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Discussion Starter #1
After a bit of a wait, I finally got aftermarket swaybars for the car. And they are definitely worth it.

The bars themselves are a custom order from Roadholder Suspension (who also fitted my dampers). He gets them made from someone else, and they're a 33mm solid bar (the OEM ones are hollow, and I'm not sure of their thickness but its less than these ones) made from spring steel. The swaybars are also 3 way adjustable, and if you've got a socket set and a trolley jack it should take you all of a couple of minutes to adjust.

Installation was pretty easy. On the front, unbolt the tray. Disconnect the connecting arms and unbolt the D-brackets, and it pops right out. For the rears, the exhaust sits a little too close to just squeeze out. We had to unhook the passenger side mounting point to get enough room to squeeze it out, but it slid back in easily.

The question is, how do they feel? In a word, fantastic. Around town there's nothing in it, but once you hit the bends you can push harder and the car will stay true. In terms of improved handling, they were far more instantly noticable than the Konis.


I went on a run through Wiseman's Ferry and the Old Pacific Highway on Saturday night, and to test I did a part of the Old Pac again (up to Mt White) tonight. So here's the test vehicle, with the handling info:


Car: Nissan 350Z Touring
Dampers: Koni Yellow set 1 revolution from full soft in all corners
Swaybars: Roadholder Suspension set to Medium
Tyres: Dunlop Direzza DZ101
Brake Pads: OEM Front, DS2500 rear


Firstly, I will say that the car felt a little less responsive just off-centre. When I turned in there was a little hesitation tonight compared to before. However, since my front pads are starting to make low grinding noises (the very familiar "low pad" warning sounds) I wasn't braking as hard tonight as Saturday night, and so I wasn't getting the same weight shift over the front tyres either.

However, once I turned in the steering felt more alive. Changes in the steering attitude while in the turn were picked up faster, which is why I suspect the weight shift being a factor during turn-in.

There was definitely more grip all round. I could pitch the car into corners with more confidence (I don't go that hard so there's always some in reserve) and I could definitely get on the throttle earlier and harder. In places where I'd hold off flat throttle because I'd run wide, I could plant the foot and the car would still follow my intended line. The LSD transition effect also was more gentle. Whereas in the past you'd feel the nose run a little wide in the past before returning to its arc, in the same corner I noticed that initially on throttle the car maintained its line, and then tightened it a little.

I will be setting them to the hardest setting soon. The kickback didn't feel too savage, nor did I pick a wheel off the ground. When I do I'll test it again and post a reply.

Whether you're doing some fast street driving or track work, I can definitely recommend getting new bars. Even if they were the 2/3 the cost of the Konis I'd say they were better value from a performance aspect (the Konis do let you set themselves softer for a smoother ride at the detriment of some low-speed handling, but tuning them to feel noticably better than stock without going too stiff was a bit harder).

The cost is $600 plus fitting. My supplier:

Greg Selby
Roadholder Suspensions
16b Flora St Kirrawee 2232
(02) 8539 7333

Install pics are here:

http://www.au-z.org/gallery/my350z_20050502_swaybars
 

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What type of % increase over stock is each adjustment on the front and rear bar?

FYI the oem front bar is 34mm and rear is 21 mm.

Go to the most aggressive setting, I wasted two to three weeks before going hardest on mine, so that time of my life is gone!

Cheers
 

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I can confirm that sway bars give a big difference in handling.

I had the Cusco sways installed two weeks ago and they made a dramatic difference, though I suspect they made more of a different to my Cusco setup than they would for most others. The arse is alot more planted and it handles like what a real sports car should.

You can push further into corners, at higher speed, right to the point of loosing traction and hold or make adjustments with alot of control. These seriously made a big difference.

Next thing to fix is the weight transfer front to rear, there is too much when I get on the throttle, so i'll be doing something to address this next.
 

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Discussion Starter #4
Originally posted by mickyboy@May 2 2005, 03:53 PM
What type of % increase over stock is each adjustment on the front and rear bar?


That one I'm not sure about, to be honest. The fact that they're solid and almost the same size means they're more rigid anyway. The "medium" setting I have them on is definitely firmer than stock.
 

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Thanks for the report Scathing.

I might be opening a 'can of worms' here, but how would swaybars (and I mean any swaybars) give a car more grip? I can see how they would make it more nimble and more direct, but not sure where 'more grip' would come from. Afterall, grip is given purely by tyres and their contact with the road. The suspension keeps the tyres in contact with the road, but that is given largely by the geometry and then springs/shocks ... I don't see how swaybars would help in terms of 'grip'.

Generally speaking swaybars are used to change the balance of the car, but not necesarily to give it more/less grip ... can anyone explain how they could be used to give a car more grip?
 

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Discussion Starter #6
The only thing I can think of is to provide more compression damping while the car's cornering. This means your inside tyre does not unload as much in the corner, providing a greater overall contact patch.

They can adjust the car's cornering balance by varying the adjustment ratio front to rear too, but you could get a similar effect by increasing the spring rate / damping force of the one end of the car relative to the other too.
 

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I believe he was talking about the change in the 'grip' of the car oversteer/understeer not the tyres loosely speaking, from the transfer of 'grip' that the swaybars cause when the front bar has been beefed up. This causes less understeer and again more 'grip' (need to find a better word) occurs on the rear wheels during the cornering cycle!!!

David, for someone who tracks his car alot I can't quite fathom why you haven't changed your bars yet? Surely you would benefit the most!

If that made sense?

Cheerio
 

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David, for someone who tracks his car alot I can't quite fathom why you haven't changed your bars yet? Surely you would benefit the most!

It's probably because I run different springs (ie. more camber) and 245s all around ... that means that my car is pretty good already and close to neutral. I took Lionking for a few laps around Winton so he might chime in with some comments.

Though personaly I'd say that on the road I don't have many complaints and even on the track it has taken me (at least) couple outings to find room for improvement (in terms of handling that is). A heavier rear sway-bar is next on my list of 'improvements' ... I'll probably get it over the next few months.

Though, I'm a firm believer in clearly indentifying the 'problem' and then chosing the 'right' thing to address it. Though, the 'indentifying' part does take a fair bit of time. For that it's also important to make sure that the 'problem' lies with the car and not the driver (ie. my driving).

causes less understeer and again more 'grip' (need to find a better word) occurs on the rear wheels during the cornering cycle!!!

Taking this a step further - a heavier swaybar at the frpont should make the car understeer-more. That is at least the common rule of the thumb. Though, heavier bar the at the rear shuuld remove some understeer. So the balance seems to lie with the front-to-rear stiffness ratio. The more rear-biased the ratio the less understeer, and vice-versa.
 

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Sure, the same size tyres allround help to relieve some understeer, same with the increased camber, but I think I have seen your camber numbers (posted somewhere else), and not meaning to be rude, they are not that aggressive and my guess is they don't contribute much.

You would get full benefit with adjustable sways, especially being able to 'tune' them for the different types of circuits that you go to.

I have left mine at 'full sick' slot, I like a bit of oversteer whenever I want, and the feeling of almost no bodyroll.

Cheers
 

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have seen your camber numbers (posted somewhere else), and not meaning to be rude, they are not that aggressive and my guess is they don't contribute much.

I had -0.5deg before, and now I have -1.5deg at the front. So that is a substantial difference even though -1.5deg is not too extreme. Then again, very few club-racers run more than -2deg of camber at the front so -2deg is plenty agressive for the club-racers.

Also for me it made fair bit of difference. I took the car to the track before as well as after, and the difference (to me at least) is very much noticable. As I mentioned before, for me my car is close to 'balanced' ... not perfect, but also not far off.

You would get full benefit with adjustable sways, especially being able to 'tune' them for the different types of circuits that you go to.

Sure thing, but I would just leave it on one setting for the road and all the tracks. For me whatever works at one place, works just as well elsewhere. So once I have the rear-swaybar I'll just find a setting that works for me and leave it like that.
 

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[/quote]


I WOULD like to comment: "WOOOOO HOOOOOO!!!!!!!!"

It's hard to comment on the difference in the performance of the car. I went from the driver's seat in an auto to the passenger seat in DavidM's car - 10 seconds faster! The car did feel very balanced though. More than mine - but I'm sure that had a lot to do with the driver.
 

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Discussion Starter #12
Originally posted by DavidM@May 5 2005, 12:39 AM
For that it's also important to make sure that the 'problem' lies with the care and not the driver (ie. my driving).


True, and everyone's driving style is different so what works for one of us may not work for another.

I haven't track tested them (but I will when I get the rest of the acceleration-related bits into the car) but on the street, where I did run my tests, I tend to slow in, fast out.

I'll brake a little early and bleed off more speed than necessary, which gives me headroom to change my line as well as compensating for changing grip levels. When I've got the car settled I'll hold it on the throttle to keep it neutral until I can pin it and exit.

With the new sway bars, that point at which I can floor it happens much earlier in the arc. The car maintains its line without running wide (which is as much a handling trait as a grip trait) in bigger lateral loads, so I don't have to ease the throttle on as slowly and can get more punch out of the corners. The steering also feels more direct, which means should I take the car into a decreasing radius turn and trail brake for the decreasing part, or need to adjust my line to avoid bumps / wild animals, the car responds a bit more quickly.
 

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I WOULD like to comment: "WOOOOO HOOOOOO!!!!!!!!"

lol ... that explains it then :)

With the new sway bars, that point at which I can floor it happens much earlier in the arc. The car maintains its line without running wide (which is as much a handling trait as a grip trait) in bigger lateral loads, so I don't have to ease the throttle on as slowly and can get more punch out of the corners.

If I'm reading it correct, you're saying that you feel like you have more grip at the rear as well as the front ... is that right? Now my question is whether the swaybars give you more confidence to push harder, or the car actually has more grip. I can understand the 'confidence' thing as the car will have less lean, but I'm still not 100% clear how the car can have more grip at both ends. As I mentioned before, my understanding is that swaybars just change balance (ie. move postions of the existing 'grip' around).

Also of interest is that racing-cars soften the swaybars (and springs/shocks) to get more grip in particluar if it gets wet of bumby. On the other-hand on a perfectly smooth and dry track they will run as stiff as possible. Still even with that they soften the rear if they want to improve power-down. So stiffer does not always equal grippier, but it always does equal 'more responsive'.

Normaly you see then fidling with the bars to address under-steer and over-steer issues.

ps. Not that I'm saying that your car cannot have more grip ... I'm just trying to understand how it would work.
 

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Discussion Starter #14
I'm comparing them back to back (well 2 days apart) on the same road, same tyres, same damper settings etc. When I went on Saturday I went with a group of like-minded individuals who have lighter, more powerful cars than me. As such, I was working hard to try and keep up (not that I did).

As such I don't think "confidence" is an issue, since I was going pretty hard on both occasions. I was probably less confident with the new bars as I didn't know how they would affect the handling and so I slowly probed their limits by pushing a little harder on each corner until the car started running wide.

It could be a matter of overdriving as well, but there's no way I can prove anything without some kind of G meter and a skidpan. I could be mistaking handling for grip (in the complete opposite to your typical WRX driver who mistakes grip for handling) but after I settle the car into a corner (so removing turn-in from the equation) and feed in the throttle I can run more now before the car's nose starts to push.

Since the 350Z doesn't oversteer at the limit (unless you intentionally drive the car to oversteer) I can't say if there's more grip in the back or if its just the front pulling itself in more, but had I gone to the Aaron McGill Drift Training day today I might have been able to tell you guys :).
 

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Since the 350Z doesn't oversteer at the limit (unless you intentionally drive the car to oversteer) I can't say if there's more grip in the back or if its just the front pulling itself in more

Thanks for the extra info and I was thinking about this a bit more and was coming to the same conclusion. Having more grip at the front would allow you to apply more power (and earlier) as you don't have to 'baby' the front as much anymore. That is certainly one possibility.
 

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Discussion Starter #16
You'll only need to soften out the rear for better powerdown if your car has enough power / torque to make it step out under stiffer suspension settings . :) That and if your range of suspension adjustability lets you run it very firm.

On dry-weather winding road runs, I have been able to punch out of mid-second gear corners flat throttle just post-apex with a relatively quick feed-in and not a hint of rear traction loss. If anything it'll run a little wide.

I think if I take an intentionally wide line with a hard cut into the apex, and just floor it at the apex I could probably get the tail to smoke out, but I'd just be as likely to plough understeer the car in that situation (from my wet skidpan experience).

Hook me up with an APS kit and a set of Tein Flex and I might need to "soften" the rear suspension out a bit. :)


Anyway, to "settle" this I've been thinking about picking up a G-Tech SS meter (this was before this discussion, but I thought the unit would be cool). I won't go back to the stock swaybars, but if someone wants to run some comparative skidpan testing we can work something out.
 
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