Will Fitting arb affect geometry
 

Hi basically as it says, iv got my car booked in for geometry on sat but thinking of updating the arb and drop links

Iv been told mixed reviews by 2 shops some say don't get the geometry done until these are fitted and others say it won't affect it???:wonder:

Really annoying as don't want to get geometry done then ruin the set up fitting the arbs

It won't make any difference to the geometry.

But could it make a difference to say the way that they would set the car up if it had them?
Iv been looking at the whitelin 24mm adj at the back with some uprated alloy drop links,

For all intents and purposes, no, it will not affect your geometry setup. Your camber and toe will remain the same if you install ARBs before or after.

However, do realize that ARB's do put tension on the suspension and can affect corner weights. If you are corner weighting your car ideally its best to use adjustable droplinks, if available, as you remove any pretention the bars put on the suspension, thus keeping your corner weights more accurate. But, if you want to be very, very picky... in this situation, if you are optimizing your corner weights, if you don't unhook your bars before setting your weights, your weights will change once you attach the bars. So technically, you would have to change the corner weights by a ride height change (which would then change your camber and toe).

No I was not going to corner weight the car, not really heard much of this so don't really understand.
U mention the adjustable drop links. I have see these for the front and would these not alter the alignment? I think I would be better off just having the fixed alloy drop links fixed front arb and adjustable rear, but didn't want to wait until after the geometry to fit these parts then mess up the cars handling.
If I order the arbs I will have to wait a week for delivery then that weekend to fit then will have to wait till the next weekend to get geometry done so another 3weeks at least.... This is y I want to make sure changing them after will not affect it. I don't want to be paying twice for the set up....
Cheers for responding

Probably adding more info than you really need! Sorry about that!

You are fine getting your geometry done and installing ARBs later. Definitely just get the alu/poly solid drop links, no need for the adjustable ones.

Corner weighting (or corner balancing) is the single most important feature of using coilovers. The process of corner weighting determines the percentage of the car's weight on each wheel. Imagine a typical bar stool with four legs. One leg is a bit shorter than the other and the chair wiggles back and forth. That's basically what is happening in a car. Each wheel has a different percentage of weight on it due to battery placement, fuel, driver, etc. What this means in car is that you have different cornering characteristics turning right and left. In completely extreme case, your car could understeer massively turning right, but oversteer turning left! So what do you do with a chair? You stack some coasters underneath and even things out. In a car, you raise or lower the ride heigh of each corner until you get the crossweights as even as possible. Here is good article describing it in more detail:

http://grassrootsmotorsports.com/art...orner-weights/

its something one does for motorsports when you are trying to gleen that last 10th out of the car, but it is something you can notice in a street driven vehicle too.

Ok thanks for that was interesting to read:)

I'm glad that I can change these parts after the geometry

Will be able to c if changing the arbs does make a difference, although I would hope that it would for the price:thumb:

Also does anyone know how the adjustable arbs work are they easy to change there settings.........

Its easy to adjust them just 2 bolts to swap between 3 holes however I dont think many do.

Must help to initially set up the cars understeer oversteer caricaturists to suit each driver tho rather than being forced to live with the preset unadjustable arb

Or is paying the extra for the adjustable just a waste of money???? And the preset will be good

I would always only buy an adjustable. its good to have the adjustability. Whether you're trying to match the handling bias to your tastes, equipment or weather conditions, its nice to have the options. Invest in a set of ramps. Its best (and easiest) to make your adjustments with the suspension fully loaded. Just drive your car up onto the ramps and loosen the bolts and insert into a different hole. I would always start at the softest setting, especially if you are using only a REAR 24mm bar. Lift throttle oversteer is always around the corner, so watch it. The softest are the holes at the very end/tip of the bar. Stiffest are closest inwards, towards the center of the bar.

As far as the worth of an adjustable, using a 24mm rear with a standard front is actually a pretty scary setup. Having the ability to set it at its softest setting will keep your car's butt pointing in the right direction. If and when you upgrade the front bar you will be able to adjust the handling bias accordingly, i.e stiffer in the rear.

Would it be worth not changing the rear first but to wait until I have funds to do the front swell?..

After speaking to one of my mates he seems to think changing the front is a waste of time. And to fit just a 22mm on the rear
Although if I was to fit a 22mm on the front at a later date then this would cancel out any gain from the uprated rear so would need to fit a 24mm rear..

I just thought fitting the 24mm in the rear to start with would give me the option to change the front at a later date if need be....
So if inwas to just uprate the rear this would make the car more oversteery??

your mate is right! are we talking classic or newage btw, for a classic a 22mm rear arb with solid droplinks is a very good mod, i would just try that to start with, 24mm for a classic isnt really needed unless you only use the car for track.

and imo i wouldnt do the geo until i had changed the arbs

It's a newage blob eye sti

Can u be more pacific as to y u wouldn't have the geom done until after???:wonder:

Yup, if you're not planning on running a larger front bar, a 22mm rear adjustable would be a good one to opt for on a Classic. Even if you do get a 22mm front bar, its still a good match with the 22mm rear. You'll probably set it at the medium or to full stiff at that point. I've run 22/22 adjustable on classics and new ages and they are still great. The UK folks tend to like the larger 24mm rear paired with 22mm front but, IMO, you can't go wrong with a matched 22/22 or 24/24. You'll still get very nice rotation at the full stiff rear setting.

I personally like running a front bar too and don't think its a waste of money. Less front end roll, more front end grip. You just need to stiffen up the rear bar to get the rotation back.

Oh, just saw your post that you have an STi. Check underneath the rear to confirm what style drop link you have. You might have the ball joint style rather than the plastic C-link style. If you have the ball joint then I'd suggest getting the Whiteline KLC139 endlink or, if you can find them in the UK the solid Alu/Poly endlinks from Kartboy.

I would look into running the adjustable 24mm rear bar on your STi, but run it at full soft first. Full stiff with a standard front bar can get a bit hairy but soft or perhaps medium if you are used to it (and can catch the snap) would be best on the road.

Thanks arnie, say that just uprating the rear and not using the soft setting will make the car hairy, and u talk of the snap....

Will this snap be the back end suddenly kicking out causing oversteer? Just unsure as to how changing settings on arbs effect how the car handles etc

I want to be able to push the car confidently as only an average driver using the car on the road and don't want to be ending up on the ditch if I can't control the new carictaristics caused from the wrong setting or arb
Cheers

The phenomenon is called "lift throttle oversteer" and it happens when you are mid corner and lift off the throttle. Lifting off the throttle or getting on the brakes causes weight transfer to the front making the rear end "light". If you do this in the middle of a corner the light rear will step out. You "catch" this by getting back on the throttle and counter steering a bit. Giving some gas transfers weight back to the rear of the car giving it traction. You can see this when you accelerate and the rear squats.

Anyway, how badly the rear snaps depends partly on how stiff your rear bar is. If its set very stiff or is a very thick bar, it can snap very quickly and have you facing backwards in a hedge in no time. If its a smaller or softer set bar the oversteer can be a very progressive controllable slide with no snap. This type of oversteer is an old Impreza party trick that can be done in a stock car too, you just have to be a bit more aggressive with your inputs.

Now, the dangerous thing about this admittedly fun dynamic is not only doing a 180 into a hedge but its having the rear step out when you have to come to a stop in a blind corner. There are lots of these potential situations on the backroads! For example, you're dicing along, carving through a left hand bend and, whoa, stopped traffic due to some livestock. You get on the brakes and the rear steps out! Only way to get it to stop rotating is to get back on the throttle. But, how do you get back on when you should be stopping? (hint, left foot brake). But its this sort of emergency situation that you have to be mindful of. Having a car that has a loose rear end (through a large or stiffly set rear bar) is very much fun to drive. However, it can be a handful in an emergency maneuver.

So what do you do? First, learn to drive. Take some time and savings and invest in some driver's instruction. Learn to handle your car in controlled environments like slaloms, where the speed is relatively low. Learn the limits of your car in various handling setups and see what happens. As far as car setup goes, regardless of whether you opt for a 22 or 24mm rear bar, start off in the softest setting. Go to the track or to an office park where the roads are wide and empty and make some left hand turns around corners. Then lift off in the middle of them. See what happens. See if the rear steps out and when. Try to induce it. Counter steer, get back on the throttle and see the car straighten out. Practice it till its instinct. You're less likely to be caught out in an emergency. When you've got this mastered, stiffen the rear bar up one notch to the middle setting, wash and repeat!

In general, the 22mm rear adjustable will be a better match to your OEM bar. You can use it confidently in all settings with full stiff not being extremely lairy. It will still mate up well with a 22mm front bar. A 24mm rear bar is a nice investment if you know you will be planning on on getting a larger front later. However be very careful as having it in its softest setting is similar to having the 22mm at around the middle setting. What you can do is buy the 22 now and sell it later when you get the 24. Up to you.

I have the Whiteline 22mm and it's plenty strong enough to give you lift off oversteer in the middle setting, so no need to go for a 24mm one for the road.

I have put it on the softest setting for winter and it was pretty easy to swap over, but you do need the right spanners to get a good grip and be aware the paint finish on the Whiteline will be damaged by the link.

I have the Anti-Dive kit as well which makes a huge difference. Comfort version so not harsh and you can really feel the difference braking on rouht roads. Loads more feel and complience and less understeer powering out on rought corners too.

You do get more pitching which you would expect. Can't wait to get the coilovers on next.

Have you got an uprated 22mm up front??.

Thanks arnie this information has been really helpful! U certainly know ur stuff!!!

Although after reading this I'm thinking that I will wait until I can afford to replace both the front and rear arbs at The same time....

This way I should be able to benefit from the loss of body roll and not have toooo much lift off oversteer, or too much for me to handle!?!

Would it be worth getting an adjustable front arb aswell or would that confuse the set-up too much for a novice and best to just keep the adjustment on the rear???

I really didn't realise how much arbs can bring ur car to life and that they have such an effect on the cars driving style.

Thanks again:thumb:

No standard. I did uprate the rear ARB mounts too but have standard drop links as the 2005 on STi has quality ones as standard.

My car has the ALK, rear 22mm and everything else is standard for now- the O.E. shocks are appauling things, soft springs and bloody bump stiops from hell!

Still, mustn't grumble- the rear top mounts haven't started knocking yet....they will soon as they're overdue!

Interesting thread - thanks guys...

Wouldn't a STD front arb offer more front end bite/grip than thicker front arb?

like everything suspension related...it depends. certainly a softer front set up will give you more grip, especially on rougher surfaces. however, you also lose front end grip through roll, especially if you aren't running enough negative camber. a larger front bar helps keep the front end "flatter", giving more grip under cornering. now, the in car feel with a larger front bar (compared to just a larger rear bar) is a car less willing to rotate. Most folk interpret this feeling as understeer. What most don't realize is that cornering speeds will have increased despite this feeling. Its just that the rear end isn't as lively feeling.

I like to set up a car to have as much front end grip as possible/necessary. This comes from a combination of front bar rate, front spring/damper rate, and geometry setting/correction (rollcenter/alk). Then I use the rear end to tune the rotational balance of the car, i.e. how willing the car is to rotate and how it rotates. you can set an adjustable rear bar at a stiffer setting to get the rotation level that you want or are comfortable with.

Like I said at the top...it all "depends". Suspension setup is all about compromise. What are you willing to give up to get where you want to go? In this case, you can use the OEM front bar, but you will be on the outside wheel's sidewall quicker than with a stiffer front bar (losing grip sooner). you can easily combat this by running more static negative camber. But then you have to deal with more inside tire wear (depending on your toe setting and how aggressive you drive day to day). Or you can run more caster, or you can use roll center correction, or, or, or...

On the whole, it is a reason why I do like to do suspension changes piece by piece rather than throwing a whole battery of new parts on car all at once. Its a good thing to be poor and only able to afford one new part at a time. You get to see what that one piece does in isolation and decide where to go from there. So perhaps try a larger rear bar first. Go through its range of adjustment and then see what you'd further like to change. Do you need more front end grip than you are currently getting? Try a more aggressive alignment next. Still not enough? Uprate the front bar. Still not enough? ......

Excellent stuff Arnie. Would you say increased front (and rear) roll resistance 'needs' or at least works best with sticky rubber?

It looks like Arnie knows a thing or two about suspension.

What do you think about my choice in arb's?

24mm adjustable front and rear.

The car is driven mostly on the road but i will go to the track about 4-5 times a year. I want the car to be pretty neutral.

For now i only have coilovers fitted.

But the car will also be fitted with the following.

Hardrace adjustable uprated rear arm kit
SUPER PRO FRONT ROLL CENTRE ADJUSTMENT KIT, maybe the whiteline kit instead so i get the track rod ends to,(people have different thoughts about this kit. Some say that the whiteline track rod ends give the car more bump steer and some say the give less. What are your thougts???)
SUPER PRO FRONT OF REAR DIFF SUPPORT
WHITELINE HEAVY DUTY STEERING RACK MOUNTS
WHITELINE ANTI-LIFT KIT
WHITELINE UPRATED REAR ANTI-ROLL BARS MOUNTS

I will of curse do a new alignment when everything is fitted.

Thanks! Don't forget, its just my opinion from what I find works for me. Its by no means set in stone and the only way or even the best way to do things. Many ways to skin a cat and get an Impreza to handle well. So here's another lengthy response to a simple question! :lol1:

In general any suspension setup should be tuned first and foremost in direct relation to the tires you are running. Stickier tires usually require stiffer springs and/or roll bars as they generate more mechanical grip and, hence, roll. So if you are running Michelin Pilot Cup Sports or Toyo R888s, etc. then you'll need a stiffer setup. Whether its through stiffer springs or ARB's or a bit of both is up to you and your own "philosophy". But you'll need to stiffen things up the stickier you go. The car will work "better" with components chosen and set to optimize the grip available from that tire.

However, that's looking at it from the "ultimate grip and performance" angle. Where you are trying to optimize everything to get that last 10th out on the track. Even on the road, similar rules apply, ideally.

But here's the thing, if you're not looking to generate the most grip possible with the tires you have through suspension fine tuning, it doesn't mean you can't enjoy a car that feels good to drive. In my situation (of long commutes to work) I had to resort to running about the cheapest tires I could find just because I was doing so many miles. It wasn't worth going with super good meats because I'd only get maybe an extra 1000 miles out of something costing 3x's as much. So, low grip, high mileage tires it was. Problem was, I had components that were designed and set up for tires with much stiffer sidewalls and more grip. Coilovers with 6/5k spring rates, 24mm bars F/R, ALK, Roll Center corrections, etc. etc. Technically much too stiff for the tires. However, I wasn't really concerned with ultimate grip, just enjoying the drive in a car that was still supple and comfortable while still handling very precise. It was a blast! I just picked milder alignment settings and away I went. Even though I couldn't go that extra 20mph around a corner like I could with better tires, the suspension setup made driving so much fun, at any speed.

I just copy and paste things I find on the internet!:D

A couple of questions, what tires do you plan to use? Are you concerned about tire wear? What spring rates are you running on your coilovers? What brand?

im running bridgestone potenza re050a 215/40 r17 right now. But later i will buy some tracktires like Toyo R888 or something. Tire wear isn't so imported but good if they last more than one summer =). Ooh, i have no idea about the spring rates. But the brand is Tein Super Street(the where on the car when i bought it, Type R import direct from japan to me here in sweden).


Edit: I did some search about the spring rates. It seems like they are. (uk site) front: 4.0 rear 3.0. or (us site) front 7.0 rear 6.0.

http://www.tein.co.uk/installation_m...GC8_92-00.html

http://www.tein.com/tech_info/s36.html