Boxed trailing arms, what is the purpose?
#1 _Big T_
Posted 04 June 2007 - 01:51 PM
I discovered on the weekend that my UC has boxed trailing arms so I told Mrs Big T. She says "thats nice dear, what do they do?" The blank look on my face and my response "dunno, something good but" suggests I need a proper explaination for why boxed trailing arms are a good thing. My assumption is that they strengthen the trailing arms for stability?
Cheers,
Mr Big T
#2 _rocket_
Posted 04 June 2007 - 02:00 PM
#3 _Big T_
Posted 04 June 2007 - 02:03 PM
#4 _rocket_
Posted 04 June 2007 - 02:07 PM
#5
Posted 04 June 2007 - 02:46 PM
#6 _Big T_
Posted 04 June 2007 - 04:40 PM
#7 _ingles_
Posted 14 June 2007 - 03:51 PM
#8
Posted 14 June 2007 - 04:01 PM
#9
Posted 03 January 2008 - 08:33 PM
#10
Posted 03 January 2008 - 09:00 PM
http://www.gmh-toran...showtopic=23896
#11 _Big T_
Posted 03 January 2008 - 09:49 PM
Anyway I digress.....
Attached are some photos as requested Mark. I just went down to the shed and snapped off a couple to give you an idea of what they look like. PM me if you want a few more and I can jack the car up on the weekend and take some measurements if you wish.
Cheers,
T
#12 _Herne_
Posted 03 January 2008 - 10:27 PM
I always knew about the trailing arms but quite frankly I had forgotten all about them.
Cheers
Herne
#13
Posted 04 January 2008 - 06:42 PM
#14 _Bomber Watson_
Posted 04 January 2008 - 07:05 PM
And remember if you have a LC/LJ you need to cut a hole so you can do up your spring...LH/LX dont have this drama.
Cheers.
#15
Posted 04 January 2008 - 08:47 PM
#16
Posted 04 January 2008 - 09:10 PM
Mag5000 What do you mean by this.
#17
Posted 05 January 2008 - 02:37 PM
artical from old mag - Building a Tougher Torana No1 - A Technical Guide , page50
#18
Posted 05 January 2008 - 02:51 PM
this is page part of another mag - Torana Power - No3 page 41
theres a sentance that starts (By simply) that tells of whats what.ive tried both boxing and lowering diff arms all work well and no big budget required
#19 _Brewster_
Posted 11 January 2008 - 08:07 PM
#20
Posted 12 January 2008 - 10:01 PM
What is happening is when you plant the right foot the shock of the tyres rotating is transfered to the diff which tries to rotate in the opposite direction, so you either bend the arms or rip the top mount off the body.
#21
Posted 12 January 2008 - 10:43 PM
Big slicks and an 11 sec pass and you are getting into the danger zone.
I wouldn't be using poly bushes in the top arms or boxing them.
Both the arms and the bushes are designed to flex for a reason.
Don't make me post a pic of my boxed upper arms with the failed polyurethane bushes again. I had only done about 10,000k's when they failed and they were the softest grade available. Clearly a result of not being able to flex as a bushing needs to be able to do with this style of rear end.
Don't worry, when I was young and silly, I wouldn't be told when it came to these types of things but guess what - some of those guys were actually right.
The top arms won't bend under accelleration because they are under tension.
Making everything mega stiff is fine for the drags but if you want to go round corners, it will make the car go round corners on 3 wheels which it will do slower than it will on 4 wheels.
Oh btw, if running a panhard, rubber upper control arm bushes are a must.
You will have a very shite setup for cornering if you use stiff bushes.
A converging arm 4 link already has a roll centre defined. Installing a panhard defines a second centre much lower and guess what? The rear end can only pivot about 1 centre, not 2 so unless you have some compliance somewhere in some rubber bushes, you will either break something or you will make the weight transfer worse than the original shite setup.
I think you will find all the old touring cars that used panhards also had rubber bushes - they knew the converging arms sucked but were stuck with them - they did the best you can really do without removing everything and changing the whole fundamental design.
Two things those magazine articles fails to mention about lowering the front mount of the top control arms is
1. It will make your rear end more prone to tramping under really hard braking.
2. It raises an already discustingly high rear roll centre even higher which will make your car handle worse around corners - one of those articels even bullshits and says it helps in all forms of racing. Typical low level bullshit that comes out in those types of mags.
That lowering the front mount of the top control arm is only a drag racing modification.
M@
Edited by Toranamat69, 12 January 2008 - 10:47 PM.
#22 _Brewster_
Posted 15 January 2008 - 08:54 PM
#23
Posted 24 January 2008 - 07:05 PM
It's funny... but in the HQ which is the same setup as an LX torana... Koni adjustable shocks, Whiteline springs ( 1.5" lower than std), boxed lower arms and nolathane bushes with rubber uppers seem to work fine for what i do with the car (Street/strip). Oh.. ive got swaybas front and rear too!
No 90/10s, nothing else trick, and running a pretty easy 11.9 on drag radials... Interesting to see tricks like this spoken about but i dont think i personally would bother!?
Cheers!
#24 _rorym_
Posted 25 January 2008 - 04:22 AM
R
#25
Posted 26 March 2008 - 09:26 PM
I read it can quicken your 1/4 mile time by up to 0.1 second.
They give you better throttle response.
s
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