GC8 Understeer fix, H&R Rear and front sway bars

gc8wrxpt

Type RA Member
Hi,

Am looking to upgrade the suspension to reduce understeer, there is a lot of information available and from the research and budget i think (please advice) the best way to do is:
Whiteline kca319a anti lift kit 150€
Eibach pro kit sprints 160€
Kyb AGX struts 550€;
Camber bolts 16€
And sway bars...
Can't find any information at all about these:
H&R Rear 25 MM front 22MM, they have 3 holes for adjustment and i am assuming, off course, they are hollow for 295€

Is this the way to go? What do you suggest?
Some items i have to buy today due discounts

Edit: The car and purpose, its a 250hp ish, I need a good compromise between some comfort and solo fast backroad driving, I think the eibach springs and agx struts should be the main ingredient here
 

SUBGT

V-Limited Member
I'll let the chassis master @2pot give you the best answer, but I will also give you my two cents.
from my own experience antiliftkit isn't that great of a deal.
too much lowering is not good (not sure how much the eibach you wrote does)
camber bolts are not needed for a street setup and even mild track.
I would say start first with only a 22mm rear bar, and see before upgrading the front, but pretty sure 25mm is way too big.
 

gc8wrxpt

Type RA Member
I'll let the chassis master 2pot give you the best answer, but I will also give you my two cents.
from my own experience antiliftkit isn't that great of a deal.
too much lowering is not good (not sure how much the eibach you wrote does)
camber bolts are not needed for a street setup and even mild track.
I would say start first with only a 22mm rear bar, and see before upgrading the front, but pretty sure 25mm is way too big.
I feel the mid-grip corning is what's lacking, also somewhat hard initial turn-in, car has brand new AD08R 215-40-17 tyres which helped overall but the tendency is the same
I have been reading how it works, but the information on this specific 25mm bar is missing, assuming that is in fact hollow it can behave as a 22mm solid rear bar or even softer, hard to tell
If the ALK doesn't make that big of a difference I will remove from the buy-list it is expensive...
I think the max camber on the front is 1.5º positive/negative, do you think a proper alignment might make use of all the tyre contact patch?
 

Ric McLaughlin

V-Limited Member
I too bowed to the wisdom of @2pot and coupled his recommended settings to my cars Cusco 22mm rear sway bar and KW V2 coilovers (had to buy WhiteLine camber bolts for the rears as mine had been replaced with what looked like scaffolding bolts). I got the car set up at a local tyre shop that also offered laser alignments for £65 and it took about 45mins. The car drives absolutely brilliantly and I'm really happy with it.
 

gc8wrxpt

Type RA Member
I too bowed to the wisdom of @2pot and coupled his recommended settings to my cars Cusco 22mm rear sway bar and KW V2 coilovers (had to buy WhiteLine camber bolts for the rears as mine had been replaced with what looked like scaffolding bolts). I got the car set up at a local tyre shop that also offered laser alignments for £65 and it took about 45mins. The car drives absolutely brilliantly and I'm really happy with it.
What would you describe the difference as before and after?
Did you also complain about the understeer?
What kind of alignment was it? Usually they try and zero out all values
Apparently the oem droplinks are rubbery and soft, meaning that if you upgrade the sway bar it won't be fully utilized due the droplinks stretching
Coilovers are badly viewed by cops in my country, need to avoid them
 

downshift1

The yank with a RA
Caster will give you the hard turn in you're looking for. Whiteline ALK for that.
More camber in the front will grip better through the corner.
Big sway bars are usually just a band aid for the wrong spring rates and loose valving.
 

SUBGT

V-Limited Member
I am not sure I really agree on the alk. it may add 0.5 of caster but also a lot of dive/lift. I would 100% take the top mount instead of the ALK.
I don't think sway bar are a band aid, more like the last thing to tune because a hard bar also have negative effects on uneven surfaces. putting a strong bar on an already loose valved shock absorber will even worsen the issue because it is the equivalent of putting a stiffer spring on this axle. An easy example is I had to put 2 more "clicks" to mey tein coil overs when I went to aftermarket sway bar, because the car has become bouncy like an over-sprung car.

and more camber is not always better, it depends on the conditions, and tyre used. the grippier the tyre, the more deformation you would expect and more is usefull, but on the road with PS4 type tyres (soft sidewall compared to ad08R) 2° is enough for dry conditions, and would even say too much if the grip is not very good. I have been able to reach 1.8° with stock top mount and no aftermarket camber bolt. having the WL top mount with more caster and camber you will even surpass 2°
 

Kanrex

Type RA Member
How I would approach this, try each step and test and see, if you are happy with the results:
- Start with changing your tyre pressures (try running a little less in the front and more in the back)
- Swap out the camber bolts and try go for 2 degrees front and 1 degree rear.
- You could try changing the springs: soften the front or harden up the rear (OEMs use this trick with sporty FWDs - this vehicles tend to lift the rear inner tyre while cornering to help the car rotate)
- Going up a size in roll bar for the back may help
- Coilovers - higher spring rate rear to front + the ability to adjust height. You could also try a little rake (nose lower and rear higher) this promotoes rotation and weight transfer in the rears
- (not ideal for road cars) Staggered tyre setups
- Try 0 toe front and 0 toe rear (the car may tend to wander - no natural centering)

I would advise against simply lowering the vehicle running stiffer springs (low and stiff). An issue with that is... your vehicle has this imaginery roll axis and by lowering the car you may end up moving it further away (unintentionally) from the centre of gravity. In other words the car on the limit will have more of a tendency to body roll, even though stiffer springs and the car is lowered. Anyhow as you can see there is many things to consider, but I would start off with the simple things and cheapest and work your way through. :thumb
 

SUBGT

V-Limited Member
running an even lower front tyre pressure (assuming his was already to spec) will require even more camber and may simply be counter productive because of increase tyre deformation
 

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