Handeling mods for gen 4 wagon

[B4 Dave]

Hi Guys,

I asked the same question a year or so ago and got some great advise about what to do with my B4 and got some great advise. Thanks to you guys the B4 got 07 STI tuned billies all round, pink springs rear, king springs front, upgraded sway bars front and rear and the anti lift kit.
The B4 now handels amazingly, ask Mick "dr2.0" after a couple of laps at Marulan a month back or so he was very impressed.

Now I have the Gen 4 JDM GTB wagon and want to start stiffening it up a bit, steering is a bit unresponsive in my opinion.

My plan was up rated sways front and rear, with hd rear mounts as I understand the gen 4 rear mounts are prone to breakage under load. I wanted to put in anti lift kit because it works so well in the Gen3 but the lower control arms are different and I am not sure how an antilift kit would work, with no shaft through the bearing to modify the angle of travel.
I have read about something called a roll center adjuster but have little idea what it is, replacement tie rods and ends?, and am not sure what the benefits/disadvantages are.

The vehicle is fitted with billies already and I am happy with them, I would love to lower it a bit but with the JDM front lip and rubber skirt I would basically have to park it on the street because I wouldn't be able to get into any driveways at all!!!!!!!!!!! I have to get lebo hectic angle to get into most driveways as it is now!!!!!!

Appreciate any help.

Dave

[Robbks]

Dave, the Gen4 has much better geometry out of the box than everything previous and as such has much more caster which helps with adding dynamic camber.

A good alignment is the first step to sorting the handling with the addition of a bigger rear bar, which also helps to increase the rear spring rate

I went far too agressive with my current alignment for the street
0' toe all round and maxxed out -ve camber on the front at about -1.5'
it's a bit susceptible to weight shift and changes in steering angle as it is, due to the huge amounts of dynamic camber that is induced once you wind some lock into it
you find yourself having to back off the steering angle halfway through a corner once the weight shifts onto that front wheel.

i'd think about -0.8' to -1.0' camber would be spot on for a street car, but for tracks like marulan the extra mid corner hook may be beneficial

[LorrenK]

Is there much adjustment in the stock suspension in a GEN4?
I'm after some more steering feel and feedback in my gtb and was thinking of a touch more caster but didn't know how much adjustment there was and then just how much is 'a touch' more. The steering response feels fine, I don't was It too darty, just some feel that I miss from my GEN3 gx.

[Robbks]

they have different LCA's and positioning to the gen3 which gives them a lot more caster to begin with
although you can still get the eccentric whiteline bushes to give more and also help stiffen it up.

[B4 Dave]

Thanks guys,

Appreciate the assistance so far.

Anyone out there who can explain what the roll centre adjuster is supposed to acheive and what it actually is?

Dave

[Robbks]

the RCA is different balljoints and tie-rod ends
it restores the geometry of the front end after you've lowered the car

http://www.amazon.com/Whiteline-Subaru- ... B004ZZVNOI

so think about when you lower it that you're effectively shortening the distance between the lower control arms and the body
or effectively pushing the control-arms upwards
this affects the angles of the hubs and steering arms.
the RCA kit puts them back wehere they should be

Product Description
KCA313 is designed to raise the front roll-centre geometry by using specially engineered ball-joints & tie rod ends while still maintaining original steering geometry.
Front roll geometry actually encourages roll the lower you go. Testing proves that raising the front roll-centre resulted in a substantial increase to front roll resistance & a significant reduction in suspension compression of the outside front wheel during cornering (less roll). This improves weight distribution & maintains a better camber angle which ultimately improves front grip. The overall outcome is significantly reduced understeer through reduced front wheel compression as well as improved steering precision & vehicle stability.

[jslayz]

Harder rear springs will tuck the nose into corners more.

J