2003350zgirl

I have had my fully loaded chrome silver touring w/AT since December 2nd and love almost everything about it except the ride quality. Now before you guys start flaming me about the way a sports car is supposed to ride let me qualify this statement. This is NOT the first sports car I have owned nor is it the most expensive or highest performance. I love a firm, rough, sporty ride and was expecting a harsh, non cushy ride when I bought this car. I can say from having owned several other high performance sports cars and have ridden in many more even more expensive sports cars that the bouncing up and down constantly is NOT normal. The car literally shakes my insides and gives me headaches at times. It reminds me of some of those rice mobiles with the chopped springs that literally bounce their way down the road. I know there has been a previous thread about possible fixes but I wanted to hear them again and see if anyone has actually tried any of these modifications. I did not buy the 350z for long distance traveling and will use my Lexus RX300 for that task. I did however expect to be able to drive to the mall which is about 15 miles down the highway without jarring the fillings loose from my teeth. When and if anyone responds to this cry for help please be VERY detailed including the brands of parts and where to find them. I do LOVE sports cars and have driven them for years but I have little to no knowledge of modifying them. Any help with this topic would be GREATLY appreciated. Also has anyone tried any of the aftermarket brake pads that are supposed to be less dusty. I have to wash my wheels twice a week to keep them clean and they get covered in brake dust faster than any car I have ever owned. Thanks again for any help with these problems.... 2003350zgirl

jelledge

I agree that the Z is just to damn bouncy. I have a BMW M3 with just as firm of suspension but the ride is not bouncy at all. Go figure.

There are a couple things that could be done. The cheapest would be to install new strut and rear dampers that have adjustable settings. This way you can dial in the dampening response you want.

That said some of the problem might just be in the spring rates Nissan used. If this turned out to be the case then you would need to install adjustable coil overs on the front and new dampers and springs for the rear.

It would be interesting to see what Nissan used on the G35C to see if they changed both the springs and dampening or just one of these items. I would suggest test driving a G35C and see if you like how it rides then try and duplicate the suspension setup on these cars. I have heard they ride much much better with little sacrifice.

My $0.02
Ja

Boomer

I have the 17" OE tires. I just replaced them w/ Michelin Pilot Sport A/Ss(all season) yesterday. The car has 1600 miles on it and the alignment was causing feathering on the outside of the tread.! The difference in ride is phenomenal, some of the bounce is still there, but it is very manageable. If you have 18" tires, no all season tires are available, but anything is better, Michelin Pilots, Bridgestone 03s, Kuhmho and Sumitomos are some of the choices. The original tires are unacceptable, their ride and wear are terrible and they are not safe under 40 degrees, they turn hard as a rock and will not hold the road, in my opinion.

I haven't tackled the brake dust problem but others on this site may have. Do a search for brakes in general.

strangebrew

I just got my touring, and didn't feel it was that bad until the one warm day that we had recently, where the temperature was a good 20 degrees higher then all the other days that I had it. This got me thinking about the relationship between temperature and tire inflation pressure and it's effect on ride stiffness. My tire pressure was set on one of the cold days. For every 10 degrees or so, I think the pressure goes up about one pound. So for 20 degrees, 2 pounds more pressure will make for a slightly stiffer and bouncier ride. If your tires were set too high to begin with (greater than 35 lbs before driving each day), or set on a much colder day, this can be part of the problem. Of course the car does ride very stiff anyway, because of the suspension and the 18 inch wheels with such short side walls (your M3 didn't have 18 inch wheels) which have no 'give' over bumps or swells. You can monitor the tire air pressure with the provided electronic gauge. As drive you'll notice that the pressure increases about 1 pound for every 12 MPH you go (because they are heating up from friction), which adds additional air pressure. If it typically gets above 38 pounds you can probably let out about 2 pounds of air from each tire, so that the tire pressure max while driving is around 37- 38 LBS to give a slightly softer ride. 37 to 38 lbs is reasonably because its based on driving the national average of 45 MPH, which yeilds +3 lbs due to driving friction from the spec 35 lbs (35 spec + 3 friction = 38 lbs max). No miracles, just a little softer. The handling might feel a little less precise, but there is always a compromise.

BB

ares

iTrader: (2)

tire pressure, if you go too hard the suspension will bounce, if you go too soft it the tread will bounce, Id reccomend 32PSI cold.

thats of course only part of the problem, springs or shocks could be mismatched, but I cant say for sure since I havent tried swapping them yet. but soon...

jelledge

I agree that the tire pressure plays a big role in the suspension behavior. However Nissan says to use 35psi cold inflation pressure and that is what I am sticking too. I don't want to eat my tires up at 5k miles.

I think the real solution is to go with adjustable dampers so you tailor the damping response to whatever you want.....

Ja

Vlad

I have a touring too, and really, I don't know what are you talking about. I live in Michigan, and winter roads here aren't exactly perfect. And still, I don't have any bouncing. If you are sure you tire pressure is right, then try going to the dealer to see probably you have some suspension defects. **** happens.

I seriously curious what higer performance sports car have you owned?

strangebrew

jelledge,

I understand your concern, but you have to keep in mind how they came up with that number, 35 PSI. They know what pressure the car should be driven at to have the best suspension characteristics and tire wear while driving. Let's say that temp is 38 PSI. But now several things have to be taken into consideration, and they all involve averages and compromises. First in order to be consistent they tell you measure the tire pressure before you drive (cold they call it). That's good. But then they tell you to set it at 35 PSI. Well what is that based on? They make assumptions that you will be driving an average of 45 miles an hour, they have to pick something, and that's the average driving speed statistically. And at that speed your tire heats up about 30 deg and so the pressure rises 3 PSI (about 1 PSI per each 12 MPH) to 38 pounds. Bingo you are at the ideal pressure for that day at that ambient temp and at 45 MPH, if you go faster the pressure will rise higher but I guess you need to have higher pressure at higher speeds for stability, but you will have more wear in the center as it overinflates. Also, if the next day or later that day, the ambient temp outside is 20 degrees warmer (not uncommon in many North American areas), and you don't check you pressure every day or hour, because most people don't, you are going to have 37 PSI when you start out, and it will rise to 40 PSI @ 45 MPH which is 2 PSI above the ideal 38 PSI. That will be a stiffer ride, but still within the tolorences, because car manufactures expext this kind of variations. The reverse happens if the temp is lowered or you drive slower. So there is a band of tolerance on the tire pressure, because of all the various changing conditions that can happen between setting the pressure. Ideally you measure and adjust the pressure continually. But most don't, so I'm just suggesting that one could set the pressure a few PSI lower than the spec to get a slightly softer ride, yet still stay within the obvious tolerance band that must exist due to changing conditions. I guess I'm saying, that cosidering all of the conditions that the tire is exposed to that can change the designers perfect tire pressure goal, 2 pounds won't make or break the goal, but might help soften the ride.

Boomer

2003350zgirl. I've had my Z since 9/6/02, I was one of the first preorders and I have complained about the bounce since day one. Any surface, bounce or crash over bumps w/the OE tires. Everyone said its just a stiffly suspended sports cars, if you don't like it, buy another car.

I have owned sports cars since 1965 and NO car I have owned has had such a poor ride. The dealer put in 32psi cold and I drove for a while, bounce was unbearable. Car still crashed over bumps and bad pavement. I changed the psi to 35 cold. The bounce was noticeably lessened but the crash over bumps and bad pavement continued unabated and not any better. The OE tires' behavior worsened as it got colder and I felt like I was riding on rocks under 40 degrees on the OE tires.

Yesterday, I changed the OE tires for Michelin A/Ss, same size. The crash is gone over bad pavement and bumps feel like...bumps from a stiffly suspended sports car, Hooray! It is being aligned as I write this to eliminate the toe-out problem I discovered yesterday after the tires were changed.

My opinion: 1. Change tires to rec's from Tire Rack.com, always had good service and was steered to good tires for the car I was driving and you should lose the crashing ride you are reporting;
2. Have your alignment checked by your dealer or an independent you trust, toe is the only adjustment apparently; and
3. Stay tuned to this site or 350frenzy.com for the latest developments on suspension parts to adjust your ride to your preference, such as: adjustable shocks/dampers, springs or a combination to stop the bouncing completely.

My preference is adjustable shocks/dampers because I don't want to change ride height. Other options are complete suspension pkgs. coming out in the near future. Some think only a change in springs is needed to correct the bouncing. We will know soon because the new products are being introduced and owner reports should be forthcoming shortly.

Boomer--my opinion, use it or lose it, I don't care.

Boomer

Reprisefrom Boomer. See my previous post, pls.

Pooh2002

2003350Z Girl,

Your message that started this thread sounded exactly like one I wrote a few weeks after getting my Touring with AT (17" wheels, no tire pressure monitor, same as yours and Boomer's). I experienced the severe freeway bounce on one particular stretch of freeway. That morning I was forced by the traffic to go at 45 MPH. I have since driven the same stretch of road when I could adjust my speed and find that the bounce can be almost completely eliminated by going faster - like 75 MPH - I think I must have been setting up some sort of resonance in the suspension that made the ride almost unbearable.

Do you experience the bounce on quite a few roads? Can you adjust your speed to make it less pronounced? I am glad to hear from Boomer that the Michelins help and I now plan to go to them when I replace my tires - but I have only 1600 miles on the car and I don't want to throw away almost new rubber - I am lucky that I live in California and so never see temperatures below 40 F.

MannishBoy

iTrader: (1)

I bought my car in St Louis, and drove back through 4 states of concrete interstates. I was seriously wondering about my decision for the Z over the G35C for awhile. Luckily, the interstates here are much better, and I don't get as much bounce, but I'm seriously considering something like the Tein coilover setup with the electronic control. That is a lot of money to spend to get rid of the bounce, but I might just do it. I think I'm going to wait and see if somebody figures out a cheaper solution that doesn't sacrifice performance, though.

Boomer

How much does the Tein run? I bought Tokiko 5 way adjustables for my 91 MR2T and they worked well but I have not heard anything about them on this site or others. Are they out of favor? Why? They were not cheap, about $800 installed, but were effective.

Also, Pooh mentioned throwing money away by getting new tires, he needs to get a tradein or put them on E-Bay or something. Having just plunked down about a grand for the Michelins, I'm not keen on spending more, but the car needs to suit me or it will be a constant irritation I don't need right now. It will be right or I will not keep it, as much pain as that statement gives me, but a sports car should not be flawed from the day of purchase and need expensive bandaids immediately.

I am still hoping the Michelins will wear down some and minimize the bouncing on the highway. I can always drop down a gear and stabilize the ride, but lose in mpg. Not an easy answer to a complex problem. Ah, well, it will work out, I feel sure. The recent improvements have already done a lot.

uro279

Hey guys!
I don't have the problem with my Track model, buy Krinkov mentioned that the 300Z had the same problem and it turned out to be the rubber bushings that caused the bounce. It was corrected by replacing them with I believe aluminum bushings. Made the ride firmer, but eliminated the bounce.f

I have sent an email to japanparts on how their stabilizer kit (includes sway bars and reinforced bushings) would affect this.

Boomer

Are you talking about the stabilizer bushings only? If you are, why buy a replacement kit? I am not familiar w/metal bushings, but urethane bushings are all over and may be a less expensive alternative. Did Krinkov replace the bushings or just get a kit? Theres a company that specializes in urethane bushings, I can't remember the name but urethane is usually very good. The aftermarket stabilizers bars I bought from Suspension Techniques had urethane bushings and they were very effective.

I don't have a problem with the cornering of my Z, so buying a whole kit seems unnecessary, unless you want a stiffer car, which I don't think I need. I'm certainly open to ideas, so bring them on or I'll ask Krinkov when he's available. Thanks for your help.

Boomer

MannishBoy

iTrader: (1)

TEIN stuff is pretty pricey About 2x what you are talking about, then add on the EDFC control equipment.

That EDFC is sweet looking though.

MannishBoy

iTrader: (1)

I think you may be confused. I doubt bushings would fix this. On the other hand, they would fix wheel hop under hard acceleration, which is totally different.

uro279

I don't know what bushings he was talking about, but I am pretty sure that he mentioned aluminum as an option. He did, however, mention urethane. As for whether or not he personally bought a kit or what, I have not idea.

I emailed Grahm at japanparts to see if he knew anything about it.

I am considering purchasing the stabilizer kit to reduce understeer. I have been reading this site and several have mentioned that a bigger and stronger rear sway bar helps reduce understeer alot. But we'll see as the actual results come in.

I am also considering the NISMO wing only if it is functional and if it does not adversely affect performance in any way.

I encourage you guys to definately talk to Krinkov extensely as he has a wealth of knowledge and can tell you what he actually said as opposed to my impression of what he said.


BTW, Krinkov installed the clear bra on my car last week and it looks awesome! Concurrently, he shares space with guys who do tinting, and they installed 50% platinum tint all around, except for the windshield. Also another excellent job!

uro279

Well, he couldn't help me with the bushing questions. He also did not know if the NISMO rear wing was 'functional', but he did state that the first NISMO body kit supplied was to a U.S. race team and that they liked it alot.

strangebrew

Boomer, are you saying now that you are NOT satisfied with the Michelins? I thought you felt that they cured the problem. Or did they just help a little, but you want to reduce the bounce and crash feeling more? Also, do you have 17's or 18's ?? Do most of the people here who are complaining about bounce have the 17 inch wheels?