# No IRS : Not important!



## Poje (Aug 2, 2012)

I looked at many reviews now on the new 2016 Cruze and the fact that it doesnt have an IRS, Independant rear suspension, isnt important at all. Of course a Double-wishbone or Multi-link rear suspension is better on paper, but the final product, the actual driveability and handling of the car has little to do with that fact.

It's like saying : "My car has 300+hp." That can be a fact, but that wont tell you if its a STI or a Nissan Titan with the new Cummins diesel!

Many in the press, reviewers and random peeps on the net cryed about the fact it wasnt an IRS, but they forget that most of the cars in this class have a torsion beam. In reality, It's all about the *Tuning*.

Chevy has done a very good job tuning the old Cruze's chassis and from the reviews i saw for the new Cruze, its even better!

I raced with my old Cruze, passing WRX and such on the Track, everyone was very impressed with my Cruze and no one EVER asked if i had an IRS, because they knew better.

For those who dont know, *Chevy has won 3 WTCC championship* in a row with the Cruze, and it had a Torsion beam rear suspension on it : https://www.youtube.com/watch?v=M19RQehDQa4

*So anyone who tell you that they dont want to buy a Cruze because it doesnt have an IRS, tell them to go Drive one and see. If they are not retarded, they will agree it has no importance.


Enjoy the new Cruze.*


----------



## ChevyGuy (Dec 13, 2014)

IRS sounds good on paper and made for some slick ads. But if you look at any car, I'll bet you'll find some kind of "connection". Such as a anti-sway bar. Truly independent is bad. Lots of body roll for one.


----------



## blk88verde (Apr 30, 2011)

IRS can provide better ride and handling over uneven / poor surfaces. Even Mustang has gone IRS. A Cruze on race track should handle well - surfaces are pretty flawless.


----------



## ChevyGuy (Dec 13, 2014)

blk88verde said:


> Even Mustang has gone IRS.


But is it truly independent, or does it have some kind of cross-connection?


----------



## Robby (Mar 1, 2013)

All/any IRS will have a cross connect or sway bar......so you are correct, there is no IRS in the truest sense of the word.

On a front driver, IRS is, for the most part, there for bragging rights.....folks love to banter the term without a clue what is going on down there.
But it creates a whole bunch of headaches, in particular camber changes that can make a evil handling car if not aligned correctly.
Add to this many more wear points that will require attention over time and the rear systems on fwd cars are not very robust.
A good pothole puts a slight bend in the flimsy control arm and camber and caster are now out of spec........drives OK but starts eating rear tires.

A beam axle starts out rather robust, the beam itself (spring steel) acts as a sway bar, the caster/camber/toe are fixed and there are only two bushings where the assembly is attached to the car.
Lastly, it has full movement with no trunk floor intrusion........nice, simple, low maintenance and inexpensive if damaged.

Rob


----------



## MP81 (Jul 20, 2015)

I am fully for this argument. The Cobalt SS had the FWD production car record around Nuerburgring (which actually has quite a few bumpy, uneven turns) with it's Torsion beam rear suspension. 

My car has those struts and shocks, the 1mm larger SS/SC FE5 front sway bar, FE5 cast aluminum control arms and the big 1.25" Powell Hardcore bar out back, and with the sticky ZIIs on there...the handling is outstanding - and yet, it still rides great (even with lowering springs) and 40-series, stiff-sidewall Direzza ZIIs with basically no tread pattern (most of the tire is contact patch).


----------



## Poje (Aug 2, 2012)

blk88verde said:


> IRS can provide better ride and handling over uneven / poor surfaces. Even Mustang has gone IRS. A Cruze on race track should handle well - surfaces are pretty flawless.


You didnt understand the point of my thread :* Its not that an IRS cannot be better, its the fact that it isnt garantied to be better.*


----------



## Poje (Aug 2, 2012)

MP81 said:


> I am fully for this argument. The Cobalt SS had the FWD production car record around Nuerburgring (which actually has quite a few bumpy, uneven turns) with it's Torsion beam rear suspension.
> 
> My car has those struts and shocks, the 1mm larger SS/SC FE5 front sway bar, FE5 cast aluminum control arms and the big 1.25" Powell Hardcore bar out back, and with the sticky ZIIs on there...the handling is outstanding - and yet, it still rides great (even with lowering springs) and 40-series, stiff-sidewall Direzza ZIIs with basically no tread pattern (most of the tire is contact patch).


The Cobalt is a great exemple of what Tuning can do : The last SS they made, the one that has the Ring record, is a very impressive car, but the same year, you could buy a base Cobalt and those cars were horible, lol.

A base Cobalt would be upset by any kind of bump in mid-corner, but the SS would be rock solid. That's tuning.


----------



## ChevyGuy (Dec 13, 2014)

Poje said:


> It's all about the *Tuning*.


Or, you could say it's all about execution. There is no technology so superior that it can't be messed up with bad execution.


----------



## MP81 (Jul 20, 2015)

Poje said:


> The Cobalt is a great exemple of what Tuning can do : The last SS they made, the one that has the Ring record, is a very impressive car, but the same year, you could buy a base Cobalt and those cars were horible, lol.
> 
> A base Cobalt would be upset by any kind of bump in mid-corner, but the SS would be rock solid. That's tuning.


Yup - and having gone from one end of the spectrum with the factory FE1 4x4 lift kit to the SS/TC FE5 shocks/struts (with the other stuff) on the same car - it was night and day.


----------



## blk88verde (Apr 30, 2011)

> But is it truly independent, or does it have some kind of cross-connection?


 Ok - so I have a car that has a De Dion rear suspension - do a search - this truly connects both sides of the suspension. Alfa and Aston Martin I believe are a few of the rare cars with this type of rear "independent" suspension. The Alfa Milano Zagato SZ could pull 1.4 g cornering with this suspension - 1989 to 1991 very limited production. This car was also known as Il Monstro / ES-30.


----------



## Poje (Aug 2, 2012)

blk88verde said:


> Ok - so I have a car that has a De Dion rear suspension - do a search - this truly connects both sides of the suspension. Alfa and Aston Martin I believe are a few of the rare cars with this type of rear "independent" suspension. The Alfa Milano Zagato SZ could pull 1.4 g cornering with this suspension - 1989 to 1991 very limited production. This car was also known as Il Monstro / ES-30.


The only cars on sell right now with fully independant suspension are the Mclaren, they have no Anti-roll bars, only an hydraulic transfer system to counter weight transfer. (Except the new 570)


----------



## brian v (Dec 25, 2011)

Guys IT is about Geometry ! 
Tension allowances to stresses at given points of given angles ....

Camber and Toe .

The New Mustang has an Integral Link Rear Suspension .


----------



## pandrad61 (Jul 8, 2015)

Agreed, not all independent suspensions are best. look at the civics. they don't ride any better maybe worse then the cruze with irs. back in 87 the dodge daytona turbo z shelby was smoking z28/mustangs with a rear torsion beam axle. while i personally am not a fan to be honest with ya it does the job great. if this was a 600 hp track car well ya irs is needed to get every second off the times and to help tune more efficiently. does it work,yes, can it be fast yes, would it be nice to be able to adjust camber on the rear axle absolutely.


----------



## 30 Ounce (Nov 18, 2012)

Go carts have absolutely no suspension and they generate massive G forces on the track. NASCAR uses solid rear axles and they generally will bend them to get a few degrees of negative camber and they can deliver massive G forces. Tires are a lot more important than the basic suspension design. Both independent and solid axle cars can be tuned to handle extremely well. The fact that either design uses a sway bar is irrelevant as they are intended to flex and act as an additional spring rate. The whole torsion beam axle is intended to flex and act independently at each corner at least until the torsional rate is met and transfers the load to the other side. And to achieve anything over 1 G you must have a banked corner or downforce!


----------



## pandrad61 (Jul 8, 2015)

Agreed, both panhard and torsion axles can be made to handle very well, NASCAR and v8 super car series proves it . go carts are very good if the roads are perfect due to weight. try a go cart on a super bumpy road course and good luck. now independent is truly better, lighter, more adjustable and superior in a racing aspect. you engineer a solid axle in a p1 lemans or a f1 car and i guarantee lap times will drop astronomically. they have there use and for 95% of the occasions will do them just fine.


----------



## Poje (Aug 2, 2012)

Good. Majority of peeps here understand and agree! :grin:


----------



## MP81 (Jul 20, 2015)

Poje said:


> Good. Majority of peeps here understand and agree! :grin:


The problem is the 99.9% of other buyers who just assume "IRS" is better because "They heard it somewhere", probably the internet, because its always right.

Then again - that "99.9%" probably only makes up 25% of buyers - the other 75% don't even have a clue their vehicle has a suspension.


----------



## spacedout (Dec 7, 2010)

The last cars I've owned with IRS with both old Buick Lesabres. For a nice ride on a rough road not sure it can be beat. It does add some body roll so handling is adversely effected. 


about 15 years ago my two brothers both bought new 4 wheelers. One was a Polaris Scrambler 500 4x4(solid rear axle) and the other a Polaris Sportsman 500 4x4 (IRS). Going across a plowed field at 40mph with the solid axle rode so rough your eyes would vibrate and you could not see(I'm not kidding). The IRS was smooth as silk in comparison. 

However all of us much preferred the solid axle, you could drift/slide the rear on demand with just a little throttle input, making it have much better handling. There also was no perceivable sway in the back end, the IRS on the sportsman you could feel it dip left/right with turns.


----------



## pandrad61 (Jul 8, 2015)

spacedout said:


> The last cars I've owned with IRS with both old Buick Lesabres. For a nice ride on a rough road not sure it can be beat. It does add some body roll so handling is adversely effected.
> 
> 
> about 15 years ago my two brothers both bought new 4 wheelers. One was a Polaris Scrambler 500 4x4(solid rear axle) and the other a Polaris Sportsman 500 4x4 (IRS). Going across a plowed field at 40mph with the solid axle rode so rough your eyes would vibrate and you could not see(I'm not kidding). The IRS was smooth as silk in comparison.
> ...


with some rebound,compression and spring tuning im sure it would make the ind way smoother i and out of turns but again its all in tuning. most riders and drivers arent good enough to surpass stock tuning.


----------



## pandrad61 (Jul 8, 2015)

i like solid axles in my utility vehicles for ultimate reliability and suspension flex/weight capacity. my jeep has double sold axle. here in the florida sand i can drive way faster then some ifs pickups becuase i have the proper suspension geometry and shoc tuning to ride the bumps vs a general ifs road set up


----------



## jblackburn (Apr 14, 2012)

You know, Honda totes (or used to, before they went McPherson strut) their double wishbone/IRS all the time. I've never found my parent's Accord (last year Accord to have that) to handle THAT well or offer a smooth ride. My fat pig of a Volvo cornered better (had a delta link rear suspension and McPherson front strut) and was much less likely to go into a 4 wheel slide when you suddenly change direction. You did feel every bump in that one, though.

I feel the Cruze with Z-link setup is a nice compromise between ride quality and handling. And I don't even have the "sport" suspension.


----------



## pandrad61 (Jul 8, 2015)

i think what also helps is a new stiff chassis. the cruze aint no sloppy joe by any means. my 87 supra had superb suspension. double wishbones front and rear.bumps where hardly noticeable and turned fantastic once i refreshed the suspension. it was heavy though


----------

