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

Go Back   Scion FR-S Forum | Subaru BRZ Forum | Toyota 86 GT 86 Forum | AS1 Forum - FT86CLUB > Technical Topics > Tracking / Autocross / HPDE / Drifting

Tracking / Autocross / HPDE / Drifting What these cars were built for!


User Tag List

Reply
 
Thread Tools Search this Thread
Old 09-17-2019, 12:55 PM   #3725
tony_r
Senior Member
 
tony_r's Avatar
 
Join Date: Sep 2017
Drives: '15 STX
Location: San Jose, CA
Posts: 218
Thanks: 9
Thanked 136 Times in 91 Posts
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Seems to me like you need to work with the rear end more and not the front. Try stiffening it and then changing the rake angle.

The car doesn't trail well, imo. Need to be soft with it and have a softer brake compound.
tony_r is offline   Reply With Quote
The Following User Says Thank You to tony_r For This Useful Post:
strat61caster (09-17-2019)
Old 09-17-2019, 01:05 PM   #3726
Breadman
Senior Member
 
Join Date: Jul 2017
Drives: 2017 BRZ w/PP
Location: Pa
Posts: 400
Thanks: 21
Thanked 104 Times in 78 Posts
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quote:
Originally Posted by Lincoln Logs View Post
It will depend on the course, but I'd wager the 255 is going to be more advantageous than not. I've driven some 13-16 cars the same day as my 17 and there is a big advantage to less shifts.

well i was talking to some people last week and non of them run 255 but they dont have 17+. someone said that 255 contact but i dont seem to be having an issue but then again i dont have REs yet. im just trying to figure out what im going to get this winter
Breadman is offline   Reply With Quote
Old 09-17-2019, 01:10 PM   #3727
CoolHandMoss
Senior Member
 
Join Date: Jan 2018
Drives: 2013 FRS
Location: VA
Posts: 280
Thanks: 1
Thanked 80 Times in 53 Posts
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quote:
Originally Posted by steverife View Post
I haven't started with STX suspension yet, so this is just general....

Where is your front toe? I feel like toe out causes mid-corner push.

Also, what happens when you stiffen the front bar or spring?

Also, is this solely inspired by Lincoln? Or does the car generally handle that way?
Front toe is 0. Rear toe is slightly in.

Tried the bar stiffer at a local even before nats and it was no good. Softened it some immediately. Ended up softening it much more at nats with some improvement.

It is based mostly off of Lincoln. The long courses there really brought out the weaknesses I think. Generally at local events I was getting some push on certain turns but usually just one or two turns on a given course. At nats there were just a lot of those turns. Basically, the more I have to turn the wheel, the more it pushes, which is to be expected.
CoolHandMoss is offline   Reply With Quote
Old 09-17-2019, 09:11 PM   #3728
H1C
Senior Member
 
Join Date: Feb 2015
Drives: 2014 FR-S MT
Location: metro-Atlanta area
Posts: 109
Thanks: 121
Thanked 71 Times in 43 Posts
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quote:
Originally Posted by CoolHandMoss View Post
Basically, the more I have to turn the wheel, the more it pushes, which is to be expected.

This is another reason why I was not fond of 7+ degrees of caster when I had adjustable front LCAs. With 4 degrees of static camber and 7 degrees of caster, your front wheels will cut increasingly sharply diagonally into the pavement the more steering input you give. With that much camber and caster, the effect is akin to an alpine skiier digging their edges into the snow. Your contact patch becomes more compromised the more you have to turn the steering wheel.



If you're not willing or able to experiment with something closer to OEM caster, I would try taking a wider arc through tighter corners to minimize steering input.
H1C is offline   Reply With Quote
The Following User Says Thank You to H1C For This Useful Post:
Racecomp Engineering (09-20-2019)
Old 09-17-2019, 09:34 PM   #3729
CoolHandMoss
Senior Member
 
Join Date: Jan 2018
Drives: 2013 FRS
Location: VA
Posts: 280
Thanks: 1
Thanked 80 Times in 53 Posts
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quote:
Originally Posted by H1C View Post
This is another reason why I was not fond of 7+ degrees of caster when I had adjustable front LCAs. With 4 degrees of static camber and 7 degrees of caster, your front wheels will cut increasingly sharply diagonally into the pavement the more steering input you give. With that much camber and caster, the effect is akin to an alpine skiier digging their edges into the snow. Your contact patch becomes more compromised the more you have to turn the steering wheel.



If you're not willing or able to experiment with something closer to OEM caster, I would try taking a wider arc through tighter corners to minimize steering input.
No dialing the caster back was another option I had considered. I just hadn't thought that one degree was enough to make much difference either way so it was toward the end of the list. Though, maybe the better option would be to keep the caster and dial in less camber to improve straight line braking?
CoolHandMoss is offline   Reply With Quote
Old 09-17-2019, 09:40 PM   #3730
H1C
Senior Member
 
Join Date: Feb 2015
Drives: 2014 FR-S MT
Location: metro-Atlanta area
Posts: 109
Thanks: 121
Thanked 71 Times in 43 Posts
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quote:
Originally Posted by CoolHandMoss View Post
No dialing the caster back was another option I had considered. I just hadn't thought that one degree was enough to make much difference either way so it was toward the end of the list. Though, maybe the better option would be to keep the caster and dial in less camber to improve straight line braking?

I found the difference between 6 degrees and anything 7 or higher pretty noticeable, in terms of steering self-centering force and the jacking up of the inside rear in tighter corners due to the cutting effect if I turned the wheel too much. The difference between 6 and 6.5 degrees maybe not so much.

For me, I'd prefer to keep the camber and dial back the caster, but I don't run as much camber as you (3.8), so I haven't found it to affect braking performance enough for me to want to dial it back.

In any case, good luck man -- I hope you can sort out this understeer issue.
H1C is offline   Reply With Quote
Old 09-17-2019, 10:02 PM   #3731
CoolHandMoss
Senior Member
 
Join Date: Jan 2018
Drives: 2013 FRS
Location: VA
Posts: 280
Thanks: 1
Thanked 80 Times in 53 Posts
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Thanks for the input. I will try dialing back the caster.
CoolHandMoss is offline   Reply With Quote
Old 09-19-2019, 09:49 PM   #3732
bmacfrs
Senior Member
 
bmacfrs's Avatar
 
Join Date: Dec 2016
Drives: 2013 FRS
Location: South Central PA
Posts: 128
Thanks: 35
Thanked 19 Times in 12 Posts
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Does adding more negative camber on the front throw the toe off significantly? I thought it would but someone recently told me that it doesnt on these cars.
I have coilovers and camber plates. Thinking about trying a bit more to see if i like it.
__________________
WIFE: "How can there be anything left to buy?"
bmacfrs is offline   Reply With Quote
Old 09-20-2019, 12:03 AM   #3733
strat61caster
Thread Killer
 
strat61caster's Avatar
 
Join Date: Nov 2012
Drives: '13 FRS
Location: SF Bay Area
Posts: 8,947
Thanks: 12,282
Thanked 8,083 Times in 4,220 Posts
Mentioned: 76 Post(s)
Tagged: 3 Thread(s)
Quote:
Originally Posted by bmacfrs View Post
Does adding more negative camber on the front throw the toe off significantly? I thought it would but someone recently told me that it doesnt on these cars.
I have coilovers and camber plates. Thinking about trying a bit more to see if i like it.
Yes it changes enough where I would adjust the toe back to zero, I've done it and not noticed the toe change as a driver but in hindsight, imho a set of $60 toe plates is worth the investment to periodically check your alignment anyway and adding a few ticks of camber and zeroing out the toe diy is a worthy experiment between spending the money to put it on a rack
__________________
Quote:
Originally Posted by Guff View Post
ineedyourdiddly
strat61caster is offline   Reply With Quote
The Following User Says Thank You to strat61caster For This Useful Post:
bmacfrs (09-20-2019)
Old 09-20-2019, 07:16 AM   #3734
cueball89
Member
 
Join Date: Apr 2016
Drives: 16 BRZ 03 Outback
Location: NY
Posts: 98
Thanks: 24
Thanked 39 Times in 26 Posts
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quote:
Originally Posted by bmacfrs View Post
Does adding more negative camber on the front throw the toe off significantly? I thought it would but someone recently told me that it doesnt on these cars.
I have coilovers and camber plates. Thinking about trying a bit more to see if i like it.
Using toe plates I have a 6mm difference in toe from maximum negative camber to minimum negative camber when adjusted at the camber plate. YMMV.
cueball89 is offline   Reply With Quote
The Following 2 Users Say Thank You to cueball89 For This Useful Post:
bmacfrs (09-20-2019), strat61caster (09-20-2019)
Old 09-20-2019, 09:41 AM   #3735
Racecomp Engineering
 
Join Date: Nov 2011
Drives: 2016 BRZ, 2012 Paris Di2 & 2018 STI
Location: Severn, MD
Posts: 4,298
Thanks: 2,215
Thanked 5,158 Times in 2,201 Posts
Mentioned: 258 Post(s)
Tagged: 9 Thread(s)
Send a message via AIM to Racecomp Engineering
Quote:
Originally Posted by CoolHandMoss View Post
Thanks for the input. I will try dialing back the caster.
I like caster, but as mentioned 7* with -4.1* of camber is quite a bit.

"As much caster as possible" has been a popular way to go on the internets but a motorsports engineer would tell you that caster is course dependent.

- Andrew
Racecomp Engineering is offline   Reply With Quote
The Following 2 Users Say Thank You to Racecomp Engineering For This Useful Post:
CoolHandMoss (09-20-2019), H1C (09-20-2019)
Old 09-20-2019, 09:33 PM   #3736
H1C
Senior Member
 
Join Date: Feb 2015
Drives: 2014 FR-S MT
Location: metro-Atlanta area
Posts: 109
Thanks: 121
Thanked 71 Times in 43 Posts
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quote:
Originally Posted by Racecomp Engineering View Post
"As much caster as possible" has been a popular way to go on the internets but a motorsports engineer would tell you that caster is course dependent.

- Andrew

I think the internets may also be overlooking the vehicle context for high caster settings: usually it's heavy German cars with 0 negative camber and little or no ability to add more from the factory that come with 7 or 8 degrees of caster. It's the only way those cars can get turned in to a corner. On a car as light and nimble as ours, and given the ability to add adequate negative camber via plates or slotted struts, I find the factory caster to be plenty.
H1C is offline   Reply With Quote
The Following 2 Users Say Thank You to H1C For This Useful Post:
DocWalt (09-21-2019), Racecomp Engineering (09-21-2019)
Old 09-21-2019, 11:00 AM   #3737
Racecomp Engineering
 
Join Date: Nov 2011
Drives: 2016 BRZ, 2012 Paris Di2 & 2018 STI
Location: Severn, MD
Posts: 4,298
Thanks: 2,215
Thanked 5,158 Times in 2,201 Posts
Mentioned: 258 Post(s)
Tagged: 9 Thread(s)
Send a message via AIM to Racecomp Engineering
Quote:
Originally Posted by H1C View Post
I think the internets may also be overlooking...
Yeeeeah that'll happen.

- Andrew
Racecomp Engineering is offline   Reply With Quote
The Following User Says Thank You to Racecomp Engineering For This Useful Post:
DocWalt (09-21-2019)
Old 09-21-2019, 02:36 PM   #3738
CoolHandMoss
Senior Member
 
Join Date: Jan 2018
Drives: 2013 FRS
Location: VA
Posts: 280
Thanks: 1
Thanked 80 Times in 53 Posts
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quote:
Originally Posted by Racecomp Engineering View Post
I like caster, but as mentioned 7* with -4.1* of camber is quite a bit.

"As much caster as possible" has been a popular way to go on the internets but a motorsports engineer would tell you that caster is course dependent.

- Andrew
Coincidentally, caster is one element of my setup that was set based directly on the advice of a reputable motorsports engineer. I think he was thinking more about optimizing behavior on track though. The car does handle very well on track!

I'm going to bring the caster back to OE before the next event and bring the rear toe to 0 also.
CoolHandMoss 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
Thoughts on a "component" setup with a 3.5" dash and 6.5" door setup? PatrickSAN Electronics | Audio | NAV | Infotainment 22 11-14-2012 03:12 PM
SCCA sway bar rules gmookher Suspension | Chassis | Brakes -- Sponsored by 949 Racing 0 09-01-2012 06:48 PM
Suggestion for vendor rules... Tainen Site Announcements / Questions / Issues 31 08-15-2012 01:53 PM
Rules for posting in this section Hachiroku User/Vendor/Sponsor Reviews, Feedback, Comments 0 06-25-2012 11:02 AM


All times are GMT -4. The time now is 05:54 AM.


Powered by vBulletin® Version 3.8.4
Copyright ©2000 - 2019, Jelsoft Enterprises Ltd.
Garage vBulletin Plugins by Drive Thru Online, Inc.