A quick question for you guys running coilovers such as the Ohlins Flag-L (which is what is currently on my car). I'm also running the Whiteline Roll-center correction kit.

I'm buildng a time attack car - or at least that's what i'm calling it. I wanted to find out what you guys are running for ride-heights? Currently i'm at about 25 in the front, and 26 in the back and think i could pull some of the understeer out of it with lowering the rear - or maybe raising the front....

So what are you running?

 

This might help:

https://www.evolutionm.net/forums/sh...d.php?t=295713

 

Yeah, i saw that. However, i'm looking more for static numbers from guys running full suspensions and not so much a suspension theory or STU thread. Those guys can't run the roll-center kit and i am.

I'm more looking for guys with a similar setup to mine and want to find out what they run for ride heights front/rear. I'm thinking i might be too low in the front, but i wanted to get a wide opinion first.

 

Even if you do run the Whiteline RC kit what is said in that thread still applies to you. You still have to be concerned about how your LCA point. Don't know if this will help but I've seen cars setup with a 1.6 inch drop in the front ....

 

I realize that. My LCA's in the front are mostly ok.. Almost parallel with only a slight downward pitch towards the center of the car.

I'm more curious about the rear susp in relation to the front and the ability of it to change understeer/oversteer characteristics.

Do you know what the stock ride height is??

 

Stock ride height in the rear is 14" from wheel center to fender. I'm sure you already know, due to the rear being multilink the roll center doesn't change as drastically as the front. I would suggest you keep adjusting the rear until you get the desired handling characteristics .... if it forces you to go too low, you many want to think about a rear sway bar .... but you'll only know after you play around with the ride height and how much space you have under the wheel well under full compression.

 

The problem here is that no two cars are alike, unless you are running exactly the same mods, spring rates, etc. In fact, most of the time if you take two evos and set them up exactly the same, they will still handle differently and have different levels of understeer/oversteer/etc.

Since you are using the whiteline roll center kit, the front should end up about the same as everyone else, since this is strictly set by the geometry concerns of a strut. I run custom spindles, so I don't know what the right number is for a whiteline kit, but it seems to be about 1.5" lower in the front from what I see on the boards.

Now to the rear, where it starts to get tricky. There are two factors involved in setting the rear ride height.

1. Effect on CG height
As you raise the rear, it raises the rear CG higher from the roll center, dynamically putting more weight on the rear tires, inducing oversteer.

2. Effect on Roll Axis Inclination.
Even through raising and lowering the rear doesn't move the rear roll center that much, it does move it. As you raise the rear suspension, the rear of the roll axis raises, and promotes understeer.

So now we have two different things happening as we try to figure out the ride height. Unfortunately, the only cheap method of finding the correct rear ride height is to experiment and find the point that balances these forces the best.

It is not very difficult to make these changes while at the track or at home, but it does take a few tools and some time and patience.

The difference is dramatic.

 

Yeah, i guess i've been avoiding trying different settings since i have to get it re-aligned each time.... Suppose it's time for a toe gauge purchase so i don't keep giving money to "the man"..

Oh well, that's what i'll do..