Rear End Sway- Problem?

[mavisky]

Oddly enough, now that its back to the correct toe angles, its tramlining WAY worse than before but the turn-in issue is gone and its on rails in the corner. Need to get the front and rear camber dialed as well, just had time to fix the toe at my dealership the other day. Front is at -3.6 and rear is -2.2. She's set up pretty aggressive right now. I'll get that set back to the street setting after my autoX event this weekend.

I'm closer to -3.3 and -2.0 for camber with oem toe in the rear and 1/8" toe out on the front. Car dives into corners on the autocross course.

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[GrayMater22]

I am one of those that checks tire pressures weekly and when there are swings in temperatures from the last time I drove the car on the street. I also check wheel lug torque about every month. It is not unusual to find a few that are a bit low once in a while.

Anytime that the car has been to a shop for any work requiring the wheels to be removed I am there and tell the wrench working on it to torque to 150ft. lbs. EVEN THEN, when I get it home I recheck wheel torque.

At most shops I have been to the “Technicians” have no clue of how to properly torque something. More often than not they have a 3’ torque wrench that has not been calibrated since it was unloaded off of the ark and they masterfully torque the lugs at warp speed and bounce on the wrench 3-4 times “just to make sure”. That is if they don’t use the 3-4 uggas is just right method.

I recommend that you have a good quality wrench ( this does not mean that it has to cost $600 ) and that you use it regularly, and especially after any shop touches your car. If you don’t already have one, you will not make a bad investment in buying one. And, chances are that you will see fit to have others suited for other purposes.

You have the same disease (OCD) as me, I do love my torque wrench

 

[Deleted member 69311]

I had sketchy wobble under load. Check your bolts that connect your sway bar to your control arm. Mine was loose. I got it tightened and it fixed the swaying.

 

[WItoTX]

I would follow the manufactures recommended 150 ft/ lbs. They won’t warranty things that break if your wheels are loose. If you run stock wheels and stock lugs then you’re not even close to the required torque to surface area.

Meh. Most vehicles are way lower. OP recommends way lower. ARP recommend way lower. Wheel isn't going to magically fall off.

I get the warranty deal. OPs car is out of warranty, or close enough. They were plenty tight, and the toe was the issue, not the torque.

 

[Jstang23]

Meh. Most vehicles are way lower. OP recommends way lower. ARP recommend way lower. Wheel isn't going to magically fall off.

I get the warranty deal. OPs car is out of warranty, or close enough. They were plenty tight, and the toe was the issue, not the torque.

If you’ve changed the type of studs and/or lug nuts then yes the spec might be different. But if you’re using OEM lugs and studs then you really need to be at or within~10 ft/lbs of 150. It’s simple math, clamping force = torque/friction * diameter of bolt. If you start torquing to less with the same friction your clamping force will drop pretty significantly. Sure the wheel won’t fall off but you’ll be putting stress on other parts of the vehicle. Again, stay with manufacturers spec, their engineers get paid to figure out the required torque

 

[TRCKWMD]

I am one of those that checks tire pressures weekly and when there are swings in temperatures from the last time I drove the car on the street. I also check wheel lug torque about every month. It is not unusual to find a few that are a bit low once in a while.

Anytime that the car has been to a shop for any work requiring the wheels to be removed I am there and tell the wrench working on it to torque to 150ft. lbs. EVEN THEN, when I get it home I recheck wheel torque.

At most shops I have been to the “Technicians” have no clue of how to properly torque something. More often than not they have a 3’ torque wrench that has not been calibrated since it was unloaded off of the ark and they masterfully torque the lugs at warp speed and bounce on the wrench 3-4 times “just to make sure”. That is if they don’t use the 3-4 uggas is just right method.

I recommend that you have a good quality wrench ( this does not mean that it has to cost $600 ) and that you use it regularly, and especially after any shop touches your car. If you don’t already have one, you will not make a bad investment in buying one. And, chances are that you will see fit to have others suited for other purposes.

Torquing these CF rims to 145ft/lb is a trust test. It felt so wrong but that’s what the Manual says so I figured why not. I don’t think the lugs would have fallen off or backed out, the rear toe alignment was the issue. So are the shit roads out here, lol.

 

[Cobra Jet]

If it was not mentioned, I would also check the following:

- rear axle nuts; they’ve been known to come loose

- rear diff mounting bolts; this is a known weak spot with the S550’s and the bolts within the bushings are known to break/sheer off. This would also cause a straying/swaying rear on the highway.

- bad rear wheel hubs; again there’s been multiple M6G members on here who have had to replace both front and rear wheel hubs due to premature failures at low miles - and with some having to replace those 2-3x under warranty. A bad wheel hub will also cause weird driving characteristics on the highway.

 

[passwords]

Oddly enough, now that its back to the correct toe angles, its tramlining WAY worse than before but the turn-in issue is gone and its on rails in the corner. Need to get the front and rear camber dialed as well, just had time to fix the toe at my dealership the other day. Front is at -3.6 and rear is -2.2. She's set up pretty aggressive right now. I'll get that set back to the street setting after my autoX event this weekend.

You definitely don’t need that much negative camber with the carbon wheels. Did the prior owner use a set of aluminum wheels on track?

 

[sukhoi_584th]

If you’ve changed the type of studs and/or lug nuts then yes the spec might be different. But if you’re using OEM lugs and studs then you really need to be at or within~10 ft/lbs of 150. It’s simple math, clamping force = torque/friction * diameter of bolt. If you start torquing to less with the same friction your clamping force will drop pretty significantly. Sure the wheel won’t fall off but you’ll be putting stress on other parts of the vehicle. Again, stay with manufacturers spec, their engineers get paid to figure out the required torque

I've never been able to understand people that refuse to follow torque specs and think they know better. It's not like we're talking engine tuning. There are very simple formulas to figure this out as you said.

 

[galaxy]

I've never been able to understand people that refuse to follow torque specs and think they know better. It's not like we're talking engine tuning. There are very simple formulas to figure this out as you said.

This is me with the wheels, bro. It’s mind boggling how many folks see 150 and say “that’s waaayyy too much”. Really? How did you come to that educated conclusion? Now if I have to torque a normal car to 100, it feels waaayy too soft, lol.

 

[Jstang23]

Torquing these CF rims to 145ft/lb is a trust test. It felt so wrong but that’s what the Manual says so I figured why not. I don’t think the lugs would have fallen off or backed out, the rear toe alignment was the issue. So are the shit roads out here, lol.

I bet! But those carbon rims are stronger than the PP1 wheels, so if you did ever over torque it, the stud would most likely be the first to go!

 

[NightmareMoon]

OP glad you found it!

The front camber will probably be a little darty on the street, but if you autocross or track much its the way to go. If it were my car I would only dial the rear back a tiny bit to 2.0.

You can dial just a slight amount of front toe in (like 0.05) to help calm it down slightly.

Tires with big flat tread blocks can make the tramlining worse, so if you’re running cup 2s then ya probably annoying, but with street tires like MP4S it should be ok.

 

[WItoTX]

Lotta folks never heard about the factory studs failing apparently. Or that Ford released longer and stronger studs to fix the failing factory studs.

 

[WItoTX]

Oddly enough, now that its back to the correct toe angles, its tramlining WAY worse than before but the turn-in issue is gone and its on rails in the corner. Need to get the front and rear camber dialed as well, just had time to fix the toe at my dealership the other day. Front is at -3.6 and rear is -2.2. She's set up pretty aggressive right now. I'll get that set back to the street setting after my autoX event this weekend.

Just curious, how did you get to -3.6 camber? That seems really high for factory parts.

 

[TRCKWMD]

Just curious, how did you get to -3.6 camber? That seems really high for factory parts.

I’ve got Camber Plates.

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