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-   -   Shock/damper question (https://www.ft86club.com/forums/showthread.php?t=107965)

FR-Sky 07-05-2016 01:32 AM

Shock/damper question
 
Currently, i am running 8k/8k spring rate front and rear.
My coilover have 24 adjustable clicks. currently running 3 clicks from very soft "front" and 3 clicks from very soft (rear).

Sadly, while i was running around the mountain today. I felt the car is a bit floaty (maybe due to the spring rate), and seems like the front wont grip as much, and the rear about to slide during corner. Also, i feel less response from steering wheel to the wheel.
P.S 4 tires are 9/10 new -2 camber front , -1.5 camber rear

I mean the grip still great when running high speed corner on road and freeway, but not on windy mountain road.
I thought soften the damper/shock can provide more grip on low speed mountain road.
So what is the problem?

Thanks

e1_griego 07-05-2016 01:35 AM

What shocks? what tires?

FR-Sky 07-05-2016 01:38 AM

Quote:

Originally Posted by e1_griego (Post 2696881)
What shocks? what tires?

Fortune auto prime coilover
MPSS 225/45/17

Tor 07-05-2016 05:48 AM

Quote:

Originally Posted by FR-Sky (Post 2696878)
My coilover have 24 adjustable clicks. currently running 3 clicks from very soft "front" and 3 clicks from very soft (rear).
...
I thought soften the damper/shock can provide more grip on low speed mountain road.
So what is the problem?

The car is probably underdamped with set to almost full soft. Setting it so soft is the girlfriend-friendly setting, not any useful setting for any kind of performance driving.

D_Thissen 07-05-2016 06:56 AM

^^ Thats my guess also. Maybe set the dampers to some where in the middle (or what ever Fortune Auto suggests) and see if that helps. Those spring rates should be fine.

MeisterR 07-05-2016 10:38 AM

For a road car, the 8/8 I think is quite a bit too stiff.
Chances are the damping is too soft, it is better to have slightly softer springs rate so you can run a stiffer damper adjustments.
Because having the stiffer adjustments is what going to help load your tires and give you that steering response you want.

Jerrick

guybo 07-05-2016 11:11 AM

That -1.5 camber in the rear isn't doing anything to help rear grip either. Set it down to -1. What sway bars are you using?

ZDan 07-05-2016 11:33 AM

Quote:

Originally Posted by guybo (Post 2697129)
That -1.5 camber in the rear isn't doing anything to help rear grip either. Set it down to -1. What sway bars are you using?

-1.5 is going to give more lateral grip at the rear than -1, and still nowhere near the point where you start to lose longitudinal grip (which is not a huge issue anyway for a stock-hp 86). For a performance street setup, I would want at least -1.5 at all four corners, preferably more up front. I think you're good with -2 front/-1.5 rear. I run -3 front -2 rear on the street/sometimes-tracked FD fwiw...

Regarding damper settings, usually you set by counting clicks from full stiff. So you're at 21 clicks out, with 24 total. Beyond some number of clicks the dampers are likely effectively at "full soft" anyway. If it feels soft, try 10 clicks out and see how that works out. Go from there...

Lack of front end grip: Square spring rates with struts up front with a motion ratio on the order of 0.95, and multilink rear with a motion ratio more like 0.75, with 8/8 springs, your wheel rates are something like 7.2 front, 4.5 rear or 61.5F/38.5R. Seems a bit front-stiffness biased to me, especially for a car without a lot of power. That said, a lot of aftermarket coils for the 86 come with same-rate springs front/rear. But it doesn't seem quite right to me. Might try either softer front springs and/or stiffer rear for more front grip. What toe are you running?

wparsons 07-05-2016 11:43 AM

Quote:

Originally Posted by FR-Sky (Post 2696878)
Currently, i am running 8k/8k spring rate front and rear.
My coilover have 24 adjustable clicks. currently running 3 clicks from very soft "front" and 3 clicks from very soft (rear).

Sadly, while i was running around the mountain today. I felt the car is a bit floaty (maybe due to the spring rate), and seems like the front wont grip as much, and the rear about to slide during corner. Also, i feel less response from steering wheel to the wheel.
P.S 4 tires are 9/10 new -2 camber front , -1.5 camber rear

I mean the grip still great when running high speed corner on road and freeway, but not on windy mountain road.
I thought soften the damper/shock can provide more grip on low speed mountain road.
So what is the problem?

Thanks

So less front AND rear grip, plus feels vague at the steering wheel. What are your tire pressures like?

What all was changed since the last time you drove it like this?

mav1178 07-05-2016 11:44 AM

Quote:

Originally Posted by FR-Sky (Post 2696878)
So what is the problem?

The problem is that you have no idea what the dampers are capable of. Without them being properly dyno'd and matched to the springs mounted, it's impossible to get proper handling out of the box.

This is why high-end coilovers often cost more, because they are better matched up from the factory out of the box. And it should also be noted that more adjustments doesn't mean they all work well. I've seen 32-way adjustable coilovers with clicks 10-25 all doing virtually nothing on a dyno.

-alex

ZDan 07-05-2016 12:24 PM

Quote:

Originally Posted by FR-Sky (Post 2696878)
Sadly, while i was running around the mountain today. I felt the car is a bit floaty (maybe due to the spring rate), and seems like the front wont grip as much, and the rear about to slide during corner.
...
Also, i feel less response from steering wheel to the wheel.low speed mountain road.
So what is the problem?

Quote:

Originally Posted by FR-Sky (Post 2696884)
MPSS 225/45/17

How long have you had these on the car? How old are they (date on sidewall)?
I had a pretty miserable experience with the MPSSs on my FD. Initially, they were fine. Great grip on the street and acceptable at the track (if not up to "Extreme Perf" tire standards). But after about a year and a half, they lost all grip on the street. No front end grip, dangerously little rear grip and worse, at the limit the back end would come WAY out. Practically zero sliding grip. Tires had one track day and ~15k miles on them, Barely less than half tread depth remaining in back and more than half up front. But they were TOAST. Seriously, they felt like a late 20th century "performance" tire that had been heat-cycled to death.
After puzzling over setup, I got new tires (B'stone RE71R) and all is well again.

I know people LOVE MPSS tires, but to me they were initially fine, but ultimately utter crap for grip, to the point of being dangerous. Somthing to consider...

Icecreamtruk 07-05-2016 12:36 PM

Quote:

Originally Posted by ZDan (Post 2697204)
How long have you had these on the car? How old are they (date on sidewall)?
I had a pretty miserable experience with the MPSSs on my FD. Initially, they were fine. Great grip on the street and acceptable at the track (if not up to "Extreme Perf" tire standards). But after about a year and a half, they lost all grip on the street. No front end grip, dangerously little rear grip and worse, at the limit the back end would come WAY out. Practically zero sliding grip. Tires had one track day and ~15k miles on them, Barely less than half tread depth remaining in back and more than half up front. But they were TOAST. Seriously, they felt like a late 20th century "performance" tire that had been heat-cycled to death.
After puzzling over setup, I got new tires (B'stone RE71R) and all is well again.

I know people LOVE MPSS tires, but to me they were initially fine, but ultimately utter crap for grip, to the point of being dangerous. Somthing to consider...

Exactly my experience with the MPSS. I think they get toasted by the heat. Mine go from cold (very little grip) to greasy (even less grip) in a single lap. Needless to say I dont run them anymore on track (still my street tire, around 60% thread left).

FR-Sky 07-05-2016 12:57 PM

Quote:

Originally Posted by ZDan (Post 2697148)
-1.5 is going to give more lateral grip at the rear than -1, and still nowhere near the point where you start to lose longitudinal grip (which is not a huge issue anyway for a stock-hp 86). For a performance street setup, I would want at least -1.5 at all four corners, preferably more up front. I think you're good with -2 front/-1.5 rear. I run -3 front -2 rear on the street/sometimes-tracked FD fwiw...

Regarding damper settings, usually you set by counting clicks from full stiff. So you're at 21 clicks out, with 24 total. Beyond some number of clicks the dampers are likely effectively at "full soft" anyway. If it feels soft, try 10 clicks out and see how that works out. Go from there...

Lack of front end grip: Square spring rates with struts up front with a motion ratio on the order of 0.95, and multilink rear with a motion ratio more like 0.75, with 8/8 springs, your wheel rates are something like 7.2 front, 4.5 rear or 61.5F/38.5R. Seems a bit front-stiffness biased to me, especially for a car without a lot of power. That said, a lot of aftermarket coils for the 86 come with same-rate springs front/rear. But it doesn't seem quite right to me. Might try either softer front springs and/or stiffer rear for more front grip. What toe are you running?

running 0 toe front and rear.
So i should try soft damper front and stiffer damper rear? Since i cant change the coilover anytime soon...
Wouldnt stiffer rear will slide during corners?

Many thanks!

FR-Sky 07-05-2016 01:02 PM

Quote:

Originally Posted by wparsons (Post 2697162)
So less front AND rear grip, plus feels vague at the steering wheel. What are your tire pressures like?

What all was changed since the last time you drove it like this?

My tire pressure was 32 after heat, i figure that would provide more grip since i was going for mountain road..but i guess not..

The only thing change was some what 7 to 9 clicks from soft on the dampers.
I mean still OK doing high speed freeway and local turns. I can feel the car and body roll,but just not on mountain road.


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