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| The front Whiteline bar in place. You can see the super short endlinks and the tight location that make it nearly impossible to design an effective 3 way adjustable bar. The angularity would be too great so Whiteline wisely limited adjustment to 2 way. We adjusted the front bar to the full soft position. |
The Whiteline bars are 27mm in the front, the same diameter as stock. The Whiteline bars are solid compared to the hollow stock parts and this is where the increase in stiffness comes from. The adjustments can vary the stiffness about 30%. The rear bar diameter is 24mm up from the stock 23mm. This offers about a 50% increase in stiffness. The adjustments can also change the stiffness around 30% as well. This increase is significant and will greatly reduce roll.
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| We set the rear bar to the rearmost, softest setting for now. When we finalize our wheel and tire selection and can book some track time, we will adjust things to optimize performance. |
To start, we are setting our bars to the softest setting in the rear and the soft, forward setting in the front. We will go from there once we know what our wheel and tire combo is going to be.
To go along with our Whiteline bars theme of adjustability, we chose KW Suspensions Variant III coilovers because they are one of the best dual purpose street/track suspensions out there. We would have preferred KW’s more aggressive track focused Clubsport dampers for our car but they are not available yet (hint, KW?).
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| KW does not make a Clubsport suspension for the 370Z yet. The V3 uses the stock rubber upper spring mounts which are preferable for everyday driving for smoothness and quietness. We would have wanted to run spherical bearing mounts in this harder edged car. KW, make some Clubsports for this car! |
Variant III’s are a unique advanced gas charged, independently adjustable in compression and rebound, twin tube damper. Although some people may dismiss twin tubes as low end dampers compared to monotubes, the KW’s are a high precision twin tube with the characteristics of a monotube. The KW’s are a twin tube mainly so that it is more straightforward to build independent adjustment for the compression damping and to allow more room to package KW’s advanced, sensitive foot valve.
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| The KW spring is barrel wound so it can work with the stock upper mount. This is great for street use but it limits us to these special springs. If we want to go stiffer, we have to figure out something with the upper spring seat. Not hard but we would rather have Clubsports designed for a race spring. The KW also has a shorter body so you don’t lose travel on a lowered car. |
The KW’s ability to independently adjust the compression and rebound damping is a huge advantage over other street suspensions that are almost always only adjustable for overall damping stiffness. Independent adjustability of compression and rebound damping is important for any car that is going to be tuned for optimal handling under a wide range of set ups and conditions like our daily driven 370Z that sees a lot of track use.
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| KW’s have the stock location rear spring set up for adjustable ride height, a cool feature. The tan bumpstop is a soft and compliant MCU or micro cellular urethane bumpstop. This sort of bump stop is preferable because it is soft and progressive so if you hit it while cornering, it won’t cause a drastic change in chassis balance. |
7 comments
Hi Mike and friends,
Great write up on the 370z. I have a 2013 G37s coupe, and am thinking that these KW V3’s are just what I have been looking for, as I don’t want to drop my car much more than an inch. Will I be needing that front A arm to dial in my camber to stock specs, as well as the rear arms? I’m most likely not going to track my car, but who knows,,a guy has to have some fun! I was giving the Bilstein B16 PSS10 kit consideration, but Bilstein said the minimum drop in front was about 2 inches, which might be too low for a street car. How did you access the upper adjusters on the V3’s?
Thanks,
Michael
For an adjustable front arm, I prefer the part made by SPL which was not available when we did this car. If you are not going to track the car, I don’t think its particularly needed. Its good to pick up some negative camber you will get from lowering the car unless maximum tire wear with less performance is important to you. I prefer the KW over the Bilstiens because of their adjustment flexibility.
Hi Mike,
Thanks for the reply. Those SPL upper arms are indeed beautiful, but I think they might be overkill for a mostly street driven car. What do you think about the SPC arms, or the Z1? I pretty much nixed the Bilsteins after going around with their tech dept. I really don’t want to drop the car all that much, and they were telling me minimum drop was about 2 inches! I’m pretty sure that I am going to go with KW. Hopefully it won’t be too much trouble dialing in the back, as the upper adjustments seem like they will be very hard to reach,, unless I drill an access hole, and buy an extender knob. I also work on the ground under stands most of the time, and as I age, it doesn’t get easier, but I still enjoy it. Cheers,, Michael
I think you probably don’t need arms for a street car and can just live with the additional negative camber which helps performance.
We drilled holes and used a long 3mm allen wrench but not KW makes optional extended adjusters so I would do that.
Hi Mike,
Did you ever install a set of SPL front upper arms or any other of their products on the 370Z? If so, how much noise and vibration transfers into the car? Do the PTFE lined rod ends last very long? I see on the SPL site that they are “For off road only”. Did you ever lower the Z more than an inch? Did the Kinetic parts with urethane bushings make alot of noise, and what about longevity? I am very much into handling, and ride quality, or I would not be looking at any of this stuff. Tire wear is a consideration, as good tires aren’t cheap. How do you compare the ride feel of the Z on the KW’s to the stock suspension? At a 1 inch drop, did alignment stay in or close to spec?
Thanks, Michael
We didn’t on the 370Z but we have on our Project 350Z and R35 GT-R. It does transfer more noise and vibration into the cabin and if you are concerned about this I don’t recommend it. The Kinetic stuff isn’t that noisy or harsh but for us, you could not get enough negative camber out of the adjustment. The KW’s ride very well, probably better than stock. Any time you do suspension work, you need to realign the car. A 1″ drop isnt very much so the alignment will come back.
Hello Mike and friends, thank you for these great write ups! Wondering if you were able to find the ideal height measurement on this car? (Hub – Fender)