what size rear ARB on wrx
 

I have just measured the rear ARB and it measures 20mm.I have read that the WRX should be 17mm and the sti one 20mm.Anyone know what size it should be (its a WRX wagon) also the one on there doesnt look like its been changed http://serve.mysmiley.net/confused/confused0024.gif

BTTT

come on someone must know .........if i put what dump valve I would have had about a million replys LOL
ps I have googled it but with no luck.

20mm? Sounds like you have a bugeye. Later models went down to 17mm. If you are planning on just upgrading the rear ARB then use a 22mm adjustable, I prefer Whiteline. Also upgrade the rear droplinks as well. The stockers have very soft rubber bushings, are made of plastic and delay the onset of the bar, reducing its effect.

If you are planning to upgrade front and rear, I would look at 22mm front and 24mm rear for a more aggressive driver. Matched 22mm front and rear if you want a less tail happy setup.

After installing, set the bar(s) at full soft and get used to the new feel. With a larger rear bar you can get severe lift throttle oversteer, so watch for that. Stiffen the bars accordingly to your taste, driving style and handling needs.

OK thanks for the answer,its a classic wagon I have got and have already changed the rear droplinks.

I was told not to bother too much with the front,but am thinking of changing the rear,so I might take your advice and go to 22mm.

Regarding the severe lift throttle oversteer,whats the best way to over come this ????Would an anti lift kit help or is this for something completely different??

Whilst on this subject since changing the rear droplinks,the front does seem to get alittle light at high speeds.Would changing the droplinks do this or is this something else??

cheers Jason

An adjustable rear bar allows you to alter the set-up to suit your driving style...

Best value mod on my car is the 22mm Whilteline ARB.

dunx

P.S. Front bar is good, but IMHO only needed when you are on track and using semi-slicks... ALK is often useful to help the front end grip.

As Dunx said, 22mm would be perfect. VERY good mod IMO

Whether you go front or rear depends on your end goals but starting with the 22mm rear adjustable is good.

Severe lift throttle oversteer (with a larger rear bar) usually happens mid-corner when lifting off the throttle, weight is transfered to the front tires and off the rear. With no more weight on the rear, the back tends to rotate around. You can stop the rotation by getting back on the throttle. Its actually a beloved Impreza party trick and something you should practice on track or in an empty industrial area. Its important to get the feel of how your car reacts in this situation. Eventually you need to learn to do this "on command". When its instinct, you'll be less caught out if it happens unexpectedly.

Its this unexpected situation that becomes the issue. This can happen, say, on a blind corner and you see that traffic up ahead is suddenly at a standstill. Or you come around your favorite bend and there is a herd of sheep in the road. Your natural reaction is to get off the throttle and on the brakes. The rear will start to come around, or depending on how your car is set up, snap around. To stop the spin all you would have to do is get back on the throttle. But you can't because you need to stop! In this case, only solution is to left foot brake and keep steady throttle on. There is no weight transfer and you can safely come to a stop. However, this is also a technique that takes practice.

So what do you do to prevent this from happening, respectively, have a "predictable and stable" rear end? A few things.

1. One, don't run your rear bar too stiff. The stiffer you make it the more the car wants to rotate and oversteer.
2. Another thing is to run more negative camber in the rear and bit of toe in. I usually run about -1.5 to -1.75 in the rear with about 5min toe in. This alignment setting gives a lot of rear grip. I then use the rear bar to set how much rotation I want. Even at full stiff, when lifting off mid corner, the rear slide is very progressive and rarely snappy. Very safe for the road where you come upon the unexpected. Its not the most nimble setting but combined with a decent amount of front neg camber (say -1.5) its a very nice fast road setup.
3. slow down! Seems a no brainer, but sometimes the obvious needs reminding. Keep the shenanigans for the track where you have a safe environment to play. :D