modrich

iTrader: (2)

Yeah, it's very easy to get into the mind set of uprate uprate uprate! So kinda thinking I've done enough chassis wise for what I use the car for but it would be rude not to get the front ARB bushes with the new front wishbones done.

What about billet front droplinks, are they worth fitting do you think, or are they overkill as well? I have fresh SuperPro bushes in the OEM plastic droplinks.

Just standard Prodive settings for the geo, -1.5 camber at the front etc

Cheers for that, so 20mm front and rear should work fine?

bonesetter

iTrader: (9)

What I meant was 22 rear, and keep your 20 front

modrich

iTrader: (2)

gotcha!

MaxA

I know this is a thread about ARBs (and it's a good thread), but I don't think the F1s and AD08s really compare, the former is a good road tyre which doesn't really stand up to the track, and the latter is a great track day tyre with a very firm sidewall that seems to last very well. And it doesn't like standing water, and there's no way I'd run it in winter (even an English one). Funnily enough I think the 2011 Impreza review from tyrereview.co.uk influenced my decision to run the AD08s on my other car for the track/high summer!

InTurbo

iTrader: (3)

Yeah I agree, I wasn't trying to compare the two different tyre types. But see how my car responded to fitting them.

MrNoisy

iTrader: (28)

Brilliant thread guys, subscribed

TBH I've never been 100% happy with the handling of mine since BC's went on it; can't seem to find a good compromise yet.
I had Race Logics which handled superbly but were a hard ride for a daily driver so switched to BC's with 6/5 spring rate which are easier to live with - as said, it's a compromise. I couldn't afford the more expensive brands.

I run a Perrin 25mm rear bar with Perrin stout mounts and rear drop links, and Whiteline roll centre correction kit, ALK and heavy duty droplinks with standard ARB at the front, with suspension height set to same as a car on standard shocks with Prodrive springs, and Prodrive geometry settings.
I find the car still rolls more than I'd like, feels unstable cornering at higher speeds (steering feels too light), and is a bit tail happy especially in the wet (part of this I put down just to running more power, but the car still doesn't feel as planted as I'd like).
I'm considering dropping down to a 22mm rear bar or uprating the front to a 22mm but having read this I'm now thinking of dropping the rear down to a 22.

What do you reckon?
I'm hoping to take the car over to Horsham Developments and get it properly corner weighted, ride height set if they think it needs tweaking, and just better setup for my needs as I'd like to be able to enjoy it more without having to worry about grip!

InTurbo, thanks for posting all your findings.

InTurbo

iTrader: (3)

So after a few months of trying to find the perfect road set up for my car I've decided to do what Bonesetter recommended and try a different spring damper set up.

After speaking to the likes of chevron and going through all the options including Custom B14 I settled on a rb320 damper and spring combo.

Main reasons for choosing this kit was it was designed for the car for use on UK roads. It also has the correct droop and bump travel and good levels of compliancy. Something that the B14 still can't match.

After lots of shopping around I finally have the all the Prodrive Bilstein dampers and Prodrive springs made up with the top mounts ready to fit.

Just hope it performs as it should.

M2RTXhawkeye

iTrader: (61)

Nice mate if you don't mind me asking what did these set you back? Looking to do something similar myself

Martin

InTurbo

iTrader: (3)

Martin.
Sent details via pm.

MrNoisy

iTrader: (28)

So what exactly is it you have above?
I thought most manufacturers didn't have OEM style shocks in a 114.3 fitment?
If you have a model number pls do share!

Incidentally, I spoke with Horsham yesterday and they echoed everything already said in this thread that by adding coilovers you stiffen the suspension meaning you don't then need even stiffer anti-roll bars as it will just make the car too stiff and twitchy.
For this reason I've decided to drop down to a 22mm adjustable Whiteline one, and will see how I get on.

InTurbo

iTrader: (3)

They are oem style dampers. Same that's fitted to the RB320. I found the car behaved a lot better after reducing the size of the roll bars.

InTurbo

iTrader: (3)

Had them fitted yesterday and the first impressions are very good.
The ride quality has improved massively.

They just soak up driving over speed bumps and pot holes I cant recommend this set up enough if your looking for a comfortable daily ride.

Can't comment on the handling yet as I've not had it set up.
Will be getting the alignment set up on Saturday.

MrNoisy

iTrader: (28)

Ordered the Whiteline BSR37Z adjustable 22mm rear bar yesterday with a set of their KLC139 drop links.
I also took a look at my rear arms as well after InTurbo's pics, and it looks like I have the same issue and that my rear suspension needs raising a little:


Versus my mate's standard widetrack at the rear:


Bonesetter et al - do you think ride height is too low?

InTurbo

iTrader: (3)

Mine now looks like this with the Bilsteins and Prodrive springs.

2pot

iTrader: (3)

That makes sense, for a daily driver, using relatively soft springs at the rear, allowing for fuel, people, goods.
How do the front arms look, with a stiffer front spring?

InTurbo

iTrader: (3)

The Bilstein damper and Prodrive spring kit has been on the car for a few weeks now and I'm still amazed at there level of compliancy. The car rides so much better.
Speed bump and pot holes are no problem they just soak them up. In comparison it's a much better ride than my friends mk4 r32 golf.

The car still feels firm but somehow manages to deal with all the bumps without bothering the driver. Also the bobbing on motorways like you get with the Sti kybs is also completely gone.

Another thing I've noticed is that braking also feels better. Before the car would dive forward under hard braking but now it's a lot more stable.
Ride height looks ok. At first the I didn't like the ride height compared to where my BCs sat. But now I'm more used to it.
It's sits at 355 front 365 rear from wheel centre to arch.

Peter Cambridge said the reason for the ride height being higher at the rear is to push the roll centre towards the rear making the rear more resistant to roll.
That In turn makes the front end roll more helping turn in response and helping to reduce understeer without the use of stiffer bars.

I met up with Peter in Warwick for the cars alignment to be optimised to my driving style and to suite the tyres that I have fitted.
He insisted I turned up with a full tank of fuel to help set the conditions for the geometry.

As to be expected after fitting the new dampers and springs the geo was all over the place with 6 minutes of toe out on the back and nearly a degree of camber difference at the front, Quite surprising the car was driving straight.

We then discussed what I wanted from the car and how I felt the car had been on the previous set up.
I mentioned that on the old geometry set up I had been quite happy but I had experienced a bit of mid corner understeer and the car wanted to push on under power in the tighter corners.

After going over my old settings he mentioned that having a higher rear camber in relation to the front really makes these cars understeer and that with the right settings the widetrack's can become a bit of a drift monster. Not what I'm after but nice to know.

So first thing we did was reduce the rear camber, The car was jacked up and bolts slackened off on the dampers to take up any slack to reduce it as much as possible.

With the car now on the lift this gave just under a degree negative in the rear.
Rear toe was then set to 0.03 total 0.06

On the front end we aimed to get a degree and a half of camber but settled quite close at -1.20 due to lack of adjustment.
Front toe was also set to 0.03 total 0.06

He also mentioned to me that the optimum settings between the Impreza years differ quite a lot. Mainly due to the different diff designs. So a good geo for a hawk won't be best for a bug. And classics needing quite a lot or rear toe for example.

Peter was a pleasure to do business with and has a wealth of knowledge about setting up Impreza's especially the classics who he has fond memory's of developing on the roads around Banbury and Warwick.
I would definitely recommend him if any of you would like your car aligned by him.

On the drive home there was a huge difference obviously due to the fact that is was badly out beforehand due to the suspension install. On the M40 back towards Oxford the car felt solid composed and planted. I didn't really get to test the handling with all the traffic.
On Sunday evening I managed to get a good run in the car from Witney to my place of work in Wiltshire over some of my well known A/B roads,

I'm so impressed with how this car is now. The car feels so well damped over bumpy roads and inspires confidence to push it.
In the corners you can really lean on it, there's a slight bit of roll but its controlled and there's so much grip there's no hint of it letting go.

In the tighter corners there's no understeer, the car feels very neutral if you apply throttle mid corner there's a nice hint of the back end moving out on corner exit.

So as you can see I'm very happy with how the car is now. It's taken best part of 9 months and many different setups but I can honestly say the suspension is finished.
I'm struggling to find a negative point, only thing I can say is this set up can be expensive sourcing dampers through Subaru uk. But a 3 year warranty and the the compliant ride with fit and forget set up is definitely worth it.

ditchmyster

iTrader: (7)

Pleased you're finally happy with it, sounds like it handles and rides like mine does, Peters springs were a revelation, he certainly knows his stuff and is a nice chap too.

bonesetter

iTrader: (9)

Great news, and pleased you have the car the way you're happy with

It's a shame about the camber up front, which would have made things perfect. Thing you can do is ovalise the TOP strut clevis hole towards the strut by ~5mm. This will get you the extra to make the -1.5°

You have the geo figures which you and PC have dialed in, so these can be easily set by any local garage now when/if you decide to go for the extra

InTurbo

iTrader: (3)

Not such a problem with the camber. We were using degrees and minutes so it was only 0.10 off our target figure of one and a half degrees -1.30

InTurbo

iTrader: (3)

Took the plunge and ordered a Rb320 rear adjustable roll bar.
It's a very small increase in diameter from the 19mm Sti one I have fitted.


Obviously I found the 22mm bars way to harsh for me with my old set up.
Will be interesting to see how it reacts with the more compliant Bilstein and Prodrive springs.

bonesetter

iTrader: (9)

I think you'll like it

Chris.air

iTrader: (1)

This made good reading. :-)
@bonesetter I have a v3 sti running standard bars I have ordered a 22mm rear just to see the difference I get. Would probly not have bothered if I had read this first. I also picked up a set of 2nd hand tein control master shocks. My real question is how do you rate these shocks or like you said to the op will these be the weakest link.

InTurbo

iTrader: (3)

Yes I do. Fitted the bar a few days ago and set it on the softer road setting. There is a noticeable increase in the firmness of the rear suspension but it's by no means hard of uncomfortable. I actually prefer the feel of the car.
It's also made the front more eger to turn in.

Did a bit of research on roll bar stiffness and moving from the Sti 19mm bar to the 21mm Prodrive bar is a increase in stiffness of around 50%

19mm to a 22mm bar is 80%
19mm to a 24mm bar is 155%
19 to a 24 on hard is a whopping 200% increase.
So I can see why I found them harsh.

Reading the installation guide that came with the Prodrive bar mentions the ride will get harder with fitting the bar.
Kind of funny really as before I originally fitted my 24mm bars early last year I read loads of threads saying bars won't affect ride quality.

Hear is a link to a roll bar stiffness chart just incase anyone what's to know how much increase a bar will add.

http://www.whiteline.com.au/docs/bulletins/BL-281.pdf

bonesetter

iTrader: (9)

So, does this mean you're completely happy with the way the car is now?

some cook

iTrader: (26)

What arb bushes and drop links do you have fitted with the prodrive arb?

plenty

iTrader: (13)

I thought I would add my own experience to this excellent thread as I too have been looking to create a compliant road setup for my 2004 JDM.

When I acquired the car it was fitted with coilovers which (as with with all coilovers in my experience) were too firm and crashy for the road. My benchmark was the P1/Bilstein setup I had on my classic which was absolutely spot-on.

After reading up on the matter my initial actions were to fit a set of KYB AGX with Prodrive Red 05+ springs. I would have liked a set of Prodrive 04 springs which have a slightly softer rate but these are more difficult to source at least at the time of my buying. As the AGX are twin-tube not inverted dampers I needed new bump stops and fitted a set of WRX bump stops (used on the front and new on the rear).

It was apparent that this setup wasn't what I was looking for either as the car was still too jittery on B-roads. I was considering trying Prodrive Blue (WRX) springs or even P1 springs but following the tips on this forum particularly from 2pot and InTurbo, as well as advice from Peter Cambridge of PCA Dynamics, I chose to (a) downgrade my 22F/24R ARBs to 19F/20R OEM items, and change my front bump stops to shorter Febi items to allow more travel. (Rear bump stops unchanged.)

I also replaced the front springs with RB320 items to create a small amount of front rake which as documented on this thread works well on the newage and reduces the amount of understeer allowing you to run a smaller rear ARB.

WOW - what a difference. The jitteriness is gone and I have achieved what I was looking for, i.e. the ability to soak up the bumps and confidently press on down a country road...the balance is fundamentally neutral, the rear is utterly planted and there is only a very small amount of understeer when really pushing on in wet conditions, all characteristics which suit my style of driving.

There is of course more lean when cornering but nothing unmanageable, and I would say it's not quite up to the standard of my P1/Bilstein setup which was truly legendary in its ability to "float" across poor surfaces, but after 800+miles hooning around Wales this past weekend I pronounce it 95% as good and I'm satisfied with it.

If I were to do it again I would probably try Koni inserts rather than the AGX which is an old design and has only coarse adjustment (four positions). I am running position 1 (softest) on the front and 2 on the rear.

Thanks to 2pot, InTurbo, Peter Cambridge and others for contributing valuable information - it's gratifying to know that there are still people out there who are interested in tuning Impreza suspension for optimal handling (as opposed to simply aesthetics).

modrich

iTrader: (2)

Just goes to show that Prodrive and Peter Cambridge really do know how to set-up a car to be used everyday and get the most out of the suspension, and that's why any current and future Impreza I own will have Prodrive/PCA Dynamics suspension in one form or another.

When I was sorting the PCA Dynamics Blob/hawk WRX Prodrive blues groupbuy Peter said he can reproduce any Prodrive spring as follows:

WR Sport 99

P1 (available via 2pots groupbuy)

Bug STi

early Blob STI (WR1)

wide track (RB320 etc)

US WRX and STi

08 STi etc

He also did some Legacy ones that Subaru UK never took on.

matt-c

iTrader: (5)

That's an interesting link on whiteline site.

No wonder we find the cars hard on our rubbish roads.

InTurbo

iTrader: (3)

Oem links and oem bushes.

InTurbo

iTrader: (3)

Very happy, It's been a good learning curve or be it a expensive learning curve over the past year.

I now have a car that's fun, confidence inspiring and a joy to drive over UK roads, Especially A B roads its planted and works with the bumps and undulations.
I love the damping on the Bilsteins there firm but somehow weirdly comfortable.
I still see unavoidable pot holes coming and I cringe before I run over them.
Then it's like ( oh thats not bad )
Where as before it would crash over them.

Very impressed with the way the car rides now. Goes to show you don't need a rock hard ride to have a good handling car.