Gigsy

Am debating what to do with the suspension on my MY02 bugeye WRX wagon.

Currently, I have Prodrive springs, front strut brace and a slightly stiffer STI rear anti roll bar (new solid drop links on the way) which I previously thought was an OK set up but was way too understeery at Hullavington on Friday. Therefore, I'd like to dial more of the understeer out and improve turn in.

The rear struts are a little tired given they have covered 90k miles (fronts were replaced about 10k miles ago) so that's not helping but they don't seem to be leaking at the moment.

So the question is should I...

a) replace the rear struts and fit an ALK (anti-lift kit)
b) replace the rear struts and fit a stiffer (22mm), adjustable rear ARB
c) upgrade both front and rear ARBs for adjustable ones
d) upgrade just the rear ARB and fit an ALK

The car is gradually becoming a track day toy so eventually, I will upgrade both ARBs and fit an ALK. I may also fit some coilovers in a year or two but, initially, I only plan on spending £300-400 so I'm just trying to figure out what is going to give me the greatest initial handling improvement.

jura11

iTrader: (7)

Hi there

Best mod which we are done is Whiteline KCA313 Front Roll Center Adjustment Kit,this transform the car absolutely,now is almost like go kart.

Second things which we are went is the ALK,but after fitting this,our front end just lift under heavy acceleration,after that we are went with different alignment setup and now feels great under heavy acceleration

Spec C alloy arms will give you more castor,which can help too and second thing which help us is too Hardrace Lateral arms which now selling the Apex Performance for half price

Jura

bonesetter

iTrader: (9)

Option c gets my vote. You'll see a big improvement from fitting 24/22 arbs over what you currently run, and will almost certainly dial out all understeer, as well as sharpening turn-in

ALK's, RC correction etc are more subtle and most noticeable on lowered cars


.

Gigsy

That's interesting, how much is your wagon lowered?

Re the lateral links, I think for the moment they're probably out of scope / budget.

I'm currently running on lowered (20-25mm) Prodrive springs and have a stiffer (19mm compared to stock 16mm) rear ARB.

Mid corner understeer is not so much of an issue at the moment, it's turn in that seems to be suffering the most at the moment.

Do you reckon a 22mm vs 19mm rear ARB would still give the greatest benefit given that I'm already lowered and running a slightly stiffer rear ARB?

I will eventually replace both ARBs and fit an ALK + RC correction but don't have the funds to do it all at once at the moment but initially want to get the biggest improvement over my current setup.

Have also been debating fitting adjustable top mounts to increase caster and the amount of camber available so will probably get some of those at some point as well.

bonesetter

iTrader: (9)

ARB's, generally speaking, will always give the most noticeable difference/change. If you went up to a 22 rear then yes, fairly big/noticeable difference. However, you want to eventually change both bars so unless you can pick up a used bar it isn't going to work out best cost wise (I run 24/22 bars on my bug wagon, and indeed seem to always settle on this combo for all my Impreza's, classic & new age).

Turn-in is another issue and is something I have worked on improving on my wagon. For this you can change the steering rack and front lower arm bushings for something like SuperPro pu's. What would be good (and not an awful lot of dosh) is if you could source a pair of alloy bottom arms if you decided to go the bushing route. This would allow you to run more camber and flip the rear fixing pin for castor increase.

Another thing to consider, and somewhat of an essential, is rear subframe lock bolts. These can dramatically 'connect' front and rear tightening up the feel of the whole car, esp front turn-in

Make sure geo is dialled with a fair bit of front (&rear) toe-in (0°08') which will sharpen turn-in a bit

DonNedly

iTrader: (10)

Sorry to hijack the thread but have you got any pictures or a guide to doing this as i want to do it but i'm well out of my depth with suspension mods

Ta

bonesetter

iTrader: (9)

This thread has some good stuff

Gigsy

Having read up and considered my options a bit more, I think I'm going to go down the route of dialling out as much of the understeer as possible with geometry "fixes" and then see what is required as far as ARB changes to make the rear more mobile.

I have the rear subframe locking bolts already - as you say, a really worthwhile mod especially for just £25! I also have poly steering rack bushes though I've not fitted them as yet.

Very interesting what you say re fitting alloy arms. As I understand it, the alloy arms provide a slightly wider track than the steel ones and thus if used with wagon struts, it would increase the amount of negative camber available? If I fitted alloy arms, would I need to change anything else (e.g. driveshafts to compensate for the wider track?).

Also, when you say "flip the rear fixing pin", what do you mean by this? Simply rotating it through 180 degrees so that what was the side where the bolts were is now the side against the arm, or swapping the left pin to the right side and visa versa?

There are plenty of arms via breakers and as I could fit ploy bushes without first needing to remove the existing ones first so this could make for a really cost effective, plug and play mod.

Gigsy

Hijack away most of the info I've come across simply relates to fitting bigger rear ARBs to mask the problem rather than actually modifying the geometry to correct the route cause so it's very interesting to hear Bonesetters info.

bonesetter

iTrader: (9)

Flipping the pin means undoing the two bolts holding it in place and then rotating it 180° as seen in this pic, not changing from side to side. The pic is taken from the thread I have linked above



You're correct what you say on the alloy arms. The biggest advantage over the steel arms is being able to increase caster with the 'free caster mod' (as well as some weight saving). You wont have to change anything else, except of course the need to change your alignment

As for making the rear more mobile, there are ways (less rear camber/toe etc, but to try with arb settings, for me and my preferred set-up anyway, unbalances the car and makes for an unpleasant feel. YMMV of course, and that's the beauty of using adjustable bars

Gigsy

Thanks, looks like a set of alloy arms is on the shopping list in that case!

bonesetter

iTrader: (9)

Let us know how you get on. Happy fettling

Gigsy

One more quick question... will classic alloy arms fit a newage wagon? or is it only newage?

DonNedly

iTrader: (10)

Thats brilliant cheers mate,
I'll definitely do this when fitting the anti-lift kit then for brucey bonus castor.

jura11

iTrader: (7)

Hi there

Our wagon not sure how much is lowered,but think is around 40mm..

Understand about the Lateral links/arms

As I said before about the more castor will give you better turn in,if you are running coilovers is easier,because you can turn the just top mounts.

If you are not running coilovers,would go with route of the Bonesetter and late Spec C arms

We are running late STi arms,not sure about the classic arms if they will fit on yours or New age.

Jura

Gigsy

The roll centre correction probably wouldn't have as much impact on mine in that case (I only have a 20mm drop) but I think it's still worth doing for me.

I'm going to hold off on coil-overs for the moment and will just focus on upgrading what I have.

With that in mind, I've just bought some buyeye STi alloy arms (Spec C arms are wider still IIRC?) and will fit them with poly bushes and caster correction bushes in the rear mount... the correction bushes don't give quite as much caster as the Whiteline/CDF ALKs but will be a fair bit cheaper With Bonesetters, "free caster" mod, I'll hopefully end up with a similar end result (or perhaps even a little bit more caster?).

Am probably going to get adjustable top mounts too and a 22mm rear ARB - might just say sod it and order the lot now

If I still need more tweaks after that, I think that's the time to move over to coil overs

Arnie_1

Sounds like you too are on the path to suspension enlightenment!

A couple of things to note for people who might read this later...

1. The Classic alu arms are different to GD alu arms. They have a narrower track, actually the same as the wagon. However the front bushin on a classic arm, IIRC, is a bit narrower than a GG steel arm (or GD steel or alu arm) and you'll need to add a spacer to make up the difference. The GD arms are wider. On a cheap budget you can just use the steel versions off a GD saloon, or the Alu if you have the dosh. I've been running a good 4 years or more with GD arms with wagon axles and they haven't died yet! So you're good to go for a little while. When they do let go, you can get saloon axles to replace. The wider arms combined with a wagon strut will give you a massive amount of neg camber possibility. I easily got about -2.5 deg using wagon struts and sedan arms. Which is good enough for for street tires on track. That combined with the caster bushing and free caster mod and you won't really need to get adjustable upper mounts. However, note that you can't get any LESS than ca. -1.25 or so. So keep that in mind if you want to run a mild road going setup.

2. GD STi arms came in two flavors the standard or the high caster Spec C arms. They were the same width but the Spec C came with more caster. They are also usually quite a bit more expensive to buy than the standar alu arm. Ideally the Spec C arms are the way to go but you'll be ok with standard and caster bushings. They are, however, the same width (normal STi, Spec C and steel GD arms).

3. The amount of caster you get from the Caster bushing is about .5 deg or so, which is the same as the Whiteline ALK. The ALK adds the change in anti geometry which effectively softens the front end under torque loads such as acceleration and braking, providing more traction in said situations. Reducing the anti geometry will increase lift and dive. The kit DOES NOT reduce lift. It increases it. But I personally don't really notice it though some do and prefer the extra platform that the standard anti geometry provides.

4. The WRX Prodrive springs are just ok. A bit soft for how much they lower. Still better than STechs though! They do lower the front end quite a bit reducing front end travel. This makes the car a bit more susceptible to mid corner bump understeer as you pretty much get straight into the bumpstops when cornering. I would suggest cutting a couple of the narrow diameter nubs off the front bump stop to give you a bit more travel before you engage the bumpstops.

5. Roll center kits - I personally feel that you'd benefit from the RCA's with the lowering of the Prodrive springs. You'll have a bit less roll and more front end grip. Its something you can do pretty easily since you'll be in there anyway with replacing the front arms.

6. ARB's, I'd eventually go with Bonesetter's rec on 22F/24R. You could get away with running a 24mm rear if you run it at full soft only with your standard front bar. Just be vary wary of lift throttle oversteer, especially on wet roundabouts! You can then buy a 22mm front (just go non adjustable) and play with the rear to suit your taste and driving style. Very important, you need to get a saloon front ARB when you switch to the STi arms. Sedan and Wagon front ARBs are different widths.

On the whole, after these mods, your dampers will be the biggest shortcoming on a bumpy b-road or track day. fortunately, you have a large selection of adjustable dampers that work with your springs and tophats without modification (Tokico DSpecs, Koni and AGX's). But after these changes you'll be much much happier on track. If you go for Semi slicks or very sticky summer tires coilovers can benefit you. But we can all talk about that when you cross that bridge. though keep in mind that all coilovers and adjustable struts are only available in saloon fitment (with the exception of KYB GR2 and STi OEM inverted wagon strut). This means that you won't have the massive amount of camber adjustment from just the camber bolt. You will have at least a max of -1.5 camber. If you want to maintain the large amounts of camber from the the wagon struts I'd suggest using the Koni inserts as you use the original wagon strut housing.