help with setting up the car's suspension

Mr GTiR

New Member
I know i have asked this before (done a search but can't find thread :oops: ) but can anyone tell me how the car's suspension should be set up?

I have the folloing fitted:

  • coilovers with Cusco pillow ball adjustable top mounts

    front upper and lower strut braces

    rear upper strut brace

    Powerstation bumpsteer kit

    front anti-roll bar poly bushes

    front drop links with poly bushes

    wishbone bushes (bush at rear of wishbone) with alu spacers

    uprated engine mounts (all 3)
I have 17" alloys with 205/40/17.

Last time i was told that the front needed negative 1.25 camber and the rear negative 1.5 camber. Does this sound correct or what should it be?
 

campbellju

Moderators
Staff member
Mr GTiR said:
Last time i was told that the front needed negative 1.25 camber and the rear negative 1.5 camber. Does this sound correct or what should it be?
Complete cr*p, suspension setup is subjective and dependant on car and driver etc but more camber at the back would give the car even worse understeer.

If you've got the money, take your car to a professional and get the coilovers setup properly through corner weighting the car with you in it (or a passenger as well if you have a navigator/girlfriend etc normally in the car) They will set the height of the springs. Don't go too low, a 40mm drop is quite enough for road use.


Get your tracking done, ideally with 4 wheel alignment. Adjustable top mounts are designed so you can mark up a few preferred settings and quickly adjust them at the track depending on its style and the weather.
A safe setting would be -1deg back, -1.25 deg's front. Get toe setup as Nissan say it should be for a GtiR. There are real advantages to playing with toe to make the car more or less stable on entry or exit from a corner but for road use you'll also get a lot of tyre wear.

Your castor is fixed.

Try to adjust your dampers so they compensate for the springs but don't go to hard. The Fronts should theoretically be about 10% higher than the back as there is more weight to control.

Drive the car for a week or so, is the balance how you like? Some people prefer understeer, others neutral or oversteer.

Though oversteer is very hairy chested, most people can drive fastest with a hint of understeer. Neutral handling is great but does require more delicate control as the front or back end can go on corners so is less predicatable.

To change the balance:

Increasing the difference in camber front to back will reduce understeer. Making them closer will increase it.

Given you have 205's I'd be surprised if you went much past -1.5 deg with -2 as an absolute max for a high speed circuit, your tyres are unlikely to support much psat this unless you went for slicks. Too much camber causes instability on the road and you can't really go cornering at 120mph so a conservative setting can also be the best handling for most road applications.

the best place to setup a car is at a circuit as you can see and feel the tyre wear over the day and adjust the camber accordingly.

there's loads of other stuff you can do like fitting a stiffer rear ARB, loosening your body shell at the front :shock: (Its very stiff/solid at the moment which is a good thing but will the car more prone to understeer and needs to be dialled out threough your suspension)

Also, what kind of driving are you going to do, A drag setup is night and day different to a track setup.

I've written loads of long posts on here as its my pet bug bear. Do a search on my name and see what comes up with handling titles.

Cheers,
Jim
 

campbellju

Moderators
Staff member
Andy,

what are your tyres as well and what pressures are you running them at. You would expect these should also be 10% higher on the front too. Adjusting these will also adjust balance.

Theory is higher pressures equals more stability but less grip. Practice is a bit more subtle and depends on tyre choice, ambient temperature and weather(Winter higher, summer lower)

With all that in mind, vary between 30 and 38 and see what works. A safe bet would be 32 back 35 front but adjust this up and down 10% and see what you prefer. Also try equal all round to see if you can feel it adjust the balance at all. Which do you prefer?

Cheers,
jim
 
C

Crazy

Guest
Wheel Alignment Specs. (5)

Suitable for use with Whiteline kit Camber Caster* Toe

*Only achievable with KCA303 kit Deg Deg mm/side

Front Road -1.5 +2.5 to +3.5 0.0

Race -1.75 to -3.5 Max 0.0

Rear Road -1.25 n/a 0.5 to 1 out
Race -1.25 to -1.5 n/a 1.5 out


That is the set up sheet I gave to the geezers that set up my car mate 8)
 

campbellju

Moderators
Staff member
Carzy, don't take offence but the whiteline settings wind me up

The camber is sensible for road.
The race settings will only work with slicks. The castor is fixed anyway, all their kit does is add a degree! If you had a blank page you would choose between 2 and 10 degs dependant on road or full race. +2.5 degs is conservative in that range.

Toe out at the back :shock: Snap or power oversteer anyone!!!

I wonder if they mixed up the front and back toe as race cars use more front tow to improve turn in.

The whiteline stuff is good but these settings were designed for their test car on given tyres etc. It doesn't even say if its designed for use with the ARB kit, bigger tyres or modified suspension. :x :x

Been doing some diggin, here is a useful page:

http://track-days.org/page8.html

Look at all the subtleties of setting us suspension and tell me how the whiteline settings can work!!

Rant over,
Jim
 

skiddusmarkus

Active Member
Andy-Carl can set it up at ADR and they did my corner weighting whilst I was on holiday.I told them how much I weigh(about 80kg)and they used weights in the car.As I don't normally have a passenger I had it set up for just me.
I asked it to be set to the same as Powerstaion set it before to start with which I think is about 1.5 degrees neg on the front and 1 degree neg on the rear.I can't remember the rest of the settings but have them somewhere and so do ADR as I emailed them to Chris.
 

Mr GTiR

New Member
hummm, Carl phoned me the other day asking for the settings. I thought it was strange as they had just set your car up. It must be right what i heard then, they guessed on yours when setting it up :p :lol: :wink:
 

skiddusmarkus

Active Member
More like they realised you'd need about 10 degrees of negative camber just to stay on the road.Plus they couldn't cornerweight it as you're belly throws it all out :wink: .
 

campbellju

Moderators
Staff member
skiddusmarkus said:
corner weighting whilst I was on holiday.I told them how much I weigh(about 80kg)and they used weights in the car.As I don't normally have a passenger I had it set up for just me.
Its a genuine joy to hear someone setting up their car the right way. A lot of people get coilovers and jus tput it on the lowest setting :roll:

Cheers,
jim
 

Mr GTiR

New Member
skiddusmarkus said:
More like they realised you'd need about 10 degrees of negative camber just to stay on the road.Plus they couldn't cornerweight it as you're belly throws it all out :wink: .
nar there's bags of sand to counteract my weight :wink:

campbellju - never been one to choose the softest setting. The coilovers are rock solid and the handling very good but with the few extra goodies i got off Ian C, the car should handle like a go kart now :D

Thanks for the advice guys 8)
 
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