options next.

1. Reinstall panhard bar for now. Buy Ford p springs to replace the eibach pro springs. Maybe the springs have gone soft or are too soft from production.

2. Replace all wheels with 19s and 285 35 19. This is the most expensive option.

3. Wait for the watts link to arrive and install that.

4. Buy Ford p springs and install, install watts link, install steeda bumpsteer kit I have on the shelf and take car for an alignment at one time.

The rear tires are rubbing on the fenders on big bumps, they are the American racing supersnakes wheels so obviously designed for the mustang but with the backspacing I believe no bigger than 285 were supposed to go on them.

The bumpsteer kit is spherical ends, I do not want more nvh and the car is not tracked so should I avoid installing the bumpsteer kit completely?

I need to get to the bottom of this soon as it's ruining the ownership experience. My daily driver is a 200,000 mile Cruze Eco which I've owned since new on factory suspension, the ride is sublime in comparison. I need to get back to what it was or just start new with another performance car. Obviously I have so much money and time invested in my Mustang I don't want to do it again.

 

[Coz]

STOP!!!!!!!! Slow Down!

You haven't figured out the source of your NVH and now you're talking Watts Link, new springs, bumpsteer, radiator support and who knows what else your contemplating.

If you have no intent to track the car what do you intend to gain with the Watts Link? Even if you got the Watts Link for 1/2 price you're talking $500-600 to essentially replace a $125 panhard bar. And if you want to lighten your car with a lightweight radiator support, you're more than offsetting that with the added weight of the Watts link.

I'm sure if you soak the panhard bar turnbuckle with PB Blaster it will free up. If its really stubborn remove the bar and find a friend and a cheater bar or a long pipe wrench to help you get more leverage on the locking nuts or turnbuckle.

You were advised to check your rear sway bar links? Did you do that? In fact, totally remove the sway bar. It's fine to drive around without one for a few days. If your NVH goes away, then replace it with a stock sway bar and rubber bushings (I don't know the diameter of the Steeda Bar - perhaps stock clamps and bushings will fit - there are 3-4 different OEM diameters on S197s)

Your UCA has a poly bushing on the chassis end. I have not seen you attempt to investigate that any further. If you still have your stock UCA, swap it and see if the NVH goes away.

And your X-Brace - You say that squeaks. Take it off and see if it makes any difference.

Do this BEFORE you starts swapping springs (although the rear ones are easy), adding a Watts Link, bumpsteer, etc.

 

[ChrisM]

I'll probably get a time out or something for this. I can understand asking stuff here because there's a lot of really knowledgeable people on this forum who can help, but it seems like you're determined to ignore them. There's a lot of people patiently trying to help you with something that is decidedly not the point of the forum.

Not trying to be an @#$, but it seems rude that someone would join a forum dedicated specifically to making a Mustang faster on the track, ask questions counter to that purpose, ignore the advice that is given to you, then compare a Mustang to a Chevy Cruze for comfort when a track pack Mustang is not built to be a comfortable street car.

Prior to the S550 I don't think most people even put "comfort" and "Mustang" in the same sentence.

 

[Hawaii50]

NVH- there is no current NVH. There was a rear end diff whine that was corrected by removing whiteline lca and relocation brackets. It now has track Pack OEM LCA and che relocation brackets.

Bumps-on bumps the tires are rubbing on the fender. I suspect the wheels were not designed to have 305's on them with that backspacing. Originally I had 285/30, no rubbing.

Watts link-My goal was to get a smoother ride and not have the car wobble Everytime it hits a bump mid turn. I'm aware of the weight gain of the watts link offsetting the lightweight radiator support, also bear in mind the deletion of the panhard bar and panhard support bar. I will hold off from installing the watts link.

I'm taking the panhard bar tomorrow to a vice and try to break it free. it is not seized due to rust but red high strength thread lock.

Once panhard bar is fixed I will center the axle. I have not checked the away bar links yet. Once I drive the car with corrected centered axle I will then inspect endlinks and remove the away bar completely.

There isn't NVH that is the problem. It's is a stiff ride on big bumps and on small bumps a constant up and down motion.

Bump stops still are the matching eibachs.

Yes I have not touched the UCA. I no longer have the OEM uca. While I like the roush uca with rubber bushings it's non adjustable. Since my lca are non adjustable and the car is lowered, my understanding is either the UCA or lca has to be adjustable.


x-brace did creak while driving, I tightened the bolts and it no longer makes that noise. The creak that is still present occurs when I drove up a steep curb to get in my driveway.


I'll get to fixing the panhard bar first.

 

[Coz]

The harshness on rough roads feels like it is front and rear.

It's is a stiff ride on big bumps and on small bumps a constant up and down motion.

That's what the "H" in NVH is about. Harshness...

 

[Norm Peterson]

The rear tires are rubbing on the fenders on big bumps, they are the American racing supersnakes wheels so obviously designed for the mustang but with the backspacing I believe no bigger than 285 were supposed to go on them.

If both tires are rubbing, centering the axle will not fix it, no matter what you try or what you use. Tire width, tire diameter, wheel width, wheel offset, and the amount lowered are all involved. I don't know what the offset spec on those rear wheels is but it's obviously wrong for that much tire (I'm guessing the problem is mainly a too-small amount of positive offset, with American Racing most likely catering to the "gotta-be-flush" appearance-centric crowd rather than those interested in a more serious performance setup).

Those 305/35-20's have cost you nearly 3/4" of vertical clearance to the fenders compared to the 255/40-19 stock tire size. That's separate from the tread being a couple inches wider than stock.


Norm

 

[TMSBOSS]

Sounds like your best option is the discuss tires, wheels and clearance with the folks at Apex. I am able to tuck 305 DH slicks in the back and front on their wheels.

 

[Hawaii50]

If both tires are rubbing, centering the axle will not fix it, no matter what you try or what you use. Tire width, tire diameter, wheel width, wheel offset, and the amount lowered are all involved. I don't know what the offset spec on those rear wheels is but it's obviously wrong for that much tire (I'm guessing the problem is mainly a too-small amount of positive offset, with American Racing most likely catering to the "gotta-be-flush" appearance-centric crowd rather than those interested in a more serious performance setup).

Those 305/35-20's have cost you nearly 3/4" of vertical clearance to the fenders compared to the 255/40-19 stock tire size. That's separate from the tread being a couple inches wider than stock.


Norm

I agree it's likely both tires will provide but I need to at least reset it to get a starting point. When I measured it was about 6/16 of an inch sticking out.

I fully agree about the offset too.

Sounds like your best option is the discuss tires, wheels and clearance with the folks at Apex. I am able to tuck 305 DH slicks in the back and front on their wheels.

Apex's postage cost to Hawaii is a lot. That is what has kept me back from purchasing a set.

I managed to break free the panhard bar and clean up the threads. I was wrong about thread lock, it was just seized on their good. Tonight I will install it and center the axle. Currently it's under it's own load as the jackstands are on the axle tubes. Once the panhard bar is adjusted and the car is lowered onto the ground it should not shift the axle any more right?

 

[Hawaii50]

If both tires are rubbing, centering the axle will not fix it, no matter what you try or what you use. Tire width, tire diameter, wheel width, wheel offset, and the amount lowered are all involved. I don't know what the offset spec on those rear wheels is but it's obviously wrong for that much tire (I'm guessing the problem is mainly a too-small amount of positive offset, with American Racing most likely catering to the "gotta-be-flush" appearance-centric crowd rather than those interested in a more serious performance setup).

Those 305/35-20's have cost you nearly 3/4" of vertical clearance to the fenders compared to the 255/40-19 stock tire size. That's separate from the tread being a couple inches wider than stock.


Norm

Another possible option for the back is I have a paid of 275/40/20. While narrower than the 305s, I'm concerned the 40 firewall may be too tall.

 

[Norm Peterson]

On 10" wide rims, the biggest differences between a 275/40 and a 305/35 are probably going to be in the tread width and in how 'squared off' the shoulders are. A 305/35 "pinches down" to about 295 at the max sidewall, and a 275/40 stretches out to about 280. There's only about 1/4" difference in the overall tire diameters - less than 1/4" if both are installed on 10" rims - and the 275 tire is actually the taller of the two sizes (think 1/8" tighter fender gap as seen in straight-on side view).


Norm

 

[Hawaii50]

The axle has now been centered and yes the tires still stick out somewhat. I'll drive it tomorrow and see how it goes. In the evening I will remove the sway bar and inspect the end links. What am I specifically looking for when I drive the car without the sway bar, to see if the bouncing on motion has been isolated?

 

[Norm Peterson]

Without the rear bar, the car may have a heavier/less nimble feel to it as you steer it into a corner taken moderately hard (somewhat harder than most people's normal cornering but well short of what the car is actually capable of).

See if you can determine where the planes of the outer flanges of those wheels are, relative to the sheetmetal. You could do this by hanging a weighted string just touching the tire sidewall and measuring between the string and the fender and again between the string and the wheel, and doing the math.


Norm

 

[Hawaii50]

There is less rubbing compares to normal. The bouncyness feels like its in the rear while the front is just stiff on bumps.

Tonight I will remove rear sway bar and inspect endlinks. I will drive it for a day and see how it rides.

 

[Hawaii50]

Without the rear bar, the car may have a heavier/less nimble feel to it as you steer it into a corner taken moderately hard (somewhat harder than most people's normal cornering but well short of what the car is actually capable of).

See if you can determine where the planes of the outer flanges of those wheels are, relative to the sheetmetal. You could do this by hanging a weighted string just touching the tire sidewall and measuring between the string and the fender and again between the string and the wheel, and doing the math.


Norm

I'm not quite sure I understand your second paragraph.

 

[Hawaii50]

I just removed the rear sway bar and end links. Here you can see the bushings.

I drive my commute tomorrow without the rear sway bar and report back.

 

[Norm Peterson]

See if you can determine where the planes of the outer flanges of those wheels are, relative to the sheetmetal. You could do this by hanging a weighted string just touching the tire sidewall and measuring between the string and the fender and again between the string and the wheel, and doing the math.

I'm not quite sure I understand your second paragraph.

I'm trying to find out how much the wheels themselves either stick out past the fender or remain tucked inside it. Just the wheels, as if they did not have tires mounted on them. Obviously, you can't make these measurements directly unless you were to unmount the tires, so I was suggesting an indirect way of finding out about what those measurements might be.


I don't remember what problem you thought the rear sta-bar might have been causing. If it was some squeaking or possibly some light clunking, my money is on the polyurethane bushings on the chassis ends of the drop links being longer than the sleeves that run through the middles of them (those brass-colored tubes in your recent pictures). There's a fairly easy DIY fix for this, which may or may not reduce gear noise coming into the cabin but at least shouldn't make that any worse.


Norm

 

[Hawaii50]

I'm trying to find out how much the wheels themselves either stick out past the fender or remain tucked inside it. Just the wheels, as if they did not have tires mounted on them. Obviously, you can't make these measurements directly unless you were to unmount the tires, so I was suggesting an indirect way of finding out about what those measurements might be.


I don't remember what problem you thought the rear sta-bar might have been causing. If it was some squeaking or possibly some light clunking, my money is on the polyurethane bushings on the chassis ends of the drop links being longer than the sleeves that run through the middles of them (those brass-colored tubes in your recent pictures). There's a fairly easy DIY fix for this, which may or may not reduce gear noise coming into the cabin but at least shouldn't make that any worse.


Norm

Norm the gear whine noise from the rear end was silenced when I switched from whiteline lca with poly bushings back to new track Pack Ford lca.

Someone had suggested removing the steeda rear sway bar with polyurethane bushings to see if the ride quality improved. The problem I am having is I feel every bump. On the interstate some sections feel very bouncy.

I just drove to work without the rear sway bar attached and it feels like the harshness of the ride went down from an 8 to a 6.

Tonight I'm going to try just the Ford performance jounce stops in the rear to see if there is any kind of difference just to rule it out.

All of the extra uninstalled parts I've installed will stay off for now until I can fix the problem.

This leads me to replacing the rear sway bar to a Ford OEM one with factory rubber endlinks. Someone had asked earlier if you can just use the Ford end links on the steeda bar. You cannot.

With the car being a track pack, I still want to improve upon the stock handling without sacrificing the factory feel so would it be ok to go to a boss 302 or Laguna Seca sway bar?

 

[Norm Peterson]

Someone had suggested removing the steeda rear sway bar with polyurethane bushings to see if the ride quality improved. The problem I am having is I feel every bump. On the interstate some sections feel very bouncy.

Response to hitting bumps can be described as firm or harsh. Firm is sort of like getting a good shove, harsh is more like a slam-bang impact.

Would you describe "bouncy" as being about the forces that result when you hit the bump or more about the up-down chassis movement that tends to happen afterward?

Norm

 

[Hawaii50]

Response to hitting bumps can be described as firm or harsh. Firm is sort of like getting a good shove, harsh is more like a slam-bang impact.

Would you describe "bouncy" as being about the forces that result when you hit the bump or more about the up-down chassis movement that tends to happen afterward?

Norm

That is correct, when I hit a bump, just a small one there's a noticeable up and down chassis movement.

 

[Norm Peterson]

That is correct, when I hit a bump, just a small one there's a noticeable up and down chassis movement.

Would you describe these chassis motions as "soft-bouncy" or more like "stiff-jiggly"? Mostly from the rear?


Norm