There's a lot of douche-baggery and misinformation in this thread.

First. Swift Spec-R spring are indeed progressive. Swift Springs USA

Their metric coil over springs are not.Swift Springs USA

"Spec-R" is a product. Swift makes a Spec-R for a lot of different vehicles. The Spec-R for the 370 is not the same as the Spec-R for any other vehicle.

That being said, OP. Do not go to the Nismo suspension. Don't waste your money. Figure out what you are going to do with the car first and then put a budget together. Suspension is expensive, and you get what you pay for. The more you pay, the better it gets.

If you are on OEM suspension, the best bang for buck you can get is a new front sway bar. Buy a Stillen, set the front full stiff and the rear full soft. The next best upgrade would be either a 1-way coilover+springs, or if you don't want to learn about springs then just buy Koni yellows + the Swift Spec-R springs. You won't be disappointed with any of the above. The nismo dampers and springs are nothing special.

Meh still need grippier tires per my post.

i agree, the best upgrade to improve braking, handling, acceleration, cornering, and overall grip, is to improve the only thing touching the ground from the vehicle.

I agree too. But you still have to keep the tires on the ground.

:iagree: and Dont forget to include a good alignment set up with the equation!

Thanks to all for their input, this is a great informational thread!

I purchased a set of nismo shocks and springs and have the swift springs on their way right now.
I daily my car and occasional autox so want it to handle better yet with DD comfort still in mind.
I will post what my opinion is on these when i get them installed. probably in a week or so.

From what i have read i agree this is probably not going to be the best track/autox setup but if its a upgrade ill be happy, Specially for the price since i got a great deal on the nismo set.

Coming from an HR 350Z, the 370Z feels soft and floaty (40th Anniversary aka Sport/Touring)

I heard the Nismos feels like a 350Z - I loved how that car handled, My favorite by far.

So i installed the nismo shocks with the Swift springs this afternoon.
Installation:
Pretty straight forward no issues.
Picture of the difference from nismo shocks with springs and with the swift ones:
http://i.imgur.com/GoMPYASl.jpg
Quick tip on compressing springs:lol they dug into the ground and stayed quite in place.

http://i.imgur.com/BK6FHK5l.jpg

Initial Impressions:
-They feel stiffer in a way that after bumps and imperfections in the road the suspension settles faster. I don't know if i can say it feels more comfortable until driven harder its just different. I like it though.

*im not going to get an alignment for a week to let the suspension settle so initial impressions might change*

Turn in is most definitely improved. Much more feedback at turn in and if front is settled it stays that way and sticks through the corner.
The rear is more loose and the back end slides out easier than before at low/medium speeds. Im guessing this is due to the increased negative camber more than the springs, at longer faster corners it feels more planted. Like i said these are initial impressions so most likely going to change.

As far as the drop I noticed it as soon as i left my driveway the plastic piece under the bumper scraped the driveway. That piece is not going to last long im sure.
These pictures are in a incline so the front looks higher than it is. i will post better pictures tomorrow.
http://i.imgur.com/UCSQEucl.jpg
http://i.imgur.com/9IydA7gl.jpg

This really makes me want to get spacers. Ive heard 15mm up front and 20mm in back is ideal right?

Ill drive it for a couple of days and post again with further impressions and pictures after it settles and from the rear to show the new negative camber.

Thanks

FWIW I have a '14 Nismo and replaced the springs with Swift's, then went to coil overs. I like the stock Nismo springs better than the Swifts. While stiff I found them more responsive and predictable and less mushy than the Swifts. The coil overs are far and away a better ride if you're looking for performance - it's really no comparison.

predictability is the name of the performance game!

Don't waste your time installing the Nismo springs on your car. It was bone jarringly stiff and terrible. I'm sure it's great on the race track though! When I installed them on my base/sports it raised my front .5" to 28" (wheel arch to ground, was 27.5 before). I went with Swifts and have been extremely happy with them. They are softer when driving around town, but really stiffen up when you drive hard. You can see why in the coil design. The close coils for comfort, and the larger gap for performance. I wouldn't discount them for street/track use they are a great spring.

It's a pickle, yes it is. Swifts or coil overs????? If you price Koni yellows and swifts you can put 1000 or so with it and score some quality coil overs. HKS, Bilstein, or KWv3's. They are not top of the line but better than the knock off arama's.

Wow. The OP asked if there is a difference between to parts and this thread goes off on some wild suspension tangent.

OP: If you want to know what combo suits you best..tell us your goals and your skill set and we can guide you from there. Personally, I don't mod a car's suspension until I cannot squeeze another second out of its performance (if we're discussing driving). If you just want to change the look of the car, you have tons of options.

After 15 yrs in the road racing world, I've driven and instructed too many HPDE's that had cars over built for the skill set of the driver. This weekend is a prime example..I spent 3 or 4 laps with the nose of my Nismo BURIED under the tail of a fully prepared track Mustang (coil overs, cage, wing, etc). My car is bone stock. After getting him so nervous he couldn't hold a line, he let me by. The factory Nismo setup is really awesome. I just think people want to play with their cars too quickly. Go drive the crap out of it first.

Attached is a pic of me after passing the stang on the front stretch

^^^^LOL, now that's how you are supposed to drive. I agree, the Nismo suspension is really good. The only downside to it on the street is on extremely bumpy roads. The bouncy rebound sucks. To me, that is an issue with the struts. I don't mind stiff, but the bounce is the ugly part.

Edit: I have noticed one thing, the faster you drive the better the suspension get's. I know the aero has something to do with it with
the increased down force. For me on the street though, I haven't even driven over 85 mph on the interstate. (Man I must be getting old or something. How did that happen??)

Very well said. There are many wannabe racers out there.

It's my opinion that the Nismo setup is rather sprung at lower speeds, so for common road use below 55 mph, it is harsh. However, that IS the reason the Nismo was made. The car doesn't need shock/spring modifications to run up against some of the most competitive cars on the road course. So when you buy a Nismo from the showroom floor and pay the extra premium, you're kind of accepting the fact that you're buying a "race version". There are trade offs to buying it. Unfortunately, I think some people consider the Nismo cause it looks amazing, but forget that they're getting a fairly prepped car. Lets face it: 75% of our competition made their highest tier cars with more horsepower, but failed to improve the suspension and braking components to create a well balanced car. The nismo has excellent balance in this area (even though the power curve is flat as hell and we'll ignore the clutch/fuel issue).

Side note: This weekend both the BRZ and Genesis clubs showed up at the track. We used to call the Miata's "moving slaloms"...this weekend it was a BRZ/Genesis moving slalom :driving:

This is a great unbiased post. Many simply add after-market parts to improve the performance of the car, but it is the drivers that need the improvements as many simply don't have the ability to reach the full potential of cars.

I personally feel that the Sport version is plenty good and a good compromise as DD.

completely :iagree::iagree:

you can install the best coilovers and suspension parts on the market... but if you dont know how to drive the car you are not doing nothing with those parts!

I personally feel the sport version is rough as a DD...It's why I drive a Forester XT as my DD. Honestly though, the sport has the LSD and wheel width to handle pretty much anything. With a better set of dampeners and wheels the driver will definitely be the limiting factor. Out of the 2 autox races and one sprint I took my car to last year, I beat several people with aftermarket sway bars, spring setups, and even coilovers. Most people don't even know how to properly tune a coilover so they're often a waste. The only person that beat me had a set of Konis and better tires. He was only .5-1 second faster in autox though, which could be more tire than anything.

On the Rocks... a Blog: Understanding Suspension Spring Dynamics & Why We Chose Dual Rate - mostly for the pic

Linear vs progressive rate springs | Automotive Thinker - Discussing the finer points of automobiles - for the explanation

Very informative
 

From the article:

Progressive springs are not common in road race cars because these cars typically operate on smooth surfaces. On a car designed for smooth tarmac, these types of springs actually decrease performance as they induce some slop into the suspension.

This is what I noticed with the Swift Spec R springs and why I upgraded to coil overs.

When you think about it progressive springs would require progressive dampening, and getting a gas based dampener to be progressive would be a very interesting feat.

It's what I've been saying all along. Swift spec R will look nice but the true performance won't be there. Stock will be better because of the predictability. How people perceive the "feel" of the car on springs is different from how the car performs...

there is always a give and take. for my Z, ive kept my springs and dampers stock, and just swapped the front bar to make it a tad stiffer. finished her off with RE11's. especially for street driving that is all she needs.

my G35C is another story. she is my dress up car. she is lowered, damped, bar'ed, wheels, s04's, looks, handles, and feels great ... but does that translate to better times on the track? probably not.

Im not going to comment no more loool!! im just going to sit and read :p

This is probably the most logical way for ANYONE here to achieve a very balanced car without sacrificing road comfort. Sway bars would be the only thing I'd add to my Nismo IF I had to add something right now (other than rear camber arms - these cars have too much rear camber).

A sport package or Nismo edition 370Z with a set of adjustable bars, carbotechs (assuming you have 4 pot brakes), and a decent tire will upset a field full of Porche's, and you could still drive this car home.

This sounds like my upgrades...:tup:

Basically what I'm running for now. As skill increases. I up grade.

Hmmm. Good luck with that.

And BTW it's Porsche.

We have always called them Porche's (pronounced Porch) LOL

some dumbarse was calling them porsha

hai undai aiei

Sorry, I missed the "S" - I forget the spelling police are everywhere on the internet.

And yes, the Zs will run with the Caymans and Boxters fine. 911s obviously require some work because they are faster in a straight line, however we can turn just as well or better in some circumstances because the engine is installed in the correct part of our car.

This has been my experience also.

And my wifes as well. The stock nismo is very capable with a good driver. :tup:

Not the new Cayman RS's :(.

So i had a autox today, first time in the Z and just reporting back with some impressions on nismo shocks and swift springs.
Unfortunately didnt autox before with stock setup so cant help with questions on comparisons.

Impressions on the suspension is that it was fantastic!!
Extremely stable and perfectly composed on the corners. There was a very long sweeper and i could control the rear of the car with the gas very well and car wasnt wobbling while making adjustments mid corner or anything.
Changes in direction were nice and suspension just settled immediately. When the back did kick out a bit it was very progressive and easy to anticipate. I was expecting some smap oversteer in some corners but never had it.
In a couple of bumpy parts of the autox the suspension soaked them up real well.

I would like to touch up on some negative aspects but i honestly dont have any. The setup really did surpass my expectations.
I have been attending autox regularly for over 7 years so im somewhat experienced relatively speaking.

Alignment is what the car got after i installed the springs so dont know exactly but from what i read about -1.3-6 in the front and -2.3-5 in the back? I have spacers and SPL camber arms for the back which are not installed yet but for autox i think the alighnment is great. If anythign maybe just a little more neg camber in the front for some more agressive turn in would be great.

Im going to dial out some camber in the back just for tire longevity alone but it felt great in Autox.

When i get it alight with the parts installed ill post the current alighment with my new one just to associate this experience with whatever alignment the car has right now.

I was in STR and did fairly ok. A bit above half way which considering the competition i was happy with. Didnt expect any higher in this class.
Any questions feel free to ask .
Thanks

So installed SPL camber arms in the back. threw suspension out wack and got it aligned today.
Here are final specs.

http://i.imgur.com/ueqUKFtl.jpg?1

Front camber is .5 off from eachother. any ideas why this could be considering there is no adjustment? something i could have done when i installed them?
thanks

You got stock front upper arms. Nothing you can do to change it unless you change the arms. The difference between the sides is tolerance when they built the car. Nothing more, and your caster is real close.

But you can't go wrong with max caster at the track :tup: