Chassis Stiffness in Hertz; How do C4-C5 Compare?
Thread Starter
Le Mans Master
Joined: Oct 2004
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From: CLT, North Carolina
Chassis Stiffness in Hertz; How do C4-C5 Compare?
I think the C5 engineering team measured around 23 hertz with the coupe; the Z06 was slightly higher and convertible slightly less. In searching the archives I found someone with an engineering background discussing the topic and he thought the C4 wouldn't be much over 15. Any forum contributors in the know able to say for sure how they compare? When you look at the spring rate chart for the various suspension packages from 84 to 96 you see the 84 with Z-51 was equipped with much higher rated rear springs than anything else they built during those years. In fact the standard FE1 84 had stiffer front and rear springs than the 85 model with Z-51. I wonder how the chassis stiffness dictated spring choice?
Thanks, Greg
Thanks, Greg
Team Owner
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From: Athens AL
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I dont believe chassis stiffness contributed to the springs being softer in 85, though they add some bracing for 86 because of some issues with spider cracks in the earlier cars, the springs were softer because everybody with an 84 was complaining about being able to feel it when they ran over a nickel in the road.
Le Mans Master
Joined: Jan 2002
Posts: 9,036
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From: Edmonton AB
Originally Posted by Greg Gore
I wonder how the chassis stiffness dictated spring choice?
the tires. The objective was to constrain roll stiffness to 3.5º/g "to
keep the tires as upright as possible." "This was accomplished by
using relatively stiff ride springs and roll bars in the front and in the rear, ..."
.
Team Owner
Joined: May 2002
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From: San Diego , CA Double Yellow DirtBags 1985..Z51..6-speed
Originally Posted by bogus
I am pretty sure the chassis hertz is referenced in Dave McClellan's book, Corvette From the Inside.
I'm actually done reading it btw. Dunno when I'll be in your area.
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Drifting
Joined: Mar 2004
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From: Grand Rapids Mi
Reeves Callaway commented about this at a workshop BG 2004. At that time he indicated that torsional integrity doubled from 87 to 88 model. I have also seen that that the inner structure or frame parts if you call it that was constantly changing and is even a different part number some years between standard suspension and HD suspension? . Everything seems to indicate small structural changes as C-4 progressed. 
Safety Car
Joined: Sep 2002
Posts: 4,030
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From: Maryland
Originally Posted by Greg Gore
I think the C5 engineering team measured around 23 hertz with the coupe; the Z06 was slightly higher and convertible slightly less. In searching the archives I found someone with an engineering background discussing the topic and he thought the C4 wouldn't be much over 15. Any forum contributors in the know able to say for sure how they compare? When you look at the spring rate chart for the various suspension packages from 84 to 96 you see the 84 with Z-51 was equipped with much higher rated rear springs than anything else they built during those years. In fact the standard FE1 84 had stiffer front and rear springs than the 85 model with Z-51. I wonder how the chassis stiffness dictated spring choice?
Thanks, Greg
Thanks, Greg
Safety Car
Joined: Sep 2002
Posts: 4,030
Likes: 6
From: Maryland
Originally Posted by jfb
Hertz is cycles per second and relates to resonance frequency, not stiffness.
Le Mans Master
Joined: Jan 2002
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From: Edmonton AB
Originally Posted by sothpaw2
My recollection was that All Corvettes are Red had it
as 23 hz vs 17 hz for C4 ...
as 23 hz vs 17 hz for C4 ...
about Reuss, his last minute insistance to do the targa and the
consequences than McLellan did. I was too tired to look for it last
night.
