GDB..I am interested in which kit you have? Is it the same kit as mine ( Ohlins MIS kit )? if the car was bouncing it could be one of 2 things. It could be underdamped (bouncing from too much spring rate) or over damped (bouncing the tire sidewall from too much damping ). You are experiencing the very reason why professional race teams spend week after week testing setups. You have a huge range of adjustment with the Ohlins - more than any other shock for the Evo. One click on the adjusters can be felt immediately - whereas one click on a competitors shock is harder to notice. I believe you are on the right track and further testing will show better gains. Sometimes what feels good isnt nessessarily faster, in my racing experience using as little rebound damping as possible and the lightest spring rate you can get away with is usually fastest (but doesnt feel the best to the driver).

Also if the car is too low it will compound any problems you have. If the shocks are bottoming out they are no longer effective - you need full travel to handle well. Also lowering the car too much changes your "roll center" and actually makes your car want to roll more.

What is your current ride height (measure from the bottom of the rim to your fender) and what spring rates are you running? Do you ave a rear sway bar? What tires (size and brand/model) do you run?

We can get you going faster, Id love to help/give you some of my setup hints.

 

In Japan it's called "Ohlins PCV"

Front 10kg/mm spring
Rear 8kg/mm spring

Sorry my way of measuring ride height was from the GROUND to the fender. So this is how I remember... They were:
Front 620mm
Rear 625mm
Approximately... I actually forgot about it!

Now they are:
Front 645mm
Rear 650mm

I don't have any other suspension mods.

Tires are rims are original (17" Enkei, 75% worn A046).

Can you tell me your ride height setup? Any way you measure it is fine, I can do more measurements later.


Yeah you're right, one click is quite a big difference. I'm planning to run 10F 20R in the future. At 4F it was unbelievable; the back end just swings around as if something was driving it outwards!

 

GDB, If your car was hopping odds are you have too much bump dialed in. Get your ride height right and start with no rebound and bump at half on. Test the car. If the car is not skipping at one end or the other, increase compression until it skips and then back that end off 2 clicks. Your bump is now set for that track. Leave it alone and start working on rebound.
Cheers,

 

Ditto wtz's comments, if the car's pattering or hopping it's too stiff.

I would suggest tuning on a street drive - start very soft, increase LSC until the bumps become a little intrusive, back off a couple of clicks. Increase rebound until the car's stops feeling soggy and the stering response becomes crisp. Take those settings as your track baseline.

My method - for autocrossing - is to now play with the front looking for maximum grip/oversteer, the use the rear adjusters to tame the oversteer down to "enthusiastic" :-) On a road course you probably want to tame it a little more !


Charles

 

First of all, I'd like to thank everyone who has posted in this thread. This is probabaly the ONLY thread on this forum in which every post is helpful and informative.

GDB - your coilovers are NOT the same ones as mine (pictured on the first few pages) your spring rates are much higher at about 560 fr and 450 rr. My setup runs a stiffer spring in the rear with about a 100lb split.

My ride height: (measured from the bottom lip of the rim to the fender *to take the tire out of the equation)

front : 22.5"
rear : 22"

I have 300lb front springs and 380lb rear

unfortunately our shocks have only one adjuster (compression and rebound are adjusted at the same time) mine are set as below:

front : 7 clicks from full closed (full hard = clockwise)
rear : 9 clicks from full closed (full hard = clockwise)

With these settings the car is fantastic.... the balance is slight oversteer and the damping feels as if god himself is monitoring fluid transfer past the shock piston.

I believe that you have a "Ohlins Licenced" coilover - only available in Japan. I will try to get more tuning help for you, I work closely with Ohlins USA.

Jason

 

Jason,

What spring rates do the Ohlins street setup come with stock?

Are the units you bought made in Sweden or made in Asia. I heard a rumor that the PCV series are made in taiwan for Ohlins.

Thx,

Steve

 

The Ohlins I have are made in sweden, the Japanese versions are supposedly "licensed by Ohlins" but are supposed to be good quality. I have never seen them myself though

I am working with Ohlins USA to come up with a good spring setup for the US. Should be finished testing in a week or so - right now they come with 220lb fronts and 275lb rears, I am leaning towards a 300 front and 350 rear for production numbers. Sounds a little soft but...... I promise it is sweet

 

Are you saying that if I was to buy the current Ohlins setup, then it is not the final production spring rates?

What if someone buys them now and they come out with the new rates after, what do they do?

Steve

 

wait for about a week...... we'll have it sorted by then

 

Keep us posted please. I would like more info on that set up.

 

As stated by ogvw, the Ohlins model I have (he has?) is not independently adjustable (bound/rebound).

Thanks for the tip anyway, I'm considering KW suspension which does have independent adjustments.

 

GDB, The advice still applies without seperately adjustable rebound. If your car hops over bumps, soften it.
OGVW, Why use softer springs in the front than rear? The Evo's weight distribution argues against it. My own experience on track, particularly with a 25mm rear swaybar, is that the car needs some front spring to lean on to help keep the inside rear tire on the ground. Most of the roadrace setups I have seen use more front spring. Personally, I think 7kg front and 5kg rear with quality monotube dampers would be a good street/track compromise. Add a front LSD, and the car gets pretty frisky on track.
Cheers,

 

take a look at the stock spring rates (180lbs front....225lbs rear)

if you actually calculate the "wheel rate" (anount of spring rate at the wheel on the car) the rear has a higher rate that the front. The front is a strut - about a 1:1 ratio, the rear is a multi link (about 0.8 : 1 ratio) and will actually move the spring less per inch of wheel travel - therefore you need more spring rate.

Basically I am looking for a neutral handling car, stiffer front springs than rears create more understeer - not what I am looking for.

Now I have seen some cars in an autocross lift the rear inside tire, I think Autocross needs a totally different setup IE Stiff stiff stiff (helps put heat in the tires QUICKLY for those short minute long runs). For road racing and performance driving it is a different animal.

If you look at current Speed World Challenge cars (a good comparison to our street cars).... almost ALL of them run stiffer rear springs - Realtime RSX for example runs about 800 lb fronts and 1800lb rears

 

I agree with OGW, wheel rate is the important factor. Typically you want to preserve the spring rate ratios from front to rear to maintain the balance of the car.

I know alot of roadracers, including honda, miata, bmw, etc...

The consensus is to maintain the balance of the car and run slightly stiffer in the rear to help the car rotate.

Steve

 

When I first tracked my Evo with stock suspension it lifted the inside rear wheel on turn-in, rolled like a Cadillac and understeered off the corner so badly that easing off the throttle was the only way to keep it on track. This is not the balance that I would want to preserve. The car was made softer for the US market with a generous helping of understeer. I understand what you're saying with regard to wheel rate, just not sure I agree.
Cheers,