Fix That Understeer!

[CEF11E]

Hey All.

I have done some basic suspension mods and have replaced the following.

Whiteline front and rear springs

Whiteline adjustable rear swaybar

Adjustable castor rods

The car understeered like a pig untill the rear swaybar went on and is now a lot better but still lacks turn in and mid conner grip. so I fitted the castor rods and am going to have an alignment done this week and would like advice on settings

I am looking at

Front Camber - 1.00 (do not have adjustment but should be close to this do not want excessive tyre wear)

Front Caster - 12.00 (is this to much? I want turn in to be razor sharp)

SAI - 9.00

Front Toe - 0.5mm Toe Out on each side ( want turn in sharp will it tramline with 0.5?)

Rear Camber - 0.5 ( is this enough?)

Rear Toe 2.0mm In on each side (Will this increse stability? is it ok to have toe out on front and toe in on rear?)

The car sees 80% road and 20% drift and skidpan gets driven fairly hard not babied.

please let me know what you think of these settings Also the rear swaybar is on medium as the hard setting decreases traction.

particularly the castor.

[Beer Baron]

yeah go for as much castor as you can get with the rods. 12 degrees will be impressive if you can get that much. if you do a bit of drift etc I would be a bit less conservative with the toe. run a bit more front. maybe 1mm each side and a bit less rear toe in. maybe make that 1.5mm in each side. it will be more oversteery but for drift that shouldn't be a problem to control. the extra front toe out (think mine is 1.8mm each side atm on the GTR yes I know different car) will make it much more pointy, possibly a bit less stable at high speed but certainly not undrivable.

[Roy]

Mt car turns in like a champion. Have tge swaybars cranked on teh harest setting and have 3.5 deg neg camber on the front. I have pretty soft springs so need that sort of camber...though i only have 5.5 castor.

Even when i had -2.2 deg camber on the front my car turned in awesome. I think you simply dont have enough camber on the front

[dangerous_daveo]

To give you an idea on what I've got is masive sway bars. I'm pretty sure its 1.5mm toe out either side on the front. 2.25 degree front camber there abouts anyway, and its about 8-9degree of castor. The rear has about 1.25 camber, and not sure how much toe in. And I gotta say its pretty much spot on. Front is 365mm from center of wheel to top of wheel arch rear is 355mm for the same.

I think there is a little improvement that could be made with just a wisker more camber and castor. But as atm its got as much as it can wound in to it, so its going to cost more money, so Im not going to bother.

[salad]

If it's used for drift/skid pan, dont go overboard with castor. When you're counter steering, castor will add camber the wrong way so you will be decreasing contact patch and hence grip. 8-9deg is a bit more normal as previously mentioned.

I would run less toe in on the rear for better turn in and a bit more camber on the front.

What's your rear camber like?

[CEF11E]

Thanks all for the replies. I will adjust my settings given your advice and go for

Front Camber - 1.50

Front Caster - 12.00

SAI - 9.00

Front Toe - 1.0mm Toe Out on each side

Rear Camber - 1.0

Rear Toe 1.0mm In on each side

If I do get 12deg castor and find it is to much, will I be able to adjust it back to 9deg without affecting the rest of the geometry?

The only good place in Canberra is on the other side of the city and i can only get there once every 2nd week so i would like to get it right the first time.

Thanks!

[BHDave]

Get your 12 degrees castor put in and do a lap around the carpark before leaving the alignment shop. It'll take it when the wheels are straight, but try and put some lock on with a bit of load and be ready to tear out inner guards and buckle the front panels.

adjusting the castor back will throw the toe settings out.

[salad]

I doubt you will get 12deg with just adjustable castor rods anyway. You will need to play with the upper arm a lot to reach that much, or keep your front bar off so your wheels dont touch it

With 1.5deg camber, you should max the castor out at around 8deg without scrubbing on things. That has been my experience with R32s anyway.

[CEF11E]

Cool thanks dudes.

The castor rods I have are rated to 12deg. and I have removed the inner guards and my front guards have been rolled so I will just ask for max castor. I will report back

[djr81]

Cool thanks dudes.

The castor rods I have are rated to 12deg. and I have removed the inner guards and my front guards have been rolled so I will just ask for max castor. I will report back

Could you do me a small favour. Measure up the wheelbase of the car before & after you wind all that caster in. just curious to see how much it changes. Also curious to see how long the upper wishbone bushes last....

[Sydneykid]

Hey All.

I have done some basic suspension mods and have replaced the following.

Whiteline front and rear springs

Whiteline adjustable rear swaybar

Adjustable castor rods

The car understeered like a pig untill the rear swaybar went on and is now a lot better but still lacks turn in and mid conner grip. so I fitted the castor rods and am going to have an alignment done this week and would like advice on settings

I am looking at

Front Camber - 1.00 (do not have adjustment but should be close to this do not want excessive tyre wear)

Front Caster - 12.00 (is this to much? I want turn in to be razor sharp)

SAI - 9.00

Front Toe - 0.5mm Toe Out on each side ( want turn in sharp will it tramline with 0.5?)

Rear Camber - 0.5 ( is this enough?)

Rear Toe 2.0mm In on each side (Will this increse stability? is it ok to have toe out on front and toe in on rear?)

The car sees 80% road and 20% drift and skidpan gets driven fairly hard not babied.

please let me know what you think of these settings Also the rear swaybar is on medium as the hard setting decreases traction.

particularly the castor.

I note the lack of shock absorbers on this list, is this just an oversight?

cheers

[CEF11E]

not really SK,

I have not replaced them. They are aftermarket japanese items. They are yellow with blue stickers and all the writing is in japanese. They are around 4 years old and seem to be doing a fairly decent job. so at this stage they will be staying.

[CEF11E]

Could you do me a small favour. Measure up the wheelbase of the car before & after you wind all that caster in. just curious to see how much it changes. Also curious to see how long the upper wishbone bushes last....

Can do I will measure the wheelbase tonight and once again after the alignment.

I will possibly change the wishbone bushes when the alignment is done if I have the time.

[Sydneykid]

not really SK,

I have not replaced them. They are aftermarket japanese items. They are yellow with blue stickers and all the writing is in japanese. They are around 4 years old and seem to be doing a fairly decent job. so at this stage they will be staying.

What's the ride height?

Should be around 350 mm front and 340 mm rear.

Did you trim the bumsptops when you installed the springs?

cheers

[CEF11E]

Ride height is 350 and 345 and yes new bump stops and covers were put on. an i trimmed them as per the guide

[Sydneykid]

Ride height is 350 and 345 and yes new bump stops and covers were put on. an i trimmed them as per the guide

The reason for the questions were that R32 2wd’s simply do not understeer badly unless something is wrong. I didn’t want to get into alignment settings until I was sure that they were the real problem.

So last question, you mention the rear stabiliser bar but not the front, what do you have there and where is it set?

You won’t get 12 degrees of caster on the front, not unless you take out the headlights. Around 7 to 8 is the best you will get.

Can I assume that you aren't running good tyres on the rear and some crap on the front?

cheers

[CEF11E]

The reason for the questions were that R32 2wd’s simply do not understeer badly unless something is wrong. I didn’t want to get into alignment settings until I was sure that they were the real problem.

So last question, you mention the rear stabiliser bar but not the front, what do you have there and where is it set?

You won’t get 12 degrees of caster on the front, not unless you take out the headlights. Around 7 to 8 is the best you will get.

Can I assume that you aren't running good tyres on the rear and some crap on the front?

cheers

Just for a bit more information.

My car was a GTS from factory and had no rear swarbar at all. it has a new engine, gearbox, gtr brakes and all other handling mods listed

once the whiteline bar was added the improvement was dramatic and improved a lot. this was why it was so bad to begin with.

I am now running a standard stabiliser bar on the front and whiteline from the group buy on the rear. (set to medium)

Tyres are 4 new fedral 595's 235/45/17. they are not fantastic but a decent budget tyre. so traction is even on all tyres

Cheers!

[CEF11E]

I have had the alignment done and encountered a bit of a problem. The rear lower left control arm bush was stuffed and could not be adjusted. so I have had everything adjusted except the rear toe.

Ended up with

Front:

Castor + 8.00

Camber - 1.50 deg

Toe 1.0mm out each side

Rear:

Camber - 1.50 deg

Toe Left +4.4mm :0 (needs to be fixed!!!)

Teo Right +2.3 :0 (Needs to be fixed!!!)

The front end feels really good now. steering is noticably heavier, turn in is a lot better and steering return is very responsive.

The rear end sucks... it is still a bit wild and needs the toe sorted out. I am also going to get the camber adjusted back to -1.0 deg.

Measurements for wheelbase are at home. I will post them up later.

[Sydneykid]

I have had the alignment done and encountered a bit of a problem. The rear lower left control arm bush was stuffed and could not be adjusted. so I have had everything adjusted except the rear toe.

Ended up with

Front:

Castor + 8.00

Camber - 1.50 deg

Toe 1.0mm out each side

Rear:

Camber - 1.50 deg

Toe Left +4.4mm :0 (needs to be fixed!!!)

Teo Right +2.3 :0 (Needs to be fixed!!!)

The front end feels really good now. steering is noticably heavier, turn in is a lot better and steering return is very responsive.

The rear end sucks... it is still a bit wild and needs the toe sorted out. I am also going to get the camber adjusted back to -1.0 deg.

Measurements for wheelbase are at home. I will post them up later.

I'm confused, the rear lower control arm bush doesn't adjust toe. Toe is adjusted at the tie rod ends, same as the front.

cheers

[CEF11E]

I'm confused, the rear lower control arm bush doesn't adjust toe. Toe is adjusted at the tie rod ends, same as the front.

cheers

strange...

I do not know anything about suspension.

looks like I will need to talk to the place that aligned the suspension. Gary if you have time would you please be able to point out on a diagram exactly where rear toe is adjusted?

or if you can just explain it?

he adjusted toe on the other side so it sounds like he was doing the right thing. it is the Canberra recomended fitter for whiteline stuff and the boss owns a stagea. I am sure you know who I mean