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Discussion Starter #1
Hey, have ben on this swaybar thing for a while now, my own personal fixation in some ways.
Anyways, emailed whiteline about their swaybar specs & have had this response; Good info on swaybars, springs & suspension overall:
Will respond to this guy & see if he wants to join forum so we can throw questions at him. This is his words directly copied from email:

G'day Michael,

Thank you for your interest in our Whiteline products.

Information on the Z33 Coupe swaybars follows:
BNF33Z has 2 hole adjustment. Increase approximately 10-40%
BNR30Z has 3 holes. Increase approximately 10-35-110%
I would like to point out that these "quantities" can be rather meaningless and should only be used as a guide unless you relate "them" to the spring rates and motion ratios of both the springs and bars - front and rear motion ratios are of cause different on this chassis. Further information on these topics can be found in our FAQ section - links are here:

http://www.whiteline.com.au/faqsprings.htm

http://www.whiteline.com.au/faqshocks01.htm

http://www.whiteline.com.au/faqelse01.htm#Motion ratio

http://www.whiteline.com.au/docs/bulletins/010barup.pdf

http://www.whiteline.com.au/docs/bulletins...d%20Swaybar.pdf

For your interest, please find some basic information on your chassis which may prove useful as a base start point when evaluating the market for this chassis:
350Z - OEM suspension (according to our measurements)
Springs; front 4 kg/mm, rear 7.3 kg/mm
Sway bars; front 34mm TUBE (solid equivalent ~ 31.5mm) rear 21mm TUBE (solid equivalent ~ 19mm)
Whiteline;springs; front 6.5 kg/mm rear 8 kg/mm swaybars; front 32mm SOLID rear 20mm SOLID

Our spring and swaybar rates have been carefully matched to the rate requirements of high performance street tyres and semi slicks and are suitable for an intensive track day whilst still providing a good ride on the street. It may also be important to remember the aim of this discussion on swaybars and spring rates and 'stuff', is to simply maximise "grip". How we achieve this is the subtle part :)

Michael, I will decline to publicly offer contact details of our customers as we must respect their privacy. I trust that if they are satisfied with their suspension setup they may not see a need to enter into a public debate on a forum, and to do so will be their choice. I trust you can appreciate our position in this regard. As a matter of interest, can you provide a link to your forum please.

I believe that you will be rather amazed at the difference these bars will make to the handling of your car :) , and I trust the above is helpful in providing a base start point for your enquiries.

good luck with your project :)

You can purchase direct on line using the link below to our secure web store

Join us at www.suspensionparts.info/

Regards

Peter Atkinson
[email protected]

Go Flat out with Whiteline Automotive
Group4 Coilovers

See what we have at www.whiteline.com.au
 

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Sounds good to me. I like the spring rates (but I think that my gf will not :) ), but he didn't answer if they are liner or progressive. If they are, they would be perfect for me. Also according to the Hotchkis website the stock spring rates are 5.5kg/mm for the front and 6.3kg/mm for the rear. I wonder if they were testing the Tracks or Tourings springs.
 

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I'm a little suspect about those measured spring rates.

The rear springs are almost twice as stiff as the fronts, and its not like its offsetting a greater weight in the rear end since our cars are front-biased when it comes to weight distribution.

That kind of setup should make the car as taily as all ****, but the 350Z is an understeerer. And the Tein Flex springs run at 10kg/8kg.


As an aside, another Z owner from another forum just had a set of Selby Swaybars installed on his Z33 Track, and he's quite happy with the results. You could give Roadholder Suspension a call and ask about them; when I can find cash after repairing my bumper, I'll be getting those bars.
 

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But you have to remember the the Tein Flex shocks could be valved differently to work with this spring rates. From example Tein S-Techs have rates of 6.9/7.2 front/rear (converted from lbs/inch). The difference is the S-Techs are progressive. I guess their spring rates could have been tunned with the rates of their swaybars.
 

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Discussion Starter #5
The spring rates on the whiteline springs are as follows. These are the correct rates straight from the horses mouth so to speak:
Front: linear 6.5kg/mm (365lb/inch) ride height 340mm-345mm (oem 35mm) drop 20-25mm

Rear: linear 8kg/mm (445 lb/inch) ride height 345-350mm (oem 350 mm) drop 25-30mm

Most car manufacturers tend to dial in 'understeering characteristic's into their chassis's in an attempt to deal with the "Wally" factor. This design feature appears to be quite apparent in the US where "feed back" from the seat of your pants and/or the steering wheel is probably considered unacceptable by most owners and nothing more than an annoyance upsetting the 'limo ride characteristics and (NVH) of the vehicle. To deal with the "no feed back" principle, understeering characteristics when approaching the limit of adhesion are seen as a basic safety feature.

I noted a comment on your forum by a concerned owner relating to how the 'GF' may react to stiffer springs in the car. Our design criteria dictates that we use the lowest possible spring rate to achieve the required handling outcome. Consequently, it is not unusual to find that our springs may be on the softer side available on the market and we consequently rarely receive comment on ride quality. I suggest that you avoid getting too tied up with specific spring rates unless you factor in the motion ratio of the relevant front and rear suspensions etc. The point here is - it is the rate at the wheel that counts not at the spring seat.

If we get down to basics, springs control bumps and keep the car a defined distance off the ground. Shocks are a vital component and their optional preferred name "damper" better describes their function - that being to control springs by dampening their bump and rebound isolations and keeping the spring under control so it can supply a constant and consistent force on the tyre to maintain "grip". Hence the need for some 'rate". If we want to go around corners resulting in a shift in lateral "G" forces, then we have two options; fit springs with ridiculously high spring rates to resist the lateral forces (and body roll) or introduce a device to deal with these forces. This device is an "anti-roll bar (ARB)" also referred to as a "swaybar", or anti-sway bar", or stabilizer etc. This device can be designed and tuned so to have little effect on "rate" in a straight line and so does not interfere with ride quality etc. The swaybar comes into play only when required - going around corners. The important thing here is to balance the "rate" of the front and rear bar and add "rate" to proportionally alter 'roll stiffness' to the front or rear corner to produce a neutrally balanced handling chassis or one that has oversteer or understeer dialled in. I have avoided other dynamics such as pitch etc. Michael, all of the above is simply to support and justify your idea of adding "rate" where you have identified the need by fitting adjustable swaybars.
 

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Discussion Starter #7
"As an aside, another Z owner from another forum just had a set of Selby Swaybars installed on his Z33 Track, and he's quite happy with the results. You could give Roadholder Suspension a call and ask about them; when I can find cash after repairing my bumper, I'll be getting those bars."

Selby is & has been owned by Whiteline for a while now. I would say that the sway bars are in fact the whiteline ones, maybe rebadged 'selby'?
 

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OK, I dug up the info from that I have in regards to the Whiteline springs and swaybars. Oddly enough I can't find much info on the springs ... must be 'burried' somewhere else ... will keep on looking. Though, I did find that Whitline claim that the springs will lower the car 'approximately 25mm'.

Anyway, here it the info on the antiroll bars that I got:

Antiroll bars:
- front = 34mm tube
- rear = 22mm tube
- The OME sway bars are hollow, while Whiteline are solid.
- On the softest setting both the front and back bars will be 9% stiffer than OME
- On the hardest setting both the front and back bars will be 38% stiffer than OME.

ps. I'll post more info on the springs as soon as I find it.
 

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Here's the info on the Whileline springs that I have from Whiteline:
- Front = linear rate, 360 lbs/in (ie. 12% stiffer than OME)
- Rear = linear rate, 445 lbs/in (ie. 8% stiffer than OME)
 

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Discussion Starter #10
Looks like I will be ordering the Whiteline sways in the next few weeks.
I will be getting the adjustable front & adjustable rear. At less than $500 it works out to be a little cheaper than from the US & also a local Aussie product.
 

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When my bank account recovers from my recent trip overseas, I'll be looking at getting swaybars as well.
 

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Discussion Starter #13
Mr whiteline,
Is my thinking correct: to 'dial out' some understeer could I just replace rear sway bar only with a slightly stiffer bar?
 

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G'day scathing,

The OEM spring rates quoted in the post (above) by mickyboy were taken from an Australian delivered 350Z Track (our project chassis).

As you all suggest, the 350Z is predominately an ‘under-steer'er’, although the full handling envelope may be a bit more complex . Roll stiffness and weight transfer can be altered/affected in the first instance by varying the ‘rate at the tyre’ (or corner under load). 'Rate' can be altered by varying the rate of the spring and/or swaybar. It may be best to apply caution when attempting to apply a direct coloration between front and rear spring "rates" without considering all the other factors for example motion ratio and bar “rate” etc.

For your information, our Whiteline swaybars come in a box with both Selby and Whiteline markings :thumbsup: .

I trust the above is helpful

Peter
[email protected]
 

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I posted this in another thread as well but since this thread actually has Whiteline sway bars in the title it belongs here.

Whiteline sway bars for the 350z:

BNF33Z has 2 hole adjustment. Increase 10%, 40%
BNR30Z has 3 hole adjustment. Increase 10%, 35%, 110%

I researched this option a while ago as well, this is from the guys at Whiteline.
 

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Discussion Starter #16
What year model was the Track that you used to determine the oem spring rates?
I ask because the roadster & touring seem to be set up a little softer than the track model. Something the press has labelled as 'European settings' for the suspension.
 

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The Touring model is not setup softer than the Track model. I have compared the part numbers from the shocks on both cars and they are not different. If you want I can compare the part numbers from the springs as well though I dont think they would use the same shock fors cars with different spring rates. The Roadster's suspension is labeled differently so this would have different suspension settings.
 

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I've drove scathing's touring equiped with track's 18" wheels and my car with koni's and his car was a lot softer then mine. I think there must be a difference some place else then just the wheels and tires. And springs could be it.
 

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Discussion Starter #19
There could be a difference in the spring rates & a slight change in the rates will be noticeable. I say this from experience with the Hotchkis springs I just installed. Those spring rates are +8% front and -3% rear, & I can notice the difference it has made going over speed humps & even general bumps in the road. My wife can't pick it, but I'm sure most people on this forum who drive zeds everyday would.

So the shocks could be the same, but the damper rates have changed, but mr chapman will come thru with the info soon enough!
 

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Originally posted by mickyboy@Jan 11 2005, 12:50 AM
Mr whiteline,
Is my thinking correct: to 'dial out' some understeer could I just replace rear sway bar only with a slightly stiffer bar?


G'day mickyboy,

I would suggest that the best start point and (best bang for your buck) improvement to this chassis would be to fit a rear swaybar to add some 'rate' to the rear end. Having said that, fitting both a front and rear bar to balance up the chassis and make it 'stand up" - particularly at turn might be the preferred option.&nsbp;&nsbp;

Cheers

Peter
 
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