Notices

S2 rear suspension geometry change

Thread Tools
 
Search this Thread
 
Rate Thread
 
Old 12-30-2016, 09:10 PM
  #1  
Registered
Thread Starter
iTrader: (1)
 
IamFodi's Avatar
 
Join Date: Mar 2014
Location: Philadelphia, PA
Posts: 862
Received 84 Likes on 68 Posts
S2 rear suspension geometry change

So... what actually IS the suspension geometry change from S1 to S2? What exactly did they change, and what was the effect? I get that there were parts changes, and that the intent was "better stability" or "better handling." What exactly does that mean? Different camber/toe curves? Higher/lower roll center? Less excess movement? I'd have thought someone would have figured this out and posted about it, but I can't find it anywhere.

The only hint I've found so far is this, from the PDF attached in this post:
Overall driving stability is also increased with a reconfiguration of the rear suspension geometry and by increasing the size of the upper lateral link’s joint section by 7.5 mm for better control of toe-out change at rebound.
Kind of suggests toe control was the point. But the wording makes it unclear whether that extra toe control comes just from the beefed-up upper lateral link or from the geometry revision as well.

Anyone have any input on this? Is there an authoritative source somewhere that I'm missing?

Last edited by IamFodi; 12-30-2016 at 09:14 PM.
Old 01-01-2017, 04:39 PM
  #2  
Registered
Thread Starter
iTrader: (1)
 
IamFodi's Avatar
 
Join Date: Mar 2014
Location: Philadelphia, PA
Posts: 862
Received 84 Likes on 68 Posts
Found another quote here:
Originally Posted by RX-8
Longer links are mounted higher in the chassis to control toe-out changes and improve stability under hard braking.
Source cited is Motor Magazine, but I can't find the issue online to verify.
Old 11-14-2017, 03:09 PM
  #3  
New Member
 
khum's Avatar
 
Join Date: Oct 2015
Posts: 4
Likes: 0
Received 0 Likes on 0 Posts
Not sure if this is relevant but according to the guys at Racing Beat, their springs do not install from gen 1 to gen 2 with the same results in performance and ride-height.

Their gen 1 performance springs will fit in a gen 2 car but the rates are off and the ride height is off (rides lower in the back!), I have yet to find a good performance (street application) spring for the gen 2 cars that will improve the handling and lower the ride height (between 3/4" or more).
Old 11-14-2017, 04:28 PM
  #4  
No respecter of malarkey
iTrader: (25)
 
TeamRX8's Avatar
 
Join Date: Apr 2005
Posts: 26,719
Received 2,006 Likes on 1,635 Posts
I bought a complete set of S2 rear arms for my S1. Other than the tie-rod arms being larger diameter (stronger) the lengths and the rest of the arms were identical to the S1 arms. And just so you know, the tie-rod arm is the lower lateral link, not the upper as was stated. So remember that as you read on ...


https://www.rx8club.com/rx-8-racing-...0/#post4686215


I thought about changing subframes, but considering I already changed the bushings to solid on my S1, the unknown factor of whether a used subframe would be true or not because about the only way to get one is from a wrecked chassis, and the all around hassle (you haven’t done anything challenging in your life until removing OE rear subframe bushings including metal sleeve/shell ) decided it probably was BS if the arm lengths didn’t change.

The rear springs don’t directly interchange because they changed the spring perch position on the S2 shock. This is documented in the race forum area.


.

Last edited by TeamRX8; 11-14-2017 at 04:38 PM.
Old 11-14-2017, 05:37 PM
  #5  
Registered
iTrader: (1)
 
Loki's Avatar
 
Join Date: Jun 2009
Location: Montreal
Posts: 7,712
Received 952 Likes on 830 Posts
Originally Posted by khum
Not sure if this is relevant but according to the guys at Racing Beat, their springs do not install from gen 1 to gen 2 with the same results in performance and ride-height.

Their gen 1 performance springs will fit in a gen 2 car but the rates are off and the ride height is off (rides lower in the back!), I have yet to find a good performance (street application) spring for the gen 2 cars that will improve the handling and lower the ride height (between 3/4" or more).
If you replace the shocks with S1 shocks (stock or aftermarket), that problem goes away.
Old 11-14-2017, 08:08 PM
  #6  
No respecter of malarkey
iTrader: (25)
 
TeamRX8's Avatar
 
Join Date: Apr 2005
Posts: 26,719
Received 2,006 Likes on 1,635 Posts
Yep, your OE shocks are likely shot any way



You have already rated this thread Rating: Thread Rating: 0 votes,  average.


All times are GMT -5. The time now is 10:11 PM.