5.0 vs R-Spec; modifications

[dinodiesel]

I just bought a 2012 non r-spec 5.0 (largely because I wanted a light colored car with a light colored interior). Besides the larger wheels/lower profile tires, what are the suspension and brake differences between the 5.0 and the R-Spec?
I am happy with the 18" Michelins.
What would be a good place to start with modifications to upgrade the suspension to as good as/better than the R Spec?

 

[jaboyd]

I'd make 2 changes: 1) coil over shocks, 2) better tires. The stock suspension is too soft with insufficient cornering grip, and the stock tires are best suited to touring on the interstate.

Elsewhere in the forum you can see that one owner went to Megan coilovers. I'm not familar with the specific units, but putting better shocks/springs on the car will make a world of difference in the overall ride/handling....and by the way you can adjust the ride height if you'd like. All it takes is a re-alignment and a few minor adjustments to install.

I'd replace the tires with an equivalent dia and possibly equal or slightlly wider tires (if the rims are wide enough) with Michelin's new Pilot Super Sport tires (not to be confused with PS2). These are max perf tires which means primarily summer tires with very good wet characteristics. The great thing is that they come with a 30k mi guarantee, if you wear them out sooner they're prorated for a repalcement. Now they are a pricey tire (I'd guess around $200 each), but they are terrific. There's actually a great writeup/comparison in the newest Car & Driver (Aug 2012).

If you make these changes your car will out ride and out handle an Rspec, and you'll spend less than $2500.

 

[Mark_888]

I just bought a 2012 non r-spec 5.0 (largely because I wanted a light colored car with a light colored interior). Besides the larger wheels/lower profile tires, what are the suspension and brake differences between the 5.0 and the R-Spec?
I am happy with the 18" Michelins.
What would be a good place to start with modifications to upgrade the suspension to as good as/better than the R Spec?

More than one professional automotive reviewer of the 2012 R-Spec said it was "unnecessarily harsh." I would not automatically assume you will like it more than what you now have unless you do a careful test drive of the R-Spec on some demanding roads (not just smooth blacktop).

But if you do want the same suspension as the R-Spec, you can probably switch out the 4 springs, and 4 shocks/struts. Not sure about stabilizer bars (they may be the same). You can get the R-Spec OEM parts online for about $1,000. I know this because I switched out my 2009 suspension for the 2010/2011 version. I got an independent suspension shop to install the parts for about $650.

 

[jaboyd]

The Rspec is very harsh on impact (sharp edge bumps) and nervous over rippled roads. While the Rspec has better roll control, it is not an ideal setup. If you're just looking for better cornering and have little $$s, you could go to larger swaybars which would improve cornering without sacraficing your current ride quality. I find that the std suspension is too soft for me so I'd go with an upgraded aftermakt setup (coil overs) and not spend the money on a less than ideal Rspec swap.

 

[gscarr]

i have a 2012 R-spec and I'm disappointed in the cornering and overall control. I don't mind the hard ride (my other cars are a vette and a porsche so rough rides are OK) what improvements can i do to improve the hold in the corners?

 

[Mark_888]

i have a 2012 R-spec and I'm disappointed in the cornering and overall control. I don't mind the hard ride (my other cars are a vette and a porsche so rough rides are OK) what improvements can i do to improve the hold in the corners?

BMW 5, or Infiniti M. Genesis R-Spec (or any Genesis V8) is too big of a car, and engine weight is too high on front end, to be considered a great car when cornering. It can be considered to be a great when going in relatively straight lines.

 

[jaboyd]

A set of stiffer/larger diameter front and rear sway bars will reduce body roll wo/altering the overall ride. But it is a larger car, so don't expect M3 type handling....the laws of physics take over.

 

[Mark_888]

A set of stiffer/larger diameter front and rear sway bars will reduce body roll wo/altering the overall ride. But it is a larger car, so don't expect M3 type handling....the laws of physics take over.

Not only the Genesis large and heavy (especially V8), but it has less than ideal F/R weight ratio (about 56/44 instead of ideal 50/50 that is typical of true sports sedans).