My current setup is Koni sport springs, Koni FSD shocks, Hotchkis 19mm rear sway (full stiff), M7 strut tower brace.

How should I go about reducing understeer? Would the TSW Xbrace help? or camber plates?

 

Camber plates....
Will provide a general increase in handling, and reduce the need for a bigger rear swaybar...

 

What should I look for in camber plates?

 

I just put these on a couple of days ago and thought why doesn't everyone have these. I found myself going through the same old curves at higher speed or lets say, "more control." Love'm!
http://www.waymotorworks.com/megan-r...er-spacer.html

In the pic you'll see two sets of spacers, the thin spacers should not be used unless your riding on 17"s or above. You run the risk of scrapping your rims ID if less. I'm on 16"s and have 1/4th" clearance from the wheels ID.
I'm not sure this will satisfy you, but I'll bet you'll be happier than you are now.

 

raise the tire pressure of the rear tires

scott

 

Start here. You'd be amazed at how you can tune the handling with tire pressure.

 

+2^

 

Is there an ideal PSI to start with?

 

Camber plates will work well with the 19mm sway bar to reduce understeer.
You can go with fixed or adjustable camber plates.

Fixed plates increase negative camber by about -1.25 degrees in addition to your stock negative camber (usually around -0.3 to -0.5). The fixed plates have a thicker plate to help prevent mushrooming but do increase the front ride height by about 1/8". Fixed plates are less expensive than adjustable and in general do not increase the harseness.
Here is an example:
http://www.waymotorworks.com/ireland...e-r50-r53.html

Adjustable plates are great but much more expensive especially if your really do not need the adjustability. I use the H-Sport plates because they do not increase the ride height. Last I knew the Helix plates do increase the ride height by about 3/16". The H-Sport plates do add a little harshness due to the steel bearing at the top mount. I found that I used the adjustability to get the camber set the way I want but I do not frequently change the camber.
Here are examples of the H-Sport plates:
http://www.waymotorworks.com/h-sport-camber-plates.html

I usually recommend the IE fixed plates for daily drivers.

 

beg, borrow, steal or buy a tire pyrometer

that is the best way to set tire pressure

my cms all4 with sport suspension and 225/45R18 pirelli p7 summer run-flats ended up at 42 front and 35 rear using a tire pyrometer

i then ended up adding +2 psi to the rears to make the handling more neutral, at 35 psi rear there was a lot of understeer, 37 psi made it more neutral

i went through the same process with my 205/70R16 dunlop grandtrek sj6 winter non-rfs, ended up at 40 psi front and 35 psi rear

i seldom have bodies in the rear seats so i expect the rear tires to need less pressure

scott

 

What is your driving environment? Are you autocrossing the car, or taking it to the track?

Where are you experiencing understeer? Corner entry, apex, or exit?

 

As i stated earlier, imo camber plates might be the best overall option..(after checking tire psi)...cause you will see an overall handling improvent, and the fixing of a potential mini issue...strut top mushrooming. But for SOME folks, simple changing the rear swaybar might be simpler...then sell the current one. Not ideal, but it will work, it just depends on your goals, asperstions, driving style, etc. 19 mm swaybar is imo a very good sized bar for many, especially when paired with camber plates, like the IE ones, but like all things, there are many considerations, and $$ is one of them, as is future plans!!

 

aggressive street driving, used my favorite back road loop for the pyrometer check

initial turnin and apex

just adding 2 psi in the rears made the chassis very neutral, made the turnin much crisper and has not resulted in any strange tire wear

upping the rear pressure to match the fronts induced mild oversteer, enough to require correctivre input of opposite lock, not how i like a street car to handle

i may track my cms all4 this spring, and i am sure if i do the pressures will change again

scott

 

"You cannot eat an elephant in one bite". For those who may not be experienced track junkies, may I suggest you go slowly and methodically with tire pressure changes, one lb. at a time, recording your pressures, ambient temperatures, suspension settings and the results achieved over the same course. In order to get sufficient heat in the tires, this is very difficult to do safely over public roads. Be careful out there.

 

I'm driving mainly on some awesome back roads we have here but this car will be autoXed causally

Understeer is usually during entrance or exit, I've been playing with different driving lines and styles such as left foot braking.

 

hmm Ill have to give these a better look sometime soon

 

Something I wanted to do but I'm not sure if is worth it is to ditch my koni sports for some swift spec R's going to a linear spring with a higher rear rate should help right?

 

Any input on the swift springs with the higher rear rate?

 

You shouldn't use the Koni FSD's with the Swift as their rates are much stiffer than the FSD's are spec'd for. The Swift's are fantastic springs, but I would match them up with either Bilstein Sports or Koni Yellows (Sports).

At the track I found that the Swift springs significantly reduced roll. With my setup, it was very neutral. When the rear did step out it was very easy to control.

 

really? Not that I don't belive you but I thought swifts where even good with stock shocks? I want koni sports but unless someone wants to trade or buy my fsd's I don't think id make the change

 

When shocks cannot handle higher spring rates, the ride can be jittery, bouncy and overall not very composed. So while Swift advertises that their springs can be used with stock shocks, I believe that is more about how the drop in ride height allows it to still be used with OEM dampers. My ride is not very good and I have the JCW dampers, which are matched to higher rate springs than stock. The FSD's operate differently than the stock shocks. From my understanding, the higher spring rate will be increasing the suspension frequency and that means, in the case off the FSD, the high frequency valving will be open more of the time. That doesn't translate too well with a stiff spring set up. Makes it underdamped in some situations, not matched at all.

I am by no means an expert in this area, so don't take my word as gospel. Perhaps others more knowledgeable in this arena will chime in!

 

From Koni's Q&A:

The KONI FSD valving performs best in combination with the car’s factory springs. Most performance springs have a higher spring rate than the vehicle's original springs. Since the shock controls the motion of the spring, increased spring rates require more rebound damping for control and that is one of the reasons why KONIs (except for FSD and STR.T) are rebound adjustable (and some are double adjustable). Using higher rate springs with OE or soft shocks will very quickly overcome and wear out the shocks. The KONI Sport adjustment range is typically about 100% (twice as firm at the full firm settings at the full soft setting) to allow for proper damping of OE springs and high rate performance springs.

 

Sounds like I need some koni sports for sure. any idea if I could sell my fsd's with my koni sport springs for the cost of some koni sport shocks?

 

I might be interested in your FSD !

 

would you be interested in the sport springs too? It would be a couple months before I'd be doing anything but pm me a offer if youd like otherwise they'll end up on the classifieds section when I'm ready to do the swap