The suspension on our 2009 Nissan 370Z is pretty straightforward. It's got upper and lower control arms and a coil-over shock.
Here you can see what is called a high-mount upper arm. The hub carrier (aluminum here) is huge, and it stretches upwards to locate the upper ball joint high in the fender well. This provides a very large moment arm to counteract side loads generated while cornering. And a large moment arm reduces the forces seen at the upper ball joint. In turn, the upper arm and the body attachment points won't see high loads either, so they can be lighter and stronger.
You can also see how the upper arm slopes down dramatically to the rear. This is called anti-dive geometry, and depending on the angle it can reduce or eliminate brake dive. It would seem that instantaneous caster would increase as the loaded side's upper ball joint moves back during cornering, and that should increase self-aligning forces and generate feedback in turns. But none of the textbooks I own delves into that aspect
Some might call this a double-wishbone front suspension, because it has a one-piece lower arm, too. But a wishbone is either A- or Y-shaped, and this one is L-shaped. It's better to describe this as double control arm suspension.
You can also see that, once again, a forward caliper placement results from a rear-mounted steering rack.
The stabilizer bar link and spring/shock assys (center) mount some ways in from the lower ball joint (left), so neither are 100% efficient. It looks like a 0.65 motion ratio or thereabouts.
But there is something unique going on here. The upper stabilizer link end and the and the lower shock mount bolt to the lower control arm in the same place with a shared bolt.
Moving on to the rear, we can see that this is a multilink design.
Multilink is a catch-all designation that applies when you don't use double control arms or a strut. But links can only hold tension and compression along their axis, so you need many (multi-) of them to orient the wheel.
The 370Z has an upper y-shaped control arm and three links. You can see one of them sprouting behind the brake caliper.
You can aslo see ventilated rear brake rotors and a 2-piston fixed brake caliper. The stabilizer bar is buried deep in the background of the picture, it's end-link attaching about halfway along the upper arm. The twin-tube shock absorber mounts directly to a protrusion of the hub carrier (aka knuckle or upright) for a 1:1 motion ratio.
Here you can see two of the lower links, a black steel one and an aluminum one that has been bloated to double as a lower spring mount.
For fun, I weighed the wheel and tire assemblies and made a few notes while they were off.
Front: 51.5 lbs 19x9 47 mm offset*
Rear: 57.5 lbs 19x10 30 mm offset*
5 x 114.3 mm (4.5 in) bolt circle.
Mind you, these are Rays Forged aluminum wheels, so the wheels themselves shouldn't be overweight. The wheels and tires are simply 19-inch monsters and they're super wide. There's a lot of material here.
Dan Edmunds, Director of Vehicle Testing @ 5,010 miles
chavis10 says:
11:21 AM, 04/16/09
Now that's the kind of post I like to read! Keep these coming.
vvk says:
11:35 AM, 04/16/09
Thank you for this post, I really enjoyed it!
lvranger says:
11:39 AM, 04/16/09
I enjoyed the article, great post. Shouldn't the wheel widths be reversed? Wider should be on the back.
greenpony says:
11:49 AM, 04/16/09
Awesome. I feel like I really learned something.
kevinlch says:
11:51 AM, 04/16/09
Great article, I don't mind reading something like this every day, rather than someone complaining about the window switch is not in the right place or something.
joefrompa says:
11:58 AM, 04/16/09
Wow, thanks Edmunds! (Ditto)
That front shared bolt through the sway bar end link and strut shared bolt is interesting. A few thoughts:
1. That end link is BEEFY....very nice. That thing is made for serious handling.
2. Making them share a bolt is beautiful simplicity and keeping things cleaner in my book, but for servicing/upgrading, it could be a small downside. You can't just unbolt the sway bar end link, you've got to ensure that side is fully articulated. Probably fine, I could be over complicating it.
3. It's nice to see vented rear rotors. Most get by with solids, and it's definitely a nod for high speed braking events.
CycloneRcr says:
12:29 PM, 04/16/09
This is an incredible post!! Thanks for it..
BTW the size of the front disc seemed to be a little to my eyes. I don't know the brake performance of 370Z but the friction surface does not look like satisfying :)
wobbly_ears says:
12:31 PM, 04/16/09
Once again, Dan writes an excellent post. Other IL editors need to learn from Dan & Karl on how to be a little verbose yet informative with their posts.
clarkma5 says:
12:33 PM, 04/16/09
More technical posts! I love some good suspension tech.
k_alexander says:
12:42 PM, 04/16/09
Actually the Z has massive 14" brakes with some pretty damn good stopping numbers. Like with everything else, a picture is worth a 1000 words, but those words can be deceiving.
iancar says:
12:44 PM, 04/16/09
Complete petrol head porno. :p
actualsize says:
01:08 PM, 04/16/09
*Dang! Sorry about the wheel-width flip-flop. It's fixed now. But now I have to wait until I can check my notes to confirm which offset is which.
subytrojan says:
01:15 PM, 04/16/09
Love blog entries like these, Dan! :thumbsup:
fordexcursion says:
01:33 PM, 04/16/09
Do most cars not come with vented rear rotors or something? It seems to come as a suprise to some. My Excursion has vented rear rotors...
fordexcursion says:
01:34 PM, 04/16/09
Oh, and nice, informative post. Would love to see more of these.
k_alexander says:
01:37 PM, 04/16/09
Agreed with everyone who thinks there should be more informative and educational posts like these.
usma90 says:
02:01 PM, 04/16/09
Simple and straight forward; written so it's easy to see and understand. Great article. I'd love to see the same write ups on some of your other long termers; like the BMW 135i, etc. Thanks!
altimadude00 says:
02:04 PM, 04/16/09
An Excursion need them for when it's towing something, as there would be more weight on the rear wheels. The rear disks on my Altima are not ventilated. There are still many cars that have rear drums still.
hondacura4 says:
02:10 PM, 04/16/09
Its good to see that people like and enjoy the details that MAKE THE PRODUCT instead of just focusing on performance numbers alone. Numbers tell me nothing as the details hold all the information.
Its also great to see how numerous subsystems work together and come together to make a larger system that actually works properly. Nissan has obviously done its homework.
Informative threads such as this, based on suspension tech, infotainment features, engine architecture/technology or whatever should be done on all the IL cars. Superb thread!
shivatron says:
02:27 PM, 04/16/09
I just wanted to echo the sentiments expressed above -- this is one of the best posts I've read on this blog. Please continue to do this for the other vehicles in your fleet!
elic says:
03:39 PM, 04/16/09
bravo!
jasbra says:
05:12 PM, 04/16/09
Thanks for the informative post. Even though I own this car I've been too lazy to pull the wheels off.
cwc1 says:
06:57 PM, 04/16/09
After reading a previous write-up about front caliper placement, I've been wondering why the Nissan FM platform cars, such as the Z and the Infiniti G35/G37, have the calipers on the leading edge, indicating the steering rack is behind the front wheels.
Since the FM is rear-wheel drive, I wondered why Nissan didn't choose the front attachment point, which should allow for better steering dynamics. I suspect it's because the FM is also the basis for the Infiniti FX, which is all wheel drive. Or is there a different reason?
dougtheeng says:
06:14 AM, 04/17/09
"Its good to see that people like and enjoy the details that MAKE THE PRODUCT instead of just focusing on performance numbers alone. Numbers tell me nothing as the details hold all the information."
hondacura4: but we all know spreadsheet shopping is the ONLY way to tell what car is the best!!
Nice post on the suspension. I'll echo everyone above and say that more content like this is welcome.
chavis10 says:
08:04 AM, 04/17/09
When is IL gonna compare the CTS-V to the M5?
canadaphant says:
08:29 AM, 04/17/09
Great post, thanks guys.
redliner says:
09:23 AM, 04/17/09
Give yourself a pat on the back. 2 Thumbs up!
70ss454_man says:
12:37 PM, 04/17/09
Very nice post! Now let's see that Challenger suspension shall we?
PDXLager says:
12:43 PM, 04/17/09
+1 for seeing something similar done for the 135i, please!
s197gt says:
06:16 AM, 04/18/09
color coded arrows pointing to the parts = perfect!
mannyljr says:
08:51 AM, 04/18/09
Great post, but it was hard to match the descriptions in the text to the actual spot in the photos. If you put numbers with the text, like (1), and placed the same numbers on the photos, it would be much clearer to understand.
actualsize says:
10:21 PM, 04/18/09
I hear you on the color coding. I'll work that in next time.
*Also note that I did indeed have the wheel offsets flipped. I've corrected them to 47mm front, 30 mm rear.
bbechtel16 says:
08:30 PM, 04/26/09
"After reading a previous write-up about front caliper placement, I've been wondering why the Nissan FM platform cars, such as the Z and the Infiniti G35/G37, have the calipers on the leading edge, indicating the steering rack is behind the front wheels.
Since the FM is rear-wheel drive, I wondered why Nissan didn't choose the front attachment point, which should allow for better steering dynamics. I suspect it's because the FM is also the basis for the Infiniti FX, which is all wheel drive. Or is there a different reason?"
I have the same question. Glad I just happened to stumble on this! I was actually looking for the long term page for the Smart. Anyone have linkage?
irvg37 says:
05:37 PM, 12/ 9/10
ultra excellent. this type of article that covers technical topics in depth is exactly the reason why i'm a giant fan of insideline.com.
if this were a concert, i'd give a standing ovation.
GREAT STUFF!!!