Need help eliminating oversteer
 

I am running a full race 370z and I have been struggling with oversteer. Now, I don't mind a car that oversteers, but I can't stand dancing the car through turns and having to wait to go to power after the apex because the *** wants to swap ends with the front.

The car is lowered and running on JRZ double adjustable coil over's. Spring rates are 1K up front and 800 rear. The bar is disconnected in the back to try to get some bite, but it's still only a partial fix. We have experimented with dampening and now I am pulling the shocks to soften the springs in the rear, but I just don't think I am going to get a marked improvement without altering the geometry in the back.

Is there anybody that has ANY feedback on the WiseFab rear suspension upgrade? Is there a significant improvement to be had by using their geometry?

Any help would be appreciated. Feel free to ask questions if you need.

Curious.....Tire compound and size? Aero? Current alignment reading?

Yep need a lot more information on your setup before we can begin to answer your questions.

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I have all the data in my binder in the transporter and the car is out of state. I will have to get back to you when I get the car back this weekend.

Thanks for the quick responses.

There's some info in here on this same topic.
http://www.the370z.com/brakes-suspen...ndersteer.html

Ok, here is more information:

Front wheels:
18x9.5 Enkei NT03+M / 275/30 Hoosier R7

Rear wheels:
18x10.5 Enkei NT03+M / 295/30 Hoosier R7

Left Front
-2.9 Camber
5 Caster
.09 Toe

Front total toe
.19

Steer ahead
0.00

Right Front
-2.3 Camber
5 Caster
.10 Toe

Left Rear
-2 Camber
.22 Toe

Right Rear
-2 Camber
.21 Toe

Rear Total Toe
0.44

Rear thrust angle
0.01

Chassis:
TC Designs custom cage with reinforcement to firewall
JRZ RS-Pro 2-way adjustable dampers with Hyperco springs 1000 / 800
SPL rear camber arms
SPL rear toe links
SPL rear knuckle monoball bushings
SPC front camber arms
Hotchkis sway bars

Drivetrain:
OS Giken 1.5 way differential with 3.54 gears
Short shift
Custom tilton/ setrab diff cooler with toggle switch
Diff Pump and cooler

Brakes
Stoptech Trophy motorsports brakes with slotted rotors. 6 piston front, dual piston rear.
Tevis stand alone motorsports ABS system with Tilton adjustable bias valve

Engine
Stillen gen 3 intake
Tuned for 93 octane 354 WHP/ 305 WTQ on Pellegrini Performance dynojet
AE Performance oil cooler
Custom 4 -> 1 SS Exhaust
Long tube headers from Fast Intentions

Fuel:
ATL 32 Gallon FIA certified Fuel Cell
Moroso Fuel Pump
Moroso fuse panel and switches

Interior
Sparco 330mm flat bottom steering wheel with quick release
Steering wheel mounted controls (Radio, Brights, Cool Shirt, PTP, Limiter)
AFFF Fire system
Custom carbon switch panel
Custom dead pedal
Battery relocated to trunk area

Aero:
Aeromotions carbon wing
Lowered front end and splitter
Front underpan
Midsection underpan
Carbon rear deck
Lexan windows
Carbon lowered side skirts
Composite fenders with exhaust ducting
3" carbon front brake cooling intakes and ducts

https://www.instagram.com/p/BmCOCkrB...y=too_cool_dad

I need to see some pictures of your car she sounds bad *** and you got all the good stuff.

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I'm not sure this will work or not:

https://www.instagram.com/p/BmCOASBF...y=too_cool_dad

https://www.instagram.com/p/BmCOCkrB...y=too_cool_dad

You may want to get her corner balanced since you gone full race car before you start making adjustments. That will help with getting your spring rates and ride height to a place you can start to work from.

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Did that.

Yep the link does not work... I sent you a follow request!

Ok cool it looks like your camber is .5 degrees apart on the front. Is that a typo? Also you could add some more front camber -3.3 and increase your caster to 6 or more. Your rear seams spot on.

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Wow standalone ABS. You weren't kidding when you said a full race car.

Could you describe the oversteer? Was it entry, mid corner, exit, or left to right transition?

When you've gone into thinking changing rear suspension geometry, I am sure you have already tried the usual suspects, like toe, downforce, rebound and compression settings, brake bias....It'll be great if you can share the different adjustments you've made and your conclusions on them.

And the SPC front camber arms...typo?

The bite at the front is good, the oversteer is the issue. I am researching suspension alternatives for the rear that can improve the grip with new geometric angles since the car is lowered.

Too add to that question. Is it tail happy all the time? Or at different corner speeds? What's your tire temps across the tires. What's your fuel level when it happens? How many heat cycles on the tires?