follow ft86club on our blog, twitter or facebook.
FT86CLUB
Ft86Club
Speed By Design
Register Garage Members List Calendar Search Today's Posts Mark Forums Read

Go Back   Toyota GR86, 86, FR-S and Subaru BRZ Forum - FT86CLUB > Technical Topics > Suspension | Chassis | Brakes -- Sponsored by 949 Racing

Suspension | Chassis | Brakes -- Sponsored by 949 Racing Relating to suspension, chassis, and brakes. Sponsored by 949 Racing.


User Tag List

Reply
 
Thread Tools Search this Thread
Old 09-14-2021, 09:44 AM   #1
Akrochik
Member
 
Join Date: Jul 2018
Drives: Golf TDI for now
Location: Nj
Posts: 16
Thanks: 0
Thanked 3 Times in 3 Posts
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Bouncing on high speed right-hander on track

My car was doing something odd on track in my last session. There's a long high speed right hander with a lot of camber and many times in that corner my car did a sort of rhythmic bouning when I was around 33% throttle. Is this porpoising? Anything else I can do to address? Thanks!

2013 FRS
Tein Flex Z coilovers set to about 66% of the way to full firm
1" lower than stock
Stage 2 tune and bolt ons
Akrochik is offline   Reply With Quote
Old 09-14-2021, 10:11 AM   #2
DarkPira7e
Yes, my car does run!
 
DarkPira7e's Avatar
 
Join Date: Feb 2017
Drives: 2013 Turbo Firestorm FRS
Location: Vermont
Posts: 3,237
Thanks: 2,413
Thanked 3,110 Times in 1,594 Posts
Mentioned: 25 Post(s)
Tagged: 0 Thread(s)
What swaybars are you running?
__________________
Turbo FR-S Build - Build Thread
JDL EL Recirc manifold, Boostlab BL58x Turbo w/ T51R, 17x9 ARC-8, IAG block
DarkPira7e is offline   Reply With Quote
Old 09-14-2021, 10:18 AM   #3
Akrochik
Member
 
Join Date: Jul 2018
Drives: Golf TDI for now
Location: Nj
Posts: 16
Thanks: 0
Thanked 3 Times in 3 Posts
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Suspension is stock besides the coils
Akrochik is offline   Reply With Quote
Old 09-14-2021, 11:25 AM   #4
bmacfrs
Senior Member
 
bmacfrs's Avatar
 
Join Date: Dec 2016
Drives: 2013 FRS
Location: Central PA
Posts: 230
Thanks: 109
Thanked 55 Times in 34 Posts
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Could be lots of things. Maybe a read thru this can get you started
https://grassrootsmotorsports.com/ar...-to-cure-them/

Sent from my SM-G960U using Tapatalk
__________________
WIFE: "How can there be anything left to buy?"
bmacfrs is offline   Reply With Quote
Old 09-14-2021, 02:15 PM   #5
CSG Mike
 
CSG Mike's Avatar
 
Join Date: Jul 2012
Drives: S2000 CR
Location: Orange County
Posts: 13,805
Thanks: 8,614
Thanked 13,315 Times in 6,441 Posts
Mentioned: 932 Post(s)
Tagged: 14 Thread(s)
Quote:
Originally Posted by Akrochik View Post
My car was doing something odd on track in my last session. There's a long high speed right hander with a lot of camber and many times in that corner my car did a sort of rhythmic bouning when I was around 33% throttle. Is this porpoising? Anything else I can do to address? Thanks!

2013 FRS
Tein Flex Z coilovers set to about 66% of the way to full firm
1" lower than stock
Stage 2 tune and bolt ons
Have a datalog?
CSG Mike is offline   Reply With Quote
Old 09-14-2021, 02:59 PM   #6
Akrochik
Member
 
Join Date: Jul 2018
Drives: Golf TDI for now
Location: Nj
Posts: 16
Thanks: 0
Thanked 3 Times in 3 Posts
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
I have the outputs from TrackAddict but I imagine you're looking for something more detailed.

I do have onboard video if that's helpful.
Akrochik is offline   Reply With Quote
Old 09-19-2021, 12:23 PM   #7
949 Racing
 
949 Racing's Avatar
 
Join Date: Jan 2012
Drives: Miata, GT350, FR-S
Location: California, USA
Posts: 314
Thanks: 6
Thanked 756 Times in 230 Posts
Mentioned: 10 Post(s)
Tagged: 1 Thread(s)
Its your shocks. FLEX-Z are a relatively cheap twin tube with a lot less bump travel than OEM. Turned up stiff enough to avoid wallowing and they'll bounce due to inadequate low speed rebound. Turned down to avoid bouncing.. and it wallows.

Make sure you have lengths adjusted so you're staying off the bumpstops. Raising the car will likely reduce the bouncing.

Swaybars are not the source of the oscillation and have nothing to do with it so ignore that.

Any adjustable shocks should always be set to the softest possible setting that controls wallow. No stiffer than that. Poorly designed shocks will often start to bounce before the wallow goes away so you can never find the right setting.
__________________
949 Racing is offline   Reply With Quote
The Following 6 Users Say Thank You to 949 Racing For This Useful Post:
alphasaur (09-19-2021), Decep (09-19-2021), kevaughan (09-21-2021), RToyo86 (09-19-2021), StraightOuttaCanadaEh (09-19-2021), Ultramaroon (09-19-2021)
Old 09-19-2021, 04:41 PM   #8
Ultramaroon
comma chameleon
 
Ultramaroon's Avatar
 
Join Date: Sep 2014
Drives: a 13 e8h frs
Location: vantucky, wa
Posts: 27,493
Thanks: 43,531
Thanked 29,543 Times in 15,694 Posts
Mentioned: 1014 Post(s)
Tagged: 9 Thread(s)
Critical damping is critical
__________________
Ultramaroon is offline   Reply With Quote
Old 09-19-2021, 09:01 PM   #9
949 Racing
 
949 Racing's Avatar
 
Join Date: Jan 2012
Drives: Miata, GT350, FR-S
Location: California, USA
Posts: 314
Thanks: 6
Thanked 756 Times in 230 Posts
Mentioned: 10 Post(s)
Tagged: 1 Thread(s)
Quote:
Originally Posted by Ultramaroon View Post
Critical damping is critical
tru dat
__________________
949 Racing is offline   Reply With Quote
The Following User Says Thank You to 949 Racing For This Useful Post:
Ultramaroon (09-19-2021)
Old 09-20-2021, 12:41 PM   #10
NoHaveMSG
Senior Member
 
NoHaveMSG's Avatar
 
Join Date: Jan 2018
Drives: Crapcan
Location: Oregon
Posts: 6,269
Thanks: 9,690
Thanked 8,665 Times in 3,935 Posts
Mentioned: 45 Post(s)
Tagged: 0 Thread(s)
Garage
Never experienced that in the couple seasons I ran Flex Z's, though I also didn't have a corner like what you described. Don't think ride height is the issue.
__________________
"Experience is the hardest kind of teacher. It gives you the test first and the lesson afterward." -Oscar Wilde.
NoHaveMSG is offline   Reply With Quote
Old 09-20-2021, 01:45 PM   #11
strat61caster
-
 
strat61caster's Avatar
 
Join Date: Nov 2012
Drives: '13 FRS
Location: SF Bay Area
Posts: 9,835
Thanks: 13,113
Thanked 8,943 Times in 4,701 Posts
Mentioned: 89 Post(s)
Tagged: 3 Thread(s)
Quote:
Originally Posted by NoHaveMSG View Post
Never experienced that in the couple seasons I ran Flex Z's, though I also didn't have a corner like what you described. Don't think ride height is the issue.
As long as OP hasn't done something to reduce bump travel I'd agree, one of the advantages of the 2-piece coilovers is they can keep the stiffness consistent at various heights. On another coilover or if the OP has reduced bump travel by lowering the spring perch and is using more bump stop due to a lower height then yes, ride height will matter for handling bumpy pavement.
__________________
Quote:
Originally Posted by Guff View Post
ineedyourdiddly
strat61caster is offline   Reply With Quote
 
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
bad window seal at high speed? slyphen Issues | Warranty | Recalls / TSB 9 03-04-2018 07:57 PM
Downshift from 6th to 5th at high speed bravedeer Issues | Warranty | Recalls / TSB 35 08-30-2017 09:26 PM
High RPM for current speed HachiRo Engine, Exhaust, Transmission 14 04-02-2015 02:59 PM
Brakes unless at high speed - what to tackle? empower-auto Suspension | Chassis | Brakes -- Sponsored by 949 Racing 44 10-12-2012 05:06 PM
Video: BRZ / FR-S High Speed Run to 124 MPH (200 km/h) Levi BRZ Photos, Videos, Wallpapers, Gallery Forum 43 05-16-2012 12:37 AM


All times are GMT -4. The time now is 09:45 PM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2021, vBulletin Solutions Inc.
User Alert System provided by Advanced User Tagging v3.3.0 (Lite) - vBulletin Mods & Addons Copyright © 2021 DragonByte Technologies Ltd.

Garage vBulletin Plugins by Drive Thru Online, Inc.