Active suspension hood - Page 2 - ZR-1 Net Registry Forums

LGAFF · 06-07-2013

If its from the GM parts bin, those have to be off a pontiac of some sort,

http://www.jamesinsogna.com/Cars/Cla...trans-am-M.jpg

mgbrv8 · 06-26-2013

I wonder how much of the active suspension was lotus's?

http://www.youtube.com/watch?v=iPQ66fW9RAM

Dave

USAFPILOT · 06-27-2013

is the modern magnetic ride control really doing what these active suspension cars were capable of? All magnetic ride control does is change the fluid inside the shock absorber. It doesn't actively level the car does it?

Corvettes White · 06-27-2013

My guess is that the magneto shocks are an application of some of the research from the active suspension program.

Traditional suspensions have three basic elements in play plus the weight of the car.

The spring, the damper, and road force. The road force is the only thing that normally changes as you drive.

The spring rates and the damper rates are fixed. The springs are soft or stiff and shocks have a fluid with a viscosity and orifice size that does not change. When you order a Corvette, the springs and shocks are selected by the factory based on the suspension ordered, if the car is a convertible or coupe, options installed, etc.

A step up from the traditional system is to make either the spring rate or the damping rate variable with conditions.

In the ZR-1’s the spring rates cannot be changed on the fly but the damping rate is. Orifice size in the shocks can be changed to; tour, sport, or track.

In the new Corvettes, instead of changing the orifice size in the shock, the viscosity is variable. So again, you have taken what is traditionally a constant and made it variable.

The active car takes the whole thing one giant step further. To spring, damper, and road force you add a counter force. This force via the hydraulic cylinder can directly counter the road force. Canceling out the therotical need for springs and shocks all together. So these cars of 25 - 30 years ago are still ahead of the technology in place today. IMHO.

So what was likely learned by Lotus and GM was how to do real time control via a computer on suspension systems, without spending a fortune on hardware. And with cars becoming lighter, this is a very big win.

The active car suspension was to have been a $20,000 option on top of the ZR-1 option effectively making the Corvette a solid $100,000 car in 1990. If you go through GM parts books from the late ‘80’s, you will even find some of the active parts listed in the GM distribution system as the option came very close to production.

So what happened? The story I heard is that the computers of the time could not keep up with the computational requirements of a 180 mph car operating on a track - iIn part because the chassis was very flexible. It may also have been cost, the stick price, service at a Chevy dealership, warrantee expenses.

The whole subject is very interesting. George

Bob Eyres · 07-08-2013

I've always thought the "Active Hood" is the one they should have used on all ZR-1's. Virtually no rise at the cowl, and a nice, subtle, power bulge over the LT5, perfect. Especially since, with phenolic spacers on my plenum, my hood has been rubbing on the plenum for twenty years.

If somehow that hood get's reproduced, count me in for a group buy. But I can do without the vents. Those "rice boy" vents looked hastily tacked on by engineers.
IMHO, one of GM's best efforts at a good looking hood vent is on the early nineties Lumina, pictured here. That would look great on the ZR-1.

http://www.futureclassicsnj.com/Cars/z34dsfrt.jpg

Functionality?

06-07-2013	#11
LGAFF Join Date: Mar 2007 Location: Crystal Lake, IL Posts: 7,193	Re: Active suspension hood If its from the GM parts bin, those have to be off a pontiac of some sort, http://www.jamesinsogna.com/Cars/Cla...trans-am-M.jpg __________________ LGAFF 90 #966-150K miles-sold 92 #234-sold 1987 Callaway TT #17 1991 ZR-1 #1359

06-26-2013	#12
mgbrv8 Join Date: Jul 2009 Location: Texas Posts: 793	Re: Active suspension hood I wonder how much of the active suspension was lotus's? http://www.youtube.com/watch?v=iPQ66fW9RAM Dave

06-27-2013	#13
USAFPILOT Join Date: Aug 2007 Location: Spring TX Posts: 1,348	Re: Active suspension hood is the modern magnetic ride control really doing what these active suspension cars were capable of? All magnetic ride control does is change the fluid inside the shock absorber. It doesn't actively level the car does it? __________________ 1994 #293 ZR-1 Stainless Works Long Tube Headers, B&B catback w/ X-Pipe, 18" Shelby Series One Wheels, SLP CAI. Last edited by USAFPILOT; 06-27-2013 at 02:15 PM.

06-27-2013	#14
Corvettes White Join Date: Dec 2003 Posts: 477	Re: Active suspension hood My guess is that the magneto shocks are an application of some of the research from the active suspension program. Traditional suspensions have three basic elements in play plus the weight of the car. The spring, the damper, and road force. The road force is the only thing that normally changes as you drive. The spring rates and the damper rates are fixed. The springs are soft or stiff and shocks have a fluid with a viscosity and orifice size that does not change. When you order a Corvette, the springs and shocks are selected by the factory based on the suspension ordered, if the car is a convertible or coupe, options installed, etc. A step up from the traditional system is to make either the spring rate or the damping rate variable with conditions. In the ZR-1’s the spring rates cannot be changed on the fly but the damping rate is. Orifice size in the shocks can be changed to; tour, sport, or track. In the new Corvettes, instead of changing the orifice size in the shock, the viscosity is variable. So again, you have taken what is traditionally a constant and made it variable. The active car takes the whole thing one giant step further. To spring, damper, and road force you add a counter force. This force via the hydraulic cylinder can directly counter the road force. Canceling out the therotical need for springs and shocks all together. So these cars of 25 - 30 years ago are still ahead of the technology in place today. IMHO. So what was likely learned by Lotus and GM was how to do real time control via a computer on suspension systems, without spending a fortune on hardware. And with cars becoming lighter, this is a very big win. The active car suspension was to have been a $20,000 option on top of the ZR-1 option effectively making the Corvette a solid $100,000 car in 1990. If you go through GM parts books from the late ‘80’s, you will even find some of the active parts listed in the GM distribution system as the option came very close to production. So what happened? The story I heard is that the computers of the time could not keep up with the computational requirements of a 180 mph car operating on a track - iIn part because the chassis was very flexible. It may also have been cost, the stick price, service at a Chevy dealership, warrantee expenses. The whole subject is very interesting. George

07-08-2013	#15
Bob Eyres Join Date: Jul 2005 Location: Jupiter, Fl. Posts: 815	Re: Active suspension hood I've always thought the "Active Hood" is the one they should have used on all ZR-1's. Virtually no rise at the cowl, and a nice, subtle, power bulge over the LT5, perfect. Especially since, with phenolic spacers on my plenum, my hood has been rubbing on the plenum for twenty years. If somehow that hood get's reproduced, count me in for a group buy. But I can do without the vents. Those "rice boy" vents looked hastily tacked on by engineers. IMHO, one of GM's best efforts at a good looking hood vent is on the early nineties Lumina, pictured here. That would look great on the ZR-1. http://www.futureclassicsnj.com/Cars/z34dsfrt.jpg Functionality?