I thought you knew !!

[Ron Earp]

[ QUOTE ]
I'd rather know something was wrong before
I headed out to the track at 150 mph. And I'd like it out in
the open for all to see so that the same mistake is not repeated. Ian

[/ QUOTE ]

My thoughts exactly - much better said that I managed three posts ago. For the record I'm not involved with this particular post other than pointing out the fact that an open posting policy on this sort of thing is better for everyone concerned - manufactuer and owner alike - for precisely the reasons Ian stated.

Ron

 

[Chris Duncan]

"" I mean really, what could I say that would satisfy everyone regarding the integrity of Mark and of MDA?""

I can't pass judgement on MDA because I haven't seen all the evidence. My only thought was that MDA was still working out some bugs and they were having success at that as evidenced by more recent owners.

Even supposing there is some safety issue a retro fix to cars that are already built isn't all that difficult, the major factories do it all the time. Making mistakes is not wrong so long as they are corrected, it's just part of the process. Mistakes in fact are expected early in a production run. You never now how something is going to work until it's tested in the real world.

""Would posting my observations of every owners build techniques and short-comings make everyone more aware of what they are doing? Would that help others, would that be constructive? ""

YES. That's the main benefit of this forum. Many minds are better than a few. Collective experience outweighs the individual and it's compiled right here.

"""Would anyone would mind if I ruffeled a few forum members feathers for the sake of bringing things to all attention?""

That's the trick my friend, to do it diplomatically. It may be just as hard as building a car LOL.

"I hope to this point I have shown professional business practices and conduct under the circumstances."

Looks like it to me.

Best wishes for you and MDA's success.

 

[Keith]

Well said...

 

[Dave Gibbins]

Having been out of circulation for a few days, this thread has certainly developed!

I posted what I still believe to be the correct action –> if you have real safety concerns then you MUST say something. We could be talking about someone’s life here and that has to be a priority!

I think that Ian K has summed it up very well – I am sure Mark will investigate this straight away and if the concerns are proved to be justified, I am sure a modification will be offered to existing owners and incorporated within any new chassis that are built. However, if the concerns are found to be unwarranted, then I am sure that Mark will publish the findings for us all to take comfort from. I am equally sure that Chris and Frank will be very relieved to be proved wrong as the safety of others is their paramount concern

 

[Howard Jones]

Chris I guess you can measure chassis deflection with a known load at the end of a lever etc. etc.

I just had to laugh at the thought of a couple of you guys doing it that way. But you have to admit it would make a funny picture with two of you guys in your swim suits standing on the end of a 2X4 attached to your chassis out on the front lawn.
No harm ment.

I really think that this is a good example of this forum doing its job. Where else can prospective buyers have a look at the current crop of avaiable cars along with the thinking of the rest of us. Or for that matter those of us who are trying to build and develop our own cars wouldn't have had a place to go for help during our own builds.

I have gotten lots of ideas from looking at other cars, many of which were not GT40's and are not on this forum. I always try to offer up any information that I might have and has been asked for.

It should be understood that information you might get here should be backed up with your own homework.

If this place isn't a FORUM for ideas then what is it?

I would guess that a lot of GTD owners have been waiting to have a look at the MDA. After all it's kinda a follow on of our type. I think it looks very interesting and I would be looking at it on my short list if I was in the market today.

The chassis thing in my mind would be fairly easy to mod if in deed a mod was necessary. I have had people I respect look at my car so that they could offer advice. The old GTD chassis is in need of several mods some of which I got the idea here for and others I worked out on my own or with help form others.

Building these cars isn't just a assembly job at least in my mind. Their development is the part that makes the whole thing interesting to me.

I would think that all of the builders we all know and love have and will make changes in their designs from time to time, some of which will result in update kits for earlier owners.

No big deal really.

 

Hi Frank and all,

Before moving to South Africa in 1987, my Welsh car builder friend and partner, Norman Lewis, was an aircraft electrician with the RAF. He told me that all over the RAF workshops were signs - 'CHECK - DON'T ASSUME.' It must have rubbed off because that was always his philoposphy and as he rightly says in that industry if you assume and don't check an aeroplane will fall out off the sky. It doesn't simply turn left and hit the Armco, it falls a helluva long way with rather unpleasant consequences!

Mind you I caught him out once. When we were building the GT40 in 1990/91 I ordered a set of Halibrands from Image Wheels complete with Gulf orange centres (BMC Marigold - remember the MGBs!). When the wheels arrived air mail late one afternoon I couldn't resist fitting them to the partly built car. You know the feeling - just to have a look!

Problem. They didn't fit.

The next morning when I told Norman that the wheels had arrived he said, 'I bet you fitted them.' (Touch of sarcasm? - playing are you?)

'Sure' I said, 'But guess what - they don't fit.'

My Welsh friend turned pale! Luckily after some machining they fitted.

I always do as I'm told. Check - don't assume!

Avoid Armco barriers. They're hard!
Andre 40

 

[Dave Bilyk]

Andre, that reminds me of Benny Hill, who in one of his sketches, as a professor at the blackboard, said something like; 'Do not ASSUME, for if you ASSUME, you will make an ASS out of U and ME.'

Seriously, as Howard has said, 'The loading issues here are dynamic not static', and in my experience (largely Gas Turbines, Diesels, and Pumps), a lot of failures are associated with high dynamic loading due to natural frequency / resonance issues. With reciprocating engines, failures in chassis members can be associated with fatigue due to excitation of natural frequencies of vibration. In the case of an engine mounted on a chassis, the stresses are a combination of static loads, excitation levels, and magnification due to resonance. It is the latter that will usually be associated with failure.
If the chassis has a natural frequency that coincides with a certain engine rpm, and the engine runs at that rpm for significant periods of time, fatigue failure can result because the magnification of stress can be very high (e.g 20)
In cases like this, a structure that is nominally adequate can still fail due to fatigue loadings.

This can make things a bit of a lottery unless it is known by measurement or analysis where the natural frequencies are. Once you know, you can do something about it, but if you dont, occaisional failures are easily attributed to a lack of strength that are actually associated with resonance.

It is not my intention to present this as a reason for failure in any particular case, but as an illustration of the complexity of the subject of material failure in rotating equipment of any sort.

regards
Dave Bilyk

 

[Jim Downard]

O.K. I'll post one. Never assume that verbal information is right. I thank all who choose to chime in with concerns, but in my experiences, you'd better have some hard facts before that chime in. Come on engineers out there. I want to see some calculations with detailed information describing the problem. i.e. "hey mister, I noticed some of your bolts are loose" instead, " hey mister, you've got 3 lug bolts loose. I can see the space between the washer and the wheel" I know, a pretty lame example, but you know what I mean. I need some detailed information to fully assess the situation. I'm no engineer, but I can stand back and see dynamic forces at work from a standpoint a theory.
Jim

 

[Pat]

I think there is an element that has gotten lost here and that is an assumption of "good faith" on the part of the message contributor. In my experience with this forum, the vast majority of posts have been done with a sincere attempt to benefit fellow enthusiasts. (Some of you may recall my own leaking fuel cell rants and related safety concerns). Certainly there has been some partisanship and brand loyalty and occasional ridiculous legal threats but by in large, I have discovered friends with which I've actively corresponded (which I've never met) with valuable guidance on a variety of problems. My conclusion then is if there is an issue - post it. We’re intelligent people, let us decide the merits. Let’s also avoid the boorish threats and other such silliness. If I want any of that, I’ll just ask my mother in law if she would like a ride in my ’40 /ubbthreads/images/graemlins/wink.gif

 

On the subject of the MDA Chassis, I feel I have to set the matter straight. My company made the vast majority of the GTD chassis's, around 350 at a guess out of a total of just under 400. I also supplied the suspension & fuel tanks for GTD. I also supplied chassis's suspension & fuel tanks for Ascari & Spectre Cars.
The MDA chassis differs a lot from the GTD chassis. The MDA chassis is by far stiffer & has more bracing, the engine bay has 6 main chassis members of 40x40mm box section compared to 4 on the GTD.
The area in question (the top suspension pick ups & shock mounts) is completely different on the MDA chassis. The GTD needed bracing in this area because of the shape of the engine bay, not only did the chassis angle up in this area, it also had a dog leg about 350mm forward of the shock & suspension brackets.
The MDA has a main chassis member in front of this area that in a horizontal plane leads directly back to the bulkhead and is also welded to the roll bar, out riggers and fuel tank rails and if you add in to this the bolted in engine cradle you have a very strong configuration.
To make other comparisons with the GTD Chassis:-
The MDA has 100x50 box section running down the middle of the chassis compared to a 25x25mm box section on the GTD. The MDA has side impact bracing above the fuel tanks, the GTD has none. Also, the MDA has a double bracing 'cross' in this area, the GTD has a single diagonal brace.
The GTD chassis was never altered at all after 1988 other than one modification to the radius arm pick ups (a slight change in angle).
MDA knew the problems with the GTD chassis and have gone a long way to addressing them - more leg room, more space in the cockpit, bigger engine bay, the engine gear box now sit horizontal and not tilted as on the GTD. These are just a few of the improvements.
I also supply MDA with chassis's, suspension and fuel tanks and know how committed Mark is to producing a good product, and like any forward looking company they want to continually improve the car.
One final point on the matter. When the first MDA chassis came out of the jig I did comment to Mark that it didn't wobble like the GTD and just by walking on it, it does't give under my weight like the GTD.
Put an MDA chassis next to a GTD chassis and the argument would be turned on its head. WHY wasn't the GTD braced like the MDA chassis?

 

[Brian Magee]

Russ

The area in question is not the top suspension pick ups and shocks mounts but the lack of a cross member between the lower suspension pick ups.

Brian.

 

[ QUOTE ]
On the subject of the MDA Chassis, I feel I have to set the matter straight. My company made the vast majority of the GTD chassis's, around 350 at a guess out of a total of just under 400. I also supplied the suspension & fuel tanks for GTD. I also supplied chassis's suspension & fuel tanks for Ascari & Spectre Cars.
The MDA chassis differs a lot from the GTD chassis. The MDA chassis is by far stiffer & has more bracing, the engine bay has 6 main chassis members of 40x40mm box section compared to 4 on the GTD.
The area in question (the top suspension pick ups & shock mounts) is completely different on the MDA chassis. The GTD needed bracing in this area because of the shape of the engine bay, not only did the chassis angle up in this area, it also had a dog leg about 350mm forward of the shock & suspension brackets.
The MDA has a main chassis member in front of this area that in a horizontal plane leads directly back to the bulkhead and is also welded to the roll bar, out riggers and fuel tank rails and if you add in to this the bolted in engine cradle you have a very strong configuration.
To make other comparisons with the GTD Chassis:-
The MDA has 100x50 box section running down the middle of the chassis compared to a 25x25mm box section on the GTD. The MDA has side impact bracing above the fuel tanks, the GTD has none. Also, the MDA has a double bracing 'cross' in this area, the GTD has a single diagonal brace.
The GTD chassis was never altered at all after 1988 other than one modification to the radius arm pick ups (a slight change in angle).
MDA knew the problems with the GTD chassis and have gone a long way to addressing them - more leg room, more space in the cockpit, bigger engine bay, the engine gear box now sit horizontal and not tilted as on the GTD. These are just a few of the improvements.
I also supply MDA with chassis's, suspension and fuel tanks and know how committed Mark is to producing a good product, and like any forward looking company they want to continually improve the car.
One final point on the matter. When the first MDA chassis came out of the jig I did comment to Mark that it didn't wobble like the GTD and just by walking on it, it does't give under my weight like the GTD.
Put an MDA chassis next to a GTD chassis and the argument would be turned on its head. WHY wasn't the GTD braced like the MDA chassis?

[/ QUOTE ]

Russ,

I know JP very well who used to own an MDA. /ubbthreads/images/graemlins/wink.gif

JP won't post his real thoughts, but I can relay some of what he has told me! /ubbthreads/images/graemlins/blush.gif

He had concerns about the chasis and recommended a full test to prove the structural strength, nothing from MDA no information at hand. /ubbthreads/images/graemlins/mad.gif

He waited 2 years and when he did finally try and drive it at GTD Goodwood Track Day the gear stick broke along with the starter motor! /ubbthreads/images/graemlins/mad.gif

A few months later he drove it again at a runway and it drove in every direction apart from the one he wanted it to go! /ubbthreads/images/graemlins/mad.gif

His wife nearly divorced him because of the mess he got himslef into with MDA. /ubbthreads/images/graemlins/mad.gif

He sold the car back to MDA before anything worse happened! /ubbthreads/images/graemlins/crazy.gif

He still reads the forum and cannot believe that serious issues such as structural integrity have still not been addressed. /ubbthreads/images/graemlins/mad.gif

He also said that Mark has a very good product if he can address the issues raised! /ubbthreads/images/graemlins/smirk.gif

But would also recommend that MDA customers look very closely at these following areas:

Bump steer on the rear.
Camber change on the rear.
Castor on the front.

And finally, I fail to see what walking on a GTD/MDA frame has to do with measuring the strength of a chasis.

I'll leave it at that. /ubbthreads/images/graemlins/blush.gif

Steve Danger..

 

My comments were about the construction of the chassis and nothing else. Also, my comment about walking on the chassis was nothing to do with measuring the strength but with the "feel" of the chassis when working on it after it comes out of the jig, as I have to walk on it to work on it!

 

I didn't realise alias Smith and Jones were back on our screens?

Regards

Chris

PS. any one herd from Frank Williams recently? even Meat would be a breath of fresh air.

 

[Chris Martino]

JP - you gotta be kidding?? You really need to chime in instead of having 'representatives' conduct the playground tattle-tales - JP says this, JP said that??

What's up??

Chris /ubbthreads/images/graemlins/shocked.gif

 

Chris
I said Smith and Jones, Steve Danger is not the only poster hiding behind an alias here is he?
/ubbthreads/images/graemlins/wink.gif
regards

Chris.

 

[Frank Catt]

A shipwrecked sailor stood on a very small island watching the sharks hungrily circulating around him. He continually threw rocks from under his feet at them, making his island smaller each time. He had already started to burn the small boat that he had arrived in, to keep himself warm at night, but would it not have been better for him to repair the small crack in the bottom of the boat and sail away to a safer place ?,

 

[Pete McCluskey.]

Frank,well said I could not agree more. Attack is not always
the best defence. Refreshing is the person who can say "yep
we have a problem and we will fix it"

 

[Keith]

I dunno, I may be thick or something, but all this has got beyond me. Aliases? Hiding? Whos hiding? Where? Why? What's going on? /ubbthreads/images/graemlins/confused.gif

 

[Ron Earp]

REMEMBER THOSE RULES YOU AGREED TO.......

Among the most important rules YOU AGREED TO when you joined this board were:

• Use your real name or something similar. We prefer it. And it is our forum. We don’t like names like “SlickRick”, “SuPeRdUpPeRgT40”, and “Ratboy4367” with cutesy pictures to match. If your name is John Brown, use it. Afraid of internet identity theft you say? Worried an illegal alien will collect your social security? Then go for John B. Trust me, nobody is going to steal your identity around here - we like ours better than yours anyhow.

• Don’t want to place an email with your name? Then you might want to think about not registering. Our active members form a community and we’d like to be able to invite you out for beers sometime.


• Don’t want flames? Then don’t tell us you are a Newbie. We’ll know by looking at your post count. If you post in the middle of a controversial topic and your post count is 1 then you’ve probably got an agenda and we know it. And we’ll tell you about it.

• Do you sell GT40 stuff? Are you promoting GT40 products? Do you like your GT40 better than anyone else’s? Then please let us know in your signature so that we’ll know your opinion is not necessarily unbiased. It is only fair. And we like fair.

• Post a little and things might get hot! Wear your flame retardant underwear while on the board, a few flames might fly every now and again. This board strongly believes in the freedom of speech so say what you like. We also strongly believe in responsibility, so be prepared to stick by what you wrote. Be prepared to back up your posts with proof and science – we’re a very analytical bunch on the board. Got a Thingamajig that ads 92 hp, unlimited torque, and cleans your house for $49.95? Prove it. And lastly, we also strongly believe in kicking your ass off of here if we don’t like what you say. We reserve that right.

• Please, use the forum as an information source and use the search feature before posting a question. And think about your question. I’m sure you want to know which GT40 to purchase or which one is the best. But face it – they are all represented here and everyone likes to think they made the best choice so how many answers do you think you’ll get? Do your research and the best GT40 FOR YOU will become clear. And if you can’t figure it out then ask me, the best GT40 is MINE.

I think that will just about do it. If you cannot live with these rules THEN DO NOT SIGN UP!!!!!!!!