BRZ not stable at highway speeds

[Legionsk88]

Originally Posted by shattered_memory

Our cars are sensitive to the wind at highway speeds.....well mine is anyway. However, I honestly don't mind it or feel unsafe. I love the feel and handling of this car. I am sorry if you are not satisfied with your purchase.

I second that. Car has always felt firm on the ground, regardless of speed or wind.

[EAGLE5]

Originally Posted by gravitylover

^^ One thing in that article bugs me. It says new tires always go on the rear. I've always done exactly the opposite, if I'm only replacing two they go on the front.

Then you have been doing it wrong.

[gravitylover]

Fronts wear much more quickly, steering and braking happen there and you need them to be better in wet so why new on the rear? It doesn't make sense to me.

[RichardsFRS]

2016?
Been over 100 smooth as butter. 2013

[EAGLE5]

Originally Posted by gravitylover

Fronts wear much more quickly, steering and braking happen there and you need them to be better in wet so why new on the rear? It doesn't make sense to me.

The goal is understeer. It's safer. More grip in the back, especially in the wet.

[angadam]

I have noticed on grooved concrete road surfaces mine tends to wander back and forth like that. On the other hand stuck like glue on asphalt. I am an alignment tech and I would also be curious to see the numbers as others have said just because it is green doesn't mean its good IMO.

[justatroll]

Originally Posted by gravitylover

^^ One thing in that article bugs me. It says new tires always go on the rear. I've always done exactly the opposite, if I'm only replacing two they go on the front.

better tires always on the rear:

http://www.ft86club.com/forums/showthread.php?t=98681

http://www.ft86club.com/forums/showthread.php?t=103302



http://www.tirerack.com/tires/tirete....jsp?techid=52

"The ability to sense and control predictable understeer with the new tires on the rear and the helplessness in trying to control the surprising oversteer with the new tires on the front was emphatically proven."

"When replacing only two tires, the new ones go on the front.
The truth: Rear tires provide stability, and without stability, steering or braking on a wet or even damp surface might cause a spin. If you have new tires up front, they will easily disperse water while the half-worn rears will go surfing: The water will literally lift the worn rear tires off the road. If you're in a slight corner or on a crowned road, the car will spin out so fast you won't be able to say, "Oh, fudge!""

http://www.popularmechanics.com/cars...nked-10031440/

"Stop with the “even ifs.” No matter if your vehicle is front-, rear-, or all-wheel-drive, a pickup, a sporty car, or an SUV: If you buy only two new tires, you should put them on the back, according to tire manufacturer Michelin North America."

https://blog.allstate.com/new-tires-rear/

"The worn rear tires have less tread and lower hydroplaning resistance. They can lose their grip on wet roads, causing the rear end of the vehicle to swing around out of control."
http://www.discounttire.com/dtcs/infoTiresRear.do

[cjd]

You may want an alignment that's 'stable' and not zero toe... This car requires attention, you can't half doze behind the wheel like you can in so many cars. Part of its turn carving comes from a sensitive setup. So, while the alignment may indeed be an issue, it may also partly be expectations that aren't quite in line with the car's tendencies.

Originally Posted by gravitylover

^^ One thing in that article bugs me. It says new tires always go on the rear. I've always done exactly the opposite, if I'm only replacing two they go on the front.

Push is the safe recommendation, so new tires always go on the rear.

[justatroll]

Originally Posted by cjd

Push is the safe recommendation, so new tires always go on the rear.

I think another way to say that is: Understeer can be recovered from by just slowing down (the automatic response by most people) while sudden oversteer is harder to recover from.

[ToySub1946]

from unplugged: "Now at 628 miles, cruising around 70-75mph (yes within speed limits) my car will literally shift left or right and it doesn't matter which lance since I know the road crown can give a slight pull."

I have a 2015 FRS bought new. I felt the same sensation when my car was new. It was an odd sensation surely. It was not as though the car was wandering, it was as though the entire car was shifting, just slightly, to the left or right in my lane (and constant at freeway speeds). Over a period of miles (can't recall how many...but I'd guess well over 1000 miles) this went away. I believe it was because the tires were new, possibly those little nipples on the surface of the tire left from the molding process. Eventually those nipples wear away...or simply that the tires broke themselves in. (My car came with the Michelin tires.)

>>So I'd say, put more miles on the car, and the problem will heal itself.<<

My advise: Give the car plenty of time to break itself in, and you getting used to what to expect from the car. Don't monkey with more alignment advise, changing tires or suspension pieces right now. Give it time and many more miles first.


As for this: "Around a slight right bend on the highway, the car literally went half way into another lane." I have no answer, as I was not in the car with you. You might want to dismiss this as a fluke, if it never seems to happen again. Possibly a huge gust of wind as you rounded a curve ?


Edit:I see now you've got a C5 Vette, so you quite possibly are already aware of things I've stated below...which may be similar to BRZ

Since this model car is lower to the ground than most other cars, we feel sensations we would not feel if the car were raised off the ground more. You'll also note: Can't tell exactly where the front of the car is when attempting to park up to a parking stop (cement strip). You also won't get the advance viewing notice of holes (potholes) in a road's surface you'd get in other cars. You'll have to be very careful entering or exiting into or out of a business entrance from a highway. Can't easily see just where the curb ends and entrance begins...you're too low to see these things. These are some of the tradeoffs of a car which can handle corners better than most other cars.

[gravitylover]

Hmmph, learned something good today. Thanx guys. I'm always surprised at how many mistakes I've made over the decades...

[EAGLE5]

One thing I've noticed is that brand new tires give a Squirrelly feel for a hundred miles or so.

[Packofcrows]

Mine pulls too. Its tire grooves. Get new tires.

[EAGLE5]

A truly good alignment guy can work wonders. The Roger Krause Racing guy ended up taking a crowbar to my xA suspension. It would align perfectly in spec bent, but it still had an issue. The tires were so out of round, the car still pulled to the right. Interestingly, they also insist on not aligning with a person in the driver's seat. They said they get tons of complaints of the car pulling when they do that. They do way more alignments and racing tires than anyone here, so I imagine they know what they're doing.