Just a little feedback on the issue:

2011 GT
Brembo brake package

When backing up or moving at low speeds (<5mph), and turning, the car exhibits a popping or shuttering motion. It's not linear, meaning it doesn't happen in a fixed interval. Once moving at speed, the issue doesn't appear to be there. Also seems to be enhanced by colder temperatures.

I did some research on the Ackermann steering geometry, and thought that might be the issue at hand, but I'm not sure. Anyone else experiencing this?

http://en.wikipedia.org/wiki/Ackerma...ering_geometry

 

Although every case is different, it's likely the tires. This time of year the temps are generally at or below freezing. The summer performance tires on the brembo package are not designed to be operated in temperatures below about 40 degrees. The compound hardens up and loses grip. What you're feeling is the tries literally "skipping" across the pavement.

Every car I've ever driven with similar tires has done this, including both of my previous corvettes which had the Goodyear F1 Supercar tires.

Once the tires warm up, this symptom should subside.

 

Didn't think of it like that, but it makes sense. I should get someone else to check if that's the case when turning.

 

Interesting......and also pretty scary if that's the case. Take it easy when it's cold out, OB!!

 

Yup, mine do this all the time if I'm moving slowly and turning sharply, I always blamed it on the cold and the Pirellis. You can even do it at 0 MPH just by turning the wheel quickly when it's really cold. Doesn't seem to be a huge deal though, but you should take it real easy on them to start when driving, they do break traction easy. It's a very good idea to leave the traction control on like this, it does a pretty good job of keeping the car in line. You can break traction in just about any gear in these conditions. I've done a few light... experiments... if you would, and under the more reasonable above-freezing and daylight situations I got severe traction loss at peak torque while floored in 4th gear, and this was a straight line. Heck, TC strangled the throttle for a good second before it finally let up. It was pretty weird flooring it and having absolutely nothing happen. Even then, when it let up I got some chirping happening and a very slight angle drift.

 

This. Rubber contracts when it's cold, makes it feel like you have bumps in your tires. Very normal.

 

My truck does the same thing, it has a Torsen limited slip axle. You've got a limited slip too, and you're probably loading the rear end and the tires are slipping to relieve the pressure.

 

It's coming from the front wheels. You can feel it in the steering wheel.

 

When I back out of my driveway with the wheels turned and roll off the 2 inch curb, sometimes I hear a pop. Mine doesn't sound like a tire issue, more like a metal sound. I go extra slow now to prevent it.

 

Mine does this almost everyday when I leave work. Or when I am backing up slow and turn the wheel sharply. I never back up fast so I don't know if it does it at higher speeds. I figured it was either the tires or the wider Brembo Brake rims hitting the bump stops. Do we have bump stops on these cars? If so maybe a little grease on them would stop the popping.

What if the suspension is shifting a bit? Some manufactures will use oval bolt holes instead of round ones, because it is easer to install parts at the factory and they can get away with crap tolerances.

 

Whaaaaaa? You're joking, right?

 

I'm pretty sure this isn't a sky is falling problem. I can give you probably a 99% assurance it's just cold tires that aren't meant to be utilized in the cold.

 

It's definitely the tires. This comes up all the time on the 370Z forums (they also come with summer tires from the factory). The summers literally turn into hockey pucks below 40 degrees and skip over the pavement during tight turns.

It is absolutely, 100% NOT a suspension problem.

 

Thanks for the feedback guys. I've definitely noticed a correlation between temperatures and frequency. I'll keep an eye on it as the temps change just to verify it.

 

OAC_Sparky,
I am not saying that is what they did with our cars, but yes that does happen. My Lightning had oval bolt holes on the outer bolt hole of the lower A-Arm. When backing up and turning the wheel all the way the rim would hit the bump stops and cause a popping sound. It was the bolt shifting a bit. It was a known thing and didn't hurt the vehicle at all. If you don't believe me check the link below.

http://www.teamjdm.com/shop/product_...49&cPath=11_14

Anyways, It makes a lot more sense that the tires are just cold and skipping. It happened today again and I could even feel the car move a bit.

 

~double post~

 

I worked in the plant that made your Lightning. As a matter of fact, OTP is now the OAC body shop and I'm sitting about 100' away from where those A-arms were installed as I write this. I assure you that there were no oval holes "because it is easer to install parts at the factory and they can get away with crap tolerances". Aren't you referring to the slots that the camber adjustment bolts go through?

 

I thought I work late. It seems you have crazy hours. I like working evenings more though. If it is just tires then with an all season, any such popping sounds can be safely ignored then.