Steering makes car feel instable?

Gnfanatic · Aug 13, 2017

Hey guys. After doing the sus mods consisting of bmr springs, steeda shocks and several IRS comp the rear is very solid and the car is flat around turns. Issue is that the front of the car is extremely sensitive to bumps and cracks on the highway. The wheel will move quickly to the left or the right scaring the shit out of me, the rear sus is solid. Some info.....

Fac sway bars and end links
No alignment done yet, going to soon.
Stock pzeros at 32 psi cold
No front end mods except for struts and springs
No noise anywhere
Steering set on sport does not fix this issue
Around town feels fantastic but hwy is another story.

BmacIL · Aug 13, 2017

Gnfanatic said:
Hey guys. After doing the sus mods consisting of bmr springs, steeda shocks and several IRS comp the rear is very solid and the car is flat around turns. Issue is that the front of the car is extremely sensitive to bumps and cracks on the highway. The wheel will move quickly to the left or the right scaring the shit out of me, the rear sus is solid. Some info.....

Fac sway bars and end links
No alignment done yet, going to soon.
Stock pzeros at 32 psi cold
No front end mods except for struts and springs
No noise anywhere
Steering set on sport does not fix this issue
Around town feels fantastic but hwy is another story.

Alignment settings?
Do you have front wheel spacers?

Gnfanatic · Aug 13, 2017

No wheel spacers. Alignment not done yet, camber is a tad off, about neg 2 degrees

BmacIL · Aug 13, 2017

Gnfanatic said:
No wheel spacers. Alignment not done yet, camber is a tad off, about neg 2 degrees

Ok. I would wait till after your alignment to worry. Target about -1.5 deg front camber and between 0.00 and 0.02 deg of toe per side (don't go negative...will improve turn-in response but will make it more twitchy). You'll want the rear at -1.25 camber and 0.10 deg toe per side.

Which BMR springs?

Gnfanatic · Aug 13, 2017

Thanks for the info. I didnt think a slight off camber can do this for hopefully it is the issue. Sp080. I believe it is a one inch drop

BmacIL · Aug 13, 2017

Gnfanatic said:
Thanks for the info. I didnt think a slight off camber can do this for hopefully it is the issue. Sp080. I believe it is a one inch drop

A lot of camber will make the car more reactive to inputs, as will negative toe in the front. You didn't go heavy enough on springs for that to make much of a difference, so it's in the alignment.

VinnAY · Aug 14, 2017

I dont like the electric steering on the car, I can feel dead spots in it when I saw the wheel L/R rapidly and that twitchy hiway feel of the bumps and such is a little better with my car on comfort steering.

Gnfanatic · Aug 14, 2017

Glad to see I am not the only one. Scary when the wheel jerks or feels loose out of nowhere when you are doing 80mph around a turn.

wildcatgoal · Aug 14, 2017

Same issue happened to me when I installed Swift Spec R springs after having Steeda Ultralites. Would only happen on my 20" wheels, not my stock 19" wheels, oddly. Anyway, alignment was done shortly after and I watched Gran Turismo East make a number of changes, to my surprise. But the weight balance between those two springs is notably different. Anyway, car drove fine after that. These cars seem affected by every little thing...

Bluemustang · Aug 14, 2017

This still happens to my car. I hate the electric steering in this car. It's my only qualm about it.

wildcatgoal · Aug 14, 2017

It's definitely not perfect... even the stiffest steering weight setting isn't weighted enough.

BmacIL · Aug 14, 2017

wildcatgoal said:
It's definitely not perfect... even the stiffest steering weight setting isn't weighted enough.

The only S550 I've driven with both excellent weight and feel is one with GT PP rear wheels all around with 25 mm spacers all around. There's enough positive scrub radius to really change it. They are basically poking out of the fender though.

wildcatgoal · Aug 14, 2017

I'm running stock GT PP wheels with stock tire sizes and 25mm front / 20mm rear spacers right now and I actually would agree. Wide-set 19" wheels I have no issues - same goes for my 305 and 285 square setups.

Bluemustang · Aug 14, 2017

BmacIL said:
The only S550 I've driven with both excellent weight and feel is one with GT PP rear wheels all around with 25 mm spacers all around. There's enough positive scrub radius to really change it. They are basically poking out of the fender though.

So, could one get aftermarket wheels to change the scrub radius in a positive manner ?

BmacIL · Aug 14, 2017

Bluemustang said:
So, could one get aftermarket wheels to change the scrub radius in a positive manner ?

Yes. The downside is that you'll also increase tramlining.

Steering makes car feel instable?

Gnfanatic

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BmacIL

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Gnfanatic

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BmacIL

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Gnfanatic

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BmacIL

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VinnAY

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Gnfanatic

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wildcatgoal

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Bluemustang

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wildcatgoal

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BmacIL

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wildcatgoal

@sirboom_photography

Bluemustang

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BmacIL

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