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Old 30 September 2005 | 06:49 PM
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Default Benefits of a Strut Brace

I have front & rear strut brace for my 03 WRX, sitting in my shed collecting cobwebs.

Even though I have bought it, I don't know whether to fit it due to insurance, warranty etc.

Do they really offer a benefit in the Scoob as I heard the Scoob has a very stiff bodyshell anyway.

I had a front strut fitted to my previous car and that was a revelation, but what about me humble wrx, is it worth it??
Old 30 September 2005 | 08:00 PM
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The new-age bodyshell is extremely rigid and the benefits when using standard suspension would be negligable. If many other components were stiffened up then it would be worth the bother and expense. Best to try it and make up your own mind though. Personally, I'd flog 'em and put the cash to a decent rear ARB and solid links
Old 30 September 2005 | 08:41 PM
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IMHO

They are right up there with VTA dump valves.

Steve
Old 30 September 2005 | 08:46 PM
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lol you`re probably right there mate and ive got both pmsl
Old 30 September 2005 | 08:58 PM
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Originally Posted by Steve Sherwen
IMHO

They are right up there with VTA dump valves.

Steve
Well I'd have to dissagree with that, big time!!

I found that the f+r strut braces fitted to my 03 STi made an unbelievable difference to the way the car handled,sooo much mure precise and predictable when things were about to go the way of the pear

...having said that, since fitting the very same braces to my 05, I haven't gained any benefit at all......but at least they don't make silly noises
Old 30 September 2005 | 09:09 PM
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i have sti front brace fitted to sti 03-i noticed big difference in turn in,noticed nothing when i got rear strut brace fitted biggest improvement was with springs and adjustable rear arb
martin
Old 30 September 2005 | 10:23 PM
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Somewhere in the SN mist, there is a very long thread about this very subject.
All I can suggest is try some blind tests...
Fix the tower mounting brackets at each end and get someone to either put the cross bars on (one end at a time) , or leave them off.
Go for a drive and see what you can feel.

Nick
Old 30 September 2005 | 11:28 PM
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Theres little real benefit to be had unless upper and lower braces are fitted; this applies to all cars btw. Consider too that they need to be triangulated to make a real difference*.


Simon

*this is chassis set-up lore, rather than my personal opinion
Old 01 October 2005 | 08:43 AM
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This is from Damian Harty aka Prodrive handling guru

"Strutbrace Q: There is an awful lot of mythology around this stuff that goes back to body-on-chassis beam-axled racers in the 20s - I'm not kidding. There are two effects that are important. Basically, the body structure is like a "fifth spring" between the front and rear suspension. If that spring is not stiff enough then the body relaxes out any redictribution of roll moment that the anti-roll bars were trying to make and so the car is unresponsive to handling balance tuning with springs and bars. However, once the body is "stiff enough" then making it stiffer offers no benefits. A good rule of thumb is that the torsional stiffness of the body (between suspension mount points) needs to be about ten times the roll stiffness of the stiffest suspension end (usually the front). If you chase the numbers through you end up with about 5-7 kNn/degree as the requirement for a body structure. Most modern monocoques comfortably exceed that and the Subaru with its bonded screens both ends does too. Somewhere I have a figure but can't recall it right now. Anything over 10 is good, 15-17 is current "state-of-the-art". So in that case, a strut brace does very little. The second effect is a bit more complicated. The body moves on the suspension but the wheel also moves on the tyre - the tyre is in many ways a "secondary" suspension system. That movement is partially controlled by the tyre and partially by the suspension damper and happens 10 to 15 times a second. The body is a flexible thing that has its own resonances and because of the shape of most cars at the front - they need a hole to put the engine in - it can get quite flexible in just about this frequency region. If the body goes flexible - goes into resonance - then the damper just moves with the body and can't contribute to the control of the tyre and in fact can do something bad called "mass loading" where the tyre is carrying not only itself but also part of the body _while it resonates_ (it's important to separate the static 'weight carrying' from dynamic things in your mind). In those cases, the strut brace can help because if it is a good design then it stiffens the front end usefully.

What all of the above means is that the effectiveness of a strut brace is strongly connected to the stiffness of your suspension. So for a Scoob that is fairly standard, the strut brace probably doesn't do a great deal, but as they get modified and stiffened the brace will contribute more to a well controlled feel over less-than-perfect surfaces.

The final point about strut braces relates to the emporor's new clothes - having bought a flash one, not many people will admit they can't really tell the difference.

Sorry for such a long answer but it isn't straightforward, especially when I'm denied my usual engineering shorthand of "Hz" and "modal damping" and so on..."
Old 01 October 2005 | 08:50 AM
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also the energy transfer of a small prang on a corner could right off a car
if they were really any good subaru would include them in the sti
or prodrive in there handling package
Old 01 October 2005 | 09:39 AM
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Originally Posted by wakeboardar
if they were really any good subaru would include them in the sti
or prodrive in there handling package
The JDM STi and Spec C have a very nice STi titanium brace and Prodrive also sell an even nicer front strut brace.
I think the question is why doesn't the UK STi have one?

NIck
Old 01 October 2005 | 04:13 PM
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Lack of a strut brace may well be a cost thing as well as the fact that the shell is "stiff enough" Did not the Classic STI have one as standard??
My son has just taken delivery of an EVO IX FQ 320 and this has one as standard which has also got a mounting on the bulkhead - that makes sense?
I have Prodrive springs and 18's on my 03 STi and will soon be fitting whiteline rear drop links, front and rear ARB poly bushes and front strut brace. Will someone please confirm that I will benefit from this combination.
JohnD

Last edited by JohnD; 01 October 2005 at 04:16 PM.
Old 01 October 2005 | 05:22 PM
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I think on balance I am going to install it.

I had one one my Z3 and it improved turn in and scuttle shake.

Therefore I know that they work, but due to the Imp's prodigous chassis wondered whether there was benefit.

Will give a report it I remember.
Old 01 October 2005 | 06:05 PM
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Just got an original STi Titanium one from ebay for £58.50.

Don't care if it works for that price and looks

Last edited by richiewong; 01 October 2005 at 06:23 PM.
Old 01 October 2005 | 09:15 PM
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I was thinking of getting a front one for my sti but have so far been put off because i didn`t know whether fitting it would upset my geomatry settings ?? does anyone know if it will put them out or if they will be the same once its fitted.

Cheers
Old 01 October 2005 | 09:18 PM
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Originally Posted by Aly Mac
I was thinking of getting a front one for my sti but have so far been put off because i didn`t know whether fitting it would upset my geomatry settings ?? does anyone know if it will put them out or if they will be the same once its fitted.

Cheers
Had my front carbon strut brace fitted at the same time as my Prodrvie springs on a Blobeye MY03 STi UK. I asked the dealer if it would upset geometry, and I was told it wouldn't. Anyway I have had this set-up for a couple of months now and the responsiveness going round coreners is fantatsic. Not sure if it's just down to the Spring kit or both.
Old 01 October 2005 | 09:28 PM
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Originally Posted by Steve Sherwen
IMHO

They are right up there with VTA dump valves.

Steve
so in other words your saying they are great? coz VTA's sound superb.
Old 01 October 2005 | 10:00 PM
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Originally Posted by JCScooby
so in other words your saying they are great? coz VTA's sound superb.


I fitted an upper and lower brace to my Tavia vRS and felt absolutely no difference. I also question the rigidity of a member that has two whopping bends in it to get around the inter-warmer!

Steve
Old 01 October 2005 | 10:13 PM
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If you already have them, then fit them and decide for yourself. You can always sell strut braces on here, or Ebay if you think they are no good.

Ive got a set on my 04sti, and wouldn't take them off.
Old 02 October 2005 | 11:39 AM
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fitted on to my old classic and it made no difference - until you were driving at about 9/10ths, then it felt more precise and less wooly on the limit, eg you had more directional control as the tyres started to lose grip. Simple answer is, only bother if you thrash the nuts off it round corners
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