JRG2000

Hi,
I just bought this past Fall a MY 2000 AP1. Fully stock and barely driven with only 21,000 miles. From the time I test drove it until now it has a vibration that begins around 40+ mph and continues to get worse as I reach highway speeds of 60+, 70+, 80+ etc... Turning, Putting in the clutch; nothing changes it other than speed makes it worse. Not a horrible vibration, but noticeable.

From the very beginning I suspected the tires were to blame since the car sat more than was driven (the original owner passed away and the widow let it sit in a climate controlled garage for almost 2 years before she sold it to me) so I took a chance. The tires on the car now were replaced a while back and look absolutely perfect with no cracking, uneven wear or dry rot whatsoever...and they only have about 4,000 miles on them! HOWEVER, they are 11 years old so I am going to replace them.

Since I don't know for sure this will solve the vibration issue I don't want to sink a ton of money into the most expensive tires possible, just in case they don't fix the problem then I have to continue down a long road of spending money. I will only drive it during the summer, on warm days with no rain. Probably only put 2000-3000 miles on it per year. I do relaxing cruises, but love to hit back country roads for some spirited driving and hit VTEC every time it's out - multiple times and love taking turns fast.

Since this is my first S2000 I have nothing to compare it to as far as handling is concerned. All I can say is it handles great now. Very precise and corners well and only slowly but predictably breaks loose. The tires on now are Bridgestone Potezna RE 960AS. My tire requirements are smooth and quiet, handles/corners well and doesn't change or ruin my current perception of how nicely the car handles and steers.

I can get any of these 3 tires installed very inexpensively at my local Discount Tire. I have done a ton of research on this site and I think the best tires for the money and my driving style and needs are the following...

Firestone Firehawk Indy 500
BF Goodrich Sport Comp-2
Dunlop Direzza DZ102

2 Questions:
#1. Do you agree that new tires and an alignment are a good place to start?
#2. Based on my needs, do you prefer any tire over the other?

Thanks!!!!!

TsukubaCody

Firestone Indy 500.

Though if I were you I'd also consider General GMax RS if available in the right sizes. From the reviews I've seen they align perfectly with your desires.

Tires are absolutely a good place to start. Those tires are way too old to be safe & likely have developed a number of flat spots. They may also be out of balance.

Between that and an alignment that gives you a very good base to figure out what else needs addressing.

HawkeyeGeoff

Yeh I'd bet it's the tires as well from my experiences.

JRG2000

Thanks for the quick response and your thoughts on the tires. I looked up the GMax and they sound great and they are even on sale at Discount Tire. However, the only issue I saw with the reviews were multiple people complaining about the sidewall being soft. Based on what I have been reading here that makes me worry that our S2000 won't like that and might affect steering feel and handling.

TsukubaCody

Relative to the all-seasons on the car right now I can't imagine them being softer sidewalls.

My thinking was that if you want a civilized ride, the RS may be ideal.

For a stiffer sidewall I hear the Indy 500 are great.

JRG2000

Good point. I am fine, happy with the way it feels and handles now and like I said I don't have anything to compare it to...With the current tires being all-season I suppose the RS would not be any softer, in fact most likely be stiffer. I'm sure that the Indy 500 and Comp-2 would even be firmer still.

engifineer

Does the vibration seem worse when under power? Aka when accelerating between 40 and 70 vs when you let off throttle? If it is noticeably more harsh when accelerating, and it is in that range of speed, it is much more likely the CV joints in the rear. Very common and you fix it for nothing but labor assuming it has never been done before. Search around for posts about swapping the CV buckets.

If it is tire related, the first thing would be to have a tire shop try to balance them. More likely to be one that is out of balance (poor balancing before or a weight has come off since then).

With tires that old I would replace them anyways.

JRG2000

I've read about the CV buckets and I don't think it is that. But, I will drive it again and pay special attention to accelerating between 40-70 mph and letting off the throttle. I thought that issue would be less likely on my care since it has only 21,000 miles and never saw rain or snow. Bolts and undercarriage still look glossy and new. I figured that was more of an issue with age/rust/corrosion.

engifineer

Its more of an issue with hard launches or wear. The inside of the joint should be sealed and full of grease so corrosion should not be a factor. If the car was launched hard much, it can pit the one side of the interface in the CV joint. Under normal driving it is not all that noticeable, but as you put it under load (accelerating) it gets much worse. It will be pretty apparent if it is that, as it will be barely noticeable if you are are off throttle and will be much more pronounced as you accelerate. This can also happen if the car was lowered or raised back to stock height after being lowered for a very long time, as a small wear groove forms in the joint, and when you change the height, the bearings then ride on the edge of that groove, causing some vibration. I think the pitting scenario is the most common though. With tires that old you will want to change them anyways so if the vibration is still there, that is one other thing to look for.

JRG2000

Thanks for the full explanation; I now understand the issue better. I'm going to start with the most likely culprit...the tires. I'm leaning towards the Indy 500 but the BFG Comp 2 are really priced well at Discount Tire and seem to have great reviews as well. BUT, lots of people really like the Indy 500's so it's a toss up. I'm going to stop at Discount Tire tomorrow and see what they say on final pricing.