Am I the only one who's noticed a degradation in steering response/handling when I upgraded to 19s?? It's happened on TWO different sets of rims: ADR M-Sports and Volk LE37Ts.

My steering does NOT feel like its "on rails" anymore. The car actually LAGS behind my steering input -- i.e, I turn the wheel, theres a brief lag, and THEN the car turns. It gets worse at higher speeds... and does NOT inspire confidence.

Does anyone else know what I'm talking about or how to fix this ? I'm running the following setup on a stock suspension (except for a sway bar, and it happened without it too):

19x9.5 (+22) 245/35/19
19x10.5 (+22) 275/35/19
Toyo T1S

My previous rims (ADR M-Sports) weren't as wide, but I still noticed the crappier response. And when I drove the car on stock 18s again, it felt beautiful! Is there any way to keep 19s and make it feel sharp again ?

Need your advice boys!

 

I have no idea why it would do that, maybe offsets? I hope not I have a set of LE37's on order in those sizes and offsets. Maybe you feel the tire starting to roll under the wheel because the 245/275 combo imo is stretching the 9.5/10.5" too far, and under hard cornering the tire begins to roll under the wheel? Ideal would be 255 or 265 front 285 or 295 rear, but then you would need to roll your fenders. Im curious to see what the wheel guru's have to say about this. BTW are you running correct tire pressure ? Do you have FLT-A2's or Tein Flex? Maybe your pre-load is set up wrong, and on 19's you feel it much more than on your 18's, thats why it feels loose...

 

I have the same tires and size wheels but I really havent noticed a reduction in handling. On the highway it still feels tight but then I haven't been pushing it on corners really hard yet either.
In general though a larger rim will not be as responsive as a smaller rim. Thats why auto-x'ers tend to use smaller size wheels. I doubt the tire is rolling on the wheel though, that would be dangerous and there is no way they could sell a setup like that. In fact the drift cars tend use stretched/tight fit tires all the time so... Also, your sidewalls are smaller so there shouldnt be a big difference really.

I have noticed a little bit of a strange hop now and then though. I hope that will get corrected when I update the suspension this weekend. I'll see what else I can find out on this too.

 

I believe that several members have posted in the past that Toyo's are lighter tires and the sidewalls are not as stiff as other brands. You may be experiencing flex in the sidewalls.

As Alberto pointed out, the tires you chose are on the small side for those wheel widths. Especially the front tires, the recommended wheel width (per Tirerack.com) for 245's is 8" to 9Ž½", so you're at the upper end.

 

Maybe - my fronts are actually 8.5's with the same tire.

 

Slay2K -
I got your PM, but Im just going to reply to everything here...

well, first, your tire sizes are a bit small for those rims. Personally, I dont like such a big stagger on my tires. The skinnier tire you have up front the more understeer it will have, but that is a subjective and personal preference. About the ride quality, it shouldnt have anything to do with the offsets. The offsets and sizes seem fine...but I would look into the tire pressures. Uneven tire pressure can possibly cause the feeling you are having. But more suspectingly would be something having to do with your suspension setup. Im not too familiar with what you have suspension wise, but if you have coilover, make sure you lower the car from the shock perch, NOT the spring perch. The spring perch is for the spring preload. If you compress the spring too much, you are going to loose travel...and if your coilover doesnt have a bumpstop, you could possibly blow your coilover if you hit a pothole.
Another thing which could be a huge problem is the alignment. Make sure you go to a good shop that knows what they are doing. Also, if you have coilovers, counterweighting the car with you in it would also greatly benefit the whole feel. Im not too familiar with those tires, but it could be sidewall flex, but Im not totally sure. If your tires dont have enough pressure in them, they could flex even more.
Well, overall I think the choice of tire and rim sizes are fine. My personal preference would be to get the front tire as close as the rear tire. But that how I personally like it. Go over some of the other things I mentioned, and let me know about your other suspension mods.
One more thing, after you get this fixed, if you don't have an LSD, that would definately be my next mod if I were you. It will greatly help all performance aspects of your car.
Jon

 

Its your alignment. I've been experimenting with this the last week and posting in this thread: https://my350z.com/forum/maintenance-and-repair/92147-solve-tire-feathering.html

What you describe is exactly what I noticed when I set my alignment to the new nissan specs. I immediately set them back to slight toe out (-.10 deg left and right, for -.20deg total toe) and the quick steering response came right back. Good luck, and if you need any more info feel free to PM me.

 

It's the toyo's. When I used to have s03's the car was VERY precise... now i'ts sloppy as hell...

 

It could possibly be a combination of both making the problem worse....Also, do you have any pics of your car with the LE37T's? I love those wheels!
Jon

 

seems to me that if the tires are "stretched" more then the sidewalls would flex less.

 

Hey guys, thanks for responding.

With regard to the alignment... I can't do it on a machine because my bumper is so god damn low to the ground (2 inches), so I had to do it at a place where you drive onto a platform and they do it from underneath. They have a good reputation around here and told me I'm "within spec", whatever that means. What the hell should my specs be with these rims, anyway ?

And about the toyos -- I don't think so... I've had different tires on my ADR rims (Dunlop Sport 9000s), and they exhibited the same problem.

I don't know what tire pressure I'm running -- I should check that out and get them to 40psi at least. By the way dank, the *ONLY* suspension mod I have is Hotchkis Sways. And heres a pic 4 u...



More:

http://web.njit.edu/~rm73/z7.jpg
http://web.njit.edu/~rm73/z8.jpg

Still don't know what to try for this crappy steering... :/

 

I'm not sure what the alternative is to the drive up on a platform machine since the one I used was like that. Drive up on the ramps, they lift up a few feet and you adjust the alignment while the computer displays the settings.

I don't know that rim size changes toe specs, but here's the problem with setting your alignment to "within spec". The specs that nissan put out is between 0deg total toe in (minimum) and 0.2deg total toe in (prefered). My car came from the factory set with about -.15deg of total toe OUT. It is the toe out that makes the steering heavier and much more responsive at the expense of increased tire wear. This is why I suggest getting an alignment done to remedy the problem. Keep in mind you will need to instruct the mechanic to set the toe out to your specs, not what the computer says.

 

I have the same size and offset rims, along with the same tires, and I agree that the steering is less responsive than my OEM setup. The major difference is the tire. T1S's are almost 5lbs lighter than the equivalent sized bridgetones (S03's or RE040), but the drawback with the lighter tire is more flexible sidewall. If you don't believe me, find a set of unmounted Bridgestones and Toyos and bend the sidewall. There is a significant difference in sidewall thickness and stiffness.

I also have a set of Conti SportContact II's that have more flexible sidewall than the Bridgestones. I expect my steering response to be just as poor as the toyos. The SportContacts are light though....

 

Okay,

So what the hell am I supposed to do ? :-O

I'm thinking of just straight downgrading down to 18s (same make/color)... unless someone can come up with a more viable solution.

Would it help if I went down to 19x8.5 and 19x9.5 ??

 

Just because the tire is lighter and flexes easier doesn't necessarily translate to handling issues. For one thing, you have considerably less sidewall than the stock setup. Your tires are also stretched much tighter onto that big *** rim and that will take out whatever excess flex there was in the sidewall. Lastly, I doubt the sidewall can flex enough to cause handling/responsiveness issues that you could notice (unless the tires were rolling all over the wheel and that's simply not happening or it would come off the wheel).

I am having my suspension tuned this weekend at Avalon Racing. I will ask the Jeff about this and see what he has to say.

 

Christ I wish there was someone on the east coast who could help me fine-tune this to my liking.

Is it worth trying a different tire ? How about a narrower rim ? What about 18s altogether ? Could really use some help here boys :[

 

Why dont you try running a 255/35 285/35 of a different tires besides T1's and get an alignmet and run recommended tire pressures? If that doesnt work I dont know what will...good luck with this, I hope I dont have the same problems with mine.

 

Yes it does. If it's more flexible, it will flex more laterally than a tire with stiffer sidewalls. It's a compromise I'm willing to take for a lighter tire, but it still translates to a handling issue for some folks. Steering response is affected but I did not necessarily say grip has been affected. I get plenty of grip with these tires, but I certainly don't feel like the car turns in as briskly as before. I would give up some weight for steering responsiveness...

 

Why don't you buy some S03's next time? If they're anything like the RE040's, you should get at least the same steering response.

 

If everything else was equal then you might have a point but given the much smaller sidewall and the STRETCH on larger rims, I cant see that being the issue. Its pure physics. If that tire stretched on a 10.5 inch rim is flexing that much that you can feel it to the extent that the car is "unresponsive" then on a smaller rim it would be almost undriveable. There are plenty of guys with T1S on 9.5 rims and they arent wiggling around on sloppy sidewalls. Sorry but I'd say there is more to this story than just the tire.