Rear Suspension Help PLEASE!

[medusa]

I own a 2004 with 40K Miles on it. I recently installed H&R spacers and replaced the supplied extended wheel studs, 15 mm (30 mm total) up front and 10 mm (20 MM total) at the rear. I widened the track simply because I didn't like the way my factory wheels looked deep inside the wheel wells, I love the way my car looks now and also the car seams to be more responsive, and it corners better then it did before.

Two days ago I noticed that when I went over speed bumps the rear left end of the car feels off. It feels "wobbely" as if the left side is more "bouncy". Also today when I parked my car on a known flat surface, I realized that the gap between my rear left tire and the top of the fender is about 1/2 an inch less then the gap compared to the right. In other words, the real left side is about 1/2 an inch lower then the rear right. Also my rear left wheel appears to be sitting 1/2 an inch behind the rear center line. Everything is stock on this car except the wheel spacers.

My question is, does anyone know if the S2000 has an irregular suspension geometry, and also how long is a stock schock supposed to last? Would the spacers have anything to do with this? My alignment was done about 9 months ago, and the wear on my tires is normal.

Thanks

[Vitt]

Given that this was posted 6 days ago, you may have fixed the problem already. If problem not fixed yet, you should try posting on The XViper's to get informed opinions on what the problem might be. You might also want to have someone take a look at your wheel hubs. Post your findings if you don't mind.

Regarding how long shocks should last, it varies depending on driving habits and quality of the road surfaces where you live and travel frequently. Usually 40K is not too long for shocks. I have over 47K on mine with 4 track days on them and no problems.



I own a 2004 with 40K Miles on it. I recently installed H&R spacers and replaced the supplied extended wheel studs, 15 mm (30 mm total) up front and 10 mm (20 MM total) at the rear. I widened the track simply because I didn't like the way my factory wheels looked deep inside the wheel wells, I love the way my car looks now and also the car seams to be more responsive, and it corners better then it did before.

Two days ago I noticed that when I went over speed bumps the rear left end of the car feels off. It feels "wobbely" as if the left side is more "bouncy". Also today when I parked my car on a known flat surface, I realized that the gap between my rear left tire and the top of the fender is about 1/2 an inch less then the gap compared to the right. In other words, the real left side is about 1/2 an inch lower then the rear right. Also my rear left wheel appears to be sitting 1/2 an inch behind the rear center line. Everything is stock on this car except the wheel spacers.

My question is, does anyone know if the S2000 has an irregular suspension geometry, and also how long is a stock schock supposed to last? Would the spacers have anything to do with this? My alignment was done about 9 months ago, and the wear on my tires is normal.

Thanks

[Coop]

moved to The XViper's Den

[repiv]

Stock shocks have lasted well over 100K miles, even when the car has been tracked. Besides, the shocks aren't what affects the ride height anyway. It's the springs and what they are mounted to. Offhand, I wouldn't consider that a 15mm and 10mm extension on the lugs would not do anything untoward to the suspension, however, it would also seem apparent that on your car, it did. You say that everything else is stock (including the rims and tires, right?), so nothing else could contribute to what has happened to your car. Addtionally, since our cars are "hubcentric" in terms of rim mounting, a spacer will play havoc with the centering of each rim unless the spacer is designed with the identical hub lip and the spacer itself uses the stock hub lip. It could turn it into a lugcentric mount. Our cars are extremely hard to completely center a rim by lugcentric mounting and depends a great deal on mounting technique and good luck. Are you experiencing any noticeable vibration at speed? Even a mild vibration can cause suspension damage if left uncorrected.
Typically, in stock configuration, the S2000 would have a larger gap between the top of the tire and the fender lip, on the left side compared to the right side. It was designed that way so as to compensate for the driver's weight. Your car is the complete opposite. Something is not right.
Moving the rims and tires out from center as what happens with spacers would effectively increase the length of the lever from the fulcrum. I'm not familiar with the H&R spacers. Are these simply discs with holes in them to match the lugs? Or are these spacers that have lugs built onto them and you bolt the assembly onto the stock lugs? If you actually removed the stock lugs and install longer lugs in their place, are you certain that you fully seated the new studs? This can require quite a bit of torque. If you didn't, then the forces encountered during normal driving can pull them further to fully seat them. In this case, go back now and check the torque on each one of the lugnuts. You may have loose ones as a result. If this is the case, continuing to drive the car may result in snapping some studs. Then you could lose a wheel or severely damage the suspension.
Regardless of the above, even if the studs never moved after installation, the longer lever will still create forces on the suspension in such a way as to pull the alignment out of spec. 9 months was a long time ago considering that you've done something that could compromise the alignment. It might be time to do it again. A longer lever will be affected far more by road bumps and dips and this transfers to the alignment adjusters.

[drobbins]

Two days ago I noticed that when I went over speed bumps the rear left end of the car feels off. It feels "wobbely" as if the left side is more "bouncy". Also today when I parked my car on a known flat surface, I realized that the gap between my rear left tire and the top of the fender is about 1/2 an inch less then the gap compared to the right. In other words, the real left side is about 1/2 an inch lower then the rear right. Also my rear left wheel appears to be sitting 1/2 an inch behind the rear center line. Everything is stock on this car except the wheel spacers.

My question is, does anyone know if the S2000 has an irregular suspension geometry, and also how long is a stock schock supposed to last? Would the spacers have anything to do with this? My alignment was done about 9 months ago, and the wear on my tires is normal.


The S2000 doesn't have an irregular suspension geometry. I am assuming you are the only owner of the car and it hasn't been in an accident?

I have an '05 S2000 and replaced my OEM shocks at 20,000 miles because I too had a "bouncy" feeling over speed bumps. It felt like the shock would start to absorb the shock but then rather than fully absorb the bump, it would bounce off of it, providing unpleasant and non-ideal response. The car also felt wobbly in general. I had some Bilstein PSS9's installed to replace the OEM suspension. The new shocks solved the "pogo" effect on speed bumps -- my car now properly *absorbs* speed bumps -- it feels great when the car's shocks do the right thing -- and the car lost a lot of the wobbly feeling overall. The remaining wobbliness was greatly reduced by playing with tire pressures (raising them closer to 40 psi) to make the sidewalls stiffer.

(So, before you try anything else, first thing to check is tire pressures, because it's free.)

But I do think that going over speed bumps at low speed *is* a very good test of the shocks. The spring will absorb the initial impact, but then it's up to the shock to take over and give you that "I absorbed the bump" feeling and not the "bouncy" or "pogo" effect. So based on what you're telling me, I think you could use some new shocks - it sounds like at least one of your shocks has a funky, out of spec damping curve. The ride height difference *could* indicate that one of your shocks or springs is funky, though it could also be normal.

Many people will tell you that the S2000 has a great set of OEM shocks -- I disagree. I think they are just adequate. For some people, they hold up fine and feel great after many miles. For others, like me, they degenerate and offer a poor ride. Since I have an '05 and replaced mine this year at 20,000 miles, it makes me wonder if some OEM shocks degrade over *time*, not just lots of miles.

One suggestion, since presumably you are out of warranty, if you have the dough, is to buy a set of coilovers. You can get a set of PSS9's for ~$1400 on ebay, new from a distributor. The KW coilovers are a bit more expensive and supposed to be good too. Ohlins are good as well. I went with the PSS9 because they have a lifetime warranty, and is a quality shock for a very good price and with very good customer support from Bilstein. With coilovers, the ride height is also adjustable. So you can take care of the ride height issue too.

So if you have the money, I would suggest ordering something like the PSS9's, finding a good alignment shop, having them install the coilovers and align *and* corner balance the vehicle. You could also take the car to a good alignment shop just for an inspection - they might be able to detect a blown shock. But it's also possible that if you have an out of spec shock, it will still look fine on the outside.

Hope this helps :)

[Vitt]

My OEM shocks are kind of "bouncy" but I think that they are valved that way for comfort, even though you still get very good handling. I heard other people describe it similar (pogo stick feeling), at least AP2. I think by having relatively soft rebound, it makes the ride more comfortable. And the '06 (which is what I have) has the softest suspension of all the years :mad:

For comparison, the OTS Koni Yellows are as soft as (or softer than--not sure) OEM for compression but stiffer for rebound (and adjustable). A Koni rep once told me that they felt that's where the S suspension needed improvement.

As far as lasting, I think the OEM are constructed as good, if not better than many OE replacement shocks and suspensions out there. Mine are still fine, but I'll be replacing them with DA Koni and stiffer springs.