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914World.com _ The Paddock _ I killed a sway-bar
Posted by: Jetsetsurfshop Sep 1 2021, 07:22 PM
I thought I'd share these pics. I never believed that a sway-bar would break. Anyone else seen this before?
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Posted by: infraredcalvin Sep 1 2021, 11:34 PM
Wow, a tarrett as well!
Sent it to them see what they’ll do for you. I know they’ll sell you a bar only, you may want to up the size though…
Posted by: Shivers Sep 2 2021, 05:22 AM
Wow, that is some hard charging
Posted by: Jetsetsurfshop Sep 2 2021, 07:23 AM
Wow, a tarrett as well!
Sent it to them see what they’ll do for you. I know they’ll sell you a bar only, you may want to up the size though…
Good info. I didn't know they would just send a bar. I'll have to hit them up. Still have to measure it but I think its their bigger one. I'm not really upset about it. It's been used hard at Sebring for 12 years. Still never expected a sway-bar to fail.
Posted by: Jetsetsurfshop Sep 2 2021, 07:24 AM
Wow, that is some hard charging
I think the four-offs has taking their toll too.
Posted by: Jetsetsurfshop Sep 2 2021, 07:29 AM
More pics. 
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Posted by: jd74914 Sep 2 2021, 09:50 AM
Curious what the bar ends that are in the arm look like.
I would expect it to break there given that is the reaction location for the bending load. Once you add the combined torsional load on you can really jack up the stresses in a Mohr's circle. You must have reached it's high cycle fatigue limit-wow.
Posted by: stownsen914 Sep 2 2021, 09:53 AM
That's impressive.
Sometimes it's hard to tell after the fact, but is there any obvious sign of damage that might have led to the fracture. Sometimes if you clean it up well and look closely at the failed part, you can tell where the crack started and look for a stress riser like scoring on the surface or some other damage.
Another thing I've noticed - I've set up a 911 and 914 with the through body front swaybar, and both of them had significant binding at triangular bushing mounts. Basically the vertical surfaces that the mount bolt to weren't parallel, so when mounted the bar really bound up to the point that I couldn't move it by hand at all. I had to put washers under two of the three triangular bushing mounts, on both sides of the car, to get them parallel.
Posted by: Jetsetsurfshop Sep 2 2021, 10:59 AM
That's impressive.
Sometimes it's hard to tell after the fact, but is there any obvious sign of damage that might have led to the fracture. Sometimes if you clean it up well and look closely at the failed part, you can tell where the crack started and look for a stress riser like scoring on the surface or some other damage.
Another thing I've noticed - I've set up a 911 and 914 with the through body front swaybar, and both of them had significant binding at triangular bushing mounts. Basically the vertical surfaces that the mount bolt to weren't parallel, so when mounted the bar really bound up to the point that I couldn't move it by hand at all. I had to put washers under two of the three triangular bushing mounts, on both sides of the car, to get them parallel.
We had to washer up mine to get it to move smoothly. When I removed what was left of the bar it moved great. No binding what so ever.
I did find a video from a recent event where a dropped the passenger front wheel in turn one at Sebring. It was a pretty hard thud. Maybe I cracked it then?? The funny part if that I had a spin the next lap. I remember thinking that I wasn't really offline and the spin shouldn't have happened.
I'll work on the video tonight. Maybe we have a smoking gun.
Posted by: stownsen914 Sep 2 2021, 11:50 AM
Maybe we have a smoking gun.
Sounds like a candidate. It does make sense that it might crack / partially break at first, and then shear off a short time later. And oversteer in the interim!
Posted by: 914werke Sep 2 2021, 12:19 PM
Is it a hollow bar ?
Posted by: Jetsetsurfshop Sep 2 2021, 02:38 PM
Is it a hollow bar ?
It is a hollow bar.
Posted by: sixnotfour Sep 2 2021, 08:10 PM
hollow hybred..or lessbred..True hollows are through hollow...I am sure you will get free replacement..lesser design..
Posted by: stownsen914 Sep 4 2021, 06:10 AM
True hollows are through hollow
Hadn't noticed that in the pics. I'd agree the fact that it broke at the interface of the hollow bar and the fabricated end, probably isn't a coincidence.
Is the square end welded to the hollow bar?
Posted by: Jetsetsurfshop Sep 4 2021, 09:53 AM
https://www.youtube.com/watch?v=a9Meh2OBiBY
You can see the wheel drop out of turn one at the 8:40 mark.
There is also a great spin at the 22:25 mark. I was P2 at this point. Before the race was done the Z-car broke. I could have finished P1!!!! 
Posted by: Jetsetsurfshop Sep 4 2021, 03:59 PM
Is the square end welded to the hollow bar?
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Posted by: stownsen914 Sep 5 2021, 06:08 AM
I'd guess it failed at the weld (or right next to it).
Tarrett might be in pictures of the failure.
Posted by: ChrisFoley Sep 5 2021, 08:23 AM
Obviously it had years of service at the mid to upper range of it's load capacity. Not much wonder it finally failed. Multiple potential failure points. I never did like that design. Splined hollow bars are the way to go.
Posted by: Jetsetsurfshop Sep 6 2021, 10:59 AM
Obviously it had years of service at the mid to upper range of it's load capacity. Not much wonder it finally failed. Multiple potential failure points. I never did like that design. Splined hollow bars are the way to go.
Hey Chris,
What does the splined bars look like?
Shane
Posted by: stownsen914 Sep 6 2021, 12:25 PM
I put a Speedway Engineering bar on the front of my 914. They come in various diameters, wall thicknesses, and lengths to fit just about any car. I've been very happy with it. Not exactly a bolt on though.
http://1speedway.com/index.php?route=product/category&path=76
Posted by: sixnotfour Sep 6 2021, 05:35 PM
https://www.jwemotorsports.com/suspension
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Posted by: ChrisFoley Sep 8 2021, 11:37 AM
I put a Speedway Engineering bar on the front of my 914. They come in various diameters, wall thicknesses, and lengths to fit just about any car. I've been very happy with it. Not exactly a bolt on though.
http://1speedway.com/index.php?route=product/category&path=76
I've been offering a 914 front anti-sway bar kit for many years using Speedway Engineering bars and arms.
I'm down to a single 1" bar in stock. After that one is gone I'm done selling sway bar kits.
Posted by: Justinp71 Sep 8 2021, 06:40 PM
https://www.youtube.com/watch?v=a9Meh2OBiBY
You can see the wheel drop out of turn one at the 8:40 mark.
There is also a great spin at the 22:25 mark. I was P2 at this point. Before the race was done the Z-car broke. I could have finished P1!!!!
Curious what do you have for a motor in your car?
Posted by: Jetsetsurfshop Sep 10 2021, 12:06 PM
https://www.youtube.com/watch?v=a9Meh2OBiBY
You can see the wheel drop out of turn one at the 8:40 mark.
There is also a great spin at the 22:25 mark. I was P2 at this point. Before the race was done the Z-car broke. I could have finished P1!!!!
Curious what do you have for a motor in your car?
Its a 4.
Heres what I can recall.
2258cc
10.5 compression ratio
Hoffman heads (Len hooked them up)
44 Webers
Performance webcam. (cant remember whats it specs were)
Tangerine Headers
Makes 160hp at 5800rpm.
The guy in the 350Z was newer to racing, but he should have really pulled away from me on the straights.
Posted by: ThePaintedMan Sep 10 2021, 12:57 PM
Good to see you back on track, Shane. I'm jealous! Your driving has seriously improved over the years.
The sway bar is impressive. I bet Chris, as usual, hit the nail on the head. Think how much abuse that bar has seen at Sebring over the years, and with that drop-off in T1, it's probably what did it in. Wear and tear, I guess.
Posted by: stownsen914 Sep 10 2021, 07:31 PM
I've been offering a 914 front anti-sway bar kit for many years using Speedway Engineering bars and arms.
I'm down to a single 1" bar in stock. After that one is gone I'm done selling sway bar kits.
Sounds like a good option! (And probably sold by now)
Posted by: Jetsetsurfshop Sep 11 2021, 07:39 AM
Good to see you back on track, Shane. I'm jealous! Your driving has seriously improved over the years.
The sway bar is impressive. I bet Chris, as usual, hit the nail on the head. Think how much abuse that bar has seen at Sebring over the years, and with that drop-off in T1, it's probably what did it in. Wear and tear, I guess.
Im sure this didn't help.
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Posted by: bdstone914 Nov 26 2021, 10:44 AM
I thought I'd share these pics. I never believed that a sway-bar would break. Anyone else seen this before?
@http://www.914world.com/bbs2/index.php?showuser=12907
Any chance that bar had been removed an reinstalled with it flipped end for end?
I can see twisting it the oposite direction could cause failure.
Posted by: bdstone914 Nov 26 2021, 03:53 PM
I thought I'd share these pics. I never believed that a sway-bar would break. Anyone else seen this before?
@http://www.914world.com/bbs2/index.php?showuser=12907
Any chance that bar had been removed an reinstalled with it flipped end for end?
I can see twisting it the oposite direction could cause failure.
Posted by: Charles Freeborn Nov 26 2021, 09:48 PM
Good to see you back on track, Shane. I'm jealous! Your driving has seriously improved over the years.
The sway bar is impressive. I bet Chris, as usual, hit the nail on the head. Think how much abuse that bar has seen at Sebring over the years, and with that drop-off in T1, it's probably what did it in. Wear and tear, I guess.
Im sure this didn't help.
Ouch. Lemme know if you need a roller to start over with.
Posted by: sixnotfour Nov 28 2021, 05:48 PM
![popcorn[1].gif](style_emoticons/default/popcorn[1].gif)
Bruce Levens 962
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Posted by: Cracker Nov 28 2021, 09:42 PM
Years of use and abuse will take its toll - I would doubt it was from your on-track use - "shock" due to the offs likely led to the failure. It probably had hairline cracks and finally let go...
Race teams will routinely x-ray stressed components for imperfections and replace them on time/hours - much like aircraft. You say you've run this for 10+ years (I believe); if so, it was LONG overdue for replacement...
Posted by: blabla914 Dec 10 2021, 07:22 PM
I put a Speedway Engineering bar on the front of my 914. They come in various diameters, wall thicknesses, and lengths to fit just about any car. I've been very happy with it. Not exactly a bolt on though.
http://1speedway.com/index.php?route=product/category&path=76
I've been offering a 914 front anti-sway bar kit for many years using Speedway Engineering bars and arms.
I'm down to a single 1" bar in stock. After that one is gone I'm done selling sway bar kits.
How did I not know this?
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