louisville13

So this may need to be in the wheel/tire section but Im not sure.

This week I finally got some new tires put on my car after driving for months on bald Yokohama s drives. I ended up going with Bridgestone Potenza S-04 Pole Positions. I went with these because they seemed to have the best rating when it came to hydroplaning and after hydroplaning at 88mph (some how managed to get out of that with out a single scratch on the car) this was a category i was not skimping out on. So anyways, I had the tires mounted (what a mess), balanced, and aligned. After finally getting the car back I was excited to see how much more grip it had compared to my bald Yokohama's. The first thing I noticed was the steering response. It sucked! It is super mushy feeling I guess? like i have to turn the wheel a lot before i get any response and then if i turn it right and left real fast it feels like I'm driving a big cadillac. The steering just feels mushy and light. the car does not feel firmly planted on the road. However, these tires are super grippy. I just don't like the feel of the steering. With my Yokohamas i barely had to turn the wheel to get a response and when i went right and left real quick the car followed suit and stuck to the ground.

Here is my question. Would sway bars help? I just spent 900 dollars on tires (plus almost 300 for mounting, balancing, and alignment) so i can't really go back to s drives quite yet. At first i thought the alignment was bad but the camber is with in .5 degrees of factory specs. They said they couldn't adjust any further whichI didn't get because I thought people with spc camber/toe bolts said they could all get back to factory specs. But the toe is within factory specs on all four tires and they were just balanced so I don't think that is it. Any input? I could really use some help, it was a very long very stressful four days getting these tires mounted on my car. I just want the handling back that I used to have...

Side noted, here is everything done to the car suspension wise: stock shocks, eibach pro springs, spc camber bolts in the rear, and 245/35/19 Bridgestone Potenza S-04 Pole Position up front (some negative camber since I don't have aftermarket a arms), and 275/35/19 Bridgestone Potenza S-04 Pole Position in the back.

iideadeyeii

iTrader: (6)

No.

turboed350z

I would say wait until the tires are fully broken in. I believe break ib time is around 500-1000 miles. Then itll change the characteristics of handling.

If after broken in, and it still mishy. Then yes adding sway bars will help

louisville13

I really hope they get better after theyre broken in. If not, looks like ill be getting sway bars in a couple weeks. Which id be excited about if i wasnt trying to save up to install my tt kit haha

MicVelo

^^^ This for sure. NEVER put brand new tires to the grip test until they've taken a set to your car. Break 'em in.... at least 100 miles of moderate driving and more like 500 as T'bo stated.

In addition:

- Check your own pressures. Pressure up over normal for super sticky tires like the S-04s initially. That'll help with the steering sluggishness.

- Also keep in mind that the trade off for additional grip CAN BE (depending on tires) numb-on-center feel and a little more effort required at the steering wheel.

- The S-04s are sticky/grippy but yes, they take away some of the steering response. I have two sets off-car right now and they are definitely NOT as responsive as the Michelin PS and even the stock sized Sumitomo HTRZ-3s I had on one or both of my Z33s; nor anywhere near the responsiveness of the Yoko Advan Sports on my Z34N but..... I still like them. Decent price point, good performance overall.

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Sway bars.... well, I can't think of any better bang-for-the-buck performance enhancers OVERALL.

BUT..... they're not going to help you with steering response in the way you're describing. That's solely the tire, tire/wheel responsibility UNTIL the car starts to actually move into the turn and weight/load transfer gives them something to "correct".

dkmura

iTrader: (64)

You didn't mention how many miles are on your OEM shocks? If they're badly worn from use with the Eibach springs, it could be another factor in your sloppy handling. I went with Koni Sport springs with my prokit springs and they've held up well for over a decade.

louisville13

/they have 50k miles on them but less than 5k miles with the eibach springs. Ive been stuck between koni yellows and coil overs for some time now since they're both about the same price

louisville13

Ill try to inflate the tires. Thank you for your input. I never really knew tires needed to be broken in but that makes sense to me. Ill probably end up going back to Yokohama's when i need new tires. The added safety of these is nice....but I need the handling so I can enjoy the car more. That was my favorite part of the car

MicVelo

I had 60% tread S-Drives on a set of wheels I bought and subsequently sold. They were OK. Never put 'em off. But trust me, don't judge your S04s prematurely. When they are broken in and you dial in your pressures to how you like it, you'll be surprised just how good they are and forgotten will be the S-Drives.

I now have a set of Yokohama AD08s on the car, just broken in. The S04s are at least as controllable - and response is superior - thus far. The AD08s will probably have more ultimate grip when fully broken in and warmed -they being pretty close to DOT-legal race rubber - but as it stands....

terrasmak

iTrader: (8)

What are tire pressures set to.

i8acobra

iTrader: (6)

This.

You said you had the tires mounted... Did you check the pressures? Most tire shops over inflate tires. Start with the numbers printed on the sticker on you door jamb and then adjust accordingly to compensate for any size difference.

louisville13

Ill have to check the front since the tpms sensors are broken, but i think the rear were at 36. I think the max psi of the tires is 50

turboed350z

Tires can handle much more than the "max" psi rating. However its there so that you understand anything pass it, and you gain norhing from not.

Never go that high unless youre on a smooth road and aiming for max mpg. Over inflating tires, aka going to max or over psi, shorten tires lifespam along with decrease handling and stopping power.

louisville13

Any tire pressure recommendations? The tire shop put nitrogen in them so i dont really want to have to take the car back to the tire shop to adjust pressures multiple times. I was thinking maybe 45 psi? Thats 10 psi more than they have right now.

turboed350z

First, break in the tires, then start playing with psi. Doesnt matter if the shop puts in nitrogen, you can air it up with regular air.

But before you do anything, breaknin the tires first.

iideadeyeii

iTrader: (6)

Chalk test to determine psi

louisville13

Not sure what that is, but ill look it up thanks.

i8acobra

iTrader: (6)

I've been trying to find the formula I used to use. Basically, if you're running non-OEM tire sizes, you calculate the size of the OEM tire's contact patch in square inches. Then multiply that by the stock inflation on the sticker. The result is the number of pounds that tire can support, or that tire's "load". You then calculate the contact patch of the new tire size. Divide that number into the "load" number for the stock size. The result should be your new tire pressure to achieve the same load capacity on the new tire. You can run higher than that if you'd like, but never go lower.

MicVelo

I'm presuming that deadeye is referring to determining rollover of the tire a pressures to work with....

Here: https://my350z.com/forum/wheels-and-...l#post10765485

And a little bit more detail: https://my350z.com/forum/wheels-and-...l#post10765673

But since you are on the same tire I've already done all the grunt work on, 40F/36R works for me - in keeping with my desired slight oversteer suspension setup. YMMV.

louisville13

Thank god haha I knew all that math would probably screw me up. Il change the front tire pressure tomorrow hopefully and seehow it drives!