slow67

iTrader: (2)

I know they are bolted together, I was just saying that there is no driveshaft between them.
Here is a quote from the www.chevrolet.com

EPP

iTrader: (22)

http://www.exoticperformanceplus.com...hassis%201.JPG Bob

TryingT/A

iTrader: (5)

Awesome pics bob

LeMansBlue04

Being a C5 Corvette owner I have always found it interesting to observe how GM engineered the car when it's on the rack. My car is an A4. If you removed my trans and placed the correct bell housing and tailshaft on it you could bolt it into your f-Body.

With the A4 Corvette the flex plate and torque converter are mounted at the rear of the car in front of the A4. A pilot shaft is splined into an aditional flex plate with the ring gear for the starter on the engine. Those splines are then clamped against the pilot shaft. The drive shaft runs down the center of the torque tube with bearings on each end and a flexible joint. However, this setup allows the drive shaft to whip at higher RPMs which tends to wear the flex joints.

Some guys running higher HP cars have replaced the shaft with a carbon fibre unit and solid flex joints from LG Motorsports.

It's a really clever design and you will note that there is no trans mount like you see in the F-Body. The torque tube bridges the gap between the rear of the engine and the front of the trans. This is what holds the rear of the engine up.

chuntington101

aston martin and ferrari use the same setup on the DB9 and 599 etc etc. i dont know if they run the tubes over the shaft or not.

why do the vets have the half shafts encased aswell???? its not done on other makes!

thanks Chris.

LeMansBlue04

Well they really aren't. If you look closely at the pictures in post #22 you can see the half shafts. They look to be partially encased but what you see is really a dust cover. The CV joints themselves are two cylinders, one fitting inside the other. Its kind of like putting a solid piston inside a hollow cylinder.

The inner cylinder is solid with three U shaped channels milled laterally along its outside walls. The outer cylinder, which is hollow, has three U shaped channels milled laterally along its inside walls. Put one cylinder inside the other so that the U shaped channels of each match up and you get what amounts to 3 bored tunnels passing through the joint parallel with the shaft.

When these two units come together they insert large ball bearings into the channels and pack in lots of grease. The result is an infinately flexible joint that not only moves through a complete arc but can move in and out as well. GM probably didn't invent it but it's pretty clever engineering.

chuntington101

LeMansBlue04, are you discribing to me a CV joint??? lol

i know what one is and they are used all the time over here (uk) and have been for years. i dont think there are any cars (and few SUVs!!) that use axels anymore over here.

so they are just dust covers????

at what point do you start to have to think aboutusing a solid axel then?? i mean with moders machineing and alloys you can make some DAM strong diff casings and equally strong half stafts! whats the advantage of a axel?

thanks Chris.

jRaskell

iTrader: (1)

I believe the largest advantages to using a solid rear axle is just maintaining ideal suspension geometries under the enormous loads that drag cars see when you add high horsepower to really sticky drag tires. Most of the problems I've heard of Corvette owners and Mustang Cobra owners have with their IRS isn't the strength of the systems, but the trouble they have setting them up to launch hard at the strip.

A solid rear axle doesn't cause so much geometry changes to the rear tires when placed under those same enormous loads. It doesn't mean an IRS can't be used, it's just a much bigger challenge getting the suspension dialed in, and keeping it dialed in. Some people prefer that challenge.

chuntington101

jRaskell, thats strange cos they say that IRS is much better for racing than solid axels!?!?!?!? why is it so hard to get things diled in?? and what is the movment that gives the IRS so much trobule??

thanks Chris.

NEVRLIFT

IRS is better for road racing where bumps and mid-corner irregularities are normal. That is why the Corvette has had it for a pretty long time.

Adnectere

IRS gets put on vettes for a smoother ride, their owners expect a better ride for the extra money they put down. A live axle can be designed in with more anti-squat than an IRS. Cars that have an emphasis on drag racing will go with a live axle. That's why f-bodies, which need to post solid numbers in the 1/4 and 0-60's and be cheap, use a solid axle (and a torque arm for good measure). Vettes get the IRS for comfort because of the extra money and they will post solid numbers because of the bigger tires/more power/lighter weight advantage. As an aside, I'm not sure which current Mustangs use solid axles. Frankly, I don't care. But I'm 99% sure that the Shelby GT500 with 500 hp uses a solid axle and the reason the Stangs use solid rears is for cost and to dial in anti-squat. You'll need all you can get on a 4000 lb 'sports car' because it needs every bit of help at launch and immediately afterwards to get some grip to haul it's fat a** around.

chuntington101

so the main advantage is in anti squat?? is it not easier to make a axel take BIIIGGGG power than an IRS???

i still like IRS, but thats just cos i have grown up with it over here. but i do see the advantages it would brinmg to a street car used manly for the 1/4mile!

OH and they can be very fun in a sharp handling car with more power than grip! try driving a Mk 1 or 2 ford Esscort and you will see what i mean!!!

thanks Chris.

'JustDreamin'

I don't think it necessarily takes that.....

Think about what a standard driveshaft goes through....7000rpm isn't all that ridiculous....If you've got a T56 6 speed with the .5:1 6th gear, and you're turning 3500 rpm (engine rpm) what speed is the driveshaft running? You guessed it, 7,000 rpm.

Those roundy roundy Nascar guys run conventional driveshafts (although they're probably made out of unobtanium for weight reduction) and they spin them hard, like 9,500+ rpm

I'm not saying that every driveshaft can do the deed, just trying to point out that with today's overdrive transmissions, a plain old driveshaft is required to run "silly" rpm (a fact that is often overlooked). And that the torque tube design isn't necessarily required. To meet GM's requirements I'm sure it was (otherwise they wouldn't have done it), but not everybody agrees with their requirements (I'd personally like to be able to buy a front engine / rear drive 2000 lb 2 seater with an 800hp v8 from GM for $25k or less, but I don't think that my requirements agree with their desire to make money).

'JustDreamin'

LeMansBlue04

Guys, you have gotten way off track here. The reason the Vette has an IRS is because it handles better than a solid axle. One tire can move without effecting the other. The F-Body has a solid axle because it cost less to build.

This fact is one of the key reasons a Corvette handles better than an F-body or a Stang.

And.... as any Corvette owners wife can tell you, there is nothing smooth about the ride of a Corvette. The run flat tires make it even worse.

SSCamaro99_3

iTrader: (1)

Steel, as per the rulebook.

'JustDreamin'

Then its an even better example of normal driveshafts spinning high rpm.


Has they always been steel, or were the rules changed when the rear gear rules were put in place?

I could have sworn they were running some exotic materials a few years back.


Still way off topic from the original poster's question, however.

'JustDreamin'

EnglandGreen