2009 Hyundai Genesis V6 Sedan: Suspension Walkaround
September 02, 2009
I've been sitting on the photos of the 2009 Hyundai Genesis V6 sedan suspension walkaround for a week because I wanted to put them up about the same time as those of a 2009 Hyundai Genesis Coupe V6.
From the name similarity, some might figure that the two share a chassis. But that assumption turns out to be bogus. There are some humungous differences within these fenders.
About all I can conclude from this exercise is this: The common thread that links the two Genesis products in the Hyundai lineup is rear-wheel drive.
The front suspension of our Genesis sedan could not be more different from that of a Genesis Coupe.
First, it's nothing close to a MacPherson strut setup. It looks like a double wishbone layout with an elongated knuckle (white) leading to a high-mount upper arm and a coil-over shock (black).
But there aren't any upper and lower wishbones because dual links with separate ball joints are used top (yellow) and bottom (green). Some people might call this a 4-link suspension, while others will include the steering tie-road and call it 5-link. But I find that nomenclature too generic without pictures to back it up.
If that wasn't enough, most of what you see here is made from aluminum. You can afford to make those sorts of upgrades when the price tag is $10k higher than your sibling's.
Imagine where these dual upper links would intersect in space if they were projected out and you'll find the location of the virtual steering axis. Yeah, that's right; about 1.5 inches out from your computer screen.
The same thing is going on at the bottom, too. It looks more like the Genesis Coupe down here, except everything is made of aluminum.
Here we can see how the short link from the front stabilizer bar (white) connects to a bracket (black) on the lower end of the coil-over housing. This means they both share the same motion ratio with respect to the lower link. I call it 0.65 or thereabouts.
The major steering and suspension components are all carried by the front subframe, Direct-mounting it to the chassis (white) is a move intended to foster good steering precision.
The front brakes are single-piston (white) sliding calipers and one-piece ventilated rotors (black) -- a tried-and-true setup that works well in cases where track use isn't in the cards.
Note the dual Hyundai and Kia logos molded into the casting.
The rear suspension of the Genesis sedan looks a lot more similar to that of the Genesis Coupe. That said, there are differences that make it likely that none of the parts are interchangeable.
Here you can see that the sedan employs a multilink suspension with 5 links -- just like the coupe. Two upper links (white) and two lower links (black) locate the wheel and describe the caster and camber. The 5th unseen link, a toe link, keeps the tire pointed straight ahead.
This view looks similar to that of the coupe, but with one exception: the rear suspension knuckle (yellow) is made of aluminum, not steel.
Here we're looking back (and up) at the rear suspension, looking at the same pair of lower links (black) and upper links (white). But now we can see the toe link (yellow) and see that it is much shorter than the other links to produce a bit of stabilizing toe-in during hard cornering and emergency maneuvers.
Now we're looking from behind, and this is where some of the more visible differences from the Genesis Coupe can be found.
For one, the stabilizer bar attachment point is very close to the hub, creating a motion ratio somewhere north of 0.8. The stabilzer bar (green) can therefore generate a decent amount of roll stiffness, despite appearing far smaller than the one in the coupe. Is it generating as much roll stiffness as the Coupe? Probably not. But the difference isn't as big as your eyes tell you it is because of the different mounting strategies. (See here for the Genesis Coupe walkaround.)
Another big difference is the rear shock mounting point (white), barely visible here. It bolts directly to the hub for maximum damping efficiency. You don't need the shock to produce overly-high forces if you can make use of all it has to offer with a 1:1 motion ratio such as this.
Here's a better shot of the shock absorber (green) and it's direct-mount to the rear knuckle.
We haven't seen a bump stop yet, which means it's more than likely hidden within the dust boot at the top end of the shock absorber.
Like the front, the Genesis sedan uses single-piston sliding calipers (white) on the rear axle. Unlike the front, the rear rotors (yellow) are solid non-ventilated discs.
Our Genesis V6 sedan rides on Dunlop SP Sport 5000M all-season tires, sized P235/50R18. Together with their 7.5 x 18-inch rims, each weighs 50.5 lbs on my garage scale.
Dan Edmunds, Director of Vehicle Testing @ 15,654 miles