Possible Suspension Arm Failure, Racing - Tornado GT40

[(C)arlos]

Guys,

sorry for being absent the last week, but as said I am working for a US company and we are approaching year end and it is q4 the almost most important quarter for us


But back to the facts...

@Andy from Tornado.

I am not an engineer, but usually the spring is the first thing that MUST BLOCK to protect the coil over. If the coil over goes on block first, it can break and based on the design, if it breaks, you perhaps loose the whole wheel...Nice idea
I am not going to explain you, how to draw pictures with all forces working on a suspension, read a book.

But the more you move the coil over away from the hub, the more load is going on the suspension arm it is mounted to, and you need to increase stiffness of the material or change the design to carry that additional load.

What we see here on the LEFT side is a bend over time because of the weak material you have chosen. I assume ( not saying it was) that the bend on the right side was the same until the car was approaching the mentioned curve on the ring and then got bend more based on the high load. This explains the different amount of bending we see.

Your suspension arm design is bad and the material you have chosen is not up to the job, not even for street use.

You can call me wrong, but pls do it like an engineer, put facts, drawings and calculations on the table, keep your wrong assumptions for yourself.

And pls don't forget to send us a picture of the improved parts you mentioned.

However, if highly encourage you to visit race tracks and look how race cars are being setup. There are several parts of the old ring for example where the spring goes on block on nearly every car, even modern ones.


Having all said all this beside this, you should be ashamed, accusing other forum member here to bend the arms more just to harm you or your business.



@all other Tornado owners and drivers. My intention was to bring this to your attention so you all can deal with the information and improve your cars or not. But reading some comments here, is a bit disappointing. Don't believe someone how claims to have sold xxx amount of cars, is right with all he is saying. Start asking critical questions and don't trust comments from someone hows only interest it is to sell cars and not to pay for a product recall. It is his right to work revenue orientated, for sure, but clearly there is a borderline between revenue and callousness of other peoples health. Andy is not your best friend, he is ( and again this is his right) a business man who sells cars for a living.

There is a bent suspension arm and the manufacture has not respond to this threat with facts, drawings, explanations or solutions in a professional way.

That was what I wanted out of this.
Instead he is threaten forum members with lawyers, or accusing other forum members

Sorry if I do sound a bit upset but it reminds me to an old saying "Eat more shit a million flys can't be wrong"

Cheers
(C)arlos

 

[(C)arlos]

D=F/(delta)l -> ever heart of that ...?
F*a = Q*b -> ever heart of that ...?
M=F*a -> ever heart of that ...?

ever heart the therms force polygon, Vector, fore arrow ?

I gave you a clue now it is up to you ...

Jac Mac

As Carlos seems reluctant I think the attached picture shows the information you are looking for.

The shock length has been adjusted to the fitted length at standard ride height.

The bottom spring seat has been screwed up the same number of turns as on the picture from Carlos.

The spring is the standard item. As you can see it is normally fitted with pre load with the bottom spring seat at or near the bottom of the shock..

The distance between the spring seats is just 5 1/4" with the bottom seat screwed up to that position.

The actual shocks we use have a shorter body length and rubber bump stops fitted.

To compress that spring to 5.25" or shorter as would happen during wheel bump would without doubt result in a coil bound situation resulting in damage to the wishbone and/or chassis.

This is why there is a warning in the manual.

The unknowing do not realise how critical shock length, spring length, bump stops and pre load are in suspension control and that damage can ocurr if all of these elements are not correct.

We have still not been contacted directly by either Carlos or the owner of the vehicle to discuss this matter directly.

Thanks

Andy

 

[(C)arlos]

Did you see at least one picture of the improved parts.
Did I miss it ?

One Pic, one Datasheet with calculations, and we all can sleep a bit better...

Beside this,
Herewith, I invite Andy/Tornado Sports Cars to come to Nuerburgring, and we drive it with video on board, on the suspension and onsite the track.
I take care of the cost for the camera equipment and I am hosting this event with great pleasure in my house.
I am just ~60km away from it ...

We take two rounds:
- standard suspension, no hard driving, just a bit faster then a street car.
- Andys mentioned enhancements on the car and we put a professional driver in it.

We take both test drives on the old track as well as on the new GP track.

This is my offer...pack your stuff, take the car of your choice and come down ...

Having read all these posts Andy Sheldon is right in what he says is causing the bent arm, re: shocks. Maybe for out and out racing with the much higher loads that are generated a different solution is required, which he has said he offers. Also i see no probs pointing out a possible prob on the forum but speaking to the manufacture first would have been the correct corse of action to take ? It may be worth pointing out that spring on car suspension should not be preloaded if you require a stiffer spring doing this will not give you one !! buy a stiffer spring !! winding it up just gives you less active coils to use !! As owners of these fabulous cars we should be using this forum to help each other not bitch about each other ? just my view

 

[(C)arlos]

Guys,

I want to add email exchange I had with Tornado in 2007.
pls read and judge yourself

///////////////////////////////

Am 7/15/07 12:14 PM schrieb "tornado" unter <[email protected]>:


Carlos



Thank you for your email and continued interest.



The most important thing to remember is that our GT40 has been in full production since 1989 and over 800 cars sold worldwide.



This is why we are the undisputed worlds leading manufacturer of GT40 replicas.



Most other replica makers began production in the last year or so to try and jump on the GT40 band wagon even though they claim to have been producing cars for decades.



Some of these companies are already going out of business due to a small customer base.



Selling a few parts as a side line to a day job does not count as producing a vehicle.



Because of the length of time our GT40 kit has been in production you are garanteed a product that is fully developed and thoroughly road tested with 100s of satisfied customers with all parts available off the shelf.



When we set out to creat our GT40 we did not want to copy the suspension exactly but improve it and bring it up to date.



We do now offer aluminium front uprights (a picture is attached) and a rear aluminium upright is now under development which will be a direct replacement.



Once again thank you for your continued interest and if you have any further questions please do not hesitate to contact me again.



Andy


----- Original Message -----

From: Carlos Heller <mailto:[email protected]>

To: tornado <mailto:[email protected]>

Sent: Sunday, July 15, 2007 8:32 AM

Subject: Re: Your Kit


Andy
I am still researching for the vendor fitting best to me.

You are still in the game

But I have to say the GT40 on mdagt40.com looks very impressive.
In detail the front axel section looks much more massive compared to yours, also the price is competitive.
Can you give me a few good reasons why you did build it in the way you did...because as far as I know mdagt40.com is closest to the original specks ( also on the rear end section)

Looking forward to hear from you soon.

Regards
©arlos


////////////////////////

I think that speaks by itself ...

As you can see I had my concerns already and was not sure the suspension would keep up with what the marketing promises.


For me that was the right point in time Tornado/Andy missed to tell me that the car is not for track and only for road use...( which by itself would be a shame but that is a different story)


Cheers
(C)arlos

 

[Seymour Snerd]

I think that speaks by itself ...

As you can see I had my concerns already and was not sure the suspension would keep up with what the marketing promises.


For me that was the right point in time Tornado/Andy missed to tell me that the car is not for track and only for road use...( which by itself would be a shame but that is a different story)

Unfortunately, Carlos, it does not speak for itself at all. There is no reference to track use or to suspension design or durability in what Andy wrote. It does say the car is fully road tested so perhaps you should have taken that as a hint. You then ask about suspension design in terms of "mass" (which has nothing to do with the failure in this thread) but you do not show Andy's reply (if there was one). Furthermore, there is no "marketing promise" about track use in your post.

So yes, you've proved you were concerned about the massiveness of the suspension (whatever that means), but that's all. And apparently you bought the car anyway, despite your concerns. Who's fault is that? Should Andy have rejected your order because he could tell you were "concerned?"

IAE this thread is dragging on with no apparent goal or direction. Since you started it I suggest you either give it some direction or terminate it.

Suggested direction: What exactly is it that you want Andy to do that would be productive? He's offered a more track-appropriate suspension in post 19, nearly a month ago, and I see no evidence that you have pursued that as a solution. The Nurburgring voyage you propose is a ridiculous request to make of a small vendor, and has nothing to do with the street-worthiness of the car he sold you.

What, in a few words, is your goal in this thread?

 

[Keith]

Carlos, is the present owner of the car holding you liable in some way?

 

[Tony Hunt]

The problem with Tornado front suspension arms has been known for some time within the GT40 Enthusiasts Club. In fact, Desmond Finnan had arm failure at the 2011 Donington track day, fortunately without any further damage or injury.
He wrote about it, and his solution, in Fortyfication 91 - the September edition - a transcript of which is attached.
While adding little to the current discussion, this post does, however, indicate how well known the problem is.

 

[Andy Sheldon]

Tony

I am not really sure why you are posting here other than you being an associate of Frank Catt of Wealden Engineering.

Perhaps you should ask Frank about him fitting A/C units to our customers cars? One conversion he did in particular stays in my mind and not for the right reasons.

As eveyone in the club knows Desmond Finnan used his car for several years on the track and for Hill Climbs.

He chose not to have the upgraded competition suspension package option fitted to his car.

Again Desmond did not contact us directly to discuss the matter.

Andy

 

[(C)arlos]

Hi Hardy, no he isn't.
He is a good friend of mine and he understands that the problem is not based on something that was under my control.

Cheers
(C)arlos

Carlos, is the present owner of the car holding you liable in some way?

 

[(C)arlos]

Didn't I make that very clear in my earlier posts?

Cheers
(C)arlos

Unfortunately, Carlos, it does not speak for itself at all. There is no reference to track use or to suspension design or durability in what Andy wrote. It does say the car is fully road tested so perhaps you should have taken that as a hint. You then ask about suspension design in terms of "mass" (which has nothing to do with the failure in this thread) but you do not show Andy's reply (if there was one). Furthermore, there is no "marketing promise" about track use in your post.

So yes, you've proved you were concerned about the massiveness of the suspension (whatever that means), but that's all. And apparently you bought the car anyway, despite your concerns. Who's fault is that? Should Andy have rejected your order because he could tell you were "concerned?"

IAE this thread is dragging on with no apparent goal or direction. Since you started it I suggest you either give it some direction or terminate it.

Suggested direction: What exactly is it that you want Andy to do that would be productive? He's offered a more track-appropriate suspension in post 19, nearly a month ago, and I see no evidence that you have pursued that as a solution. The Nurburgring voyage you propose is a ridiculous request to make of a small vendor, and has nothing to do with the street-worthiness of the car he sold you.

What, in a few words, is your goal in this thread?

 

[(C)arlos]

Hi,

thx a lot ...
And that is exactly the thing that should really worry all Tornado Owners..
How many years is that...

Cheers
(C)arlos

The problem with Tornado front suspension arms has been known for some time within the GT40 Enthusiasts Club. In fact, Desmond Finnan had arm failure at the 2011 Donington track day, fortunately without any further damage or injury.
He wrote about it, and his solution, in Fortyfication 91 - the September edition - a transcript of which is attached.
While adding little to the current discussion, this post does, however, indicate how well known the problem is.

 

[Tony Hunt]

Tony

I am not really sure why you are posting here other than you being an associate of Frank Catt of Wealden Engineering.

As everyone in the club knows Desmond Finnan used his car for several years on the track and for Hill Climbs.

He chose not to have the upgraded competition suspension package option fitted to his car.

Again Desmond did not contact us directly to discuss the matter.

Andy

Andy,
As I said in my original post, I wanted to highlight that this is not a new problem. Desmond and the Club have known about it for some time - at least since the article was written.
Why is any link between me and Wealden Engineering relevant?

 

[Seymour Snerd]

Didn't I make that very clear in my earlier posts?

No Carlos, I re-read the entire thread, and you did not.

Andy has offered you what he believes to be a solution to the failure that will work under your usage conditions. You have not accepted that solution. Therefore you must want something other than to have the mechanical problem fixed.

Why not just say what you want in a few words? To resist doing so makes you look evasive.

 

[Andy Sheldon]

Tony

I think you answered your own question there.

Why would you want to highlight anything thats absolutely nothing to do with you??

 

[Jac Mac]

Guys,

sorry for being absent the last week, but as said I am working for a US company and we are approaching year end and it is q4 the almost most important quarter for us


But back to the facts...

@Andy from Tornado.
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
I am not an engineer, but usually the spring is the first thing that MUST BLOCK to protect the coil over. If the coil over goes on block first, it can break and based on the design, if it breaks, you perhaps loose the whole wheel...Nice idea
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXI am not going to explain you, how to draw pictures with all forces working on a suspension, read a book.

But the more you move the coil over away from the hub, the more load is going on the suspension arm it is mounted to, and you need to increase stiffness of the material or change the design to carry that additional load.

What we see here on the LEFT side is a bend over time because of the weak material you have chosen. I assume ( not saying it was) that the bend on the right side was the same until the car was approaching the mentioned curve on the ring and then got bend more based on the high load. This explains the different amount of bending we see.

Your suspension arm design is bad and the material you have chosen is not up to the job, not even for street use.

You can call me wrong, but pls do it like an engineer, put facts, drawings and calculations on the table, keep your wrong assumptions for yourself.

And pls don't forget to send us a picture of the improved parts you mentioned.

However, if highly encourage you to visit race tracks and look how race cars are being setup. There are several parts of the old ring for example where the spring goes on block on nearly every car, even modern ones.


Having all said all this beside this, you should be ashamed, accusing other forum member here to bend the arms more just to harm you or your business.



@all other Tornado owners and drivers. My intention was to bring this to your attention so you all can deal with the information and improve your cars or not. But reading some comments here, is a bit disappointing. Don't believe someone how claims to have sold xxx amount of cars, is right with all he is saying. Start asking critical questions and don't trust comments from someone hows only interest it is to sell cars and not to pay for a product recall. It is his right to work revenue orientated, for sure, but clearly there is a borderline between revenue and callousness of other peoples health. Andy is not your best friend, he is ( and again this is his right) a business man who sells cars for a living.

There is a bent suspension arm and the manufacture has not respond to this threat with facts, drawings, explanations or solutions in a professional way.

That was what I wanted out of this.
Instead he is threaten forum members with lawyers, or accusing other forum members

Sorry if I do sound a bit upset but it reminds me to an old saying "Eat more shit a million flys can't be wrong"

Cheers
(C)arlos

(C)arlos, the statement from you in the above post is totally incorrect, The coil spring should NOT go into BLOCK or COIL BIND, to do so creates an instantaneous shock load thru the coil over to both the bottom arm and chassis points at which the coil over mounts, coil overs usually have a rubber or soft compound buffer fitted to the coil over shaft as seen in the attached photos, if not fitted then you must fit a rubber 'bump stop' to some part of the car chassis or suspension arm to perform this function. I have read both this thread & your build thread....you chose to not use the Tornado spring damper units, but sourced & fitted the ones on the car yourself, given the above statement its obvious you made a bad choice & chose/fitted a spring that was/is totally unsuitable for the application, under the circumstances you should perhaps be thankfull that the bottom arm failed in the manner it did. Would not matter what type of bottom arm was fitted, if you use BLOCK or COIL BIND as a travel limiter in any form of suspension it will eventually cause further damage or component failure. Looks like you might be the guy who needs to read some books!

 

[helloyes]

(C)arlos, the statement from you in the above post is totally incorrect, The coil spring should NOT go into BLOCK or COIL BIND, to do so creates an instantaneous shock load thru the coil over to both the bottom arm and chassis points at which the coil over mounts, coil overs usually have a rubber or soft compound buffer fitted to the coil over shaft as seen in the attached photos, if not fitted then you must fit a rubber 'bump stop' to some part of the car chassis or suspension arm to perform this function. I have read both this thread & your build thread....you chose to not use the Tornado spring damper units, but sourced & fitted the ones on the car yourself, given the above statement its obvious you made a bad choice & chose/fitted a spring that was/is totally unsuitable for the application, under the circumstances you should perhaps be thankfull that the bottom arm failed in the manner it did. Would not matter what type of bottom arm was fitted, if you use BLOCK or COIL BIND as a travel limiter in any form of suspension it will eventually cause further damage or component failure. Looks like you might be the guy who needs to read some books!

somebody else with a brain….

 

[Seymour Snerd]

somebody else with a brain….

Yes, and quite a good one....

So, Carlos is the architect of his own demise (or at least of his A-arms). Now would be a good time to issue a polite apology to Andy and move on. Oh, and don't forget to buy you car's new owner a new set of A-arms and some properly set-up spring-shock units. I'm sure Andy would be happy to supply those.

 

[Tony Hunt]

Tony

I think you answered your own question there.

Why would you want to highlight anything that's absolutely nothing to do with you??

Andy,
See the bottom line of my post. I am the Editor of the GT40 Enthusiasts Club magazine. The issue is obviously of interest and relevant to me.
How long the Club has been aware of the problem with your suspension arms is also of interest and relevant to my post.

 

[Terry Oxandale]

Gord

Spring lengths and rates are not relevant.

You can clearly see in the picture that the correct spring will not fit between the shock seats without being coil bound when adjusted as in the picture from Carlos.


Thanks

Andy

I don't have a dog in this fight, but purely for my better understanding of the factors involved, I had to take the photo, determine the wire width, multiplied by the number of turns (and partial turns), to come to the conclusion that the binding point at full compression was most likely the spring, but it was very close between that, and the shock itself binding. The thick black line (in the photo below) is the full length of the spring at full compression, as I've guessed it to be based on adding up the wire width turns.

Even though it has been stated that spring length and rate are "not relevant" in this discussion, I ask, "how can that be?". Is this because a too severe a rate would have been only slightly preferrable to the weaker rate that would have bound (and thus causing the arm to bend)? Was the rate so weak that it had to have all that preload in order to hold the chassis at a proper ride height?

 

[Doug S.]

I've been watching this thread with great interest. Why? Not because of the hidden agendas that seem to be dictating the postings, but because the Tornado is very interesting to me because of the highly complete nature of the kit.

What I have seen in this thread has not dissuaded me from that interest in the least, it has simply educated me that there is a factory option that I will want to mark on my order form if/when the time comes for me to place an order.

It seems that all component cars have their areas of weakness, no doubt some more than others, but areas which are possibly unsafe SHOULD be addressed in some manner...as Andy has done by pointing out that there is a more robust factory alternative to the road tested standard A-arms for driving styles that may stress the road tested parts....and we, as consumers, and more importantly end-users of the product who determine the style in which they will be driven, must make the decision regarding those alternatives for ourselves.

Good to know.....

Cheers!

Doug