That's what I needed...thanks

 

pretty much. I run a 265/35/18 all around works great for me

 

Those were my street/autox set-up, and are SSR GT3s. They are a real 3-piece wheel. Not ideal for autox, but I was in the middle of changing set-ups (now have 17x10 FN01R-Cs), so I ran these (305RR, 275FR).

Laze1 - I do have sway bars.

 

When I was a noob, I ran Kumho MX as well. Great tire for the price.

+1 on the tire pressure and track surface. Adjust for each event.

 

Kumho how has the new XS tire. It's supposed to be a step up from the MX and a direct competitor of the Falken RT-615.

 

Forget the XS, get the DX. Its got a nice Lavender smell.

 

HUH??

 

http://www.kumhousa.com/pressrelease.do?newsId=156

 

this could so happen ^^^

 

So I'm going to try to explain my thoughts/feelings about going from the OEM staggered setup to a square setup. Please keep in mind that this is my first season auto-xing, track driving, anything. Hell, I just got the car in April. So I may be wrong on some of my assumptions.

I've been to about 4 or 5 autox's this past season and 3 HPDE events. Up until my last autox and my HPDE yesterday, I was running on the OEM 225/50/17 (FR) and 235/50/17 (RR) setup on stock RE040's. I knew this setup gave me some understeer and to be honest it felt comfortable. At autox's I felt significant understeer, but that could also be because I was going into the corners too hot. But on the track, I felt I could turn the wheel harder in corners and even if the car began understeering, I could add some oversteer just by control of the throttle. Overall it felt comfortable.

Last month I switch to 255/40/18 Falken Azenis 615's all around on 18x8.5 Track rims. Immediately I noticed how much less steering angle I needed to make normal stop light turns. Now to performance driving: For Autox's, I noticed the car had better response ( may just be due to better tires and wider footprint), I also felt the car was very predictable like most people say. You could definitely start feeling the rear come loose and be able to control it with throttle. It was also easier to control if you entered a corner too hot. So for Autox's I give the square setup a thumbs up!

For tracking driving, I had a completely different experience. So I've only been going to our local track this season, and I've developed a good rhythm with the car. In the past I'd be able to push the car pretty hard through each turn and pretty much be one of the fastest in my group. Yesterday I attended a HPDE with my new setup and it was not comfortable at all. Maybe it was me, but I felt the car was very unstable, and I was very uneasy driving it. Turns where I'd have to slowly increase my steering angle felt scary cuz I would think the rear end was coming out all the time. And there was even one time where I had throttle on oversteer and almost lost it but that was just bad driving. Even my instructor (who is a Porsche cup car racer) mentioned he could tell I knew the lines, I knew exaclty when to turn it and when to apex. But it seemed like I would input an action but not know how the car would react, which was true.

So I guess i'm trying to say/ask a couple things.

1) Is this normal? Do I just need to get used to the car again? Cuz where I would normally be passing people, I was getting walked all day. Maybe I just suck.
2) How do I improve on this?
3) I've noticed a lot of the pro drivers running staggered setups, maybe I should go back? I definitely like track driving more than autox.
4) For all the people dumping all these mods into their cars, be careful. All I did was change my wheel/tire setup and the dynamics of the car totally changed. This is a good reason why people should get as much seat time as possible and learn about their car before doing mods. I was gonna do swaybars and coilovers in the winter, but now I'm a little hesitant cuz I don't even feel comfortable with the car now.

Thanks.

Lesson from the day: I want a Porsche 996 GT2. Those things are ***** fast!!!!

 

1) Most likely its normal and you're just not used to a neutral (not oversteering) car. A balanced tire setup on an otherwise stock 350Z does NOT change the balance into an oversteerring balance. It reduces the existing understeer and makes the car closer to neutral.

2) Learn how to drive the car with its new balance.

3) You're not a pro driver, ignore what they are doing with their car setups. There are lots of reasons (rules, sponsorship, driver preferences, power upgrades) that may require a staggered setup. You're not in that situation.

4) Track time and instruction will make you more comfortable.

You're heading in the right direction regarding car setup.

EDIT:

If, right now, you're uncomfortable driving a stock 350Z with a balanced tire setup then a GT2 will just mean you'll be slow in a more expensive car.... and you'll get all the ridicule that people throw at slow Porsche drivers. :-)

 

My square setup (275/40-17 RA1s) is a little "loose" at times...but I use that to my advantage. And I adjust that with tire pressure changes and Sway Bar adjustments...to change behavior.

I currently run my rear sway bar on max-soft, the front bar is one-hole up from full soft...and normally run a 2 lbs lower rear tire pressure. However, This is still a little on the loose-side, but great for HPDE, and just having fun.

But I have now gotten into Time Trials, and will go back to a stagered setup, 275/40-17 and 295/40-17 running Kuhmo 710s. I think this will give me that extra traction/comfort when driving at 100% and more overall speed.


Note: I have the Hotchkis TVS kit, that has adjustable sway bars, and SPL F & R Camber arms, but still run stock shocks.

 

Your reaction sounds pretty normal the way you describe it.

My first step up in tire and wheels was for a square set up, with 275 all around and some more aggressive front negative camber at -2.5 degrees.

Took it out to Buttonwillow, California and ran #13CW and the difference over the stock 225F/245R was jaw dropping. The wider grip and neg camber up front had the car biting into the turns where before it was pushing, and I began experiencing a lot more rotation of the back end. That totally changed where I had to get on and off throttle, the driving line in the corner entry phase.....I was a mess the first few laps trying to survive. And yes, slower. But after a few sessions, hands down faster, several seconds a lap in fact.

The next iteration was more power, and the need to get more grip in the rear to hook it up. So.............back to a stagger set up and 275F and 315R. And back to school again.

Hang in there, drive it some more, and I think you will find that you will ultimately be quite a bit quicker with it once you get more comfortable with knowing where the edge of control lurks.

 

you need to learn the car again. that's it.
and it's going to be a little steeper learning curve because the car full potential is just increased.
track time, track time, track time, track time, track time.
completely different story. different cars, different suspensions, different weight distribution, different angles, different rules.
have more track time, and more and more.. you'll feel when you'll be ready for the next step (one hint... coilovers or good shocks will help you keeping the car more stable and a less "floating" rear end... but when the car will loose grip it will be more sudden)
have more track time, have FUN! that's the important part... have your quota of turn sideways, spins and you'll be more confident

I still think that I'd like a GT3 RS (euro edition, with carbon seats, cage, flywheel, lexan windows) it's a more appropriate track car. if you like to go fast into the corners.

 

a couple things to keep in mind:

as track speeds increase, a neutral car will become loose (and scary), and a car that understeers at low speeds will feel just right.

make sure your tire pressures aren't too high after you get your tires hot at the track.

azeni's get a little greasy when too hot.

if tire pressures check out, then it's just a matter of getting more seat time.

 

just need more time on the setup to get comfortable rotating the car. sometimes properly rotating the car can feel like youre throwing it almost out of control depending on the turn. Some adjustable sways could help dial out a little on-the-limit oversteer and also hitting those azenis with water after every session will help keep them from getting greasy and loose.

 

That's not true.

Well... let me quality my statement. Its not true unless there are aero changes to the car's balance. A car's velocity has little affect on balance until the driver does something inappropriate at the higher velocity (turns the wheel too fast, stomps on the throttle, slow in corrections, etc.) As speeds increase, driver inputs need to be more subtle and quicker.

 

What tire pressures were you running? I've got the same tires as you do (with the exception of 245 in front) and the car feels very balanced. I keep the tires at 38f/36r (hot)

 

Yea I agree with everybody with the fact that I need more seat time. Somebody said that the cars potential increased with the square setup? Is that true? Is the only reason people run staggered is because of the large amounts of horsepower?

And I definitely felt the azenis get more slippery towards the end of each session. Maybe these are better autox tires than road course tires.

As far as tire pressure goes, I wasn't playing with that because I wanted to get a full understanding of my setup first. I was at 38f/38r hot. Next time I'll probably drop the rears a bit like Slow*Jim to get some more rear grip.

 

John, I think you mean the input needs to anticipate. It is not actually "quicker", it just happens a bit sooner and is subtle, such that it "takes" precisely at the point on the track surface you want it to, which at higher speeds is quite a bit farther down the road than when you initiated the command with your hands and feet. We are getting to the "next level" of driving consistently at and sometimes over the edge and maintaining control or regaining control, at your observation. Which is all fine, but he has to creep up there in stages.

Some skid pad time would be a real good idea. Just get it going in a circle and find out where it starts sliding, do some weight transfer exercises, play with triggering throttle on and throttle off oversteer. Try a corner until you push, then do some brake into the entry to load up the front a tad and take it the same velocity and see if you can get it to bite and take a set where before you were pushing, just from controlling weight transfer. Just make some smoke.

Then track it again. And try starting out with your psi at 30 cold. If you are more than 36 hot, draw it down just a skosh.

This is fun stuff. Enjoy every moment of it!

Cheers,
Ed