I was one of the people that wanted a beefed up live axle over the IRS for the 5th gen. Since we know that it is getting IRS what does everyone think the durability is going to be like?

So far I have heard nothing but bad things dealing with the IRS in the CTS-V. And we know the Camaro will at least have that much power....

 

If I recall corrctly, the Cadillac's rear was quite close to destruction. It has had a few problems. I remember reading this, but it may be the wrong car. And I believe wheel hop was an issue.

 

Are you talking about the IRS itself, or the differential? Yes the CTS's differential is a pretty fragile unit, mostly attributable to the aluminum case not being strong enough and allowing flex under high loads. And they are definitely prone to wheel hop, which will hasten the demise of the diff due to extreme shock loads.

Let's hope the Camaro's rear end will behave more like a Corvette's than a CTS's

 

^^^ seeing as how the Camaro's new chassis is more closely related to the outgoing GTO and the current CTS chassis , and it will more likely than not share center section if not most of the rear end with the Sigma chassis ....I wouldnt get my hopes up .

 

Yep. CTSv has rear suspension issues. The last Cobra's wasn't as bad, but it adsorbed alot of power. Corvette in some situations has wheelhop, but at 3200 pounds, isn't likely going to grenade the rear.

Current GTO's semi trailing arm setup is the only IRS setup that seems capable of handling gobs of torque without dancing or throwing off parts, even when drifting. But some of the more demsnding people here see it's suspension as "old" or "archaic" (for the record, I'm not one of them ).

Chrysler's IRS setup also seems hop-proof and drag friendly. But again, the more demanding among us are appalled by the weight of the thing (again, I'm indifferent to it).


This is one of those things where you need to be careful about what you wish for because you just might be even more unhappy when you get it. IRS is great if you are carving up corners that are less than smooth. Having a sophisticated IRS is fantastic as far as bragging rights and great handling. Alumunum parts are great as far as weight..... till you apply massive amounts of torque & stiky tires through inherently soft metal. The CTSv is a great handling car, but I don't think you'd want to put that identical suspension on a Camaro.

Making a good IRS is a balencing act between handling, cost, weight, and durability during "abuse". You can't have a featherweight, durable, hothandling IRS that costs nothing to make.

Of course, there's going to be a few who will swear that there's a free ride, and I'll probally hear about it again (nothing new ). If there is such thing as a free ride insofar as IRS, no one has invented it yet.

 

I think it was JasonD or Chris F. that got rid of their CTS-V because of wheelhop. I don't think GM is unaware of this and it is probably one of many issues it is working into the new Camaro.

 

I was nervous about IRS wheel hop before I got my GTO. But it turned out to be a total non-issue. I drive my cars hard (I like to do a lot of hard launches ) but not once have I noticed wheel hop on my GTO. In fact I get better launches at the track with my GTO than I did with my 02 TA (although I believe a lot of that is due to better tires, went from Kumho 275's to BFG GForce Sport 245's). And on real roads, the IRS is MUCH better at handling bumps, ruts, and holes.

 

So then whats the problem with a near-GTO-like rear set up? Is it heavy or something?

 

I have heard of GTO owners complaing about wheelhop. Wasn't there a TSB out on it. I know there was for the CTSV.

 

The GTO's semi trailing arm is not as sophisticated as a multi-link set up. It's basically a diagonally-mounted lower control arm with the wheel hub mounted on it. There's no articulation of the hub, which means you can't control camber or toe. On the other hand it's relatively cheap, strong, simple, and compact. Personally I think it would be a good compromise for a car like the Camaro.

 

There are exactly 4 GTO TSBs related to suspension. 2 are winter driving advisories, one is the finish on the rims, and one is a front suspension knock:

Make : PONTIAC Model : GTO Year : 2004
Manufacturer : GENERAL MOTORS CORP.
Service Bulletin Num : 040310013 Date of Bulletin: OCT 01, 2004
NHTSA Item Number: 10011058
Component: SUSPENSION
Summary:
DRIVING CHARACTERISTICS OF REAR-WHEEL DRIVE AND AVAILABLE WINTER TIRES. ALSO INCLUDES THE 2004-2005 CADILLAC CTS-V. *TT
Check to Request Research. Submit below.


Make : PONTIAC Model : GTO Year : 2004
Manufacturer : GENERAL MOTORS CORP.
Service Bulletin Num : 040308014 Date of Bulletin: AUG 01, 2004
NHTSA Item Number: 10011196
Component: SUSPENSION
Summary:
KNOCK NOISE FROM FRONT SUSPENSION WHEN DRIVING AT LOW SPEEDS OVER BUMPS/UNEVEN ROAD SURFACES. *TT
Check to Request Research. Submit below.

Make : PONTIAC Model : GTO Year : 2004
Manufacturer : GENERAL MOTORS CORP.
Service Bulletin Num : 040310010 Date of Bulletin: AUG 01, 2004
NHTSA Item Number: 10011199
Component: SUSPENSION
Summary:
REFINISHING GTO SILVER PAINTED WHEELS. *TT
Check to Request Research. Submit below.

Make : PONTIAC Model : GTO Year : 2005
Manufacturer : GENERAL MOTORS CORP.
Service Bulletin Num : 040310013 Date of Bulletin: OCT 01, 2004
NHTSA Item Number: 10011058
Component: SUSPENSION
Summary:
DRIVING CHARACTERISTICS OF REAR-WHEEL DRIVE AND AVAILABLE WINTER TIRES. ALSO INCLUDES THE 2004-2005 CADILLAC CTS-V. *TT

None related to wheelhop.

 

Everything R377 said.

Although this is also a very simple, and cheap IRS set up (it doesn't require a rear subframe like the newer ones do), it's the same attitudes against this setup that exists in the OHC vs pushrod mentality.

Although pushrod V8s are better as far as torque, fuel economy, packaging, ease of maintence, and cost to manufacture, OHC engines are seen as more advanced and the toy that measures a cars sophistication to just about everyone.

The Holden VT-VZ rear suspension of the GTO is the lowest price, most durable, least expensive, easiest to manufacture, and potentially the lightest (by almost every account, it's over-engineered... tougher & heavier than it needs be). But the new IRS under the CTS and the VE has the type of higher handling abilities (which 99.99% of us wouldn't notice anyway), and the fact that it's a more complex (and more expensive)toy.... of course everyone wants one. Also....of course..... everyone thought there'd be no trade-off. Like I said before, there's no such thing as a free ride.

Hopefully, Holden was able to engineer most of these problems out of the Sigma IRS (one of the reasons I suspect Holden got the project). Chrysler was able to do it, so Holden should be.... I hope.

 

Z284ever says 25-50 pounds is the weight penalty, though he hasn't indicated for what type of IRS or what amount of durability. He also says that he *knows* this is correct.

I remain skeptical that even 50 pounds would be the penalty for a rugged IRS, though perhaps a simple VZ-style IRS would carry a penalty of only that much.

I agree that if it's going to have IRS, the Camaro should go for rugged and light over complex and optimized for bumpy roads. Camaros have always been about simple, rugged cars that can run down the dragstrip and drive well on a smooth raceway. It would be great if they could have good bumpy road handling too, but not if it greatly increases costs or weight or reduces ruggedness.

Put the complex IRS in the Pontiacs or Cadillacs and let them take on the BMWs. If I buy a Camaro, I'm not expecting to go M6 hunting.

 

Most of the CTS's wheelhop issues will go away on the 2nd gen CTS. There were many lessons learned on Sigma that should be applied to Zeta 2.

 

I think you have some misconceptions here.