tires and wheels Rear suspension too hard?

[AustrianVespaGuy]

I'm not really well versed in the ways of suspension tuning yet, so I'm hoping to get some more experience opinions. My current 02 has several suspension components that were upgraded by the PO. It is currently set up with:

H&R springs

Bilstein Sports

3.91 LSD

I believe both sway bars are stock, but everything has been re-bushed w/ urethane

Tires are 195/60/R14 on 14" baskeweaves and the rear wheels have been spaced out on ~1cm spacers. I keep tire pressure at 32psi all around.

It rides pretty low and hard but I'm OK with that, however in a hard turn, I'm worried that especially in the rear things are too hard, and the rear has a tendency to get loose and oversteer some. I don't get that feeling of the car 'squatting' on the outside rear wheel like I did in my old stock 2002. Is this maybe just me being unfamiliar with the different setup, or is the suspension truly too hard and adversely affecting cornering? If so, what would be the best place to start fixing it? Thanks for any advice!

-Carl

[ClayW]

Try new subframe carrier mounts, possibly with the polyurethane inserts.

http://store.nexternal.com/shared/StoreFront/product_detail.asp?RowID=47&CS=ireland&All=[/img]

[Chris_B]

Having too-stiff springs in the rear will indeed effect the compliance of your rear suspension, causing an oversteer like condition because your wheels will bounce off imperfections on the road, reducing tire adhesion. Stiff springs will also effect short-term weight transfer in turns.

My 02 had a pair of KYB shocks on the rear when I first bought it. They were incredibly hard and caused the rear of the car to skate around any turn in which the road surface was not perfectly smooth. I replaced the KYBs with Bilstein HDs, and the problem completely went away. I originally had stock springs, but replaced them with H&Rs, and am still very satisfied with the compliance in the rear.

[Arshloch]

Technically, it should not oversteer at all, quite opposite to that, lowering the thing offers you more camber (traction in turns) and loads of toe-in. Lots of toe-in means a lot of understeer.

If the subframe mounts are worn, they might as well steer the car a little.

If your rear literally drifts, you should be one happy men, as long as you are in control.

Does it look all stock under there? Any damage? How low's it sitting? Approximate camber, toe settings on the back?

[Chris_B]

Under ordinary circumstances and all other things being equal, I would certainly agree with you: firm up the rear to reduce understeer. However, if you are at the point where you have almost no compliance in the rear, particularly short-term compliance as can be caused by stiff shocks, grip on rough surfaces can be tricky. As I said, when I moved from KYB to Bilstein shocks, it was a day and night difference in rear grip, even on relatively smooth surfaces. Not that I am not equating Bilstein Sports to KYBs...

Otherwise, Power-off oversteer is pretty unusual in an 02. I don't see what would cause that with the setup Carl described.

[TobyB]

Stiff springs will also effect short-term weight transfer in turns.

My 02 had a pair of KYB shocks on the rear when I first bought it. They were incredibly hard and caused the rear of the car to skate around any turn in which the road surface was not perfectly smooth.

Stiff springs will affect steady state suspension travel. Weight transfer

happens no matter what you do! Think about it- if the car rolls or doesn't

roll in a corner, weight transfers to the outside wheels right up until the inside

pair comes up off the ground. Then it's 100% transferred, and there's not

a lot more to be done.

Shocks will change transient suspension travel, aka. bumps in said corner, and thus reduce (or enhance) traction at that corner.

Yes, lowering a 2002 will increase rear grip up to the point that you are

adding more camber than the tires can use in a given corner. That point

is determined by how hard you're cornering, surface conditions and your tires. All else being constant, lowering a car makes it more likely

to understeer on radial tires, since front camber doesn't increase much

as you lower.

All this said, yes, stiffer rear springs reduce dynamic rear squat and thus

that 'pat on the butt' that you get from cambering in the rear wheels.

But the other side of that is that you already HAVE that grip in the

static state of the suspension. You also TEND to reduce the 'trailing throttle oversteer' that a stock car has, since the trailing arms don't

raise up as high when you lift. It's not gone, just reduced. And it may

be harder to sense its onset...

All THAT said, most of this really only applies to cornering at a higher

rate of speed than you should be carrying on occupied public streets...

ok, done now.

t

[Chris_B]

Stiff springs will also effect short-term weight transfer in turns.

My 02 had a pair of KYB shocks on the rear when I first bought it. They were incredibly hard and caused the rear of the car to skate around any turn in which the road surface was not perfectly smooth.

Stiff springs will affect steady state suspension travel. Weight transfer

happens no matter what you do!

t

Sorry, I meant to say "stiff shocks" not "stiff springs," and by "short-term" I was referring to the speed at which weight is transferred during a turn.

[AustrianVespaGuy]

Having too-stiff springs in the rear will indeed effect the compliance of your rear suspension, causing an oversteer like condition because your wheels will bounce off imperfections on the road, reducing tire adhesion. Stiff springs will also effect short-term weight transfer in turns.

I think this pretty accurately describes what I'm feeling, with the rears 'skipping' a little off any bumps. I've also heard plenty of good things about Bilstein HDs, so I think I will start there. I'll also take a look at my rear subframe bushings, as I don't think I've paid them much attention yet.

Do you think I should do HDs in all 4 corners at once, or just start with the rear and see how it affects things, and continue 'fine tuning' from there?

BTW, thanks for all of the great responses! As usual, there's no garbage on this FAQ, just sound knowledge, and I always appreciate that!

-Carl

[Tommy]

If the price is same per piece why not try only rears first.

I sold my Sports because they were just too stiff for me. Now waiting for set of Konis. I would have taken HD originally but they are expensive and hardly available in Europe.

Tommy

[TobyB]

I suspect you'll like the Konis...

t