follow ft86club on our blog, twitter or facebook.
FT86CLUB
Ft86Club
86WORX
Register Garage Members List Calendar Search Today's Posts Mark Forums Read

Go Back   Toyota GR86, 86, FR-S and Subaru BRZ Forum & Owners Community - 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 12-21-2011, 12:06 PM   #1
Spec-Al
Is it track season yet?
 
Spec-Al's Avatar
 
Join Date: Dec 2011
Drives: Evo IX MR, 240SX (SR)
Location: United States
Posts: 4
Thanks: 0
Thanked 0 Times in 0 Posts
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Weird GT 86 factory spring rates in GT5?

So, Gran Turismo 5 came out with an update yesterday that includes the new GT 86. Awesome, I think, I'd love to try it out in the game.

So in the setup and settings menu, I noticed that the stock spring rates were 6.0 kg/mm front and 2.0 kg/mm rear. This strikes me as being strange for a few reasons. 6/2 seems like a much wider differential in rates in a car as well balanced front to rear as the 86. Also 6.0 kg/mm is a pretty damn stiff spring to put on a stock car which weighs as little as the GT 86.

For those unfamiliar with GT5, I know it's just a video game, but they are usually anal retentive when it comes to modelling and accuracy. Just for fun I went and checked the rates for the GR STI and they were 4.2 front, 4.0 rear and that sounded pretty accurate to me (or at least close, I'm only familiar with the USDM models).

Any thoughts out there?
Spec-Al is offline   Reply With Quote
Old 12-21-2011, 12:07 PM   #2
Spec-Al
Is it track season yet?
 
Spec-Al's Avatar
 
Join Date: Dec 2011
Drives: Evo IX MR, 240SX (SR)
Location: United States
Posts: 4
Thanks: 0
Thanked 0 Times in 0 Posts
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Just for fun checked another car...

1991 Acura NSX

'Official' from NSXPrime
F: 170 lb/in, R: 220 lb/in

GT5
F: 179, R: 213
Spec-Al is offline   Reply With Quote
Old 12-21-2011, 12:20 PM   #3
Racecomp Engineering
 
Join Date: Nov 2011
Drives: 2016 BRZ, 2012 Paris Di2 & 2018 STI
Location: Severn, MD
Posts: 5,375
Thanks: 3,392
Thanked 7,209 Times in 2,945 Posts
Mentioned: 302 Post(s)
Tagged: 9 Thread(s)
Send a message via AIM to Racecomp Engineering
Sounds funky to me. How does it drive?

- Andrew
Racecomp Engineering is offline   Reply With Quote
Old 12-21-2011, 12:22 PM   #4
Spec-Al
Is it track season yet?
 
Spec-Al's Avatar
 
Join Date: Dec 2011
Drives: Evo IX MR, 240SX (SR)
Location: United States
Posts: 4
Thanks: 0
Thanked 0 Times in 0 Posts
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quote:
Originally Posted by Racecomp Engineering View Post
Sounds funky to me. How does it drive?

- Andrew
Exactly how you'd expect it to based on the info out there so far. Nice and lithe, not a ton of power but enough to get it to move with the light weight. Jacked up the power a bit, and you could feel that the stock tires did not offer enough grip for that power level, and the understeer at the limit becomes more apparent. But really fun, and nothing surprising.

Also, RCE I love your stuff.
Spec-Al is offline   Reply With Quote
Old 12-21-2011, 03:30 PM   #5
RRnold
2 wheel member
 
RRnold's Avatar
 
Join Date: Feb 2010
Drives: JZA80, 997.1, Taco
Location: SoCal->NorCal
Posts: 4,330
Thanks: 1,318
Thanked 938 Times in 480 Posts
Mentioned: 9 Post(s)
Tagged: 0 Thread(s)
In stock trim, to me the car did feel stiff with very minimal front end compression, little body roll (compared to the real Toyota 86 reviews which seemed to have a lot more roll) and the steering was very responsive. I was impressed for it being an unmodified car and if this thing is as accurate as it is in the game as it in real life, this car is going to be something special.
__________________
RRnold is offline   Reply With Quote
Old 12-21-2011, 03:37 PM   #6
Spec-Al
Is it track season yet?
 
Spec-Al's Avatar
 
Join Date: Dec 2011
Drives: Evo IX MR, 240SX (SR)
Location: United States
Posts: 4
Thanks: 0
Thanked 0 Times in 0 Posts
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quote:
Originally Posted by RRnold View Post
In stock trim, to me the car did feel stiff with very minimal front end compression, little body roll (compared to the real Toyota 86 reviews which seemed to have a lot more roll) and the steering was very responsive. I was impressed for it being an unmodified car and if this thing is as accurate as it is in the game as it in real life, this car is going to be something special.
Good points. Agreed on there being less body roll than one would expect to see in real life.
Spec-Al is offline   Reply With Quote
Old 12-21-2011, 03:41 PM   #7
Racecomp Engineering
 
Join Date: Nov 2011
Drives: 2016 BRZ, 2012 Paris Di2 & 2018 STI
Location: Severn, MD
Posts: 5,375
Thanks: 3,392
Thanked 7,209 Times in 2,945 Posts
Mentioned: 302 Post(s)
Tagged: 9 Thread(s)
Send a message via AIM to Racecomp Engineering
Quote:
Originally Posted by Spec-Al View Post
Exactly how you'd expect it to based on the info out there so far. Nice and lithe, not a ton of power but enough to get it to move with the light weight. Jacked up the power a bit, and you could feel that the stock tires did not offer enough grip for that power level, and the understeer at the limit becomes more apparent. But really fun, and nothing surprising.

Also, RCE I love your stuff.
Thanks for that. We've got big plans for this car and hopefully we'll have some awesome stuff coming for it as soon as we can.

I'll have to test the car out soon on GT5....gonna convince Myles to bring the PS3 in!

- Andrew
Racecomp Engineering is offline   Reply With Quote
Old 12-21-2011, 04:15 PM   #8
Dimman
Kuruma Otaku
 
Dimman's Avatar
 
Join Date: Dec 2009
Drives: Mk3 Supra with Semi-built 7MGTE
Location: Greater Vancouver (New West)
Posts: 6,854
Thanks: 2,398
Thanked 2,265 Times in 1,234 Posts
Mentioned: 78 Post(s)
Tagged: 2 Thread(s)
Garage
Quote:
Originally Posted by Spec-Al View Post
So, Gran Turismo 5 came out with an update yesterday that includes the new GT 86. Awesome, I think, I'd love to try it out in the game.

So in the setup and settings menu, I noticed that the stock spring rates were 6.0 kg/mm front and 2.0 kg/mm rear. This strikes me as being strange for a few reasons. 6/2 seems like a much wider differential in rates in a car as well balanced front to rear as the 86. Also 6.0 kg/mm is a pretty damn stiff spring to put on a stock car which weighs as little as the GT 86.

For those unfamiliar with GT5, I know it's just a video game, but they are usually anal retentive when it comes to modelling and accuracy. Just for fun I went and checked the rates for the GR STI and they were 4.2 front, 4.0 rear and that sounded pretty accurate to me (or at least close, I'm only familiar with the USDM models).

Any thoughts out there?
It does have to do with the leverages an mounting angle on the suspension, too. (I'm just learning about this, but hopefully Old Greg or some other knowledgeable person can correct any errors I make here...)

In the front it is a MacPherson strut design, which are pretty close to 1:1 leverage on the spring. So the wheel only sees the spring rate of the mounting angle.

In the back it is a multi-link design (3 lower links and an upper wishbone). So depending on where the coil-over mounts to the lower link, relative to the outer most link, there will a change in leverage. So it won't be the same 1:1 as the front struts.

So even though the spring rates are very different, the effective wheel rates are probably much closer to being the same.
__________________


Because titanium.
Dimman is offline   Reply With Quote
Old 12-21-2011, 04:26 PM   #9
Racecomp Engineering
 
Join Date: Nov 2011
Drives: 2016 BRZ, 2012 Paris Di2 & 2018 STI
Location: Severn, MD
Posts: 5,375
Thanks: 3,392
Thanked 7,209 Times in 2,945 Posts
Mentioned: 302 Post(s)
Tagged: 9 Thread(s)
Send a message via AIM to Racecomp Engineering
^ You're correct that the motion ratio must be taken into account to get actual wheel rates and I do not know how or if GT5 deals with this.

BUT the rear motion ratio is less than 1....probably somewhere between 0.7 to 0.9. This means that the rear 2kg/mm spring (according to the game) will actually be softer "at the wheels." It has less leverage than the front spring.

So really it's like 6 kg/mm front and 1.3 kg/mm rear if it's a .8 rear motion ratio. And I would be shocked if those are the actual spring rates. It's not impossible, but that would be....interesting.

- Andrew
Racecomp Engineering is offline   Reply With Quote
Old 12-21-2011, 06:27 PM   #10
Dimman
Kuruma Otaku
 
Dimman's Avatar
 
Join Date: Dec 2009
Drives: Mk3 Supra with Semi-built 7MGTE
Location: Greater Vancouver (New West)
Posts: 6,854
Thanks: 2,398
Thanked 2,265 Times in 1,234 Posts
Mentioned: 78 Post(s)
Tagged: 2 Thread(s)
Garage
Quote:
Originally Posted by Racecomp Engineering View Post
^ You're correct that the motion ratio must be taken into account to get actual wheel rates and I do not know how or if GT5 deals with this.

BUT the rear motion ratio is less than 1....probably somewhere between 0.7 to 0.9. This means that the rear 2kg/mm spring (according to the game) will actually be softer "at the wheels." It has less leverage than the front spring.

So really it's like 6 kg/mm front and 1.3 kg/mm rear if it's a .8 rear motion ratio. And I would be shocked if those are the actual spring rates. It's not impossible, but that would be....interesting.

- Andrew
Hmmm... I couldn't remember which way it went, so I weaseled and just said that it was different. This makes it even more odd.

With the low CoG it won't need crazy rates to resist pitch and roll. But what does the difference mean? They made a big deal about 'dynamic balance' with this car.

With more front it will resist dive better, and softer rear means it will squat and plant the back end easier, right? Roll can be balanced with bars.

Fronts being stiff will also reduce camber change, maybe?

Seems that it may be setup to rotate easily, but the soft rear makes it safer when you get on the throttle? So it turns nice and when you get on the gas it just straightens out?

Something like that?
__________________


Because titanium.
Dimman is offline   Reply With Quote
Old 12-21-2011, 06:57 PM   #11
fatoni
Senior Member
 
Join Date: Apr 2011
Drives: miata, mazdaspeed protege, ls430
Location: socal
Posts: 4,416
Thanks: 599
Thanked 1,442 Times in 787 Posts
Mentioned: 28 Post(s)
Tagged: 0 Thread(s)
yeah i was thinking about how to get that to make sense. it could just be something as simple as using a sway to make that up and keeping the bounce freq more streetable. or maybe the multil link allows for much wider range of useable camber. i mean, i think you would want the softest suspension possible while staying in a desirable suspension geometry. more likely that any of that, its just a stupid game. the stock suspension on the ae86 wasnt close iirc
fatoni is offline   Reply With Quote
Old 12-21-2011, 06:58 PM   #12
old greg
Rocket Surgeon
 
Join Date: Apr 2011
Drives: PSM GGA OMG
Location: FL
Posts: 1,312
Thanks: 10
Thanked 141 Times in 84 Posts
Mentioned: 2 Post(s)
Tagged: 1 Thread(s)
Quote:
Originally Posted by Dimman View Post
Something like that?
Almost all of that was right, but the huge disconnect from reality is the ludicrously stiff front spring rate.

6kg/mm would mean ~2.1 Hz ride frequency in the front, which is stiffer than most race cars. While the rear would be ~1.2 Hz which is somewhat stiff for a passenger car. I would be willing to bet at least two quarters that the front spring rate is actually 1.6 kg/mm and somebody at either Toyota or Polyphony Digital just screwed up. 1.6 would be a much more realistic number; It would put the front ride frequency @ 1.1 Hz which, aside from being a sane number; is just a touch less than the rear ride frequency and that is entirely right and proper from an NVH standpoint.
old greg is offline   Reply With Quote
Old 12-21-2011, 07:27 PM   #13
Homemade WRX
Pro Subie Engine Nerd
 
Homemade WRX's Avatar
 
Join Date: Dec 2011
Drives: BRZ has a reserved space
Location: 3MI Racing LLC
Posts: 261
Thanks: 0
Thanked 1 Time in 1 Post
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quote:
Originally Posted by Racecomp Engineering View Post
Thanks for that. We've got big plans for this car and hopefully we'll have some awesome stuff coming for it as soon as we can.

I'll have to test the car out soon on GT5....gonna convince Myles to bring the PS3 in!

- Andrew
Glad to see that you and Myles are on board. I know of two local customers (old nasioc guys) who will be picking up cars, one an FRS and the other a BRZ. Both are going to have planned down time for some component development. Perhaps we can work on getting some components to you for measurement and then you'll have to chassis' for guinea pig testing too.

-Micah

P.S. the guys are in Falls Church and Hagerstown and the cars will be on the lift in Hag...
Homemade WRX is offline   Reply With Quote
Old 12-21-2011, 08:05 PM   #14
Dimman
Kuruma Otaku
 
Dimman's Avatar
 
Join Date: Dec 2009
Drives: Mk3 Supra with Semi-built 7MGTE
Location: Greater Vancouver (New West)
Posts: 6,854
Thanks: 2,398
Thanked 2,265 Times in 1,234 Posts
Mentioned: 78 Post(s)
Tagged: 2 Thread(s)
Garage
6kg/mm is ~335 lbs/in and that doesn't sound like a huge number. 111 lbs/in on the rears sounds soft.
__________________


Because titanium.
Dimman 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
Red Toyota 86 with factory aero kit and spoiler wing DIG1992 FR-S & 86 Photos, Videos, Wallpapers, Gallery Forum 112 02-04-2014 01:16 AM
Factory Roof Rack? \o/ Scion FR-S / Toyota 86 GT86 General Forum 92 02-15-2013 04:25 AM
Just got off the phone with Scion... FR-S release date late spring 2012 nate89 Scion FR-S / Toyota 86 GT86 General Forum 13 12-03-2011 04:00 AM
Official: Subaru BRZ Will Be Released in Spring 2012 EyeZer0 BRZ First-Gen (2012+) -- General Topics 22 11-09-2011 02:14 AM
FR-S to be priced at $22k and coming in Spring of 2012? vh_supra26 Scion FR-S / Toyota 86 GT86 General Forum 92 10-25-2011 10:06 PM


All times are GMT -4. The time now is 09:08 PM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
User Alert System provided by Advanced User Tagging v3.3.0 (Lite) - vBulletin Mods & Addons Copyright © 2024 DragonByte Technologies Ltd.

Garage vBulletin Plugins by Drive Thru Online, Inc.