I went through this recently with mine. It was a sum of things. New tires road force balanced was quite a bit better, but you are there. I actually had a shot inner tierod (at 50k miles). I couldn't see or feel it until I had the boot off.

I would also put a micrometer on the hub, and make sure your hubs spin true. Mine was also slightly out of spec. I suspect the previous owner hit something.

 

How slight of hop? I true wheels to within .005" less than the thickness of a business card.

You could also have out of round tires that still balance out. You need to consult an expert. What does your wheel rebuilder say? He should be able to measure any out of round with tires mounted. Shave true the tires or recommend a shop to do it. If the wheel has a slight hop, the rim may be able to be pressed straight or spun in a lathe to improve it.

If you're a hands on guy, check you toe in the driveway. Toe out can cause wander and possibly some shake. Deflate front a bit down to 30 PSI and in 5 lb increments to 45 PSI and see if there is any difference.

If none of this works go to a respected indy or the P dealer.

 

Check your rotor runout also.

 

Checking the runout on the car seems like the prudent thing to do. You may have some rust or other crud between the brake rotor and the hub that causes the wheel to not run true. I just had a set of PS2s put on with road force balancing. I looked up the machine that they were using and it uses laser sensors to check the rim for runout and then tire for side force. They then removed 3 out of 4 tires, rotated them to match it up and re-balanced them. i have had it up to ??? (really fast) and they are smooth as silk. My car had an annoying shake in the front end with the old set of tires. Had them balanced several times never really went away for more than several weeks. Also mark your valve stem position on the tire and check to see if it is rotating. At the SVR autocross a couple of weeks ago one of my rears rotated almost 4" on the rim.

 

thanks guys! will keep you updated.

 

Are you running spacers?

Are you using conical seat wheel bolts where ball seat should be used or vice versa?

 

this is with and without spacers. Tried the stockers without.

Have an update:

So took it in for an alignment, everything was dead on (he didn't even charge me). What he did ask was had I swapped wheels side to side, and ironically I had yesterday, but hadn't driven it really yet. Sure enough, get on the freeway and the vibration is very very minimal (and at this point, may be in my head). Need to get the car in anyways so gonna have my shop do a thorough once over anyways.

 

I run a custom wheel company and you said you refinished them? I would bet your children they didn't mask off the centerbore's on them or allowed material to get in there making the wheels no longer hubcentric.

They would balance out perfectly on a road force (or any other machine), an alignment wouldn't show anything, and yet above say 60-70mph you'd start to get a shake in the steering wheel.

Seen it a hundred times in this industry. Check your centerbores.

I should also mention I had my original wheels on my car from a well known brand I worked for at the time and they weren't hubcentric and I had the EXACT same issues you're describing so I do have first hand experience with the exact same symptoms and went through the exact same things you did trying to eliminate them. Turns out the wheels I had weren't cut to spec and their CB tolerance was over what it should've been and they vibrated like crazy over 70mph.

 

yea, they originally coated the center bores...was rather frustrating, but we solved that issue

With that. When I put the stock wheels back on over the weekend they shook too. What wheel company do you own? I use to work for toyo.

 

If the area of the wheel was powder coated where it bolts to the barrel a precision fit will be lost. Machined mating surfaces must be free of PC. So many in the industry, don't get it.

 

yea, these guys are pretty well known, people send wheels from all over the country (They were doing two sets of original GT40 wheels while I was there last). It blew my mind that they didn't mask it off.


the biggest thing that still makes me say it's not the wheels is the stockers did the same thing

 

Guys, I think he's eliminated the wheels as the issue here. lol

 

What speed, acceleration or decel, higher speed than wheel speed?

 

50-60 and 70-80


I haven't 100% Ruled out wheels. It's always a possibility. Will drop them off next week at a place called custom alignment that I'm told is the spot to go as that "I've tried all the other place and didn't work" spots; works out as I have a meeting next week down by them.

 

Really sounds like wheels, there is nothing as expensive as a cheap set of used 3 piece wheels. I have learned that, and don't appreciate them much.