Ride height Vs Handling

[Tensiion]

Hey guys,

Just recently purchased and installed a set of tein superstreets for my MKIV SZR, and I was wondering what your opinions were on which settings to have them and ride height to reap the best on handling.

I have let the springs settle and sag for a little bit and a couple of days ago I have wound the coil in the downward direction as far as it can go to lower the car. I was then going to leave it for a while then see how I liked it and find out more on where to have them levelled for the best handling/practicality.

So yeah basicly what are your opinions or experiences as this is my first time dealing with coilovers.

Thanks

[?uestlove]

Probably best to take it to a proper suspension tuning place such as BT Motorsports in SMithfield, Heasmens in Sydneham or East Coast Suspension in Sutherland to get teh best setting for handling.

If you want your car really low tho (The SS dont go that low anyways, mines on teh lowest setting at the rear and about an " up from the lowest at the front), you can add some RCA (Roll Centre Adjusters)

Stock.


Lowered.


Fixed with the roll centre adjuster.
The key is those 2 black and white circles.

The top circle is the centre of gravity of your car. That's relative to the body gets lower with lower ride height (natch).

The lower circle is called the roll centre. It's as a result of the relationship of all the suspension arms, but the end result is that if a sideways force is applied to the roll centre, the suspension will not body roll. This can be kinda hard to understand...but if you look at the top pic with the horizontal arms, if you push at the side of the box, you'll just be pushing against a horizontal arm and it will not roll. On the other hand, if you push the same point in the middle pic, you can kinda see that the arms will "dip" and the body will roll more easily.

So the idea is to get the roll centre as close as possible to the centre of gravity for an anti-roll effect. The bottom pic, the different angles of the modified arms raise the roll centre much closer to the centre of gravity.

Also the roll centre blocks correct the camber curve. If you look at the middle pic, the amount of camber that the suspension will gain as it rolls might be a bit extreme. So that's another thing these blocks will address.

[onggie]

Hey Tensiion, just out of curiosity how many mm you reckon from the highest setting to the lowest setting from the ground, if you know what I mean?

[ViPeR_NiPPleX]

Good diagrams! For further reading i'd suggest a book on suspension tuning by Fred Puhn (Can't remember the name of said book :P).

Also the "invisible" link or relationship between the COG (center of gravity) and suspension roll center is known as a "Roll Couple". I think it may be possible to have a higher roll center than COG which may cause undesired suspension characteristics, but i'll have to check myself on that!

[Lawson]

My Supra Tein Supersteets and has been setup by Fulcrum. Took them 3hrs of fine tuning on and off the rack, and it's handles like it's on railroad tracks. The ride height they set (from the ground to the top of the wheel arch) is:
Front 645mm
Rear 657mm.

You can look through my project thread for tyre and rim specs here:

http://www.supraforums.com.au/forum/...ead.php?t=4216

Not sure if you also want the other settings, but I'll have to look and try and find my setup docket for the Caster, Camber and Toe.

[ASSAIL]

my tein ha's go way too low for driving on roads.
ive only had it fully down at the front and rear once and it took me an hr to get out my driveway using planks of wood and tiles.

then when driving and coming to a roundabout there was a slight bump in the road before it (nothing major at all, so id have been fucked if it was a big bump) and under braking my front bar hit the ground!

mine handles best wound around 8 threads up from the bottom on the rear and around 12 on the front.

driving with them at legal (100mm) height feels terrible. the car is so unsettled, it tramlines badly and im constantly fighting the wheel to stay within my lane on undulating roads.

ive never had them wound all the way up. it gets too hard to turn them as they get over halfway up as the spring pressure is too great.

id say that there is a range of about 10cm in the useable height adjustable range.

[Barley]

im constantly fighting the wheel to stay within my lane on undulating roads.

I got stock suspension on my supra and yeh my steering kinda tugs a lot, not sure if it's as bad as you've described up there though, but just wanted to know if this is normal?

[ASSAIL]

I got stock suspension on my supra and yeh my steering kinda tugs a lot, not sure if it's as bad as you've described up there though, but just wanted to know if this is normal?

tyres also play a big part in tramlining etc but the difference in ride quality with the same tyres and different height settings is night and day

[blackRZ]

I've played around with ride heights alot between track days to find a sweet spot. It has Teins. I found when I first took it to a racetrack at something near stock height it was very oversteery at QR - Lawson can probably attest to that if he remembers the black RZ at QR in January... After that I lowered it alot and found it was noticeably understeery even on the street, so i gradualy raised it in stages until I got it fairly nuetral. I'll check my ride heights when I get home