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"Project Locomotive," Suspension build log

PostPosted: Mon Oct 12, 2009 7:18 pm
by teK--
I have been a bit late in starting this thread as I am about to start stage 2, but better late than never!

Car: MY04 Liberty 2.5i Safety, 5MT sedan.
Mileage: 50,000Kms

Stage 0 (stock): When I bought the car it was 100% stock even down to the RE050A tyres. I was quite surprised at how well the car handled, my first spirited run being through the twisty mountain dropoffs on the way out to King Lake.

Initial thoughts are that the springs and swaybars are setup too soft. Bump rate is too soft, but surprisingly rebound rate is reasonably high for a stock car. There is substantial body roll on tighter corners. Turn-in was relatively poor with plough understeer at higher speeds. Generally, driving this car under its design intent it handles quite well. Tyres are excellent and offer very good steering/road feedback.

Tyres are set to 42/40psi front/rear (measured cold). I suspected that the wheel alignment must be out as the rear is nervous and the previous owner reportedly did not have a wheel alignment since the car was delivered new! Tyre shoulders were indicative of this also.

Re: "Project Locomotive," Suspension build log

PostPosted: Mon Oct 12, 2009 7:35 pm
by teK--
Stage 1 (pics to come):

The scrubbed and unevenly worn RE050As were changed for RE-001 Adrenalins. Initial thoughts are that these are softer in the sidewall, however once scrubbed in I found these to be a very close match to the stock tyres in terms of outright grip. For just over half the price of the stock tyres, they are a cost effective alternative.

Tyre pressures maintained at 42/40psi cold front/rear.

The following parts were then fitted:

- Whiteline 20mm adjustable rear swaybar BSR39Z and set the stiffer of the two settings.
- AVO Heavy Duty rear swaybar mounts
- Whiteline antilift caster bushes KCA334 (front control arm rear bush)
- Whiteline front control arm front bush W0506

Wheel alignment revealed that the toe settings were all over the place as anticipated. RR was +5.0mm and RL was -3.0mm, fronts had about 3 or 4mm of cross toe as well. No wonder the tyres were stuffed! Rear camber is -0.5deg on one side and -1.0deg on the other. Front camber is -0.5deg on both sides. I will leave these for now until I have the car lowered. Toe has been set for 0deg front and rear.

At stock ride height, I found that the caster bushes added 1.0degree of positive static caster to each side as compared to Whiteline's rated +0.5degrees per side. Fitment and orientation of the bush was double checked and Whiteline consulted and this is indeed correct. Perhaps Whiteline's advertised ratings are conservative. The more the better!

First drive around the block revealed instantly noticeable improvement in the handling. Turn-in is improved substantially and the back of the car just follows where you point the front. Fixing the wheel alignment no doubt played a part as well.

A few hundred Kms later, the lasting impression is that the front is much more willing to go where you point the wheel, however it is still noticeable that the front swaybar is inadequate as the uprated rear bar makes it much more pronounced. Straightline stability is noticeably improved due to the increased caster. It is much easier to start feeding in more accelerator earlier in the corner on exit. Road/steering feedback is also improved due to the cushy stock rubber bushes being replaced. I would say that it feels like I am running RE050A again.

NVH levels increased a tiny bit at the front end on coarse roads. Liftoff oversteer is very rare even when pushing the car relatively hard. I feel this is due to the stock springs/dampers.

If on a budget I would recommend that the mods in my Stage 1 are the most cost effective as it is how I invisage a "sports edition" of this car to handle.

Notes:
I chose to install the AVO heavy duty swaybar mounts as I have read many reports that the stock mounts are inadequate when using uprated bars. They can bent or snap when driven hard. I have not upgraded the swaybar endlinks at this time as I honestly do not find any of the aftermarket items to be acceptable given their price.

I.e. Rose joint/ball joint endlinks are notorious for drying up and causing play/rattles on cars that are daily drivers. Solid endlinks which use urethane bush designs all appear to have the common problem of splitting bushes. Copies of the OEM design (ball joint enclosed with rubber seal) do not appear to be durable and I have seen lots of reports of stripped threads or broken balljoints. For now it appears that the OEM ones are a decent design for now.

The following Whiteline endlinks appear to be a good design by all accounts and are reasonably priced:

Image

Re: "Project Locomotive," Suspension build log

PostPosted: Mon Oct 12, 2009 8:06 pm
by teK--
Stage 2 (in progress):

I have the following parts awaiting to be fitted this weekend:

- Swift Springs Part #4F008. These lower the car 30/25mm front/rear. Spring rate is 4.3/6.6kg per mm front/rear. These are stiffer than STI pink springs and Eibach Pros however not as firm as Tein S-Techs. I settled on these because they are Japanese made and used widely in motorsports there. Plus they are a linear rate spring with a reduced amount of coils. This equates to lower unsprung weight, predictable handling, increased suspension travel and less chance of coil binding.

I found an independent review: http://www.northamericanmotoring.com/forums/suspension/157535-swift-springs-dynoed.html which includes dyno testing of these springs. The writer's experience is that these are one of the few brands of spring which actually match the advertised spring rate at varying levels of compression.

Nick of Entra Imports has just become the exclusive importer of these springs: http://www.entra.com.au

- Bilstein B8 Sprint dampers Part #TBN. These are a short body design intended for running lowered springs. When lowering a car using stock ride height dampers, the dampers are under undue compression even when the car is stationary. This increases its duty cycle and hence its service life. The 2.5i front strut tops should bolt on fine *touch wood* as Aus DM models run JDM spec strut tops on KYB dampers. This is the reason why the stock front suspension ride height is so much higher than the back. (Secondary reason is simply due to the way in which the wheel arches were designed).

- Whiteline rear control arm upper bushes (camber adjustment) part #KCA399. Once the car is lowered I invisage that the amount of negative camber will increase. I want to run -0.5deg camber on each of the rear wheels, then run -1.0deg camber on the front wheels via the stock adjustment bolts, to induce less understeer.

The springs just landed today after doing a round trip around the world: Japan>USA>Australia. Mega excited they look great!:

Re: "Project Locomotive," Suspension build log

PostPosted: Tue Oct 13, 2009 9:10 am
by nytrojen
Nice work Tek! Very informative... though I fear you may be convincing to spend even more money on my lib now :(

Re: "Project Locomotive," Suspension build log

PostPosted: Tue Oct 13, 2009 9:57 am
by teK--
Cheers Avon. I have gone into a lot of detail as I spent a very long time researching my options prior to setting out this plan. If anyone has any further questions about why I selected each part then feel free to ask away.

e.g. I also considered KONI yellow dampers as well, in lieu of the Bilsteins.

Update 13/10/09. The Bilsteins are on BACKORDER!!! :( Looks like this weekend will only involve fitment of the Swift Springs and the rear camber bushes. I cannot wait until the Bilsteins to come in as I have a track event in early Nov.

The upside is that it will give you all an idea of how well the uprated springs will run with stock dampers. My hypothesis is that they will be quite bouncy :)

Re: "Project Locomotive," Suspension build log

PostPosted: Tue Oct 13, 2009 10:33 am
by tangcla
Let me know how you go with the endlinks. I'd be looking for a replacement item which is not going to be noisy - at the same time the endlinks are the cheapest of all components if something were to break.

I'm using the AVO adjustable endlinks at the moment.

Re: "Project Locomotive," Suspension build log

PostPosted: Tue Oct 13, 2009 10:42 am
by Arith
Great work and nice write-up Jim! Any more info on the springs? I'm sure there are quite a few folks on here that don't qualify for the Teins S.Techs due to not having Bilsteins, and are finding alternatives to lower their Libs.

Re: "Project Locomotive," Suspension build log

PostPosted: Tue Oct 13, 2009 10:59 am
by teK--
tangcla wrote:Let me know how you go with the endlinks. I'd be looking for a replacement item which is not going to be noisy - at the same time the endlinks are the cheapest of all components if something were to break.

I'm using the AVO adjustable endlinks at the moment.


Agreed. I have not heard of one complaint about OEM endlinks being noisy, only that they bend or even break when using very stiff swaybars or if the suspension is put under very high loads (e.g. impacts). In other cases they will only wear out eventually. In my case at 50,000Kms they still look very good when I inspected them. With my rear bar set on hard, I understand it effectively is as stiff as a 21mm bar which is still nowhere near some of the monsters the Yanks fit (24mm).

The stock rear bar is HOLLOW and weighs next to nothing, it is 18mm based on my eyeballs.

I understand that the Whiteline double eye S links which I posted the pic of, are doing quite well for people who use them for 4WD'ing.

Re: "Project Locomotive," Suspension build log

PostPosted: Tue Oct 13, 2009 11:03 am
by teK--
Thanks Arith,

The springs are being fitted to the stock struts this weekend. The Bilsteins are unfortunately on backorder for another 4 weeks. I will be doing ride height measurements and also spring weight measurements and post up results next week.

p.s. Drndrn has fitted S Techs to his stock 2.5i KYB struts. IMHO the car does not look that low but he said it rides very firm but quite undamped on bumpy roads. There is a moderate drop of probably 25mm or so front/rear.

Re: "Project Locomotive," Suspension build log

PostPosted: Tue Oct 13, 2009 12:33 pm
by tangcla
teK-- wrote:I understand that the Whiteline double eye S links which I posted the pic of, are doing quite well for people who use them for 4WD'ing.

Noisy though? Will it affect NVH/comfort if it's got no flex at all like the stock ones?

Re: "Project Locomotive," Suspension build log

PostPosted: Tue Oct 13, 2009 12:51 pm
by teK--
There will be greater NVH in terms of road noise compared to the stock endlinks, but I doubt it would be noticeable and it is more than compensated by the increased effectiveness of the swaybars.

When I talk about unacceptable noises I am talking about squeaks and rattles :)

Re: "Project Locomotive," Suspension build log

PostPosted: Tue Oct 13, 2009 12:55 pm
by smythie
teK-- wrote:The stock rear bar is HOLLOW and weighs next to nothing, it is 18mm based on my eyeballs.
Using verniers mine (spec B fwiw) measured at 17.75mm. Being hollow reduces torsional stiffness by a factor of SFA btw :wink: (if the 17.75mm bar has 5mm walls you'll lose 3.6% of the stiffness; 3.5mm walls, 11.1%)

Re: "Project Locomotive," Suspension build log

PostPosted: Tue Oct 13, 2009 1:00 pm
by teK--
Yes the swaybar outer diameter is ultimately what determines its stiffness, but a hollow bar is slower to respond to changes in suspension travel :). The weight of a swaybar in that sense tells a lot about how it will perform.

Damn I was 0.25mm off my eyeballs need to be calibrated :P

Re: "Project Locomotive," Suspension build log

PostPosted: Tue Oct 13, 2009 3:08 pm
by smythie
how would a hollow bar be slower to respond? I'm interested because to me less mass means less inertia and thus better response

Re: "Project Locomotive," Suspension build log

PostPosted: Tue Oct 13, 2009 3:30 pm
by teK--
Hopefully I'm explaining myself correctly, but what I mean is, is that with a hollow bar the ends of the bar are typically formed by squashing down the tube then punching a hole through it to bolt on the endlink.

IMHO it is at this junction (where the tube ends and where the squashed section begins), that there must be a lot of flex and stresses in the material when the bar was manufactured. Further, hollow bars must be mandrel bent when you need complex curves which means that the wall thickness is going to vary in these areas as well, and makes those areas of the bars less stiff/weaker.

The only benefit where a lighter bar would benefit is to reduce unsprung weight of the car, but going for a solid, larger bar definitely provides better benefits than having the 1-2kgs less unsprung weight of a hollow OEM sized bar.