Fisher Fury - Snapped chassis rail
Discussion
Anyone seen anything like this before? Not sure why it should snap but it went with a hell of a bang!
http://www.robcollingridge.com/kitcar/drive/2011/0...
Rob
http://www.robcollingridge.com/kitcar/drive/2011/0...
Rob
robcollingridge said:
Anyone seen anything like this before? Not sure why it should snap but it went with a hell of a bang!
http://www.robcollingridge.com/kitcar/drive/2011/0...
Rob
http://www.robcollingridge.com/kitcar/drive/2011/0...
Rob
What is the dark brown part in the foreground of the picture?
Looks like it, or a mount for it, is welded to the underside of the rail.
If suspension stresses are going through that joint then repeated flex could cause the failure. Also the material alongside a weld will normally be weaker having been heated during the welding process.
Steve
Having read your page about what you found, is it possible that by using only one of the two mounts that the resulting twisting has caused the metal to fatigue and then snap?
Also the weakest point of a tube is about 10-20mm from a weld so triangulating and using all the mounts should help.
Also the weakest point of a tube is about 10-20mm from a weld so triangulating and using all the mounts should help.
They all seem crap as standard on the lower wishbone and diff mounts. Mine is freelander, but I had the same issue. Mounts twisted then snapped. Had to box & triangulate the brackets.
Given that it's hard mounted and bike engined the diff gets a lot of shock so it's not surprising, but then again it's something that should be stronger from the factory.
Given that it's hard mounted and bike engined the diff gets a lot of shock so it's not surprising, but then again it's something that should be stronger from the factory.
Sorry only looked at the first picture...didn't realise there were more.
How is the front of the diff mounted?
If it is on rubber mounts then that will be why the rear mount has failed.
As has been said the OEM mount for the diff would have been a large rubber mount using both of the fixing holes.
A triangulated bracket will go some way to resolving the problem but will not be ideal if the front is rubber mounted. A better solution would be a rubber mount on that chassis rail.
Do you have someone to do the work? Where are you based?
Steve
How is the front of the diff mounted?
If it is on rubber mounts then that will be why the rear mount has failed.
As has been said the OEM mount for the diff would have been a large rubber mount using both of the fixing holes.
A triangulated bracket will go some way to resolving the problem but will not be ideal if the front is rubber mounted. A better solution would be a rubber mount on that chassis rail.
Do you have someone to do the work? Where are you based?
Steve
There are no rubber mounts on the Fury installation. The diff is mounted at the front using some very strong mounts. There is a 10mm plate which is also used for the harnesses at the front lower edge. At the top there are dedicated mounts using a 10mm through bolt.
I'm going to get this looked at by someone who race prepares and repairs these cars. Hoping AB Performance can do it for me as they are quite close (I'm in Suffolk). I want some triangulation added too. I've heard people have had issues with V8 engines in the Fury but I've got an R1 engine in mine.
Rob
I'm going to get this looked at by someone who race prepares and repairs these cars. Hoping AB Performance can do it for me as they are quite close (I'm in Suffolk). I want some triangulation added too. I've heard people have had issues with V8 engines in the Fury but I've got an R1 engine in mine.
Rob
robcollingridge said:
There are no rubber mounts on the Fury installation. The diff is mounted at the front using some very strong mounts. There is a 10mm plate which is also used for the harnesses at the front lower edge. At the top there are dedicated mounts using a 10mm through bolt.
I'm going to get this looked at by someone who race prepares and repairs these cars. Hoping AB Performance can do it for me as they are quite close (I'm in Suffolk). I want some triangulation added too. I've heard people have had issues with V8 engines in the Fury but I've got an R1 engine in mine.
Rob
Mines R1..... Top diff mount twisted and snapped and the front one cracked. Was a Freelander diff though not sierra. They're obviously not made strong enough.I'm going to get this looked at by someone who race prepares and repairs these cars. Hoping AB Performance can do it for me as they are quite close (I'm in Suffolk). I want some triangulation added too. I've heard people have had issues with V8 engines in the Fury but I've got an R1 engine in mine.
Rob
robcollingridge said:
There are no rubber mounts on the Fury installation. The diff is mounted at the front using some very strong mounts. There is a 10mm plate which is also used for the harnesses at the front lower edge. At the top there are dedicated mounts using a 10mm through bolt.
I'm going to get this looked at by someone who race prepares and repairs these cars. Hoping AB Performance can do it for me as they are quite close (I'm in Suffolk). I want some triangulation added too. I've heard people have had issues with V8 engines in the Fury but I've got an R1 engine in mine.
Rob
Mines R1..... Top diff mount twisted and snapped and the front one cracked. Was a Freelander diff though not sierra. They're obviously not made strong enough.I'm going to get this looked at by someone who race prepares and repairs these cars. Hoping AB Performance can do it for me as they are quite close (I'm in Suffolk). I want some triangulation added too. I've heard people have had issues with V8 engines in the Fury but I've got an R1 engine in mine.
Rob
Rob, Andy will sort it , no problems.
A lot of the earlier Fury racers regularly pulled the wishbone ears off the chassis before everyone started to triangulate them.Im pretty sure its one issue Martin Bell was in the middle of resolving.
Dont panic, Ive seen some RGB racers which looked like wrecks welded bck up and winning within weeks.
A lot of the earlier Fury racers regularly pulled the wishbone ears off the chassis before everyone started to triangulate them.Im pretty sure its one issue Martin Bell was in the middle of resolving.
Dont panic, Ive seen some RGB racers which looked like wrecks welded bck up and winning within weeks.
I had a similar issue with the diff mounting in my fury (sierra diff)
When I built the car the rear diff mounting wouldnt line up, so after speaking with Martin Bell he advised that using the front 2 mountings would be enough. After race 1 the diff moved and started baging around.
To solve the problem Ive build a mounting bracket from the lower metal work of the diff carrier to bolt to the backplate of the diff. Its been fine for a good 3 years.
If you want a pic of what ive done, let me know.
Lee
When I built the car the rear diff mounting wouldnt line up, so after speaking with Martin Bell he advised that using the front 2 mountings would be enough. After race 1 the diff moved and started baging around.
To solve the problem Ive build a mounting bracket from the lower metal work of the diff carrier to bolt to the backplate of the diff. Its been fine for a good 3 years.
If you want a pic of what ive done, let me know.
Lee
Yep, classic case of metal fatigue centered on that weld as the start point. If you look carefully, you might be able to see rust in the part of the crack by the weld.
It would fail with quite a bang which would sound worse by it resounding through the chassis and any panelling!
By the looks of it, that member is part of quite a minimal cage which takes all the loads, not only from the continual twisting of the diff in acceleration and deceleration but massive suspension and braking loadings in such a performance car. If the weld was not done adequately (looks like a 'blob' to me!) a small indentation in the tube would be left as a weakness. Over time, this is sufficient to provide a starting point for a crack caused by the alternate tensions and compressions of the member concerned. Eventually, it just can't take it anymore and bang!
Some more triangulation would definitely help in containing these forces but any faulty welding could lead to the same result eventually. My son suffered the same thing with an old TVR 3000M which I spent many happy hours underneath!
It would fail with quite a bang which would sound worse by it resounding through the chassis and any panelling!
By the looks of it, that member is part of quite a minimal cage which takes all the loads, not only from the continual twisting of the diff in acceleration and deceleration but massive suspension and braking loadings in such a performance car. If the weld was not done adequately (looks like a 'blob' to me!) a small indentation in the tube would be left as a weakness. Over time, this is sufficient to provide a starting point for a crack caused by the alternate tensions and compressions of the member concerned. Eventually, it just can't take it anymore and bang!
Some more triangulation would definitely help in containing these forces but any faulty welding could lead to the same result eventually. My son suffered the same thing with an old TVR 3000M which I spent many happy hours underneath!
Not quite the same, but my Phoenix a couple of weeks back had a similar "tear" on my engine mounting frame ( R1 ). The square tube was torn through on 3 sides, due to an M12 Engine mount bolt (diagonally opposite on the other side of the engine) shearing flush in the block. This was causing the frame to twist under load, and despite the rail still being relatively straight it still tore through on 3 sides. The engine was litterally about to fall out, and not what you want to find at Ashford services 45 minutes before your tunnel crossing.........
I know many Fury / Phoenix in the past having suffered similar to yours, indeed my own one snapped its rear diff carrier when new 8 years ago. Was beefed up at factory back then, and never been an issue since. If yours has not been beefed up already and triangulated / gusseted etc, don worry too much just get it strengthened, lots of us have already. Doesn't make it right, but not the end of the world either. Just check like mine that you do not have and sheared bolts which look OK to the eye but actually do bugger all and allow twisting under load.
I know many Fury / Phoenix in the past having suffered similar to yours, indeed my own one snapped its rear diff carrier when new 8 years ago. Was beefed up at factory back then, and never been an issue since. If yours has not been beefed up already and triangulated / gusseted etc, don worry too much just get it strengthened, lots of us have already. Doesn't make it right, but not the end of the world either. Just check like mine that you do not have and sheared bolts which look OK to the eye but actually do bugger all and allow twisting under load.
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