scoobyc

iTrader: (2)

Alright chaps,

Just done. my own setup on my coily's and there are a couple of things i want to run by you.

Basically, after doin the setup for ride height, my suspension is not symmetrical.

I measured the ride hight all round as stock. It was all around 63.5cm,

So set one side up to drop 30mm, and measure the distance between the locking rings and copy it to the corrosponding coilover. Now when i put the the other sides coilovers on, the ride height was different to expected on the front right. it was 16mm too high.

The rear was more out of whack. The rear right rings are 12.15cm apart to produce 60.5cm RH. But the rear left is 14.6cm apart to again produce 60.5cm RH.

Is this normal; and due to the weight over each corner? Is 14.6 too much? I saw that snapped coilover, it looked quite extended (previously posted by someone on here) Can anyone confirm this is within tolerance? The springs are preloaded the same. I.e. hand tight plus 5mm.

Also i was using a dry car. 1/4 fuel and no ballast for my weight. No extra weight, only thing i took out was the spare wheel.

Also the rear right was a total pain, hard to get on, difficult to adjust ride height and camber. The others u could virtually do with your hand. Even with both back wheels off the floor.



My "between rings" measurement goes from below the plasic spacer below the spring and ring, to the black metal below the bottom ring. I.e. the bit the bottom ring buts up against.

So my final settings:
FL
-1.6Deg camber
60.5cm ride height
8.4cm between rings

FR
-1.6Deg Camber
60.5 RH
10.2?between rings


RL
-1.6 DC
60.6 RH
14.6 BR

RR
-1.6 DC
60.5 RH
12.15 BR


They are all set at the same damping during setup also.


Hope someone can shed light/confirm/this may be useful.

t7srt

iTrader: (2)

Hi mate,

Each corner will sit diferently, If you were to measure a std car it would probabally sit lower on the drivers side, Dont know why but my experience has always found the same,
I took a long time etting mine up, started with equal lengths of gap between spring and bottom bracket, then dropped the car down on a falt surface and measured all round, As you move one strut setting it will affect the other three so i found that small increments were needed, Once equal all round i left it at the and done about a hundred miles on the softeset setting to allow the units to settle down,
Measured the distance between wheel arch and floor, then adjusted each corner to suit,

My bottom bracket is screwed up so far that the thread on the strut sits all the way to the bottom of the bracket, It was difficult to bolt these up to the knuckles but didnt want to chance a snapped strut, Like you said. ( I have the inverted struts so may be different to yours,

By looking at your pics, I would bring the back up a little as having the back too low will affect the handling,
Looking good though mate

scoobyc

iTrader: (2)

Yeah spent ages doing this too. a good 3/4 hours. Pretture sure it good, have had them on 4 a week now so hopefully they setlled enough before today. will keep an eye on it.

Will check the ride heights all round this week and see what happens. Yeah the rear does look a little low, but all the numbers add up so im gonna see how i get on.

Corner weighting costs far too much so adjustment by feel i think.

What symptoms is a low rear gonna have? less rear end grip due to increase weight over the rear?

t7srt

iTrader: (2)

corner weighting wont do anything to the ride height, Corner weighting is for track set up so the car has a nuetral balance,

Having the rear too low may be a bit twitchy, Remember where all the weight goes when you put your foot down and then brake hard, the back end will be unsettled,

I'll measure mine and let you know the heghts, are they 17's you got on there? Mine are 18's

scoobyc

iTrader: (2)

Yeah 17"s

Ride height is from top of arch to floor by trye through wheel center.

Yeah but adjusting the ride height is going to shift the corner weighting. So if i get it checked, shouldnt matter what the height is as long as each corner is relativly balanced.

Car is to be used on trackdays. You can buy a corner weighting gauge for about 120 quid. might do that to double check. Or see if i can borrow one off someone on here.

scoobyc

iTrader: (2)

Right. Had chance to take it for a good spin. Here are my observations with these alignment settings.

The car feels un-stable. especially under hard accelleration and braking.

Cornering wise, it was dry to wet is very good. Excellent grip now, i still get more understeer but its much more progressive now, and has1000% more grip before the front lets go.

Not managed to get the **** out, probably due to lack of guts now there is significantly more grip. It seems the rear is much more planted, i fear power oversteer is going to be very snappy now rather than progressive like before.

I think i may up my front camber to -2deg and leave the rear as is /-1.7deg, that might give more of a balanced front the rear grip due to the weight of the engine etc.

As for the instability, i can only put this down to changing the camber affecting the amount of toe. could this be the case? It seems to tramline n wander, when it was running stupid camber it didnt. Perhaps more camber induced a bit of toe in which stablised the front a bit?

Opinions welcome.

Would like to confirm with someone the rideheight settings all round for the classic sti for good weight distribution.

All comments welcome.

dunx

iTrader: (3)

I'd raise the rear end as suggested, or ask on 22B for the best road/track settings for a classic.

Mine was dropped on the floor, and handled o.k., BUT the ride quality was BAD !

Raised it 40 mm for the run to Thoresby car show on Saturday and the ride quality has improved, but the handling hasn't suffered.

Good luck with the tweaking.

dunx

P.S. A touch of toe at the rear may help turn-in (?)

JDM_Stig

iTrader: (3)

Didnt you say you had tramlining on the run over ?

scoobyc

iTrader: (2)

im really reluctant to increase the rear ride height as all the numbers match at the mo. I dont wanna do that untill i can get a corner weighting gauge to ensure i dont screw it up.

The exahust ****** on my drive, and my work car park now, and as its brand new n still shiney i think ill raise it 10mm. I like the look of them low tho.

t7srt

iTrader: (2)

Forget about numbers for ride height mate, The rear end is too low, Raising the back end 10mm isnt going to effect a car that was never corner weighted from factory, I think you are confusing corner weight with weight shift acceleratig and decelerating.


If you bring the back up it will give a tiny amount of weight to the front giving a little less understeer, running too much camber on road tyres will also give excesive understeer as you will be running on less tyre than more mid corner, Try running 1.3 neg camber all round. You'll find a road set up will not work on track and visa versa.

t7srt

iTrader: (2)

I've just had a look at those measurements again, Did you adjust the braket at the bottom of the strut so they all match before you fitted them?

Thats a big difference in spring height between sides, each spring will be preloaded at differents rates, If i can find a pic I'll show you what i mean.

t7srt

iTrader: (2)

The bracket that I have circled in red screws up and down on the threaded strut, This is the bit that needs to be equal on all 4 corners, I set mine so that the bottom of the threaded strut is flush with the bottom of the bracket, So the maximum of thread is inside the bracket

scoobyc

iTrader: (2)

Cant see your pics at work.

Yes the springs were preloaded as accuratly as i could.

I am also confused by the big difference between sides.

my point about the measurement is that i dont currently have sufficient equipment/testing area to start chaning things like ride height. I have a standard which is what the car was originally, and i shall stick to that blue print for the setup of the other aspects untill i can get a corner weighting gauge.

I dont think people can judge the rear is to low from those pictures.

However i have taken your advice on board re the rear and will think about adjusting it up a bit.

Not to worried about tyres, and im after a setup which will be good on the track. but still usable on the road.

This weekend ill have a think/re-measurement of everything and see what i can change.

scoobyc

iTrader: (2)

The only reason i can think the difference could be caused is that the rear left and front right have less weight over them, compressing the spring less, and so the ride height being too high.

Currently the car handles very well in the corners, as stated id prefer slightly less understeer, slightly more over steer. However under braking and hard accelleration the car is all over the place.

A high rear left, should mean a low front right, as raising that corner should shift weight across (not specifically ofc). But the opposite seems to be the case...


If you wholly contribute the difference between the rings as due to the compression of the spring (compresson making it lower, and so counteracted by increasing ring distance to return the RH to equal levels. It would dictate the front right and rear left are taking higher weight loads...

scoobyc

iTrader: (2)

Do we not want symmetrical ride height? and symmetrical spring preload? Other wise things are going to react differently under weight shifting on accell.decel as you say.

Far to much to consider when trying to get a perfect setup without the eqipment/room to do it. Will get under it again on the weekend n see what i decide to do after measuring everything again.

scoobyc

iTrader: (2)

Just want to add one last thing to this.

It feels like under hard braking the front left is first to lock. It feels as if its rotating anti-clockwise, then the abs kicks in on that wheel, and the car rotates clockwise, then the ABS disengages, and i get this snaking effect under very hard braking. I hope this is due to setup changes. This ring any bells with anyone?

Shaun

t7srt,
I won't ask you to set my car up then, as that is EXACTLY what corner weighting will do with the ride height!!

Also you mention about camber..... 1.3degs is paltry. Fast road can be closer (and over) 2degs.

scoobyc,
If you car is all over the place under throttle and braking, you have something seriously wrong at the front.

Does the front rise under acceleration and feel light?

What is happening under braking to the car.... pitching forward and light at the back?

scoobyc

iTrader: (2)

well all over the place is perhaps an exxaggeration.

On accelleration it feels a little bit like torque steer, a little twitech of the steering wheel anti clockwise is caused, not input.

On braking as i say, it feels like the front left locks, then abs lets it unlock and so end up with a snaking effect. It only does this however only just before the ABS kicks in. You can brake 90% in a perfect straight, but that extra 5% seems to make strange things happen.


So yeah only happens on max throttle and 90%+ braking force.


I could say a lack of weight over the front left would cause it to lock first, but you would also think that as the car is rotating anti lock wise, that means that corner is ok for weight, if anything perhaps has to much brake blance. Which has not been messed with. and wouldnt affect accelleration.

Shaun

I have no experience of BC Coilovers, but are yours adjustable, by means of a rotating ****... if so, is it single way adjustable (i.e. one ****). If this is the case (so many if's lol), what is your **** setting from full soft (how many clicks on EACH front strut) and how many clicks in total have you got available from full soft to full hard?

The feeling you state could be all manner of things, from geometry issues, to brakes binding to also being soft at the front etc.

The twitching anti-cockwise, together with the left front locking..... seems to point to a specific issue with that corner.

scoobyc

iTrader: (2)

They are fully adjustable and yes have a twisable know.

30 settings. currently run at 15 all round.

Pitch is massivly reduced over my stock suspension.

Yes perhaps there is something wrong. I have changed steering rank and ALK both with positive effects but the car is still not stable enough. next step i think will be chaning both the front wishbone bushes.

As far as i know the brakes are fine, they have chewed through a similar amount of pad, however i suspect the left brake gets hotter for some reason, as the pain on this one has turned purple much worse than on the other caliper.

seems a few sites are recommondeing -2 front -1.5 rear ish settings.

Ill mess around with the suspension again, see what happens. trial and error. see what improves where why when how etc.

From a geometry point. What could be the likley cause of this anti-clockside motion under braking? rear left too high?

scoobyc

iTrader: (2)

Been reading alot. Surley adjusting the preload on the spring on these only adjusts the rideheight/max damper travel?

So if i have preloaded the springs slightly wrong, the adjustment in ride height should compensate without having any effect on the spring.

I can only see spring preloading affecting the spring when it is shortened beyond the max rebound the damper. I.e. still compressing the spring when the damper is fully extended..

So i guess we can rule out any issue with spring preloading if this is the case..

Which leaves:
Corner weighting/ride height
Camber
Toe

or as you say. perhaps these are all perfect and something else is wrong..

Shaun

Your single adjustment will do rebound/compression together I suspect. This may only be low speed compression as high speed maybe fixed.

Regardless of that, your rear springs will be softer than your fronts and your adjustment on front and rear struts should follow suit to a degree. i.e. less at the front and more at the back. This is not what is causing your left front passenger wheel area problem, but is something to think about as regards to your set-up. Trial and error.... so go and have a play and see what you think.

Something definately sounds hooky with that braking system on the front passenger left. That may certainly cause grabbing (steering) and the brake overheatings on that side.

As regards to your suggested camber settings for fast road..... yep, they are pretty normal.

The anti-clockwise motion of the steering wheel on braking, sounds like it is grabbing the brakes more on that side..... this is backed up by the fact that you say that side is overheating. I can not see this having anything to do with geometry. That smashes your tyres up, not over heats your brakes.

Take the caliper off on that side and make sure the piston is not seized.

scoobyc

iTrader: (2)

Yeah had the caliper off the other day and it seemed fine. Will have a further look. its only a guess at the temp. I may have painted that side more/less which could have caused it.

Then what could be causing the acceel unstability? Would increase toe in counteract and movement in bush? Making a more toe in setup more stable hiding the defect perhaps?

Im not totally convinced the bloke who did my tracking when i changed the rack got it 100% spot on, thought it pulled a bit to the left after that, but managed a track day with some hard braking so coundlt have been too bad.

Guess the car is old, suppose a few hundred quid n a weekend on bushes will be good for it.

So ill mess with the suspension see if that can fix it. if it cant, then get back into replace bits.

Cheers for the advice. Learning lots

t7srt

iTrader: (2)

I was simply trying to explain that the op shouldnt need to worry about corner weighting at this stage, may not of made myself clear and should of re read it before posting, LOL


I think we have all missed one important question which is what tyres are on the car, Are they all the same make? and if so, are they a good branded tyre or budget?
Also did the car have these charachteristics before fitting the BC's even if very slight, As the better suspension would possibly exagerate this.

I fully aggree with Shaun that it could be a braking issue and that they could also be out of balance, but a hot caliper would concern me.

There are so many varables that could affect the cars handling. It may pay to have the car set up with the prodrive settings and go from there and atleast you know that everything measures up right, I.e camber, toe and caster.

Just out of interest, Scoobyc, have you been on a track day yet?
Also what other mods chassis and brake wise have you got?

I wish you all the luck in the world and possibally meet up on a track day at some point

dunx

iTrader: (3)

1. Ask John Felstead for his ride height recommendations.
2. Set the car as instructed.
3. Brake like crazy, and then increase the pre-load on the wheel that locks.
4. Repeat until the braking is stable.
5. Choose a road setting for damping and then adjust to get over/understeer as required.
6. Go on track and alter damping to suit.

Over simplified I know, but "feel" is as good as any measurement you can take.

IMHO

dunx

scoobyc

iTrader: (2)

Hi. The caliper is an assumption its getting hotter as the paint has changed move of its colour. This could be total BS on my part tho....

Had the car on the track many times. My handling problems started at brands hatch back in Jan after i decided to try some slidage and went 360. Didnt hit anything, wasnt even on the track, it was on the massive expanse of tarmac at the end of the day.

I have had GRD fully setup my which made no difference, i have changed to ALK as i suspected those bushes were gone which made some difference, finally i changed the steering rack which seemed to fix the issue. I was never more than 90% sure it was fixed. I then did a track day at bovington and the car was fine cept the PS overheated a couple of times.

Tyres are all prada spec 2's all decent tread all round. My other set of tyres makes the steering more off, so perhaps either those tyres are screwed or they exhasibate whatever is wrong.

Only had my set of cut slicks on for a quick blast and it felt ok before i did this suspension.

Brakes are stock except braided lines. I put ds2500's in for the track, and am on another new set of disks afted my last lot broke. Actually. interestingly, it was the front left which had the worst crack in it. adding substance to that caliper getting hotter.




FFS another day wasted....

Ive checked everything today.

FL
60.5 RH
31.5 Suspension Length
8.4 between rings
=Spring Length
-2camber


FR
60.5RH
33.3 Suspension Length
10.3 between rings
=Spring Length
-2camber

RL
60.5 RH
34.6 Suspension Length
12.4 between rings
=Spring Length
-1.7camber

RR
60.5RH
37.0 Suspension Length
14.65 between rings
=Spring Length
-1.7camber


Check my old suspension roughly and they were all roughly the same height/total length.

Car handling is a mess, its squirmy on accelleration and braking and i have no faith in it to push it hard. (however when cornering it feels balanced n grips like hell, lil bit understeery if anything which is ok)

The only consistent reaction in the car i can mention is. When driving the car pulls slightly to the left. When driving straight, i can feel weight turning the steering wheel anti clock wise. When i accellerate i can feel this weight increase.

It kinda feels like the tracking is off and ill take it down the local monkeys to get checked.

You know the centered steering wheel, well it kinda feels like its centered when its turned clockwise about 5 degrees.



Notice the differnce in the total lengths of my shocks is circa 2cm different in opposite corners. Can anyone please advise why this may be the case n wtf is happening? and yet my ride height is exactly equal.... Will corner weighting solve this definitivly?

i REALLY dont wanna spend 400 quid getting it setup (alignment n corner weighting), especially if that doesnt fix the problem!

Who are the reputable scoob specialist in the berk area? Or alignment specialist in the berks area?

As for the Braking. That felt alright today much much less squirmy than before but still not ace. Felt more like a real car tho. I exercised all the pistons in each caliper. Noticed, when free, the top move first then the bottom. The front right caliper, bottom inside most piston was slightly less free than the others so worked it well it it was perfect. Not sure that was enough to cause anything tho..











Can i atleast get longest reply award or "currently most pissed off member of SN" award?

scoobyc

iTrader: (2)

Right had another go today..

Noticed one of the fronts had much more preload than the others. Not sure how i screwed that up.

Either way i took them both off and adjusted them both, i increased the length of the shorted so they were both identical.

When i first measured afterwards the ride height was out. Also removed the arb and its fine.

So went for a sping, and the strange braking and accelleration has gone. feels more balanced. However it still pulls to the right a bit and every tiny imperfection in the road un settles the car.

Re-measured my rideheights after a spin and this is what i have.

fl 61.5
fr 61.3
rl 61.5
rr 60.3

Interestingly reducing the sping load on one and increase in the total length has left the ride height about right.

Only the rear right is now 1cm low. And i know the two shocks are of differing lengths. the rear right being the lower by 2cm.

So it seems adjusting the front has a big effect on the others heights.

I need to adjust the rear to suit, however i couldnt get the lock ring undon, and have destroyed the teeth. Ill now need to take it off to find a way around an perhaps get a new locking ring.

it seems my usual bump n rock is not enough to setlle the suspension.
Hopefully if i raise the rear right to be equal it wont push the front left down to much..

scoobyc

iTrader: (2)

Here is another update after the usual work test drive route.

Now the suspension setup is symmetrically. To the mm

Now Ive measured the ride heights in a few places and i just cant find somewhere flat enough. The readings differ by about 1cm wherever i stop. The rear is about 0.5cm higher than the front.

Overall its driving ok. The diving under braking is gone. however it does still feel a little light i think you would describer it.

Cornering it does rather well. However it seems very suceptible to any grooves/marks ont he road. It tends to pull all the time based on what the road is. Even a change in camber. I take this is to do with the toe setup?

I think i can now feel that when it does pull under accelleration or braking its due to imperfections in the road.

Id still like to reduce this if possible, so any ideas?


In the mean time awaiting a reply from API and subaru4u regarding doing a setup for me. I think its good enough for road use now. Its just not perfect...



in summary. The only thing i could find wrong was one of the front springs was compressed about 1cm more than the other side. This seems to have thrown all the ride heights quite a bit.

Ben@Driftworks

iTrader: (1)

Unless you're cornerweighting then fudging about until corner ride height measurements match up isn't a good idea IMHO!

If everything is correct then you should be able to set the spring preload and overall length the same side to side, once it's been aligned (with proper alignment gear) the measurements should be as near as damn it perfect. NO car is going to measure up 100% perfect for ride heights, cars aren't 101% perfect, tyres don't wear 101% perfectly, to acheive equal alignment it won't always end up with both sides wheels in EXACTLY the same place in the arch, nevermind the arch being IDENTICAL from side to side.

By guessing and altering lengths as much as you have you'll probably be completely screwing up the loading on each wheel, and ruining handling. Seriously I'd take a step backwards, set the preload and length to be identical side to side, get it aligned and drive it. If the measurements work out that it's sitting slightly unevenly don't worry as long as it drives properly!

Remember the original struts you took off will all have been equal length.

scoobyc

iTrader: (2)

by my previous post when i say the setup i mean i took them all off and made them symetic off the car which did indeed change the corner ride heights.

getting corner weighting done at API which will resolve any issues i have about the car once and for all.

Did some tests with changing the height of the car whilst using my camber tool. Even a 1cm change really messes up the camber. I need a much flatter road to do my setup.

Fortunatly once API have had a go it should be sorted.