S550 rear end movement

[Mustang Mikes Queen Creek]

Have a base model 15 ecoboost,17 inch rim I'm fine with the size wheel and tire setup,not a big fan of large rims has anyone else experienced a rear side to side wiggle when driving,Ass end of the car seems hyper sensitive to any road deviations,The cars down right annoying to drive,is it tire related or is it realated to the IRS systems,Really miss my live axle coyote.If it's tires then that should be a simple fix,car is wearing the factory tires from Ford,If it's the character of the car,I may sell it, the constant steering input is annoying.Only driven the car 3000 miles in 6 months.Havent data logged for my tune plus e tune and trans tune yet,Loosing interest fast.

Sponsored

 

[Witj85]

I have the same wheel and tire setup mine drives good.. Now on my way to work there's couple roads that see heavy truck traffic and it can feel squirrely on those roads. Steering is a lot more sensitive then anything else I've driven though.

 

[klineka]

I have the same wheel and tire setup mine drives good.. Now on my way to work there's couple roads that see heavy truck traffic and it can feel squirrely on those roads. Steering is a lot more sensitive then anything else I've driven though.

Have you tried the sport steering mode? That seems to stiffen the steering up a bit

 

[Mustang Mikes Queen Creek]

I've had multiple foxbodys,sn,s197s,Ive been building efi Mustangs since before they became mainstream,I have never felt this kind of squirmy or rear end tracking in a mustang before,Ive tried all the steering input modes,Ive tried more tire pressure,I def wouldn't feel comfortable drifting the car like a 10sec foxbody due to the lack of force feed back from the steering,even know it's hyper sensitive while driving.What kind of 17 inch tires are you running on your ecoboost,brand and so fourth.Thanks for the input.

 

[Edkiefer]

Your dealing with independent rear suspension verse a solid rear in older mustangs.

 

[TEXAS HEAT]

You can stiffen up the rear end with stiffer bushings, cradle locks, etc. BMR makes some pretty economical suspension components which will help to stabilize the rear suspension and cure the sloppy feeling you're describing and give you better driver feedback on what the car is doing.

 

[Mid_life_crisis]

My wife and I both have 2016 Ecoboost Mustangs. Hers is a Premium convertible with upgraded rims. Mine is a Premium coupe with PP. Neither one squirms.

 

[Mustang Mikes Queen Creek]

I'll look into the bmr stuff,Did the sn99 cobras with the IRS do the same squirmy stuff,? The more Known about these mustangs the more I miss my fox stuff,I nsold my 190000 mile Brembo after 10 months because of the issue and investment required to keep the mt82 trans in one piece,Shifters,supports,oils,inserts,etc etc and was still worried I'd pop the gearbox,Plus the 8.8 howled like a wolf and the yote motor made all sorts if weird ticks and noises,all in all also annoying.What brand tires comes with the 17 inch wheel cars,If I knew that these cars would drive with a wiggle waddle I would have passed.Plenty of stories of these rearends comming around on people trying a controlled drift, its a Peppy car good on gas for long trips,but sits for the most part.The focus probably would have been a better pick in terms of power and handling.

 

[speedfrk]

I put the Steeda IRS subframe braces on my car. Very noticeable difference. But my car has 18's with Eagle F1's, so different wheels, tires. I'd let the dealer check the torque on all the subframe and diff mounting bolts too.
Also, rotate your tires front to back to see if maybe you have a bad rear tire. Most of those 17's had Hankook tires on them... just sayin.

 

[BMR Tech]

Have a base model 15 ecoboost,17 inch rim I'm fine with the size wheel and tire setup,not a big fan of large rims has anyone else experienced a rear side to side wiggle when driving,Ass end of the car seems hyper sensitive to any road deviations,The cars down right annoying to drive,is it tire related or is it realated to the IRS systems,Really miss my live axle coyote.If it's tires then that should be a simple fix,car is wearing the factory tires from Ford,If it's the character of the car,I may sell it, the constant steering input is annoying.Only driven the car 3000 miles in 6 months.Havent data logged for my tune plus e tune and trans tune yet,Loosing interest fast.

I highly suggest that you look into our CB005:

http://www.mustang6g.com/forums/showthread.php?t=23215&highlight=cb005

This is the best $200 you will spend on the car.

Also, with those wheels and tires...I suggest running the toe in per side at about .13 - .15 ....and do not exceed a total toe of .30.

Sometimes, these cars will feel odd out back with those wheels and tires and anything less than those toe specs.

CB005, and that toe...and I think it will be a step in the right direction.

 

[TheLion]

Have a base model 15 ecoboost,17 inch rim I'm fine with the size wheel and tire setup,not a big fan of large rims has anyone else experienced a rear side to side wiggle when driving,Ass end of the car seems hyper sensitive to any road deviations,The cars down right annoying to drive,is it tire related or is it realated to the IRS systems,Really miss my live axle coyote.If it's tires then that should be a simple fix,car is wearing the factory tires from Ford,If it's the character of the car,I may sell it, the constant steering input is annoying.Only driven the car 3000 miles in 6 months.Havent data logged for my tune plus e tune and trans tune yet,Loosing interest fast.

If your referring to the "rubber band" sensation when corner, where it feels like the rear suddenly is giving out, but then it doesn't, that would be attributed to the IRS bushings moving. After I installed the steeda IRS bushing lockouts / supports, it completely change the rear end of the car. In fact, the entire car feels like it's on rails now where before it would feel inconsistent and some what unpredictable. I was surprised at how much just stiffening up the IRS bushings made to the over all handling.

Diff bushings will solve IRS hop during drag launches / hard accleration and sub-frame bushing collars or sub-frame bushings (much more of a pain to install) will solve the "soft" rear end characteristic.

Steeda IRS Sub-frame Bushings:

http://www.steeda.com/steeda-s550-mustang-irs-sub-frame-bushing-support-system-2015-555-4437/

I have yet to find a single review that was negative on the sub-frame bushings and I can now understand why having just done them myself.

 

[TheLion]

Although, if you combine the IRS bushings with BMR's toe link change above, I'll bet the two of those will completely change the car's handling for the better and solve your issue.

 

[Mustang Mikes Queen Creek]

Great info guys thank you,I will look into all of it.Mike

 

[ForYourOwnGood]

I have the same thing (19" Premium wheels here) and its very off-putting. Usually out of a corner you can feel the wheels keep going sideways while the body doesn't. They probably made a lot of concessions for NVH, but the sideways movement feels really weird compared to the front/back movement I had on my 99 and 03 Cobras.

 

[Bennington]

I highly suggest that you look into our CB005:

http://www.mustang6g.com/forums/showthread.php?t=23215&highlight=cb005

This is the best $200 you will spend on the car.

Also, with those wheels and tires...I suggest running the toe in per side at about .13 - .15 ....and do not exceed a total toe of .30.

Sometimes, these cars will feel odd out back with those wheels and tires and anything less than those toe specs.

CB005, and that toe...and I think it will be a step in the right direction.

I agree with the CB005. The rear end of the car always felt too soft and sloppy to me. I did BMR cradle locks, toe links, and vertical links and its 100 times better. Doesn't feel like a stick axle, but feels like a solid irs. I think the change is mostly due to the CB005 cradle lockouts. Also, I have the 255/19 tires so can't comment on the 17 inch feel.

Sponsored