marl

Hi, frst post on EVOm.net so be kind!!

I have a Evo 8MR320
Running standard Bilsteins and Eibachs with whiteline ARB and i want to fit a rear Brace to complete my package.

1.What Rear Brace do you have?
2. Or Which one would you reccomend?

Its just a fast road,with a little track work Car so your advice is appreciated.

On a previouse 8MR i ran a DC Sports titanium brace but we dont seem to be able to get them in the uk very easily?

Marl
Buckinghamshire
UK

MinusPrevious

iTrader: (3)

Hey Marl
Youre referring to a upper rear strut bar?
Most here will say it does absolutely nothing to stiffen the strut towers. If it does you are very unlikely to notice any difference other than it looks good
I run a Tein bar & use it to strap my gas tanks down on track days

Personally I would run a bar that has no hinges at the strut towers

Have you chimed into MLR. Great forum for good track worthy components

Cheers, Joe

gsrboi80

iTrader: (38)

I have the Cusco and agreed that it's useless, or should I say noted absolutely no difference at all.

I use it more for as stated above. If I don't want something to move around in the trunk I'll bungee it down to the bar



In other words don't waste your money

marl

Thanks for the candid replies, i thought as much ,good for bling but not for structural rigidity!!
that is unless a three point upper brace is used so that it forms a triangulation between the strut towers and so strengthens them against flex.;?
The DC brace i used before was a non hinged one so even though it was only a two point brace, it was however quite stiff!!

Cheers
Marl

WRC-LVR

iTrader: (1)

3 point FTW....not legal on SCCA autocrossing unless you go tp the mod classes.

FYI a non hinged version is best with the 3rd point being the trunk floor. BTW its a biotch getting bolts up over the cradle and rear diff carrier.... best done when that is out for a diff upgrade or plate re-arrangement on the CT9a chassis

barneyb

Since shock towers have no side load and only take the vertical weight of the car there is no reason for them to flex. Any flexing likely to occur would be down where the control arms bolt to the body.

MinusPrevious

iTrader: (3)

How does this theory apply to the front towers

I will have to disagree. Mitsu spent the engineering time & developed not only a front upper but have a rear upper as well. I believe there is enough uni-body flex to justify their existence

Dallas J

iTrader: (1)

We already have a rear brace just in front of the tower, its why your seats don't fold down and what gives Subaru drivers envious dreams. There is a small amount of movement with no bracing as seen by this video in a buddies STi


The brace shown here is supporting the towers side to side and you can see the combined chassis flex is upwards of 1/4" when measured at this location. Let me reiterate though, we already have this brace from the factory!

The front will have some amount of movement too, but like said tying the towers side to side isn't helping a whole lot. Also of note a 3 point is only as good as the strength of the 3rd point... I haven't investigated but I'd like to think mitsu put some effort into bracing the stock 3point bar middle mount.

In my floppy noodle dsm days, my RRE strut bar would go on only if the car was jacked up. If it was on the ground the towers flexed about 1/8" inward (combined flex) and it wouldn't fit anymore.

barneyb

[QUOTE=MinusPrevious;10807371]How does this theory apply to the front towers/QUOTE]

The front suspension has three points that carry side loads: the two bushing of the lower (only) control arm and the bearing in the strut tower. The Evo front strut uses a thick shaft in order to withstand side loading without flexing or binding.

At the rear there are four control arms, all bolted to the underbody or to the crossmember which is in turn bolted to the underbody. The shock and spring assembly bolt to the lower arm with a pivoting joint. Any side loading presented to the shock tower would be by way of the rubber bushing which is supposed to be tightened with the weight of the vehicle on the bushing. In other words, whatever torque the bushing delivers through the long arm of the shock.

MinusPrevious

iTrader: (3)

That was a good vid. Shows the STi unibody flex during hard driving

I dont think there is much of a debate here. These uni-bodies have some inherent flex & strut bars probably add some additional stiffness that may not be as noticeable as the STI
Thats why caging or even adding a rear roll bar adds noticeable stiffness. I run a rear roll bar & you can here it creak when torquing the EVO into a driveway

silverevo05

iTrader: (7)

I have this one

It's a 4 point without any flex points which attaches to the RS trunk bar holes as well

Dallas J

iTrader: (1)

Its been said over and over again, the extensions to the rear do nothing.

silverevo05

iTrader: (7)

^ Oh I must be retarded sorry

mrfred

iTrader: (50)

so, a rear shock tower brace is not needed?

Dallas J

iTrader: (1)

In reality, the minimal help you may get from a 2 point brace will not be seen as a time improvement on track, and for me that's the metric that matters.