A question on handling
07-18-2017, 06:31 PM
#31
Ok, so here's the prognosis...
Alignment was totally out of whack. Both front and rear, toe and camber! Not sure how this happened other than stresses on the suspension on track (as mentioned above) since I haven't hit anything on the road that would cause such an "adjustment".
I'll post the printout of the settings pre and post new alignment when I get the car back tomorrow or Thursday. Stay tuned...
Alignment was totally out of whack. Both front and rear, toe and camber! Not sure how this happened other than stresses on the suspension on track (as mentioned above) since I haven't hit anything on the road that would cause such an "adjustment".
I'll post the printout of the settings pre and post new alignment when I get the car back tomorrow or Thursday. Stay tuned...
That's what I suspected. sounded like you were describing a more "serious" issue like a rear toe out problem.
Could the OEM rear toe links also not hold there setting under enough load?
Keep us posted..
07-18-2017, 07:38 PM
#32
Advanced
Thread Starter
Will do.
There definitely was a toe out issue but I am unsure to what degree... in addition to the camber.
I also question why the settings didn't hold but didn't get a really good answer other than the suspension being stressed on the track... doesn't really make sense to me since its a trackable car. Of course I will be inquiring again
There definitely was a toe out issue but I am unsure to what degree... in addition to the camber.
I also question why the settings didn't hold but didn't get a really good answer other than the suspension being stressed on the track... doesn't really make sense to me since its a trackable car. Of course I will be inquiring again
07-18-2017, 07:50 PM
#33
Something else to check regarding allignment issues too - especially if you are using tarret end links..
I got an alignment with some tarett parts:
-Tarett Front Tie Rod
-Tarett Rear Toe Link
-Tarett Thrust Arm Bushing
allignment was where i wanted and 1st day was great. middle of 2nd day I had a Super uncomfortable feeling under braking at Summit Point. I finished the weekend running a few tenths slower but definitely felt like driving a boat braking into turn 1.
So, I came home. Visually I could see my right rear toe was out by 1 inch out compared to other. Allignment shop confirmed "outa-wack".
Turned out the Rear Toe can adjust under high stress (at least with Tarett). So, I got this:
-Locking Plate Kit, For Adjustable Rear Toe Link
If you felt more extreme tail wiggle under braking - you may be dealing with a rear toe out issue. And you may want to see if the stock rear toe links can accidentally adjust under load too..
Good luck and let us know if you determined a cause...
I got an alignment with some tarett parts:
-Tarett Front Tie Rod
-Tarett Rear Toe Link
-Tarett Thrust Arm Bushing
allignment was where i wanted and 1st day was great. middle of 2nd day I had a Super uncomfortable feeling under braking at Summit Point. I finished the weekend running a few tenths slower but definitely felt like driving a boat braking into turn 1.
So, I came home. Visually I could see my right rear toe was out by 1 inch out compared to other. Allignment shop confirmed "outa-wack".
Turned out the Rear Toe can adjust under high stress (at least with Tarett). So, I got this:
-Locking Plate Kit, For Adjustable Rear Toe Link
If you felt more extreme tail wiggle under braking - you may be dealing with a rear toe out issue. And you may want to see if the stock rear toe links can accidentally adjust under load too..
Good luck and let us know if you determined a cause...
07-20-2017, 11:13 AM
#34
Advanced
Thread Starter
So as promised, here is the printout of my alignment specs both before and after. So the car was definitely out of whack across the board. Still not sure if this is a normal occurrence after a few track days. Also not sure why the front left caster is still slightly off even after the alignment... any thoughts?
As a follow on... how often do you guys check your alignment or have the cars aligned?
Thanks again for the feedback, its really helpful.
Stu
As a follow on... how often do you guys check your alignment or have the cars aligned?
Thanks again for the feedback, its really helpful.
Stu
07-20-2017, 06:46 PM
#36
Rennlist Member
I have experienced this in my GT4 with stock suspension with track alignment. Mainly on the front straight into turn 1 at VIR. Speeds are 120-130 mph-ish. Also going uphill braking into Oak Tree where speeds are about 100 mph.
I sat with a very experienced instructor at one event who was driving a pure stock GT4 and putting up fast times (like 2:02 - 2:05). We talked about this and he insisted it happens only when you start braking while the car is not going exactly straight or is otherwise unsettled.
I experimented several times and it seemed to me he was right. It has never felt like I was going out of control during the braking sequence so I have not thought much about it since then except for knowing what it is when it happens.
I sat with a very experienced instructor at one event who was driving a pure stock GT4 and putting up fast times (like 2:02 - 2:05). We talked about this and he insisted it happens only when you start braking while the car is not going exactly straight or is otherwise unsettled.
I experimented several times and it seemed to me he was right. It has never felt like I was going out of control during the braking sequence so I have not thought much about it since then except for knowing what it is when it happens.