Vibration

[Boxer12]

My car '00 GTS with stock wheels/tires and 6K mi, vibrates rattles shimmies whatever you wanna call it, around 80 mph. Is that likely a tire balance issue? Can these big tires be perfectly balanced from 1-150 mph? It is worst coasting at 80 than accelerating. Tx

[Bad_Byte]

I'm sure there are probably many things that could contribute to the vibration. (Shocks, bushings etc.)

I would recommend taking the wheels to a shop that can 'ride match' the tire to the wheel and then balance. I have an ‘America’s Tire Store’ and they have always given great service and done a flawless job for me. Make sure you get a reputable tire store. My fist experience was with a shyster that said he could do the job but didn’t. There will be a very noticeable difference if done correctly it also takes some additional time because they have to mount and un-mount (or at least break the bead) the tire from the wheel to match them.

Ride matching gets the slight differences in wheel and tire weight in balance, or as close as possible. After that then they spin balance and add weights to fine-tune the balance. (This is my layman's explanation) I'm sure some will say that it is not necessary, and perhaps it’s not. I go with what works for me.

[GTS Bruce]

Do you feel it in your hands or in your seat?

[Boxer12]

That sounds like "road force" balancing? Yea, I have some experience with that, just wondering if your cars go thru the entire power band without any spots of vibration. Never did get there with the last set of tires I tried that with, similar in size to Viper sizes, even after sending a few back to Tire Rack. Got tired of messing with them and accepted it as unavoidable, but it was not a track car. I just picked up a new set of wheels and tires that were mounted and road force balanced at Tire Rack, so I can swap and see if I still have a problem.

[Boxer12]

Well, new wheels and tires fixed the problem. With the smooth tubes installed, new BBS LM's, the car is smooth as silk. I noticed the OEM wheels have not been properly balanced, without weights on inside of wheel, outer wheel clip on weights, etc., no wonder. Is factory install that
poor or some local shop??

[EllowViper]

I had/have the same situation on my 2001 GTS. Just mounted a set of 345-35-18 Bridgestones on the rear after just a basic spin balance (they put the stick-ons just in the center of the rim with no lip or inside weights..said that was the best on Viper wheels..??). Now right at 80mph the thing is shimmying and vibrating like crazy....just at 80+/-...weird. It did it a bit before with the stock 335 Michelins, but this is crazy. I wil be taking the car to Heffner's in a few weeks for the Eibach install, alignment, and dyno runs...I'll have all re-balanced and see what happens.

[Boxer12]

Ellow, it sounds like your fronts are the problem if you put new tires on the rear. Did they road force balance them? That machine will tell you if you have a flat spot on the tires. If they are bad, the road force machine will tell you and then you can replace or balance them as appropriate. Jim

[EllowViper]

Kinda had the same thought...just did the rears and when I checked the tire pressure on the fronts, I was down to 25psi on each. I increased to around 31psi each and hit the road for a road test with thenew rears. I figured I'd get more steering input (feel) with more air in the fronts, but didn't think the shimmying would be that bad. I still think I have a combination of out of balance fronts and rears since the rears were not very well balanced (IMO)...with just one set of stick-ons in the middle of the wheel. Last time I had them all balanced, they used clip-ons on the inner rim and stick-ons as for in against the spoke as they could fit. Seemed to be pretty smooth from what I recall (months ago). I'm sure Heffner's boyz will figure it out next week after the Eibach spring install.

[BADMOFO]

Quick question, I'm getting new wheels soon and I was wondering what is the best way to balance them. Basically what should I ask for.

[Luke@tirerack]

Just mounted a set of 345-35-18 Bridgestones

Bridgestone makes a 345/35-18 ???

[EllowViper]

They are a set of discontinued Expedia S-01 Assymetric matched that I picked up a few months ago (OEM for some early 1990's Jaguar I'm told). I think the production date was in 2003. New, never mounted. Nice tires that I will be curious how they fill-up the rear wheelwells when I get my Eibachs installed next week. Right now, the car has a front-to-rear rake that I do not really care for (I read the earlier thread regarding mixing 18/20 inch ofsets...sort of the same issue here with a 345-35-18 vs 335-30-18), although the wheelwell gap from front to rear is pretty much equal now. With the Eibachs and alignment, it'll be curious as to how it sit/set/handles.