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Stallion
01-29-03, 08:42 AM
I was just thinking about the Corvette's suspension design and how the front suspension is independent as well as the rear suspension. I was just wondering what exactly the suspensions are independent from.

Thanks! :D

TR

Tom73
01-29-03, 08:58 AM
The wheel moves independent from the other wheels. One can go up and down without moving the others.

tom...

Mako
01-29-03, 09:04 AM
Here are a pair of Chevy 12 bolt axles for 4th gen F-body cars:

http://www.caspeed.com/gallery1/images/KTRE_Strange%20007.jpg

You already know what a Vette setup looks like.

Independant suspension means each wheel is independently suspended from the other wheel. When a solid axle car like a C1 or Camaro etc. hits a bump, the rear wheels both move., since they both share the axle.

IRS means Independent Rear Suspension, so if the left wheel hits a bump or pot hole, the right wheel is uneffected.

Not so on the solid axle car and now you know why.

Front wheels on most every car made since the 30's have been independently suspended. No doubt there probably are exceptions, but you get the point.

IRS is much more expensive to build and maintain (4 u-joints vs. 0 in an axle for example) compared to the solid axle setup. But the handling improvements are worth it.

The weak spot is the IRS is weaker than an axle - it can't handle the power a solid axle setup can without extravagently expensive parts.

CYa!
Mako

Stallion
01-29-03, 03:16 PM
Thanks, guys! Mako, in that picture of the two solid axles, what is in the middle of the solid axles? It can't be a differential, right, because the differentials are so the wheels can turn independently (I guess another advantage to IRS), correct? So if it's not a differential (is it?) then what is it?

And also, do most cars now have IRS? Or is still still a luxury to have on a car?

And what exactly allows one wheel to independently move up and the other wheel not? It isn't the shocks, is it? Do solid axle cars have shocks on them?

Thanks! :D

TR

JohnZ
01-29-03, 07:22 PM
The "bump" in the middle of the axles in the photo is the differential housing - the ring & pinion gears and the differential assembly (which allows the wheels to turn at different speeds when you turn a corner) are inside that housing, with solid axle shafts going out to the wheels inside the tubes that also carry the spring and shock mounts. The inner workings of a differential are explained at www.howthingswork.com (it's easier to understand it when you see it in a diagram than to explain it in words).

The IRS system (on Corvettes and almost all other cars these days) allows each rear wheel to move up and down independent of the other rear wheel, as the two wheels aren't connected together; the differential (on rear-drive cars, not used in the rear on front-drive cars) is solidly mounted to the frame, and is connected to each rear wheel by the half-shafts, which have joints at each end to allow the wheels to move up and down independently of the wheel on the other side while the differential is fixed.

The conventional solid axle assemblies shown in the photo (most commonly seen these days on trucks) are one large single member consisting of the differential, solid drive axles, and wheels, all in one piece; when one wheel moves, the entire assembly moves.

All cars, regardless of suspension design, have shock absorbers; they hydraulically dampen suspension motion to keep the tires in contact with the road surface; without shocks, the springs would just keep "bouncing" the wheels up and down (and would let the body bounce up and down on the springs) after they hit a bump.


:beer

Stallion
01-29-03, 10:55 PM
As far are the IRS goes, I think I pretty much understand the functionality. But, I don't know what this U-joint looks like and anybody wouldn't happen to have a picture lying around on what it looks like, would you?

Thanks! :D

TR

JohnZ
01-30-03, 09:11 PM
"U-joint" is a contraction of "Universal Joint"; they're used at both ends of the main driveshaft, and at both ends of the half-shafts on a Corvette IRS. They allow rotating shafts to transmit power smoothly while the angle between the ends of the shaft changes constantly (as when the wheels move up and down). The driving shaft has a U-shaped "yoke" with two holes in it, and so does the driven device; the two yokes are displaced 90 degrees from each other, and the four holes are joined by a 4-way steel "trunnion" with four caps that turn on internal needle bearings. Check the illustration in this link:

http://www.tciauto.com/yokes_u-joints.htm



:beer

Stallion
01-30-03, 10:56 PM
Okay, thanks for the link, John. Now I pretty much understand functionality and I know what it looks like. ;)

Thanks again! :D

TR