Sway Bar for SP20 2003

[twilightprotege]

wotjek's reply - ps ezin, looks like Mazda told us all a dodgy - we all have 17mm rear bars not 16! :

Hi Andrew,

Thank you for contacting us, although I am concerned about the tone of your email.

I would like to start by setting a base line with original suspension.
Mazda 323 BJ2 is fitted with 22mm front and 17mm rear OE sway bars.

The actual cornering balance of the car is only partly dependant on the sway bar rates. There are many other factors that come into this equation, including wheel alignment settings. Changes to camber, caster or toe settings do change the handling of the car, so there are different ways of achieving similar result. In this example, option 1 can be the first mild improvement, and can be followed up by option 2.

Option 1.
front 22mm sway bar (OE), rear sway bar 20mm (BFR59Z) Result it greatly reduced overall body roll, as well as understeer.

Option 2.
front sway bar 24mm (BMF50), rear sway bar 20mm adjustable (BFR59Z) Result is even bigger reduction to overall body roll, as well as understeer and sharper steering.

So, to answer your questions....

What went wrong?
- Nothing.
What happened?
- We have improved the handling of Arden's Mazda 323.

I find it strange and disapointing that you are disappointed with the outcome of what we did, when you say... "I would have thought the front bar would have gone to 25 or 26mm, and then a rear bar made to suit, 21 or 22mm."

With 24mm front and 20mm rear, the increase over standard is 2mm front and 3mm rear.

Using your analogy, the effective increase in sway bars is 3/4mm front and 4/5mm rear. How will this change the cornering balance?

We also did not want to use any bigger then 24mm front sway bar, as that will start to have a detrimental effect on front grip, which is why we decided to use 24mm front and 20mm adjustable rear.

Lastly, I am not sure what you mean by; "In addition, what were done with the mounts?"

Regards,
Wojtek Rogulski

[twilightprotege]

my reply to wojtek :

Hi Wojtek,

Sorry if the tone of the email was in any way concerning, that was not it's purpose.

In terms of what a way bar does, yes I have a good understanding of what each part does in terms of a complete package for handling.

In terms of the "what did you do with the mounts" question, I was just wondering (which I'm sure you did) if you changed to polyurethane bushings and new brackets etc?

Now in terms of the options you provided. Obviously I am not as knowledgeable with suspension as you, but 24mm on the front still seams to be undersize for weekend racer handling. I compare with the available sway bar kits in Japan kit for the SP20. Mazdaspeed makes a kit where the front is 25mm and the rear is 20mm. Ok, this is quite comparable with what you are proposing. Autoexe makes a kit with 26mm front and 21mm rear. Is the front bar you designed adjustable? What do the bars adjust to and from (equivalent mm sizing)?

I see the N15 Nissan Pulsar has 26 and 28mm front bars available. Surely that car is very similar in handling to the SP20. This especially is why I am very unsure why you say bigger than 24mm is detrimental to front grip.

Another concern is that you say the 20mm rear bar suits both the OEM and 24mm front bar. I know you state that the 2nd option is adjustable, but wouldn’t a package designed for a daily driver/weekend racer be adjustable everywhere anyway?

A question I also had was why you decided on 24mm and 20mm bars. Was any testing undertaken and can you explain how this was carried out and what results were found with larger/smaller than 24mm bars on the front and 20mm bars on the rear?

Finally, what is the part number for the 24mm front bar?

Look forward to hearing from you again soon,

Andrew Bode

[twilightprotege]

hopefully that should get some decent answers.

[Riceboy]

hey dude looks like u guys having pretty dodgy probs with whiteline...

well atm im using the autoexe sway bars and result so far is not good ....

the fronts hit something in the engien bay dunno wat it is yet .. im getting that trouble shoooted by centrax tomorrow morning.

also if u dont wanna spin ur car at some long corners i suggest to buy some grippier tyres at the rear coz with the upgraded sway bars the astinas get very very tail happy. i nearly had a incident last nite on the inner city bypass .... scared the **** out of me

well i think with the setup that whiteline have chosen shoudl b good but still i dont think it would only take a few days to research and develop tho.

did u try fulcrum for ne suggestions ????

[arden]

BMF50 is the part number for the front sway bar.

[twilightprotege]

well whiteline does have the reputation in oz so that's why we went there.

yeah i was a big shocked they only needed the car for 2 days - almost like they already knew what they were doing to do

[Riceboy]

well they should know wat to do tho but not enough time for testing n stuff ....

makes u think how long they took testing and developing the current range tho ey ....

[twilightprotege]

was the front bar adjustable?

[Riceboy]

on the whiteline one or my one ???

mine isnt adjustable

and also reading the past few pages im guessing the white line isnt either

[chicaboo]

Hey guys,

Has anyone else had a tower/strut brace made up by whiteline? Cos mine has come in and to my surprise it is an RHS section and not a CHS like the Mazda oem...

Gav.

[SFC01]

Slightly off topic but the whiteline front strut brace is an ovoid-ish extrusion, as opposed to the OEM circular profile, so you seem to have received the "correct" part.

Andrew, I have been on record as questioning why the front sway bar needed to be upgraded in size. Chasing what is available on the US market doesn't necessarily mean that is the be all and end all in terms of what is ideal. That said one persons sense of ideal would be very different to anothers.

I guess the point I am trying to make is what was the purpose of whiteline's "development" of the BMF50? To make the 323 handle better. For me that means dialling out understeer. Now if I go and fit the new front bar I have no doubt that the body will roll less. I also have no doubt that with my set up all being equal I will wind up with an increased tendency to understeer. As Wotjek stated wheel alignment can have a huge effect on the handling of the car of and by itself. What I am interested in is how Whiteline aligned Arden's car and how those specs compare to stock.

I disagree that you can make any kind of analogy between the handling of a 323 and a pulsar (unless of course they have shared components and specs).

Also, understanding how swaybars work means that it is known that increasing the front rate for road use will wind up having a detrimental effect on front grip.

For mine I would have liked to see Whiteline offer a rear bar increase proportional to the increase in the front bar which to my thinking (42% increase in rate front and rear over the OEM/BFR59Z stiff combination) would be a 22.7mm effective rear bar diameter. Frankly why bother introducing another product line when 22mm is already available as the BFR59Z?? Maybe they rationalised on the front bar size to match the max rate of the available rear bar, I dunno just making conjecture.

Sorry for the length of the post...

[twilightprotege]

riceboy - was meaning the whiteline, but interesting to know the autoexe isnt.

SFC - all completely valid points. i'm mainly interested in seeing why they went for a 24mm size and what testing was undertaken to decide on that size. i used the pulsar size just to see what they'd say. same goes for the mazdaspeed and autoexe bars. if they can give me a great and informative response i'll be happy. either way i will be getting the setup just like arden. and yes, i'd love to see what they did with arden's alignment etc

[Riceboy]

hey yo

i think the thing with wat whiteline did is so that they can match up the same front sway bar to the rear sway bar that they have already made.

yeah i agree that it will be better then stock but then u have to decide wat u r using the car for. if its just for normal street boy racer then its fine but if ur afta track weapon then i guess its not wat you are looking for because also that the sp20 or astina in general is not really a sport car. compared to main stream cars like wrx and 200sx etc...

so thats why i think that whiteline didnt go into much development and research to make a overly pricey and track weapon type sway bar.

Twilight: got the bars fixed it no longer bumps .. so track day here i come

[twilightprotege]

make sure you tell me how your times decrease. my mate in his 200sx lost something like 2 seconds just from changing to the whiteline sway bars.

yeah i think that's what whiteline probably did - just match the front bar to the existing rear bar on the stiff setting. hmmmmm

[Riceboy]

man u should just come and race too

u will have ur car back by then wont u ??

the next one is last saturday of october

i should have my exhaust by then...

>.< i want my exhaust >.<

bit off topic but yeah u should come racing dude

[twilightprotege]

that was one of the ideas behind the brakes - dont think i will be making any until next year though - baby due 8 november

[preeman80]

ok so, wats the verdict guys? Should I order one or not? :shock:

[SFC01]

Wheel alignment specs?? -bump-

[arden]

Originally Posted by SFC01

Wheel alignment specs?? -bump-

i will scan it 2nite.

[arden]

Originally Posted by preeman80

ok so, wats the verdict guys? Should I order one or not? :shock:

Id say do it if u can manage to install it. only $150 for the bar.