S2000 Racing and Competition The S2000 on the track and Solo circuit. Some of the fastest S2000 drivers in the world call this forum home.

handling issue

Thread Tools
 
Old Mar 15, 2007 | 02:16 PM
  #1  
mikegarrison's Avatar
Thread Starter
Registered User
 
Joined: Apr 2003
Posts: 22,888
Likes: 3
From: Covington WA, USA
Default handling issue

Heres my car:

welded roll bar so stiff rear
KWv3, lowered a bit from stock height, shocks set as recommended by instructions
205/245 RA1s on AP1 wheels
BSK
approx -3 camber F/R, 0 toe front, a small toe in rear
approx 2950 lb with me in it
OEM sways
OEM drivetrain
OEM aero (hardtop, no spoiler, no wing, no splitter, no lip)

Heres the issue:

1) car turns in great, very mild understeer to very mild oversteer, depending on driver input
2) mid-corner and transition feels very twitchy, hard to get on the throttle in chicanes
3) will not four-wheel drift in high speed sweeper, instead the back end just steps out
4) this culminated in looping the car in a 65-70 mph sweeper (some favorable camber, instructor was trying to get me to rotate the car a bit with the throttle, but it wouldn't stop rotating....)

My instructor thought it felt like not enough front sway. Thinking it over, that seems quite possible. Another option would be to disconnect the rear sway, I suppose. Depends on whether it wants more sway control in total.

Or is there something I should try with the shock settings?
Reply
Old Mar 15, 2007 | 02:53 PM
  #2  
rlaifatt's Avatar
 
Joined: Jan 2002
Posts: 4,666
Likes: 2
From: Encinitas (San Diego), CA
Default

Interesting that it oversteers with such relatively narrow tires in front. Assuming tires are okay and matched, sounds like the rear is too stiff (rebound and/or compression; stepwise, I'd soften rebound first).

BTW, why don't you have a wing, esp. as this is a track-only car?
That's one of the first changes to do for decreasing laptimes.
Reply
Old Mar 15, 2007 | 03:26 PM
  #3  
mikegarrison's Avatar
Thread Starter
Registered User
 
Joined: Apr 2003
Posts: 22,888
Likes: 3
From: Covington WA, USA
Default

[quote name='rlaifatt' date='Mar 15 2007, 03:53 PM'] BTW, why don't you have a wing, esp. as this is a track-only car?
Reply
Old Mar 15, 2007 | 03:47 PM
  #4  
l8brakr's Avatar
Registered User
 
Joined: Jan 2004
Posts: 1,610
Likes: 0
From: Ph-Ph-Ph-Phoenix
Default

If you add a stiffer front bar your car will turn into a understeering pig. That may not be that much of an issue if you're about ready for tires because you could go with the 225/50 RA-1 up front and have more overall grip. Like richard said you could soften the rear too. If you are using the stock recommended settings I would maybe try to stiffen the front first and see what you get. I can't speak for KW but their base settings may be set on street rubber so R comps should be able to take a little more damping. Good luck!!
Reply
Old Mar 15, 2007 | 03:50 PM
  #5  
mikegarrison's Avatar
Thread Starter
Registered User
 
Joined: Apr 2003
Posts: 22,888
Likes: 3
From: Covington WA, USA
Default

Originally Posted by l8brakr' date='Mar 15 2007, 04:47 PM
If you add a stiffer front bar your car will turn into a understeering pig. That may not be that much of an issue if you're about ready for tires because you could go with the 225/50 RA-1 up front and have more overall grip. Like richard said you could soften the rear too. If you are using the stock recommended settings I would maybe try to stiffen the front first and see what you get. I can't speak for KW but their base settings may be set on street rubber so R comps should be able to take a little more damping. Good luck!!
Well, I don't have time to get a front bar before my next track day, but I suppose I do have time to disconnect the rear and see what happens.

When people say "stiffen up" or "soften" the shocks, are they mostly talking about rebound?
Reply
Old Mar 15, 2007 | 04:11 PM
  #6  
krazik's Avatar
Administrator
25 Year Member
Liked
Loved
 
Joined: Oct 2000
Posts: 17,004
Likes: 7
From: Santa Cruz, CA, US
Default

start with both for right now. For every turn you add of rebound add the same for compression. You can fine tune them seperately later.

It seems odd to me with that setup your car wants to rotate so easily. Not sure what the problem is tho. I'll think more on it.

-Ry
Reply
Old Mar 15, 2007 | 04:13 PM
  #7  
BKL's Avatar
BKL
Registered User
 
Joined: Mar 2005
Posts: 1,248
Likes: 0
From: Vancouver
Default

Well, for me i tend to adjust rebound along with compression (its a balance for me). I would personally try decreasing the rear compression first.
Reply
Old Mar 15, 2007 | 04:14 PM
  #8  
krazik's Avatar
Administrator
25 Year Member
Liked
Loved
 
Joined: Oct 2000
Posts: 17,004
Likes: 7
From: Santa Cruz, CA, US
Default

Btw I'd get the car handling better before you complicate it w/ a wing.

I know the answer, but you're sure your tire pressures are ok.
Reply
Old Mar 15, 2007 | 04:21 PM
  #9  
TC Design's Avatar
Registered User
Gold Member (Premium)
 
Joined: Dec 2002
Posts: 82
Likes: 0
From: sf bay area
Default

Mike try a little more rear toe and also disconect the rear bar for a session to see how that feels.

On the shock settings you would need to call me so I can ask you some more questions on how the car felt in different areas. I am at the track tomorrow, but you can try and reach me on my cell I PM'ed you.

-tony
Reply
Old Mar 15, 2007 | 04:22 PM
  #10  
mikegarrison's Avatar
Thread Starter
Registered User
 
Joined: Apr 2003
Posts: 22,888
Likes: 3
From: Covington WA, USA
Default

Originally Posted by krazik' date='Mar 15 2007, 05:14 PM
I know the answer, but you're sure your tire pressures are ok.
I was running about 37 psi (measured just after coming off track). I suppose I could bump that up a tad.
Reply



All times are GMT -8. The time now is 02:56 PM.