Roadster's handles poorly in ruts (HELP!)

[John Oliveira]

Ran this thread before and was told to put miles on it to cure problem. I have a 2010 Roadster, less than 20k miles, new tires on back (300 to 400 miles)and about 70% on front. Alignment checked out fine. This car runs great on new flat asphalt but on L.A. and Orange County typical freeways its terrible. It's squirrely to the point that its unpleasant to drive. Have a 2004 350z thats been ruuning just fine on the same roads since 2004. I know the technology has improved. Am I stuck with this problem??? Really could use some good advice and hear results from other 370 Roadster owners.THANK YOU in advance.

[WhiskeyHotel]

Groved pavement? I have noticed my 370 "tramlines" badly on groved pavement and/or along seams. High performance tires really exacerbate the problem. Check you your tire pressure and make sure it's not above the suggested value - higher tire pressures make for stiffer sidewalls and more tramlining.

Another option is to buy tires with softer sidewalls - a trade off to be sure.

[Guard Dad]

Am I reading your post correctly, you have mismatched tires? Several folks have complained of poor handling and wandering as a result of running different front and rear tires, exactly what tires are you running?

[NYBladeZ]

Does the fact that the Z's sports wheels are staggered have anything to do with it?

[slo]

Originally Posted by NYBladeZ

Does the fact that the Z's sports wheels are staggered have anything to do with it?

It could since it would have more grip on the back, less forgiving than the front, depends on road conditions and what type of tires (and pressures) you are running.

On my EVO X I had 275 wide tires (square setup), and it tracked badly on certain parts of the highway commuting. My EVO IX as well since I went wide on tires.

A buddies Viper is insanely scary to drive normally on the highway, to the point that you need to keep both hands on the steering wheel at all times.

[cptspeed]

tell us more about those new rear tires

[Thechidz]

mine seems to do it when it's cold. but being in CA thats probably not your problem

[John Oliveira]

Theyre all stock Bridgestone Potenzas ....225/50 on front and 245/50s on the rear (all 18's). I took it today to have an aggressive alignment done to it. I googled "tramlining" and it seems this is a very common occurance with several sports cars (BMW 325i, Infinities, just to name a few). My alignment guy tells me that the old Acura NSX's were really bad too. The aggressive alignment made em run like they were on rails but ate tires quickly. I'ts 10pm but I'm gonna go out now and see how it does. If it handles really well I'll leave it aligned that way and see how long tires last. Its a trade I'll gladly make.

[John Oliveira]

Alright........back. A good run down the 91 and 5 freeways to the Disneyland offramp and back home. Major amounts of grooves and rutts. The verdict.........................CURED! One hand in my lap with 2 fingers on the wheel. Comfortable, stress free, excellent ride. Once I became consience of the tramlining issue I drove my 745 BMW down the road and focusing on it, I noticed even it will occassionally move in a rutt. Thats one the premier highway luxury cars! Any sports car with performance tires and suspension is going to have a minimal amount of tramlining. It just needs to be minimized to be a non issue.

[Thechidz]

So what exactly did you ask your alignment guy to do to fix it?

[slo]

What were the specs of the alignment he put them to? I am guessing possible toe out and slight camber changes and minimized?

[John Oliveira]

Says the camber is set on the rear left at neg 1.6 and neg 1.5 on rear right. Previously was toed in 1/32 on rear and was changed to 1/8 (1/16 ea. sde). at zero thrust angle. Front was originally toed a total of 1/64 and moved to 1/32 (total) w/ 1/2 degree negative on camber and the caster @ 5. Thats a bit more than I fully understand but the car rides nice now. We'll be watching for signs of tire wear, but he expects it to be minimal. These specs are at the edge,:happydance : but within the limits of the factory specs. Hope this helps some people because it sounds like a lot of people just accept this condition and live with it.