Notices
Autocross/Road SCCA Solo II, SCCA Club Racing, Redline Track Events, Speed Trial, Speed Ventures, Grand-Am Cup, JGTC, Procar Australia

Inside rear wheel lifting in turns

Thread Tools
 
Search this Thread
 
Old Apr 8, 2013 | 03:44 PM
  #21  
terrasmak's Avatar
terrasmak
Super Moderator
MY350Z.COM
Premier Member
15 Year Member
Liked
Loved
Community Favorite
iTrader: (8)
 
Joined: Jan 2007
Posts: 29,119
Likes: 2,400
From: Sin City
Default

Come on out of the 20th at Big Willow, I can get a better look at it then.
Reply
Old Apr 9, 2013 | 07:21 AM
  #22  
betamotorsports's Avatar
betamotorsports
Registered User
iTrader: (1)
 
Joined: Jul 2006
Posts: 1,393
Likes: 3
From: La Habra, CA, USA
Default

KSports are crap. You most likely have a droop problem on the right rear shock that lifts the rear wheel. Remove the rear coil overs and install the stock components and see if that solves the problem.
Reply
Old Apr 9, 2013 | 07:56 AM
  #23  
ntrinsik's Avatar
ntrinsik
Registered User
iTrader: (8)
 
Joined: Oct 2008
Posts: 274
Likes: 0
From: San Francisco
Default

Never had that issue with my 5AT G35 Coupe. Was on Bilstein PSS10s though.
Reply
Old Apr 9, 2013 | 05:14 PM
  #24  
lotteman's Avatar
lotteman
Thread Starter
Registered User
 
Joined: Dec 2010
Posts: 89
Likes: 0
From: North Hollywood
Default

Originally Posted by betamotorsports
KSports are crap. You most likely have a droop problem on the right rear shock that lifts the rear wheel. Remove the rear coil overs and install the stock components and see if that solves the problem.
Yes, this. I think this is exactly what is happening except at the fault of my owns hands rather than that of ksport lol. Im a tinkerer and i tend to mess around with things when i dont fully understand it yet. When i first got my ksports they first came with zero preload which left my grossly overweight car to smash against the bumpstops whenever i ran over a dime or something of that size. Eventually i got tired of it and adjusted my preload WAY up; probably in the neighborhood of 8mm... maybe even 10mm. Now i have a superb ride on the street but im now just realizing the negative effects it has on handling. I think the cause of me tripoding is that i have way too much body roll from too much travel on compression and not enough suspension droop. That would make sense.

Ill try adjusting my preload when i get a chance and see how that works out. How much spring preload should i try at first?
Reply
Old Apr 9, 2013 | 05:30 PM
  #25  
terrasmak's Avatar
terrasmak
Super Moderator
MY350Z.COM
Premier Member
15 Year Member
Liked
Loved
Community Favorite
iTrader: (8)
 
Joined: Jan 2007
Posts: 29,119
Likes: 2,400
From: Sin City
Default

Linear spring, rate does not change with preload. Set the suspension travel, then set the ride height with preload.
Reply
Old Apr 9, 2013 | 06:52 PM
  #26  
lotteman's Avatar
lotteman
Thread Starter
Registered User
 
Joined: Dec 2010
Posts: 89
Likes: 0
From: North Hollywood
Default

Originally Posted by terrasmak
Linear spring, rate does not change with preload. Set the suspension travel, then set the ride height with preload.
I meant that the ride was rough because i had very little travel when i hit bumps. The car was literally driving on the bumpstops which led me to crank up the preload like crazy so i would be no where near them.

also, terrasmak. I really wanna try your method but im scared i wont have any travel over bumps and be left with the bumpstop ride i had before. Also, would i run a small risk of the spring unseating itself?

Last edited by lotteman; Apr 9, 2013 at 07:11 PM.
Reply
Old Apr 10, 2013 | 12:41 PM
  #27  
kfoote's Avatar
kfoote
Registered User
 
Joined: Dec 2004
Posts: 70
Likes: 0
From: NH
Default

Originally Posted by lotteman
Also, would i run a small risk of the spring unseating itself?
There is a small risk of the spring unseating itself, but it has to be a very specific set of conditions for that to happen. Basically, that corner of the car has to be in the air for 3-4+ seconds and simultaneously have a lateral load applied to the spring to get it to move out of the perch. In the overwhelming majority of situations that this is likely to happen in, you will have much bigger issues to worry about than the spring coming out of the seat...like fixing the chassis after the car hit the wall when it was in the air.

The required springs in Spec Miata have no preload on them, and in 10+ years of working on them, I have never seen one dislodged except when the car hit something hard and had other damage that made the car undriveable. My daily driver STi with a Bilstein PSS9 kit on it has no preload in the rear, and I have never had an issue with it in 140k+ miles either.

What you ahve described in this thread is more likely to be a diff issue than a suspension issue. In the couple of days that I have driven my 350 track car with the stock viscous LSD, it did have issues spinning the rear tires on a couple of corners where a properly tuned LSD can make a huge difference. Though it is probable that the suspension isn't helping the issue, I doubt that it's the root cause.

Last edited by kfoote; Apr 10, 2013 at 12:48 PM.
Reply
Old Apr 10, 2013 | 10:11 PM
  #28  
lotteman's Avatar
lotteman
Thread Starter
Registered User
 
Joined: Dec 2010
Posts: 89
Likes: 0
From: North Hollywood
Default

Originally Posted by kfoote
There is a small risk of the spring unseating itself, but it has to be a very specific set of conditions for that to happen. Basically, that corner of the car has to be in the air for 3-4+ seconds and simultaneously have a lateral load applied to the spring to get it to move out of the perch. In the overwhelming majority of situations that this is likely to happen in, you will have much bigger issues to worry about than the spring coming out of the seat...like fixing the chassis after the car hit the wall when it was in the air.

The required springs in Spec Miata have no preload on them, and in 10+ years of working on them, I have never seen one dislodged except when the car hit something hard and had other damage that made the car undriveable. My daily driver STi with a Bilstein PSS9 kit on it has no preload in the rear, and I have never had an issue with it in 140k+ miles either.

What you ahve described in this thread is more likely to be a diff issue than a suspension issue. In the couple of days that I have driven my 350 track car with the stock viscous LSD, it did have issues spinning the rear tires on a couple of corners where a properly tuned LSD can make a huge difference. Though it is probable that the suspension isn't helping the issue, I doubt that it's the root cause.
Im starting to get the feeling that its a compound between shitty suspension setup and the stock diff/open.

another question i have is about terrasmak's method coilover setup(which i've learned is the most commonly used proper way) If i setup my coilovers that way, would i be hitting bumpstops a lot? When i first got my coilovers, they came with zero preload and it felt like iwould bottom out the shock over the smallest bumps and dips which drove me crazy. It was an insanely uncomfortable ride because it seemed like i had less than an inch of travel and would always be hitting bumpstops. This prompted me to preload my springs like crazy so i could stay away from hitting the bumpstop.

Last edited by lotteman; Apr 10, 2013 at 10:13 PM.
Reply
Old Apr 11, 2013 | 08:50 AM
  #29  
kfoote's Avatar
kfoote
Registered User
 
Joined: Dec 2004
Posts: 70
Likes: 0
From: NH
Default

Originally Posted by lotteman
Im starting to get the feeling that its a compound between shitty suspension setup and the stock diff/open.

another question i have is about terrasmak's method coilover setup(which i've learned is the most commonly used proper way) If i setup my coilovers that way, would i be hitting bumpstops a lot? When i first got my coilovers, they came with zero preload and it felt like iwould bottom out the shock over the smallest bumps and dips which drove me crazy. It was an insanely uncomfortable ride because it seemed like i had less than an inch of travel and would always be hitting bumpstops. This prompted me to preload my springs like crazy so i could stay away from hitting the bumpstop.
I am not familiar enough with your particular setup to know for sure, as it is highly dependent on exactly what the ride height ends up being and how much travel there is from static ride height before you hit the bump stops. Depending on how long and how stiff the bump stops are, that is definitely a possibilty, and cutting the bump stops may be a viable option to help your issue.
Reply
Old Apr 11, 2013 | 03:43 PM
  #30  
Zazz93's Avatar
Zazz93
New Member
iTrader: (2)
 
Joined: Jul 2009
Posts: 1,769
Likes: 8
From: So Cal
Default

Pick the rear of the car up on jack stands and see if one side hangs lower than the other. I've noticed in the past, today's coilovers have far too many adjustments for most people (no offense). Your probably looking and a wacky setup on the coils, too much shock height adjustment with too little spring perch adjustment or vice versa. Check with Ksport and ask them for the base setup they ship with.

Last edited by Zazz93; Apr 11, 2013 at 03:57 PM.
Reply
Old Apr 12, 2013 | 12:12 AM
  #31  
lotteman's Avatar
lotteman
Thread Starter
Registered User
 
Joined: Dec 2010
Posts: 89
Likes: 0
From: North Hollywood
Default

i was revising my setup on the coilovers earlier tonight with terrasmak over the phone giving some guidance. I discovered 1 VERY interesting flaw on these that i would never have even thought of. Shitty shock internals and damping is one thing but when the shock bottoms out 1cm before even touching the bumpstop I'm ready to throw these coilovers off a bridge hoping they get run over by a semi.

Last edited by lotteman; Apr 12, 2013 at 12:17 AM.
Reply
Old Apr 12, 2013 | 05:05 AM
  #32  
terrasmak's Avatar
terrasmak
Super Moderator
MY350Z.COM
Premier Member
15 Year Member
Liked
Loved
Community Favorite
iTrader: (8)
 
Joined: Jan 2007
Posts: 29,119
Likes: 2,400
From: Sin City
Default

You should also mention how much total travel they provide!!
Reply
Old Apr 17, 2013 | 04:16 PM
  #33  
lotteman's Avatar
lotteman
Thread Starter
Registered User
 
Joined: Dec 2010
Posts: 89
Likes: 0
From: North Hollywood
Default

a whole 3 1/2" in front and an amazing 2 3/4" rear. How is this considered pass-able in anyones book?
Reply
Old Apr 18, 2013 | 08:26 AM
  #34  
Zazz93's Avatar
Zazz93
New Member
iTrader: (2)
 
Joined: Jul 2009
Posts: 1,769
Likes: 8
From: So Cal
Default

How long are the bumpstops (were they trimmed)?
Reply
Old Apr 18, 2013 | 08:58 AM
  #35  
terrasmak's Avatar
terrasmak
Super Moderator
MY350Z.COM
Premier Member
15 Year Member
Liked
Loved
Community Favorite
iTrader: (8)
 
Joined: Jan 2007
Posts: 29,119
Likes: 2,400
From: Sin City
Default

Originally Posted by Zazz93
How long are the bumpstops (were they trimmed)?
Stock K Sport bumpstops, rear bottoms out before the bumpstop engages.
Reply
Old Apr 18, 2013 | 08:59 AM
  #36  
zfamous's Avatar
zfamous
Registered User
 
Joined: Apr 2013
Posts: 19
Likes: 0
From: Southern, CA
Default

rollcenter adjustments!
Reply
Old Apr 18, 2013 | 04:22 PM
  #37  
lotteman's Avatar
lotteman
Thread Starter
Registered User
 
Joined: Dec 2010
Posts: 89
Likes: 0
From: North Hollywood
Default

Originally Posted by terrasmak
Stock K Sport bumpstops, rear bottoms out before the bumpstop engages.
Actually when i found out and told you over the phone i was adjusting the front LOL so both front AND rear shocks bottom out before the sorry excuse ksport had for a bumpstop. The bumpstop provided was literally a hard rubber hockeypuck with a dustboot around it. The sole of my shoes would probably make a better bumpstop.

And no the bumpstops were not trimmed at all since i bought them new.
Reply
Old Apr 19, 2013 | 08:50 AM
  #38  
Zazz93's Avatar
Zazz93
New Member
iTrader: (2)
 
Joined: Jul 2009
Posts: 1,769
Likes: 8
From: So Cal
Default

Just curious how were you testing the shock's range... on the car with no springs?
Reply
Old Apr 19, 2013 | 08:56 AM
  #39  
terrasmak's Avatar
terrasmak
Super Moderator
MY350Z.COM
Premier Member
15 Year Member
Liked
Loved
Community Favorite
iTrader: (8)
 
Joined: Jan 2007
Posts: 29,119
Likes: 2,400
From: Sin City
Default

Originally Posted by Zazz93
Just curious how were you testing the shock's range... on the car with no springs?
Both on and off the car.
Reply
Old Apr 19, 2013 | 05:47 PM
  #40  
lotteman's Avatar
lotteman
Thread Starter
Registered User
 
Joined: Dec 2010
Posts: 89
Likes: 0
From: North Hollywood
Default

Originally Posted by Zazz93
Just curious how were you testing the shock's range... on the car with no springs?
I tested it with it off the car without the spring at first. Compressed the shock by hand and felt the shock just stop. I listened closely and i could hear the piston stop. I thought maybe im just a little girl and im not strong enough? Put the shock on the car without a spring and used my floorjack to compress it. the shock stopped at the exact same place it did when i had it off the car.
Reply



All times are GMT -8. The time now is 11:44 AM.