car is swaying

[Realist_Sting3r]

I have a 2020 kia stinger gt and I recently got the subframe bolts installed and new apex sm10 rims. Ever since then my vehicle sways under heavy acceleration now and im guessing its because the rims are way lighter weighing at 22lbs. Do I need more grippy tires (I have michelin pilot sport 4s all season) or should I get the tires rotated again with alignment? (had an alignment done too recently) I have the front and rear sway bars as well set to soft.

 

[JSolo]

Define swaying? Accelerating in a straight line? Sway bars do little when going straight.

 

[Realist_Sting3r]

Define swaying? Accelerating in a straight line? Sway bars do little when going straight.

Yes accelerating in a straight line on WOT. Im AWD by the way.

 

[Realist_Sting3r]

Define swaying? Accelerating in a straight line? Sway bars do little when going straight.

Swaying as in the tail fish tails side to side.

 

[Snicklefritz]

'swaying' I wasn't sure about what, but 'fishtailing' I can understand. I bet it is tires. your on a/s 10" wide, is that right? what were you on before the new wider wheels?

 

[JSolo]

Does that even have a posi rear end? I thought all awd had open rears?

 

[Realist_Sting3r]

'swaying' I wasn't sure about what, but 'fishtailing' I can understand. I bet it is tires. your on a/s 10" wide, is that right? what were you on before the new wider wheels?

New the tire specs are (Rear: 265/35/19) (Front: 235/35/19). Before that I had the stock tire setup which was 255 rear and 225 front with NGT spacers

 

[Realist_Sting3r]

'swaying' I wasn't sure about what, but 'fishtailing' I can understand. I bet it is tires. your on a/s 10" wide, is that right? what were you on before the new wider wheels?

the wheels are 19×9 squared

 

[Rodtheviking]

With that wide of a tire/wheel combo I would get Megan camber and toe arms for the rear and have them set for a little less than OE spec. A Burger diff brace wouldn't hurt either

You should have the LSD on the 2020 AWD, could also help to put in fresh diff oil.

 

[Realist_Sting3r]

With that wide of a tire/wheel combo I would get Megan camber and toe arms for the rear and have them set for a little less than OE spec. A Burger diff brace wouldn't hurt either

You should have the LSD (Limited Slip Differential) on the 2020 AWD, could also help to put in fresh diff oil.

yes i have the megan racing arms as well for the rear

 

[Snicklefritz]

the wheels are 19×9 squared

well, shoot, the tires can't be the problem, since 235 is the minimum tire for a 9" rim and 265 is the maximum for a 9" rim. fishtailing, you say. I've got nothing. will watch this play out with interest.

 

[vipeboy2000]

With that wide of a tire/wheel combo I would get Megan camber and toe arms for the rear and have them set for a little less than OE spec. A Burger diff brace wouldn't hurt either

You should have the LSD (Limited Slip Differential) on the 2020 AWD, could also help to put in fresh diff oil.

Does that even have a posi rear end? I thought all awd had open rears?

in the states, AWD models did not get a LSD unless it's a GTS d-awd, or Indigo d-awd.
In canada i believe some years after the first got lsd + awd on the top trim?

 

[Realist_Sting3r]

in the states, AWD models did not get a LSD (Limited Slip Differential) unless it's a GTS d-awd, or Indigo d-awd.
In canada i believe some years after the first got LSD (Limited Slip Differential) + awd on the top trim?

im in the states with the indigo version

 

[vipeboy2000]

im in the states with the indigo version

nice! same.. but i'm on the stock wheels and i think the same pilot sport all season 4 tires.. what sizes are you running for tires? stock? Is it actually fishtailing or perhaps something with the subframe bolts something didn't get lined up correctly and there is extra movement there? My car puts the power down very well even in the wet without fishtailing even with all the tcs and ecs off...

 

[Realist_Sting3r]

on the aftermarket rims im 265/35 and 235/35. I'm pretty sure the subframe bolts are in properly because i watched my mechanic the whole time while installing it and he torqued them to spec which is 135 ft-tq. I'm going to another shop today to get an alignment and tires rotated again to see their opinions on it. Im thinking its the aftermarket rim itself since its 11lbs lighter than stock

 

[vipeboy2000]

on the aftermarket rims im 265/35 and 235/35. I'm pretty sure the subframe bolts are in properly because i watched my mechanic the whole time while installing it and he torqued them to spec which is 135 ft-tq. I'm going to another shop today to get an alignment and tires rotated again to see their opinions on it. Im thinking its the aftermarket rim itself since its 11lbs lighter than stock

are you sure the fronts are 235/35? not 40? if so, your rears are going to be almost an inch larger which would be like having the rears spin faster than the fronts by quite a bit causing issues/binding transfer case wear which would definitely cause the rears to break traction on accel and fishtail more.

 

[Realist_Sting3r]

are you sure the fronts are 235/35? not 40? if so, your rears are going to be almost an inch larger which would be like having the rears spin faster than the fronts by quite a bit causing issues/binding transfer case wear which would definitely cause the rears to break traction on accel and fishtail more.

yes the fronts are 235/35. Well if its still swaying under heavy acceleration im going to put back on my stock rims and see if the problem still occur. If it do, then I will know its the subframe bolts.

 

[vipeboy2000]

yes the fronts are 235/35. Well if its still swaying under heavy acceleration im going to put back on my stock rims and see if the problem still occur. If it do, then I will know its the subframe bolt

are your wheels different diameter front to rear? if they are the same diameter, the front tires are too short with that aspect ration vs the rear which will destroy your transfer case in the long run.

 

[Realist_Sting3r]

are your wheels different diameter front to rear? if they are the same diameter, the front tires are too short with that aspect ration vs the rear which will destroy your transfer case in the long run.

No they're squared at 19×9

 

[vipeboy2000]

No they're squared at 19×9

then you definitely need to change your front tire size to bring it up to within 1% size difference.