Nissan 370Z Forum - View Single Post - Rear-end wanders at speed Help please

GSS138 · 03-11-2015, 12:10 AM

Well my track day spec has varied quite a bit for the last few months because I have been fighting some issues, been changing springs, sways ride height a lot trying to trouble shoot the weird snap over steer problem. Without going into too much detail:

In the front, I am thinking but can't prove yet that -4.0 camber is out of the question, I ran it for two weeks and it felt great, but it's still a DD so that will kill your street tires fast and my "track spec" was -3.2 on both fronts.

-2.0 camber in the rear for street or track is too much. Our rear end likes to camber out-too much. Even when pushing hard on track with a rear end that was dangerous, I could never even come close to heating up the outside of the tire like the inside at -2.0 static camber. 1.6-1.8 is probably ideal even for a pretty hardcore track setup.

I went too low on front ride height and too soft for my initial spring rate up front (and too stiff in rear) and I started to have problems with suspension bottoming and throwing weight around-not to mention the rear end trying to show off at the same time.

The rear toe I left at 0, with a little toe out in front.

I removed the rear bar, it was much better, but then would still snap oversteer at really weird times, not in high speed corners and sweepers, but at 60-80 MPH and at really weird times, but mainly on exit when I was pushing hard on entry.

My Toe settings were close to 0 and 0. I have since dropped spring rates on the rear and have no idea what my current alignment settings are but will get them next week. The car currently feels very good for the first time since aug/sept.

In regards to your situation, there is nothing in a basic alignmentclose to factory spec that could be creating the situation you are describing. I ran my RS3's with 30+ track days and 15 K total DD miles with 1/16th of tread and cords showing at Big Willow in the rain in Dec and the car still did fine.

Basically, I can not see how even really f-ed up street tires and a so so alignment like yours could be creating a semi dangerous situation.

03-11-2015, 12:10 AM	#26 (permalink)
GSS138 Track Member Join Date: Mar 2013 Location: Mission Viejo, CA Posts: 769 Drives: '12 370Z 6M Sport Rep Power: 13	Well my track day spec has varied quite a bit for the last few months because I have been fighting some issues, been changing springs, sways ride height a lot trying to trouble shoot the weird snap over steer problem. Without going into too much detail: In the front, I am thinking but can't prove yet that -4.0 camber is out of the question, I ran it for two weeks and it felt great, but it's still a DD so that will kill your street tires fast and my "track spec" was -3.2 on both fronts. -2.0 camber in the rear for street or track is too much. Our rear end likes to camber out-too much. Even when pushing hard on track with a rear end that was dangerous, I could never even come close to heating up the outside of the tire like the inside at -2.0 static camber. 1.6-1.8 is probably ideal even for a pretty hardcore track setup. I went too low on front ride height and too soft for my initial spring rate up front (and too stiff in rear) and I started to have problems with suspension bottoming and throwing weight around-not to mention the rear end trying to show off at the same time. The rear toe I left at 0, with a little toe out in front. I removed the rear bar, it was much better, but then would still snap oversteer at really weird times, not in high speed corners and sweepers, but at 60-80 MPH and at really weird times, but mainly on exit when I was pushing hard on entry. My Toe settings were close to 0 and 0. I have since dropped spring rates on the rear and have no idea what my current alignment settings are but will get them next week. The car currently feels very good for the first time since aug/sept. In regards to your situation, there is nothing in a basic alignmentclose to factory spec that could be creating the situation you are describing. I ran my RS3's with 30+ track days and 15 K total DD miles with 1/16th of tread and cords showing at Big Willow in the rain in Dec and the car still did fine. Basically, I can not see how even really f-ed up street tires and a so so alignment like yours could be creating a semi dangerous situation. __________________ Current Mods: Vorpal Weapon +5. Last edited by GSS138; 03-11-2015 at 12:28 AM.