TCS Issue

[subaruatheart]

Not sure where to put this. I recently had coilovers installed (alignment/corner balance coming soon), everytime for example I take a 45mph freeway roundabout at around 60ish mph my TCS would engage causing a vibration from I beleive one of the rear brakes depending on which direction of turn it is and the TCS light blinking. What could be causing this issue? Could this an an alignment/corner balance issue?

[CSG Mike]

Originally Posted by subaruatheart

Not sure where to put this. I recently had coilovers installed (alignment/corner balance coming soon), everytime for example I take a 45mph freeway roundabout at around 60ish mph my TCS would engage causing a vibration from I beleive one of the rear brakes depending on which direction of turn it is and the TCS light blinking. What could be causing this issue? Could this an an alignment/corner balance issue?

If it does it in one direction but not the other, then probably a corner balance issue.

If it's consistent in both directions, then its either the driver or the setup (spring rate choice, damper settings, alignment, could be a ton of things)

[celica73]

something binding/a short shock topping out and picking up the inside back tire?

just throwing out ideas.

[Calum]

Originally Posted by celica73

something binding/a short shock topping out and picking up the inside back tire?

just throwing out ideas.

Stiff rear bar could be picking that inside tire to.

[celica73]

Originally Posted by Calum

Stiff rear bar could be picking that inside tire to.

Agree, but there is no good reason to run a stiff rear bar on these cars, aside from a desire to ruin the handling.

Now, if you dump the car, and have coilovers with short springs that unload at the first sign of droop, then the stock rear bar will probably pick up the inside tire. If the inside tire comes up, the Torsen turns into an open diff and the unloaded tire spins freely. Then, traction control engages.

[SubieNate]

What coils? Too short droop travel + swaybar = picking up tire = TCS freaking out.

[Calum]

Originally Posted by celica73

Agree, but there is no good reason to run a stiff rear bar on these cars, aside from a desire to ruin the handling.

Now, if you dump the car, and have coilovers with short springs that unload at the first sign of droop, then the stock rear bar will probably pick up the inside tire. If the inside tire comes up, the Torsen turns into an open diff and the unloaded tire spins freely. Then, traction control engages.

Can't argue with any of that, I agree completely. The only reason I mentioned it was because I don't know what the OP has on his car.

[subaruatheart]

Thanks for the inputs

Coils are Megan Street Series, I've talked to a couple of other users on this forum and they don't have this issue with Megan Sreet Series. Rear bar is stock. I also have SPC's adjustable LCAs installed. Dampers are set pretty stiff right now (7/32). My car isn't slammed, maybe a 1.6 inch drop at the most. I doubt anything is binding as my rim size and tire choice is pretty conservative (17x9 +30 225/45) besides the more aggressive offset. Well see, I have a feeling it's a alignment/corner balance issue which I already have an appointment to do.

[Trashed675]

225 on a 9 seems a little stretched to me

[subaruatheart]

Just a little, didn't want to run into any rubbing issues with a wider profile tire, but still wanted the concave look on the rims.

[Calum]

Originally Posted by subaruatheart

Just a little, didn't want to run into any rubbing issues with a wider profile tire, but still wanted the concave look on the rims.

You, Sir, get a big plate of cookies. 1 you lowered your car to get the look you wanted without being stupid about it and going too far. 2 you put the rims and tires on that you wanted, but made choices that would keep things safe while still getting the look you wanted. 3 you realized that you were going for a look, not just a performance gain, and that is awesome.



I'm not being sarcastic here, I really appreciate that you didn't try to sell this as a performance only setup and that you're proud of the fact that you got the look you went after.

[celica73]

Are the springs loose if you jack up the rear (jack under the diff)? Now, jack from the side of the car, do you have a loose spring on the airborne side)?

[mad_sb]

Originally Posted by subaruatheart

Not sure where to put this. I recently had coilovers installed (alignment/corner balance coming soon), everytime for example I take a 45mph freeway roundabout at around 60ish mph my TCS would engage causing a vibration from I beleive one of the rear brakes depending on which direction of turn it is and the TCS light blinking. What could be causing this issue? Could this an an alignment/corner balance issue?

well, if you feel it start to rotate before the TCS kicks in then it's surely a setup issue (damper setting, alignment, spring rates). If not then the most reasonable explanation seems like lifting the inside rear just enough to open the diff.

I suppose it could also be one of the wheel speed sensors got damaged somehow.

[SubieNate]

Is it possible that your rebound damping in the rear is set too high and when you corner the wheel is slow to react and you're lifting for a short while before the wheel can reconnect with the ground?

If the compression on the outside rear corner is soft and the rebound on the inside is very stiff, the car could lean on the outside and pick up the inside even if the sways are stock. Some suspension setups can even get to the point where repeated hits cause the car to squat down because the rebound damping is so stiff that the wheel can't return to neutral before more hits come.

Nathan