matt12

iTrader: (2)

Have a v8 sti with standard suspension so looking to upgrade within the near future, have a few questions that I hope you can help me out with,
Is there a noticeable difference when fitting front and rear strut braces and are the cheaper braces made from reputable subaru websites of same quality as the more we'll know brands or are you just paying for the brand?
Also does anyone know the clearance from the sti intercooler to the strut brace as I have a larger TMIC and unsure wether one would fit or not,

My last question is about arb's, what are your suggestions for the best setup concerning the diameter size, what would be best for front and rear,

Any help will be much appreciated

Jdm-brad

iTrader: (1)

I went to a subaru specialist last month and was asking about a rear strut brace they advised me that there isn't really any noticeable difference with one fitted! So maybe it isn't worth spending a fortune on a branded rear brace! Think you can pick some non branded ones up for less than £50!

As far as arb I believe the best set up is to have 24mm front and 22mm rear! I think the reason for this is to make the front stiffer than the rear, this then transfers weight to the rear in corners ect improving rear end grip!

Hope this helps, brad

Welloilbeefhooked

iTrader: (3)

I would be looking at a smaller diameter front arb than the rear one otherwise you would be increasing understeer

matt12

iTrader: (2)

Thanks for the help so far, two conflicting bits of advice on the arb's, what is the best setup for more oversteer then, thicker arb on the front or rear,
Cheers

forgedmarco

iTrader: (10)

I believe its thicker on the rear mate

Jdm-brad

iTrader: (1)

Could it be down to the model/year of the car as to which setup works best as mine seems to want to oversteer a lot more than understeer at the moment on standard anti roll bars?

Fat Boy

or crap tyres/alignment - all subarus need thicker or at least equal on the back to the front otherwise they will understeer like a pig.

They also need a bit of positive rake ( rear ride height higher than front by about 25mm).

forgedmarco

iTrader: (10)

+1

Jdm-brad

iTrader: (1)

Please don't take this the wrong way! If having a stiffer front anti roll bar than the rear would make the car understeer like a pig! Why would certain subaru specialists sell this setup? Like I said its not a dig in anyway just interested to know as I'm interested in improving handling and got told this was the way to go!
Cheers

forgedmarco

iTrader: (10)

A stiffer front end is less forgiving therefore creates understeer.

matt12

iTrader: (2)

50/50 here, now I'm confused, I would of thought I thicker bar at the front would make the front end more stiffer hence making the balance more prone to the rear!!!!

forgedmarco

iTrader: (10)

Well they say I you have an upgraded rear and then you set it to full stiffness it is more tail happy especially throttle lift off oversteer? Somebody more technical might be able to put the record straight lol

MrNoisy

iTrader: (28)

Having had cars with just rear and front and rear I wouldn't go for a thicker ARB at the front, it would understeer even worse than the standard setup.

You fit a rear ARB, less understeer, but as above, go too stiff and car will be more tail happy if you get your entry speed into a bend wrong.
Fit a front ARB, same size, car will be more or less similar to original setup again.
I believe ride quality will also suffer the stiffer you go.

In terms of strut braces I've had one on a bug wrx and blob STI and I can't say I noticed any difference...although they look nice .

Having run twin adjustable Whiteline 22mm bars on my WRX (soft on front, medium on rear) I went for a thicker rear ARB on my current car and much prefer the feel - 25mm Perrin one on mine with uprated links and mounts, just don't lift off into a bend if you're going some or you'll find the rear popping round for a visit

just me

iTrader: (3)

Is yours a widetrack?

matt12

iTrader: (2)

Cheers for the help guys, car isn't a widetrack,
Will be looking to add an anti lift kit at some point aswell!

MrNoisy

iTrader: (28)

My car is a widetrack, old one wasn't. Handling ain't all that different, so not sure why you asked the question.

To the OP an anti lift kit I found very good at making the front more stable under heavy braking.

matt12

iTrader: (2)

Thanks all for help, will go for a thicker arb on the front then, will just leave the strut braces for time being as suggested don't gain much from them

Jdm-brad

iTrader: (1)

Do you mean thicker on the back? I suggested thicker on the front but by the sounds of it probably not the best way to go lol! Have you got coilovers?

sivo

iTrader: (30)

In no particular order:
22mm front
24mm rear
Anti lift kit
Whiteline droplinks
Eibach springs or coilovers
Good tyres
Geometry setup

For a quick fix a 22mm bar on the rear on a standard blob sti will see a significant improvement.

Siv

matt12

iTrader: (2)

Right thicker rear arb, cheers lads, will be doing the whole hog eventually, the bushes are perished so will be upgrading sooner rather than later,
Hanvt got coilovers, whiteline lowering springs

Fat Boy

No offence taken at all, but it may be that they are selling upgraded front ARBs for when people have already upgraded rears to balance the car out again?

For instance on my car I have (somewhat unusually) equally sized 24mm front and rear eibach arbs, instead or the more normal 20/22R or 22/24R upgrades. So in my case if I had just fitted the rear bar I would then have had a very tail happy car and would have need to go out and get an upgraded front bar to neutralise the effect of the rear.

I have the unusual arrangement partly as an experiment and partly as the car is meant to be used hard/ on track where it will be running at least semi slicks and so will need the extra roll resistance and because its a 500 bhp classic with a dccd so it is naturally rear biased anyway. I also have exe-tc coilovers, droplinks, polybushed all round, etc, etc.

The theory- google is your friend:

>>>>>>>>>>>

Tuning advice

Just like spring rate, you want to run as soft an ARB as possible while maintaining sufficient control of the car and body roll and the proper handling balance. Softer settings lead to more compliance and more grip on that end of the car. They also tend to be slower responding and easier to drive, but stiffer settings can be more stable and faster responding.

Front:
(1) Stiffer: Will increase overall car stability (reduces roll) and shift the car’s balance toward UNDERsteer (push), thus allowing the driver to be more aggressive with the steering. The compromise can be on bumps and/or braking. A stiffer front bar will reduce compliance, so when one tire hits a bump the entire front axle will be affected through a loss of overall grip.
(2) Softer: Allows more roll and will shift the cars balance toward OVERsteer (or less UNDERsteer.) And the front will improve in compliance, which improves performance in brake zones and over bumps.

Rear:
(1) Stiffer: As you add throttle through the corner while the steering wheel is still turned, the rear anti‐roll bar becomes very effective. Stiffening the bar supports the rear and shifts the balance to less UNDERsteer at corner exit. Again, the compromise is in compliance; a possible SNAP or FLAT OVERsteer may result if rear anti‐roll bar is TOO stiff.
(2) Softer: Allows more roll at the back of the car, which will be most evident at corner exit. If the bar is TOO soft, the car will exhibit exit OVERsteer. In this case, compared to a rear bar that is TOO stiff, the exit OVERsteer condition will be more gradual instead of a snap, hence the phrase “roll OVERsteer.”


>>>>

So, to go back to the start, if the "specialists" are genuinely selling just upgraded fronts as a means of making the car turn in better then/less understeery, then I am afraid that they are not specialists....

20mmF /22mm R on an ordinary scooby with solid droplinks and a decent geometry set up is a great start towards chassis tuning.

Anti lift kit you will also hear about (although it's actually the opposite - it's pro lift/dive in actuality and works by allowing the car to put more weight transfer onto the front wheels in corner entry) helping combat a scooby's natural tendency towards understeer.

Have fun

JGlanzaV

iTrader: (3)

very interesting this is...

What size is the standard ARB on the rear of a classic? I have a modified from arb, but standard on the rear, and it is very tail happy...

Fat Boy

Geometry plays a big part too - e.g. if you have too much toe in on the rear it can make it very tail happy.

Have you had your geom checked and set up properly? Most scoobies are way off whack when they roll off the showroom floor never mind after several years.

The so called prodrive settings make a big difference over standard oem.

Standard size - can't remember off hand but I think it might have been 19 F and 20 or 21 r on the P1? I haven't had standard on there for ten years or so

JGlanzaV

iTrader: (3)

haha, Geo settings are fine, got the sheet here somewhere as to how i got it set up

I wanted it a bit more oversteery as it is easier to control, but its quite "snappy"

just me

iTrader: (3)

I havent driven my car properly yet, was wondering if messing with the dccd meant you could get away with not fitting a rear arb?

Fat Boy

Maybe how you "got it set up" is the answer then.... or maybe lingalonga mdf tyres

Snappy oversteer is usually the symptom of a very stiff rear set up or poor alignment and is definitely not caused by putting a stiffer bar on the front. Is your car lowered?