Broken sway bar stud...

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Junkwhale
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Broken sway bar stud...

Post by Junkwhale » Fri Feb 06, 2015 9:57 am

Was swapping my rear sway bar this morning and managed to snap one of the studs/bolts that the sway bar bracket bolts on to.

Does anyone know if these are just pressed in or welded? Tried giving it a good few whacks with a hammer to push it out but doesn't want to budge...

The culprit:
Image

Snapped bolt/stud
Image

back side - bit hard to take a good pic
Image

any ideas?

SLYDIT
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Post by SLYDIT » Fri Feb 06, 2015 10:01 am

more than likely spot welded in.
drill it out and fit a new grade 8 or 10 bolt in there
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Brainflex
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Post by Brainflex » Fri Feb 06, 2015 10:02 am

if hitting it with a big hammer n punch hasn't moved it then drill it out. 3mm bit first them move up in size to diameter of the bolt. Centre punch before drilling.

Junkwhale
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Post by Junkwhale » Fri Feb 06, 2015 10:04 am

yeah thats what I figured, was hoping there might be some other way as that will mean buying a drill... good excuse I guess!

4A-GE
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Post by 4A-GE » Fri Feb 06, 2015 10:19 am

Moar powar tools are nevar a bad idea.

Junkwhale
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Post by Junkwhale » Fri Feb 06, 2015 6:26 pm

Thanks for the input all - sorted now - new impact drill and a high tensile bolt where the old stud was :D

Image

SLYDIT
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Post by SLYDIT » Fri Feb 06, 2015 7:42 pm

what shock/spring setup are you running?
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Junkwhale
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Post by Junkwhale » Sat Feb 07, 2015 8:12 am

OEM bilsteins that came on jdm NB RS's + some secondhand flying miata springs I bought off a US forum. Not sure if they're gen 1 or 2 of the FM springs- Spring rates are 348f/233r lbs/in for earlier ones and 318f/233r lbs/in if they're the later version (6/4 and ~5.5/4 kg/mm respectively).

jtsoldier
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Post by jtsoldier » Sun Feb 08, 2015 1:00 pm

Let us know how they go, will ya? since you're essentially driving on the same shitty roads as I...

Junkwhale
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Post by Junkwhale » Mon Feb 09, 2015 11:44 am

jtsoldier wrote:Let us know how they go, will ya? since you're essentially driving on the same shitty roads as I...
I'm in Wellington now mostly, so the roads are (ever so slightly) less crappy, but I did drive around chch a fair bit with those springs/shocks. If anything I think going to the stiffer springs and shorter bumpstops improved the ride quality over rough stuff when compared to the same shocks on the OEM springs which have approx half the spring rate.

The FM springs do feel better controlled in terms of roll/dive/squat, although there was still too much roll & dive/squat at high speeds/high loads. The big sways seem to have tamed the roll significantly; cornering is very flat now and feels much less dramatic. I don't really notice any difference in harshness/ride quality with the sway bars vs without either, so pretty happy with them.

Front roll couple % is at about 64% so should have a small tendency to understeer at the moment. Going to get a wheel alignment this week and will go with more camber in front than rear to push it more towards neutral. Probably something like -1.8 front, -1.4 rear, ~5 degrees caster, and 0 toe as a baseline.

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Post by SLYDIT » Mon Feb 09, 2015 8:21 pm

so you have front and rear upgraded sways?

generally as people go stiffer springs they keep the rear sway standard or delete it all together as the rear becomes too lively.
your spring rates arent that stiff. 8kg or even 10kg frnts are pretty common. most common seems to be a 8kg/5kg with an upgraded front bar standard rear bar.
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Junkwhale
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Post by Junkwhale » Tue Feb 10, 2015 10:22 am

SLYDIT wrote:so you have front and rear upgraded sways?

generally as people go stiffer springs they keep the rear sway standard or delete it all together as the rear becomes too lively.
your spring rates arent that stiff. 8kg or even 10kg frnts are pretty common. most common seems to be a 8kg/5kg with an upgraded front bar standard rear bar.
Yep I'm aware the springs are soft - they're just as stiff as I want to go on old OEM NB bilsteins. Will go for stiffer springs with coilovers that can handle the higher rates when I get to it - 700lbs/400lbs (12.5kg/7kg) is common for sticky 225 tires. Going to get the safety equipment (half cage, seats, harnesses, fire extinguisher etc) sorted first and actually do some events before I worry about that though. I've joined the Harbour capital car club ( http://www.hccc.org.nz/ ) here in welly and plan on doing some autocross, track days, sprints, hill-climbs etc.

Current sways are an RB 1.125" (28.5mm hollow) front bar and 14mm mazdaspeed rear. I put the 14mm on to try it as it was pretty understeer-ey with the stock 12mm rear and big RB front. The RB bar is borderline too much for street tyres, but I figured I might as well buy the front bar I plan on using in the end so will manage with softer springs and big bars for now...

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Post by Junkwhale » Tue Feb 10, 2015 11:06 am

Front bar + RB mount reinforcement blocks:
Image

marcellarius
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Post by marcellarius » Tue Feb 10, 2015 2:20 pm

Rear sway bar delete is a good way to fail a WOF, I discovered.

Seemingly the WOF rules allow you to upgrade to a larger diameter bar, but going to a smaller bar or disconnecting entirely is a fail.

jtsoldier
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Post by jtsoldier » Tue Feb 10, 2015 2:55 pm

Are you serious?

Only thing I've found about sway bars in the thresholds for LVV Certification was requiring it for upsized sway bar mounts, suggesting larger bars should be the ones considered illegal...?

Junkwhale
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Post by Junkwhale » Tue Feb 10, 2015 3:39 pm

That is pretty surprising (and a bit dumb in the context of an mx5 missing one - it's just going to make it understeer a bit more and roll slightly more in the rear before reaching the limit of traction).

Looks like you could get away with a smaller bar, but disconnecting breaks 13. a) on this page of the VIRM- http://vehicleinspection.nzta.govt.nz/v ... on-systems
13. Any other suspension component (including air suspension):

a) is insecure or missing

marcellarius
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Post by marcellarius » Wed Feb 11, 2015 10:26 am

Yeah, got failed on the missing suspension component thing. I forgot to put it back on when I had the car jacked up and figured it wouldn't be an issue because it's not a safety issue... hah.

Table 9-1-1 lists the modifications excluded from LVV certification and it specifically says "Larger diameter anti-sway bar"; nothing about smaller, or removing.

jtsoldier
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Post by jtsoldier » Wed Feb 11, 2015 3:28 pm

bloody thing.. in some cases it's always excluded, other times certification is always required! Should probably re-read the whole thing properly.

Cheers on the heads up. Odd one...

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Post by SLYDIT » Wed Feb 11, 2015 8:41 pm

have a look at MCA suspension in australia. they do an NB coilover set with high spring rates that might just be what you are after.
oh sway bar blocks are good..
https://www.youtube.com/watch?v=CQG5aUr ... qisWRnG3Bg

and then with reinforcing blocks...
https://www.youtube.com/watch?v=CQG5aUr ... qisWRnG3Bg
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