Holy Understeer!

igota21incher

All great ideas guys! I'm going to do my alignment this weekend with the sway bar install.

I'm going to try -2.0 (f) and -1.5 (r) camber settings with the whiteline sway bars set at full soft front; full stiff rear and see if that helps, unless anyone would advise against it.

Hotrodz

Good full stiff on the front to reduce the understeer. I like no bar in the rear like Eagle stated. I would recommend just leaving the oem bar and try that setup and if that doesn't help the rotation then remove the passenger side end link to disconnect the rear bar and see if you like that better. If that does not work then you can add the Whiteline rear bar and start adding more bar.

Getting your suspension tuned properly is a slow stepwise process and you really only want to do one thing at a time so you know exactly what is working and what is not. One thing is for sure with the Z...you can't have too much front bar!

Sent from my SM-G965U using Tapatalk

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igota21incher

Full stiff on front? I'm seeing two different trains of thought on this thread and throughout the forum. Albeit, everyone's car is tuned different, but is there some rational to this?

Ways to Correct Understeer
Raise front tire pressure
Lower rear tire pressure
Soften front shocks and stiffen bump
Stiffen rear shocks
Lower front end
Raise rear end
Install wider front tires
Install narrower rear tires
Soften front sway bar
Stiffen rear sway bar
Increase front negative camber
Increase positive caster
Soften front springs
Stiffen rear springs

2011 Nismo#91

It's not a simple question or a simple answer. Assuming your doing all the right things with the brakes throttle and steering inputs (not an easy thing to do). Here's a nice little flow chart.

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yaoxiao4

I would really advise against full stiff rear, I would actually do the opposite. Heck I don't even run after market rear sways. Being full stiff rear is going to make the Z very very unpredictable at the limit, sure you might start to oversteer not but it's not going to be the fun type, it's going to snap at you

if you have camber arms then I would actually go even more negative to like -2.5

igota21incher

Found this Gem in another thread; looks like a pretty comprehensive guide into suspension tuning:

Car Suspension Tuning Guide| Rapid-Racer.com.

Any thoughts??

yaoxiao4

probably a good guideline, but remember every car is set up differently, though I honestly haven't heard many good things about stiffening the rear sway on the Z. most people keep it OEM or the softest setting unless you want to make the car unpredictable and snap oversteer a lot

Eagle

While I agree that in a typical setup for an FR car that is seeing track duty this would make the car snap oversteer, the problem is the OP is saying that his car is massively understeering now and after reviewing everything he has and the things he's not willing to change, he is really backing himself into a corner. So either he stiffens the rear via the sway bar, full stiff is probably too aggressive so maybe soften the front sway bar to the softest setting instead and leave the rear in the middle or wherever it's currently at. Or he has to play with camber and toe, my guess is that if I'm running a square setup with -3.25 front camber and -2.4 rear he's going to need more negative camber than me to get close to the same feeling i'm getting. That brings in a whole new problem with tire wear due to the camber.

Thanks for having my back Bob, you da man In all seriousnes everything i've learned about suspension has been from my driving coach, my friends who have been doing time attack for years, the racers who have come before me on this forum and the past 12 months of tracking that have allowed me to test and tune and see what really works and doesn't.

@igota21incher The ball's in your court dude, there are different schools of thought on how to tune the car to your liking but it really comes down to you. Caution should be exercised whatever the case may be.

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Hotrodz

LOL, your results says it all. Yep, one ride with Steve and I learned a ton. I won't get some more time with him at course like Streets or Buttonwillow. Something more technical than Auto Club. He was the one that told me to get rid of rear bar. I need him to drive it and give some additional advice on my suspension. It is a little more complicated having a big arse wing, spiltter and canards.

Let me know the next event you are going to attend after this month and maybe I can go play too.

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Fast Intentions TT Installed and Tuned by Seb at SpecialtyZ 610whp 560tq:|Fast Intentions 3" TT-TDX|SpecialtyZ/Fast Intentions 72 Row Oil Cooler|SZ 6 Puck Clutch & Flywheel|3GsCustoms|Z1|Wavetrac|Hotchkis|Whiteline |Blitz|Fortune Auto 500|Fujimura|SPL|H&R|TK|TWM|RPM Rollbar|Sparco|Next Level Performance|TrackSpec|AeroFlow Dynamics|Pioneer|