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Old 11-30-2010, 11:33 AM   #21
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Quote:
Originally Posted by 90R View Post
the height should be set so you can draw a horizontal line. From the center of the lower control arm bushing and the lower ball joint.
That makes sense. If that is parallel to the ground so is the tie rods.
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Old 11-30-2010, 11:56 AM   #22
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Quote:
Originally Posted by 90R View Post
the height should be set so you can draw a horizontal line. From the center of the lower control arm bushing and the lower ball joint.
Does this jive with the 4.0 and 4.25" recommendation from 949/California MC guys? If not then the "optimal ride height" is not the "fastest ride height."
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Old 11-30-2010, 12:44 PM   #23
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Quote:
Originally Posted by hustler View Post
Does this jive with the 4.0 and 4.25" recommendation from 949/California MC guys? If not then the "optimal ride height" is not the "fastest ride height."
Don't know

I halfassed measured mine. I'm 1/4" higher than the "spec" on a 23" tire.

Last edited by 90R; 11-30-2010 at 03:29 PM.
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Old 11-30-2010, 08:19 PM   #24
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Originally Posted by Savington View Post
As low as possible without bottoming the suspension or screwing up geometry, so basically 4" with rake to taste.
^^^thread
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Old 11-30-2010, 08:23 PM   #25
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Originally Posted by jacob300zx View Post
^^^thread
Would have been thread if it was said 4" from where...
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Old 11-30-2010, 08:29 PM   #26
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Quote:
Originally Posted by hustler View Post
Does this jive with the 4.0 and 4.25" recommendation from 949/California MC guys? If not then the "optimal ride height" is not the "fastest ride height."
I don't think so. 949's cars are all pretty low and they measure from the "pinch weld".... I know my front pinch welds may be pretty fucked up, but in any case, I dialed in 4 1/8" FRONT and 4.375" REAR to take into account if my pinch welds had crushed upwards a bit... and my front tie rods and control arms are angled upwards (1990 non-LE tie rod ends).
Quote:
Originally Posted by jacob300zx View Post
^^^thread
Anyone know what amounts of travel we need front and rear? I have yet to take off my wheels to check zipties on shock pistons after this weekend's event, but prior, my zipties pressed the bumpstops all the way up... and left 3" F and 2" R travel before shock body hits the bumpstop. Probably down to 2" front travel and 1" rear travel considering the weight of the car and my 10kg/mm (560lbs/in) and 8kg/mm (448lbs/in).
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Old 11-30-2010, 08:41 PM   #27
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Quote:
Originally Posted by greeenteeee View Post
Anyone know what amounts of travel we need front and rear? I have yet to take off my wheels to check zipties on shock pistons after this weekend's event, but prior, my zipties pressed the bumpstops all the way up... and left 3" F and 2" R travel before shock body hits the bumpstop. Probably down to 2" front travel and 1" rear travel considering the weight of the car and my 10kg/mm (560lbs/in) and 8kg/mm (448lbs/in).
What bumpstops are you using? FCM recommends 18mm or 12mm bumpstops for that low of a car... and at least 650 rate springs.
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Old 11-30-2010, 08:53 PM   #28
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Quote:
Originally Posted by Nagase View Post
What bumpstops are you using? FCM recommends 18mm or 12mm bumpstops for that low of a car... and at least 650 rate springs.
I am using bumpstops that came with my coil-overs... for the front specifically, since I had 115mm (4.5" ish) of available stroke and left with 3" of travel with bumpstop @ full droop, I assume they are probably 1.5" long.

Do you have a link to what FCM recommends for Miata's of different heights? I will be raising mine to gain clearance for the addition of a splitter, as my lip was scraping along a turn in 3rd gear (steeply banked section of the track, "the bowl" of SOW CW) as it is.

This is what my car looks like coming out of the skidpad, I am in 2nd, i think at around 4-5k rpm?



EDIT: My bumps are 1.5" and I have 1.0" bumps (of rubber though) at my disposal...

Last edited by greeenteeee; 11-30-2010 at 09:04 PM.
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Old 11-30-2010, 08:59 PM   #29
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Quote:
Originally Posted by greeenteeee View Post
I am using bumpstops that came with my coil-overs... for the front specifically, since I had 115mm (4.5" ish) of available stroke and left with 3" of travel with bumpstop @ full droop, I assume they are probably 1.5" long.

Do you have a link to what FCM recommends for Miata's of different heights? I will be raising mine to gain clearance for the addition of a splitter, as my lip was scraping along a turn in 3rd gear (steeply banked section of the track, "the bowl" of SOW CW) as it is.
Yeah, my recent question on the XIDA vs FCM thread at m.net brought this out from him:

http://forum.miata.net/vb/showthread.php?t=401320
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Old 11-30-2010, 09:03 PM   #30
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Originally Posted by wannafbody View Post
What is the optimal front ride height for different springs.
Somewhere between this


and this
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Old 11-30-2010, 09:10 PM   #31
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Quote:
Originally Posted by greeenteeee View Post
I don't think so. 949's cars are all pretty low and they measure from the "pinch weld".... I know my front pinch welds may be pretty fucked up, but in any case, I dialed in 4 1/8" FRONT and 4.375" REAR to take into account if my pinch welds had crushed upwards a bit... and my front tie rods and control arms are angled upwards (1990 non-LE tie rod ends).
how much static camber do you have?
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Old 11-30-2010, 09:34 PM   #32
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-2.9 front -2.2 rear. I tried to copy 949's -2.5 but my toe ended up being 0 at -2.2 so I left it. On my best session going clockwise, my driver rear was all within 1 degree btwn the inner, mid and outer tread. The driver front had more heat on the inside, but it was only 9 degrees off from the outer tread-- I will probably leave it as the inside takes care of all the braking anyway.
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Old 11-30-2010, 09:36 PM   #33
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Quote:
Originally Posted by greeenteeee View Post
-2.9 front -2.2 rear. I tried to copy 949's -2.5 but my toe ended up being 0 at -2.2 so I left it. On my best session going clockwise, my driver rear was all within 1 degree btwn the inner, mid and outer tread. The driver front had more heat on the inside, but it was only 9 degrees off from the outer tread-- I will probably leave it as the inside takes care of all the braking anyway.
I can see where these ride heights and camber setting work with the radials out there.
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Old 11-30-2010, 11:12 PM   #34
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Originally Posted by 05pearl View Post
Somewhere between this


and this
The first pic looks optimal for rallying and the second for hardparking
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Old 12-01-2010, 02:21 PM   #35
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nagasee - ground
greeeeeeeeeenteeeeeeee - those spring rates you posted are crap. run a larger front rate or smaller rear
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Old 12-01-2010, 02:39 PM   #36
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Heavier than 560lbs/in up front? I'm only using street tires though... with 560F 448R, I've thought of going down to a 392R before going w/ a stiffer spring up front.

EDIT: Unless you think RE-11s can handle a 12k up front, I am willing to try on my next setup, which will include raising the height a bit and adding some aero. (stock power)

Last edited by greeenteeee; 12-01-2010 at 03:49 PM.
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Old 12-01-2010, 03:54 PM   #37
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Old 12-01-2010, 07:39 PM   #38
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Quote:
Originally Posted by greeenteeee View Post
Heavier than 560lbs/in up front? I'm only using street tires though... with 560F 448R, I've thought of going down to a 392R before going w/ a stiffer spring up front.

EDIT: Unless you think RE-11s can handle a 12k up front, I am willing to try on my next setup, which will include raising the height a bit and adding some aero. (stock power)
Emilio recommends 450# for a streetcar with 205/50/15. 560# should be plenty of front rate but I'd drop the rear down to 350.
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Old 12-01-2010, 10:05 PM   #39
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If your running a stiff sidewall the spring rate is not as critical. ie re-11, rs3, azenis
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Old 12-02-2010, 09:07 PM   #40
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Quote:
Originally Posted by wannafbody View Post
Emilio recommends 450# for a streetcar with 205/50/15. 560# should be plenty of front rate but I'd drop the rear down to 350.
This is why I was reluctant on changing the front spring, I am staying away from R comps. I barely did my first track day w/ an EHP tire on the Miata.
Quote:
Originally Posted by jacob300zx View Post
If your running a stiff sidewall the spring rate is not as critical. ie re-11, rs3, azenis
I agree 10/8 is not a commonly used rate as the FRC is indeed pretty low. My setup now is 53.3%. Sonny/VagaXT is one of the fastest drivers in Cali and he uses 10/8... with that said I cannot readily agree that the 10/8 is simply "crap,"

I think it is also a matter of driver preference, and after 2 trips to Streets of Willow and 1 trip to Buttonwillow, I do not yet know what kind of spring change I want to do. I'm doing Buttonwillow again later this month so hopefully I will be able to figure out my next step. My last trip to SOW did net me a new personal best time (first time using RE-11 on the Miata) so it's hard to change the setup so soon.

Didn't know the RE-11 had a stiff enough sidewall to warrant that stiff of a spring, I thought 12k and up was solely for R compounds. I am contemplating going down to 10/7, or up to 12/8. FRC will be 61% either way, but since I might be running into travel issues, I may try going to 12 up front.

EDIT: corrected FRC to 53.3%

Last edited by greeenteeee; 12-10-2010 at 08:40 PM.
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