Interesting Observation About Ride Height Adjustment

[SS_1182]

I just started tuning a newly purchased S2000 R1 '04. In general I don't like the look of the S2000 cars, although I know they are usually very good. But this one just looked really cool for some reason, and its performance is no exception. It handles very well with no adjustments other than that it sways moderately at stock. So I thought I would see what effect lowering the ride height would have on this situation before jumping straight into adjusting the anti-roll bars.

Since the car feels pretty balanced already, I keep the height equal for front and rear. First I just slammed it to the ground, which is -25/-25 for this car. Interesting observation... the car handled worse. Assuming this was perhaps too low for the suspension to work properly, I set it back to 0/0. The car's handling improved a lot. So the next time I set it to -15/-15, with almost the same results as -25/-25. Not only does the car not handle as well, but the tires noticeably squall much more in the corner.


I'd appreciate hearing any experience and/or knowledge on this subject, and I will also continue to test away and I'll report my findings.

 

[Adrenaline]

Suspension geometry.

The lower the ride height, the stiffer the springs need to be, the more camber you need to add.

This is why when people "cut" their springs, their cars drive like ****.

 

[VTiRoj]

When you lower a car, you should stiffen the springs accordingly. A low car with soft springs will bottom out easier and cause some unwanted behavior around corners. Once you've got suitably (idealy not max) stiff springs for the ride height, you should notice an improvement in handling. 👍

 

[SS_1182]

 

[RollingThunder]

The car is sitting way to low. So low in fact, that the tires are rubbing inside the wheel wells and there isn't enough room for the shocks/wheels to travel in the vertical. You need to stiffen up the spring rate before you hammer the car. Stiffen those up, making the front a little more stiffer than the rear, then you can start lowering the center of gravity. Unitl then, the car is going to handle like gooey boogers.

 

[SS_1182]

Well here are some more observations:


The car comes with default (fully customizable susp.) spring rates of 7.8/7.1. I again lowered the height, but this time to only -10/-10, and I increased the springs to 11.8/11.1. It didn't help the issue at all. In fact the car was a little too stiff over bumps at Nordschleife. Now I'm at 10.8/10.1 and it's still counterproductive to use -10/-10, which is in millimeters, btw. Seems too subtle to me to render such results. Either way, I guess some cars are best left at stock height settings.

 

[supersquirrel]

i like driving all of my cars stock.

 

[BlueShift]

The lower the ride height, (...) the more camber you need to add.

Interesting, I almost never do that because I don't think there's a very strong dependancy but maybe I'm wrong.

The less RH, the more SR, you're rigtht about that.

---
Not related, but since the OP started from flat RH (0/0), goes to another flat one (-25/-25) and found the car drove well, he only needs to stiffen front/rear SR with the same pourcentage number.

Let's say @0/0 the car is 10kg/12kg and the car drives well.
@-25/-25 he could try 10kg + x% / 12 kg + x%, x being the same front and rear positive number, then he tests it and put more or less % according to the drive, but always the same % number.

So, for exemple he could add 20% front and rear to his 0/0 - 10kg/12kg, that would make -25/-25 - 12kg/14.4kg. Then try and if it's too stiff, then boost or nerf the SR by +10%/+10% or -10%/-10% to his 12/14.4 until he's happy.

If you go like +10%/+5% you induce oversteer, if you go like +5%/10% you'll induce understeer.

On a side note, stock spring rate is actually one of the 3 methods I know to determine weigth distribution :
- front weigth % is front SR / (rear SR+front SR)
- rear weigth % is rear SR / (rear SR+front SR)

Using this % for your front/rear SR will give you incredible curve speed (in fact, the best you can acheive with that car, where's lateral force plays the main role), and on top of that that will give you :
- less to brake at corner entry
- better corner exit speed

But... Of course there's a few but...
* Aero play a great role in that, and I don't know yet, by number, what is it very precisely (yet, but I'm close to a model)
* This method is not 100% ok, I'd say it's 75% ok. I know cars with stock SR that don't enter that rule (speed 12, yellowbird, zz-s, zzII).
* Another method is googling the car and hoping for that front rear weigth distribution, this is what I used for the ZZII. Remember, like with the SR method, that weigth reduc remove sometimes more % in front than in rear, or the opposite, so it changes front/rear weigth distrib. The only way to figure it is to test the car and feel it.
* The third is still so experimental so I won't talk about it (yet).
* Unflat SR aren't covered by this explanation. I've got a (perfect) way to figure it out, I will post that after the first tuner challenge entries is closed.
* sometimes some crap-to-tune cars (speed 12, yellowbird...) naturally and massively are under or over steering. Using their natural weigth distribution will help in curve speed but it will destroy the ability of a car to turn... So you have to choose to sacrifice something, what will it be ? Handling or speed ?
There comes the aero part, unusual camber settings or the only toe tuning I make ("eek toe", or better called the "destroy your everything but handling, on some moments, somehow" toe) to compensate that.

 

[BlueShift]

The car is sitting way to low. So low in fact, that the tires are rubbing inside the wheel wells and there isn't enough room for the shocks/wheels to travel in the vertical. You need to stiffen up the spring rate before you hammer the car. Stiffen those up, making the front a little more stiffer than the rear, then you can start lowering the center of gravity. Unitl then, the car is going to handle like gooey boogers.

Nope, that thing is only possible with low damper settings, low RH and low SR. Anything in the middle won't do that.

Especially on a S2000, the true RH should be @ something like 80 or something like that.

 

[Hoodie1878]

Are you getting understeer or oversteer? I would try having the front lower than the rear by about 10 or so, it's helped me with various cars.