shaddoe
Member posted 04 September 2002 07:51 PM
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Everyone that is interested in trying to copy the Diablo chassis should
keep in mind that the steel used to make the origional chassis was a steel
alloy. This meant that it was lighter but stronger than mild steel which
is what you get if you go to your local steel supplier. Heres the thing,
if you use a thicker mild steel thinking that you'll make up for not having
the same alloy steel you're not going to correct the problem. As you increase
the size the weight will change the way the chassis can handle the flex
and stress. Unless you have the knowledge and software to run the numbers
like cincidiablo you shouldn't try to copy the origional desing without
knowing what steel was used. I would also like to comment on the "using
the fiero chassis discussion" by saying that if you build your steel
tube around the fiero tub correctly that you'll have a very sound chassis.
I have pictures with dimensions that fletch posted on his site but noone
has seen the steel that is added after the main rails. I will post some
pictures of what it looks like after the rollcage and other bracing is added
for those looking to use the fiero but are worried about your chassis handling
the stress. |
shaddoe
Member posted 05 September 2002 03:51 PM
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Below are a few pictures showing the bracing. as you can see from
the pictures we addressed the weakness of the stretch by tieing it
into the main rails. the misconception that people have is that using
thicker steel for the stretch will handle the stress but they don't
realize that the problem comes where the extra steel is welded. when
you have a tube that is a certain thickness and you cut it and add
thicker steel between and cause the steel to flex, instead of the
steel flexing evenly it will cause tremendous stress at the weld points
and cause fatigue in the thinner steel and cause it to fail. this
is the basic principle to follow when doing your stretch, these pictures
may look like a lot of work but it isn't reall that bad and all together
you're only talking about $350 of steel. i'll post more pictures of
the front of the car which is also very important since there is so
much of the front steel cut off but i wanted to post these because
the rear is where the most weight is and where the torque of the engine
gets to the ground and also where the stretch occurs. |
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Filip
Member posted 05 September 2002 04:47 PM
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I just wanted to say that it looks very sturdy. Evidently not all Fiero
stretches are created equal. The design of the rear sides will hold up very
well, especially under torque from the engine. I don't think I've seen a
triangular cross-section there (on the sides) before. It looks more like
a hybrid space frame / fiero tub than just a stretch. Nice work. I'll look
forward to see the front.
By the way, you're assuming that the Lambo won't roll over right? It seems
like the tubing by the roof is a little small...allthough well supported.
Not that I know HOW you could roll over but...
Was the steel alloy you were talking above chrome-moly? I know it needs
to be heat treated after welding. I've seen ppl heat treat using a torch
but oven is more reliable.
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shaddoe
Member posted 05 September 2002 09:11 PM
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I don't think the diablo's chassis was made with chrome-moly, i think it
was a different alloy. i've tried to find that info but can't find it anywhere
but remember reading what it was some time back and don't think it was the
chrome-moly. the firewall isn't complete so when we add the rest of the
steel at the roof line plus the steel at the winshield it should hold if
the car is rolled. we have looked at a lot of open top cars to try to come
up with the best design for safety. through out the rear stretch we tied
the remaining fiero parts to the main rails which should give ue all the
strength we need. one thing i have to add about this design is that if you
have a se, vt, sv or 6.0 the chassis will have to be different at the firewall
where the quarter glass is located, i've been trying to put something together
for fletch to post on his site to cover it but its kinda hard since everyone
that we are building for wants the roadster. |
wrkitcars
Member posted 07 September 2002 08:39 AM
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In June of this year, I stopped by CRP and was able to see a chassis
and jig that had been built right off a Real Diablo Chassis (the real
chassis was sitting right next to it and I have no idea how they got
hold of this diablo). It had to be the most complicated jig I have
ever seen but it was a tube by tube copy. I also saw the suspension
jigs and I must tell you guys, It was pretty neat. I had hoped to
order up a chassis sometime next year, but we all know the fate that
befell CRP. I can't imagine going through so much trouble only to
let your business go down. I'm very curious to see where this chassis
jig turns up. |
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Endre Bujtas
New Member posted 08 September 2002 05:06 AM
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Speaking of copying the Diablo chassis, I don't know why anyone would do
it anyway because even if you do copy it you are not going to get the same
handling characteristics of the real car anyway. Sure you copied the chassis
with the same wheelbase, track width and suspension, but the weight distribution
will not be the same. The location of mass points such as the engine/trans
combination, the fact that you are using a fiberglass body that may not
have the same weight distribution will change the center of mass of the
car. All these things will cause the roll center to change. So why bother
duplicating the chassis? |
kevkev 60
Member posted 08 September 2002 06:41 AM
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This is exactly the point people are tring to make in this industry. It's
an evolution starting out with stretched fiero's, to tube chassis, which
will lead to copiing the whole car and this will eventually end up with
the transmission in the tunnel as the original Contach/Diablo thats why
I'm designing my replica this way, then role center and CG etc will be one
with the car we all study or close enough. Tranny in the tunnel, there are
so many benifits. It will not require cable shifting instead the shift can
be connected to the gear box. the person that come out with this first is
going to rock the Diablo replica world. keep
checking my diary. |
horsethang
Member posted 08 September 2002 07:51 AM
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"Tranny in the tunnel"?
Sorry I have no idea what that is.
Please expand as I am very curious. |
shaddoe
Member posted 08 September 2002 09:47 AM
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the tranny on the real car goes forward under the center console.
not quite sure how you would get this to work though. |
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