Eccentric bolt torque - 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 11-24-2011, 11:33 AM   #1
Elite Member
Thread Starter
iTrader: (5)
 
Join Date: Dec 2010
Location: Raleigh, NC
Posts: 1,970
Total Cats: 49
Default Eccentric bolt torque

Hey all, Just wanted to get some advice from you track guys on what you torque the lower control arm eccentrics to? I used the FSM spec and I have been getting a noise which I am 95% sure is my eccentric bolts moving around some. From reading around, I have seen posts from as low as 100 ft-lbs to as high as 180 ft-lbs.

Is it safe to say that 130-150 ft-lbs is fine? My car is tracked frequently, and I would like to avoid having to torque my eccentrics at the track, but have no problems doing it before the event.
Seefo is offline   Reply With Quote
Old 11-24-2011, 02:21 PM   #2
Elite Member
iTrader: (4)
 
MartinezA92's Avatar
 
Join Date: Aug 2009
Location: Mountain View, CA
Posts: 1,702
Total Cats: 28
Default

That's more than enough, however if you think your eccentrics are making noise....I would suspect that you'd notice it in the steering wheel with your alignment being horribly off. They should not move. At all. Unless you torqued them to like 30 and expected them to stay put.

tl;dr I'd suspect that the noise is something else.
MartinezA92 is offline   Reply With Quote
Old 11-24-2011, 03:03 PM   #3
Junior Member
iTrader: (1)
 
Join Date: Sep 2009
Location: Colorado
Posts: 166
Total Cats: 5
Default

If they are not tight enough, then you will get a clunk in one direction, then maybe in the other, but again in the first direction. I have "been there done that" double wrench them for leverage. You can not get them tight enough with a normal length 3/8 ratchet. DOT-R tires have lots more grip and put more stress on the bolts.
GraemeD is offline   Reply With Quote
Old 11-24-2011, 03:07 PM   #4
Supporting Vendor
iTrader: (31)
 
Savington's Avatar
 
Join Date: Nov 2006
Location: Sunnyvale, CA
Posts: 14,357
Total Cats: 1,322
Default



As tight as you can humanly get them.
Savington is offline   Reply With Quote
Old 11-24-2011, 03:49 PM   #5
Elite Member
Thread Starter
iTrader: (5)
 
Join Date: Dec 2010
Location: Raleigh, NC
Posts: 1,970
Total Cats: 49
Default

Quote:
Originally Posted by MartinezA92 View Post
That's more than enough, however if you think your eccentrics are making noise....I would suspect that you'd notice it in the steering wheel with your alignment being horribly off. They should not move. At all. Unless you torqued them to like 30 and expected them to stay put.

tl;dr I'd suspect that the noise is something else.
You maybe right, but I have searched through my car in every place I can reach and can't figure it out. Here what I can deduce about the noise:

1) it sounds like what the brake clips sound when they are bit loose and rub around on the caliper (but less high pitch and louder). high pitch, metallic, tink tink style noise. I suspect its a loose bolt or washer some where thats hitting against metal.
2) its audible at 55mph, and doesn't necessarily change with speed beyond that. I think its slightly more frequent at 80 mph, or perhaps slightly louder, but not much.
3) its not tied to any particular action. for example hitting bumps doesn't cause it, nor does turning, braking, or anything. purely speed and maybe vibration related.
4) its not tied to engine speed or clutch
5) I first got it after spinning out at CMP, which royally fucked my alignment.
6) I got the car aligned for the next weekend and never heard it.
7) I put in new CA bushings and coilovers, torqued everything to FSM spec. and the noise came back.
8) I got an alignment done, and it went away again.
9) I drove down to Atlanta, did my first day on track, no noise.
10) Halfway through the second day, the noise came back. I pretty much run up most gators and had one small on track spin which was nothing compared to the one at CMP.



I got back home, checked the torque on all my Eccentrics and only 2 were still torqued to spec. the rest where well below 83 ft-lbs. I am torquing them down now to 130, I shall report back.
Seefo is offline   Reply With Quote
Old 11-24-2011, 06:26 PM   #6
Supporting Vendor
iTrader: (3)
 
emilio700's Avatar
 
Join Date: May 2005
Posts: 5,309
Total Cats: 1,328
Default

Quote:
Originally Posted by Savington View Post

As tight as you can humanly get them.
+1

The more grip you generate, the more you have to over-torque them and the more frequently they have to be replaced. We consider the eccentrics to be consumables and bring spares to the track.
emilio700 is offline   Reply With Quote
Old 11-24-2011, 09:02 PM   #7
Senior Member
iTrader: (4)
 
Join Date: Nov 2009
Location: Toronto, ON
Posts: 1,479
Total Cats: 6
Default

Quote:
Originally Posted by Savington View Post

As tight as you can humanly get them.
Does this mean by hand, or air tools?
dgmorr is offline   Reply With Quote
Old 11-24-2011, 09:19 PM   #8
Elite Member
iTrader: (12)
 
Join Date: Apr 2008
Location: Springfield IL
Posts: 2,750
Total Cats: 24
Default

Mark the eccentric with a marker on one of the notches and then etch that area in on the subframe as a reference point.
chpmnsws6 is offline   Reply With Quote
Old 11-24-2011, 09:23 PM   #9
Supporting Vendor
iTrader: (31)
 
Savington's Avatar
 
Join Date: Nov 2006
Location: Sunnyvale, CA
Posts: 14,357
Total Cats: 1,322
Default

Quote:
Originally Posted by dgmorr View Post
Does this mean by hand, or air tools?
I usually stick a 1/2" ratchet on it and pull as hard as I can.
Savington is offline   Reply With Quote
Old 11-25-2011, 12:48 AM   #10
Elite Member
Thread Starter
iTrader: (5)
 
Join Date: Dec 2010
Location: Raleigh, NC
Posts: 1,970
Total Cats: 49
Default

Quote:
Originally Posted by Savington View Post
I usually stick a 1/2" ratchet on it and pull as hard as I can.
I pretty much did this, with an extension on the end. After a few, I checked the torque to make sure it was atleast 130 ft-lbs. I think I can probably feel it after a few times torquing them all down.
Seefo is offline   Reply With Quote
Old 11-25-2011, 09:00 AM   #11
Junior Member
 
Join Date: Sep 2008
Location: Davie, Florida
Posts: 66
Total Cats: 3
Default

As Emilio mentioned, if you think it's the eccentric bolts try replacing them and see if that fixes the problem.
CoralDoc is offline   Reply With Quote
Old 11-25-2011, 09:30 AM   #12
Supporting Vendor
iTrader: (3)
 
emilio700's Avatar
 
Join Date: May 2005
Posts: 5,309
Total Cats: 1,328
Default

The oem bolts off of the NA don't last very long. by the time you own the car the bolts have rt been used several times and theyre already stretched out. when we acquire an NA or NB, we just start with brand new bolts. the old part number has been superseded by the NB bolt.
emilio700 is offline   Reply With Quote
Old 11-25-2011, 04:49 PM   #13
Elite Member
Thread Starter
iTrader: (5)
 
Join Date: Dec 2010
Location: Raleigh, NC
Posts: 1,970
Total Cats: 49
Default

Well, Martinez might be right. I had my brother sit in the car and he says its coming from behind the driver's side, where that cluster **** of wires and connectors are right beside the roll bar foot. I will do more investigating, I just wish I could take my seat out and drive the car so I can hear where behind me, but thats not really safe lol.
Seefo is offline   Reply With Quote
Old 11-25-2011, 11:23 PM   #14
Elite Member
Thread Starter
iTrader: (5)
 
Join Date: Dec 2010
Location: Raleigh, NC
Posts: 1,970
Total Cats: 49
Default

Found the offending bolt and nut. Two of the bolts on my passenger side seat rail had loosened up and one fell off. I was removing my bose amplifier and brain storming on gutting the doors and noticed that my seat had an awful lot of play in it that I didn't remember being there when I first put it in. slid my had down and noticed the loose nut. pulled the seat and there was the nut that had fallen off. put it all back together, took it out for the test drive and everything is nice quite (well not quite at all, but no more pinging noises). I am really surprised none of my instructors mentioned anything during my last event, but whatevers. Tomorrow, I tackle a bit of wire tucking and door gutting.

Either way, I am glad this happened, I learned all about my eccentrics and torquing them. And it motivated me to start tacking some serious weight reduction behind the dash.
Seefo is offline   Reply With Quote
Old 11-28-2011, 01:28 PM   #15
Junior Member
 
Join Date: Oct 2010
Location: Wake Forest, NC
Posts: 175
Total Cats: 0
Default

I usually torque mine with a breaker bar.

Ive never seen mine move over a year of track events, street driving, curb hopping, two wheeling and a couple of lawn mowing excursions.
cucamelsmd15 is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Another Cast Manifold Corky Bell Prefabbed Turbo Kits 18 11-22-2016 10:01 PM
Need help - Stock Balancer and Fastforward overlay pulleys Frank_and_Beans Supercharger Discussion 13 09-12-2016 09:17 PM
WTB MP62 (Hotside) (NB2) Rick02R WTB 3 01-03-2016 08:18 PM
WTB Bellhousing Bolts patsmx5 WTB 1 10-01-2015 10:43 AM


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 06:41 AM.