I wander why anything would brake, if it runs down the road and doesn't wonder and has a good set of breaks

 

Off-topic, but FYI the "snow tires" disappeared from F1 this past season in favor or returning to slicks, and it was a blast watching the Brawns kick a$$. ...tho the skinny 2009 rear wings are fugly IMCO, and the compromised front a-arm angles (which I guess means the engineers believed aero more important that roll center height for the '09's) just look wrong.

OK, where were we??

 

I wonder why I wander, but I need to break off so I can brake my car from being over the speed limit.

 

Now they gotta make them look cool again saw Mario Andretti drive one of these John Player Special Lotus in the late 70's in an F1 race at Mosport



Sorry to the OP poster that's the end of this OT stuff from me, hope you solve your problem

 

what about suspensions stiffness causing the car to wander?
My corvette tends to follow the ruts above all at the rear. possibly too stiff suspensions-sway bar (acting as increasing stiffness spring when just 1 wheel goes on the ruts). going now for QA1 shocks at rear ( after trying both bilstein HD and sports: too soft-too stiff ) and hopefully find a good setup and have my wheels following the road imperfections and not jumping onto them or go sidewise . my mercedes A class wanders much more than other same size modern cars because Mercedes made very stiff susp to avoid car's excessive roll ( a dsesigner mistake "fixed" with stiffer suspensions in a hurry...)

 

I think there are some good suggestions for the OP.

Tight steering box or linkage.

Caster angle, although from the shop figures that looks ok.

IMO though, if the wheel offset is quite a lot off factory you're never going to correct this.

Unfortunately (this isn't aimed at the OP) some people choose wheels that 'fit in the fender' rather selecting the correct wheel offset. They then spend time and money trying to correct their steering because they don't want to accept the fact that they bought the wrong wheels.

 

I have 10X17 front wheels with 275 tires. With 4 inch BS would give me 2 inches of scrub.

If your car is scary with correct alignment specs the two things I would look at are stiffening up the front frame with welded gusseting and a front spreader bar and then investigate installing a "zero" front bump steer.

IMO - the rear would have very little to do with handling under braking because of weight transfer. You have frame flex up front. I would also inspect the frame in the A-Arm area for cracking

 

What is: a "zero" front bump steer?

 

http://en.wikipedia.org/wiki/Bump_steer


Simple example is: You have your alignment set to "0" toe no toe in or out. But as you compress the front end from either braking in a straight line or turning which compresses one side or the other. The stock suspension causes additional toe out. Which cause unstable hunting or the twitchy feeling.

Stiff springs limit wheel travel and toe out. But if you install a bump steer kit on our c-3's to min. the change during wheel travel it makes the car more stable. stiffer springs are good up to the point where it actually causes the frame to flex.

If you look at track race cars the tire is very close to the wheel fender well or even the nose splitter ground clearance. they have very little vertical wheel travel under braking or turning. you do not want additional camber or toe out with wheel Vert. travel.

I get to roads course late model vettes. They have 40 years of improvements, but they compromise also for comfort of the average Joe buying them.

 

Back in the earlier days of GM (before bankruptsy or the Delphi spin-off). Oldsmobile, Pontiac, and Saturn were still around. I was the competitive analysis manager at Saginaw Steering Gear Division. Since we were a Division of General Motors, we had ready access to all General Motors new vehicles. Being a part of GM, we also had access to their competitive analysis fleet of passenger cars and trucks. Every year GM purchased a couple hundred new vehicles from their competitors. These vehicles were based at the Milford Proving Grounds and were circulated throughout the Corporation on two week intervals.

Every year (from the early to late 1990s) I would make out a list of new competitor vehicles that I wanted to evaluate for steering performance. And for the next year, just like clockwork a different competitor car would show up at Saginaw on Monday afternoon for a two week stay. Since they were on two week intervals there were always two vehicles at Saginaw for evaluation. As the competitive analysis manager, I always evaluated every vehicle and most times had one of them for a weekend evaluation.

The evaluation vehicles ranged from luxury cars, pickup trucks, small economy cars, etc. (you name it - if it was new, I drove it and evaluated it.) I had a very identical evaluation schedule that included a 12 mile drive to my home that had expressway, city traffic, and parking type evaluations. I always wrote a comprehensive report on each vehicle.

There was one stretch of rural highway that had fairly significant (what we called) truck troughs in the right hand lane. I found a number of vehicles that suffered truck trough wander. Some cars would literally "take off" with a mind of their own as they jumped in and out of the troughs. These were quite new cars with very minimal use.

I found that for the most part the problem was with sporty vehicles that were front steer, narrow tread, with large cross section tires.

I always attributed the problem to the fact that the large tires would actually span most of the width of the trough and it was one edge of the tire climbing up and over highway groove. Since the car had a narrow tread it was only one side of the car that was sort of trapped in the trough. I know that I evaluated new (C5) Corvettes during that time, I just don't recall truck trough wander or not. I did own a C3 Vert during that time. I always had GR70-15 steel belted radial tires on it. I do not recall wander with it.

I have now been retired for the last nine years after a 39 year career at Saginaw. My retirement checks come from the Feds (the Pension Benefit Guarantee Corporation.) I get virtually nothing from GM or from Delphi. I still drive GM cars mainly because Saginaw (now called Nexteer) still supplies components to most of GM. For some reason I still get a GM (employee - retiree) discount. They must be making money on my transactions.

Jim