Advice on suspension tinkering - Miata Turbo Forum - Boost cars, acquire cats.

Welcome to Miataturbo.net   Members
 


Race Prep Miata race-only chat.
Sponsored by:
Sponsored by:

Reply
 
 
 
LinkBack Thread Tools Search this Thread
Old 05-23-2015, 10:02 PM   #1
Newb
Thread Starter
 
Join Date: Jul 2013
Posts: 18
Total Cats: 0
Default Advice on suspension tinkering

Background: Car is a 99 NB1 (2380lbs with rollbars/harness bars/seats/hardtop)

I am currently on FCM flat rides (550/425) with sport bumpstops running 1" front bar and 11mm rear. Alignment - F Camber -2.4/ 0 toe/ 4.6 caster, R Camber -2.1/ 0 toe - Ride Height at 12"F/12.25"R roughly 4.25"/4.5" - 225/45/15 NT01s on 15x9 6ULS

Car turn in is absolutely fantastic at my home tracks (MRLS/THILL/Sonoma) but am having issues with oversteer. Have taken rear bar off and it has helped slightly but still unsettling mid corner.

Have been too meek to ask for additional support from FCM besides the initial email i sent to which i was instructed to remove rear bar and play around with alignment.

I am thinking of changing spring rates at this point. Was told front shocks could handle +/-100 and rear +/-50 lbs. Also getting 1.25" RB Front Sway Bar.

Would 650/425 with 1.25" front bar/ 11mm bar be feasible? Or would i understeer like a pig?

Any input from more experienced drivers would be highly appreciated.

Thanks!

Last edited by thoreau; 05-23-2015 at 10:16 PM.
thoreau is offline   Reply With Quote
Old 05-23-2015, 10:14 PM   #2
Supporting Vendor
iTrader: (3)
 
Join Date: Jul 2006
Location: San Diego
Posts: 2,863
Total Cats: 485
Default

A missing part to the equation is what tires you typically run.

-Ryan
ThePass is offline   Reply With Quote
Old 05-23-2015, 10:15 PM   #3
Newb
Thread Starter
 
Join Date: Jul 2013
Posts: 18
Total Cats: 0
Default

Sorry about that. Edited first post. I run NT01 225/45/15 on 15x9 6ULs.
thoreau is offline   Reply With Quote
Old 05-23-2015, 11:11 PM   #4
Senior Member
iTrader: (1)
 
Join Date: Nov 2010
Posts: 951
Total Cats: -252
Default

Either increase the front spring rate or decrease the rear rate. 700/425 or 550/350.
wannafbody is offline   Reply With Quote
Old 05-23-2015, 11:38 PM   #5
Supporting Vendor
iTrader: (3)
 
Join Date: Jul 2006
Location: San Diego
Posts: 2,863
Total Cats: 485
Default

As a rule of thumb, 1.5-1.65:1 is a good range for front to rear ratio. 550 is on the soft side for NT01s, I'd stiffen the front springs.

-Ryan
ThePass is offline   Reply With Quote
Old 05-26-2015, 12:10 PM   #6
Junior Member
iTrader: (5)
 
Join Date: Oct 2014
Posts: 473
Total Cats: 23
Default

I bet that bar makes a big difference as well. Maybe keep the current rates with the larger front bar and see how that goes. Still not what you want then start playing with spring rates.

In my autocross car I noticed a massive difference in feel with a slightly stiffer front bar. I am on 140TW R1Rs though. I am sure the NT01s have much more to offer in overall grip.
90civichhb is offline   Reply With Quote
Old 05-26-2015, 01:27 PM   #7
Elite Member
iTrader: (1)
 
Leafy's Avatar
 
Join Date: Jun 2012
Location: NH
Posts: 9,091
Total Cats: 90
Default

Yeah I'd do 650/400 and the rb race front bar and see how with or without the rear sway works for you.
Leafy is offline   Reply With Quote
Old 05-26-2015, 04:04 PM   #8
Supporting Vendor
iTrader: (1)
 
OGRacing's Avatar
 
Join Date: May 2014
Posts: 1,764
Total Cats: 46
Default

what is your toe looking like?
OGRacing is offline   Reply With Quote
Old 05-26-2015, 05:59 PM   #9
Supporting Vendor
iTrader: (3)
 
Join Date: Jul 2006
Location: San Diego
Posts: 2,863
Total Cats: 485
Default

Quote:
Originally Posted by OGRacing View Post
what is your toe looking like?
zero:

Quote:
Originally Posted by thoreau View Post
Alignment - F Camber -2.4/ 0 toe/ 4.6 caster, R Camber -2.1/ 0 toe
ThePass is offline   Reply With Quote
Old 05-27-2015, 12:52 AM   #10
Senior Member
 
Join Date: May 2011
Posts: 549
Total Cats: 56
Default

echo leafy and thepass regarding spring rate. Any reason you went to an 11mm bar over the stock nb1 12mm bar? RB race front bar is a necessity imo.
EErockMiata is offline   Reply With Quote
Old 05-27-2015, 10:58 AM   #11
Supporting Vendor
iTrader: (1)
 
OGRacing's Avatar
 
Join Date: May 2014
Posts: 1,764
Total Cats: 46
Default

Quote:
Originally Posted by ThePass View Post
zero:
I'm sharp


might want to double check your toe before spending $$. the suspension bolts might have loosened, it sounds like you have a bit of + rear toe.
OGRacing is offline   Reply With Quote
Old 05-27-2015, 11:33 AM   #12
Elite Member
iTrader: (2)
 
Join Date: Aug 2012
Location: Indianapolis
Posts: 3,325
Total Cats: 235
Default

<p>With regards to spring rates, have you tried playing with FCM's suspension calculator? &nbsp;I've played around with it a bit, you'll want to search the forums for threads about it so you can know how to interperate the results.</p>
thenuge26 is offline   Reply With Quote
Old 05-27-2015, 12:35 PM   #13
Senior Member
iTrader: (2)
 
Join Date: Aug 2013
Location: Houston, TX
Posts: 598
Total Cats: 30
Default

Needs more front spring.
I'm at 600/350 right now with the 1.25" rb front and 14mm rear with similar alignment numbers and have just the touch of understeer that I desired over the 550/350 spring rates.

Same home tracks as you...

Or try dialing in more rear camber... that's what some of the local folks seem to do. +2/10ths split in back.

Last edited by SchmoozerJoe; 05-27-2015 at 12:57 PM.
SchmoozerJoe is offline   Reply With Quote
Old 05-29-2015, 04:35 PM   #14
Supporting Vendor
iTrader: (3)
 
emilio700's Avatar
 
Join Date: May 2005
Posts: 5,311
Total Cats: 1,335
Default

700 front springs and 1/16" rear toe in

Last edited by emilio700; 06-02-2015 at 01:33 AM. Reason: Doh
emilio700 is offline   Reply With Quote
Old 06-02-2015, 12:04 AM   #15
Senior Member
iTrader: (1)
 
Join Date: Nov 2010
Posts: 951
Total Cats: -252
Default

Pretty sure Emilio means 1/16th inch toe in.
wannafbody is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Project Gemini - Turbo Civic on the Cheap Full_Tilt_Boogie Build Threads 58 Yesterday 10:04 PM
1994 Spec Miata Race Car SM/SM2/SSM For Sale Quinn Cars for sale/trade 6 10-23-2016 08:58 AM
Hey everyone another n00b here Big_gumby Meet and Greet 80 10-05-2015 05:06 PM
3rd Time's a Charm...hopefully. zephyrusaurai Meet and Greet 2 09-28-2015 11:59 PM


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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 05:52 AM.