Why a 3RB?

[GTSPECB STI]

Dave, any NVH increase from the new sways?

Nope not a hint

[smythie]

Stock sways are like tooth picks on Spec B's for a start and are hollow and not very effective.

Contrary to popular belief, being hollow doesn't affect the stiffness anywhere near as much as you might think. For example, a 15mm thick bar with a 5mm hole down the centre is still 98.77% the stiffness of a solid bar. Even with a 7.5mm internal diameter, the hollow bar will have 93.75% of the stiffness of the solid bar.

However, going from (solid) 15 to 16mm yields an almost 30% increase in stiffness

The relationship is a 4th power relationship (ie diameter^4)

[GTSPECB STI]

Stock sways are like tooth picks on Spec B's for a start and are hollow and not very effective.

Contrary to popular belief, being hollow doesn't affect the stiffness anywhere near as much as you might think. For example, a 15mm thick bar with a 5mm hole down the centre is still 98.77% the stiffness of a solid bar. Even with a 7.5mm internal diameter, the hollow bar will have 93.75% of the stiffness of the solid bar.

However, going from (solid) 15 to 16mm yields an almost 30% increase in stiffness

The relationship is a 4th power relationship (ie diameter^4)

LOL I reckon I could bend the hollow stock rear sway bars without much effort and I would love to know the metallurgical composition of them as they pretty soft and appear cheaply formed. The whitelines I have replaced them with are 22mm diameter round bar and well finished. Big difference I promise you.

[smythie]

Ok, I crawled under the Lib this morning with some verniers and the stocker is 17.75 OD. Solid vs solid, your WL would be around 236% as stiff. If the stocker had a 5mm wall thickness (7.75mm ID), the WL would be almost 245% as stiff, with a 3.75mm wall thickness, the WL would be 262% as stiff. As you can see - losing the centre of the bar doesn't make a massive difference in stiffness. This is all assuming identical materials and heat treatments.

Weight is the reason manufacturers use hollow shafts – with a 5mm wall, the stocker would be 81% the weight of a solid bar (for a 3.7% loss of stiffness), while with a 3.75mm wall thickness it would be 2/3 the weight (for an 11.1% loss of stiffness)

[subnub]

Does that make an assumption of identical materials? Because that may or may not be the case.

Interesting figures either way

[smythie]

yeah, at the end of the first paragraph

[subnub]

Doh missed that haha

[Mav]

Bought the 3.0rb after upgrading form the gen 3 2.5l rx.

got it due to p plate restrictions, they are one of the best looking libertys and the full option list is awesome, not to mention they do keep up with turbos and the 6 spd sti box is awesome such a nice drive its great having hte power there thru the rev range with no lag

first thing i did was HID kit and strut braces. got the swaybars coming - the back moves far too much but nothing that the swaybars etc wont fix haha

lookin forward to redoin the exhaust system and gettin a set of quad tips.

but need more money haha

[GTSPECB STI]

Does that make an assumption of identical materials? Because that may or may not be the case.

Interesting figures either way

tensile strength of material is the real test I suggest

[Zoo Tv]

I took out a 2nd lease on an 05 Spec.B (or RB) because for the price, a new car got me either:

*Mazda 3
*Base Honda Euro
*Mid-end Liberty
*etc

So I went for it due to the:

*3.0L 6 (non Turbo was a big plus)
*Leather
*McIntosh
*Power everything
*Sunroof
*6spd manual
*AWD
*Climate

etc
etc

[BUDDAH]

Funny the main reason I went for the 3RB was it could tow my boat with out any problems .

My first choice was a GT and the local dealer was kind enough to loan me his car for the weekend and how pleased I was I didn't go for a GT it just reved its tits off and didn't know which gear it should be in and seldom went into 5th (Auto ) the temp gauge always was on the high side.

[GTSPECB STI]

Funny the main reason I went for the 3RB was it could tow my boat with out any problems .

My first choice was a GT and the local dealer was kind enough to loan me his car for the weekend and how pleased I was I didn't go for a GT it just reved its tits off and didn't know which gear it should be in and seldom went into 5th (Auto ) the temp gauge always was on the high side.

slush box for the loss every time

[GHW]

I only went for the Liberty because I found out I couldn't split fold the rear seat on the IS-250 Lexus I was ordering, I'd already sold my A4 1.8TQ so I was stuck without a car!......true story

[mianos]

I only went for the Liberty because I found out I couldn't split fold the rear seat on the IS-250 Lexus I was ordering, I'd already sold my A4 1.8TQ so I was stuck without a car!......true story

Yer I drove the IS before I got my 3rb. The backseat was too small for a reverse child seat. There is a very nice finish on the IS but not an exciting car to drive for me.

[GHW]

Totally agree mianos, now if they bought in the IS-350 that'd be a different story.
Pretty happy with the Subie though.