How strong is the IRS?

[99-LS1-SS]

Just wondering how weak the rear end is on the G8s. Anyone have any info?

[R.Penguin]

Made by ZF I believe. http://www.zf.com/corporate/en/homepage/homepage.html

As to the IRS, don't pay your taxes and they'll show you what strong is. :p

[Mike@NewEra]

Lol , so far we haven't exactly figured that out , will happen soon though ...

[99-LS1-SS]

IRS :no: :punch: Me :hang:

[jbradsh1]

'cept they make it last longer, like years, and add so much money to what you originally owed you can almost never get out from under 'em, 'less you obtain some know how.

[E.A.]

Most IRS failures are due to wheel hop, or high RPM clutch dumps.

With these cars being Autos, and from what I can tell pretty hard to make wheel hop, I am guessing we will see these things going way 10's for a good while before any real IRS failures start happening.

[jbradsh1]

Most IRS failures are due to wheel hop, or high RPM clutch dumps.

With these cars being Autos, and from what I can tell pretty hard to make wheel hop, I am guessing we will see these things going way 10's for a good while before any real IRS failures start happening.

"Wheel hop, you want to see wheel hop, just jump in my ride, you'll see it. I have to baby it out of the hole to avoid it.

[wreckwriter]

"Wheel hop, you want to see wheel hop, just jump in my ride, you'll see it. I have to baby it out of the hole to avoid it.

Do you get on dry street pavement too? Mine only hops if I don't get all the water from the water box at the track off. Any dampness=hop.

[E.A.]

Do you get on dry street pavement too? Mine only hops if I don't get all the water from the water box at the track off. Any dampness=hop.

Waterbox? Street tires?

With the stock tires even at the track I personally have not had any issues with wheel hop. I don't dare put stock tires into the water cause there is no point, and then it just throws water all over inside the wheel wells, and drips down on the tires at the line. Just a quick 10sec spin to clean the dirt off the tires, and its good.

Maybe the 18's don't wheel hop as bad as the 19" wheels?

[99-LS1-SS]

Well, given your 11.00 second run I guess the IRS is pretty strong! I'm sure that thing was grunting for all it's worth.

[wreckwriter]

Waterbox? Street tires?

With the stock tires even at the track I personally have not had any issues with wheel hop. I don't dare put stock tires into the water cause there is no point, and then it just throws water all over inside the wheel wells, and drips down on the tires at the line. Just a quick 10sec spin to clean the dirt off the tires, and its good.

Maybe the 18's don't wheel hop as bad as the 19" wheels?

You have no choice here, the water extends all the way across. In the right lane you can get around most of it but not all; in the left no chance.

[Robert@KBXPerformance]

I don't dare put stock tires into the water cause there is no point, and then it just throws water all over inside the wheel wells, and drips down on the tires at the line.



Street Tires don't throw much more water around than what most DR's do. And they will not throw much water around as long as the crew isn't totally soaking the hell out of the water box. I always back just barely into the water box "damp area" and then do enough of a burnout to clean the tires, heat em enough to get all the water off, and soften the tires a bit. Then continue spinning out of the box to prevent tracking any water out. Streets sure as heck don't like a John Force burnout but they usually like a little one depending on the compound in the tire.

[GFORCE1320]

Eveyone thought the GTO IRS was junk until people started going really fast on the stock.
Give it some time and I bet we find out that the stock G8 diff is pretty strong or can be made strong as well.

[Crazy Paul]

I've been told the ZF diffs in these cars are plenty strong.

While researching replacement diffs and diff gears for you guys I was told by the warehouse that sells me Holden parts that they have never sold a diff or diff gears to suit VE. That's since about August 2006, and there's only 2 such warehouses that supply all the Holden dealerships, repairers, and people in a city of over 1.5 million people. The VE Commodore is the single most popular car here.

It's possible drag people are buying their gears elsewhere for ratio changes, but I don't believe Holden dealerships would be buying from anywhere except the 2 warehouses.

[99-LS1-SS]

That's good news Paul.

How much do GTO's weigh?

[Crazy Paul]

That's good news Paul.
How much do GTO's weigh?

04 LS1 GTO was listed as 3725lb Curb weight.

Pretty sure the GTO's used a Borg Warner = BTR = Dana diff.
Has nothing in common with the ZF in the G8.

[99-LS1-SS]

Thanks again Paul.

[PontiacDan]

I've been told the ZF diffs in these cars are plenty strong.

While researching replacement diffs and diff gears for you guys I was told by the warehouse that sells me Holden parts that they have never sold a diff or diff gears to suit VE. That's since about August 2006, and there's only 2 such warehouses that supply all the Holden dealerships, repairers, and people in a city of over 1.5 million people. The VE Commodore is the single most popular car here.

It's possible drag people are buying their gears elsewhere for ratio changes, but I don't believe Holden dealerships would be buying from anywhere except the 2 warehouses.


Well, my friend ripped an axle shaft out of GTO, L92heads, mid cam & 150 shot on et streets haha

[Crazy Paul]

Well, my friend ripped an axle shaft out of GTO, L92heads, mid cam & 150 shot on et streets haha



Pretty sure the GTO's used a Borg Warner = BTR = Dana diff.
Has nothing in common with the ZF in the G8..

[GFORCE1320]

I've gone low 9's on the bone stock GTO diff. 9.41 @ 144mph so you cant say it is junk.
Hopefully the zf rear is at least as strong.

[cobrakid]

.....just drive around the water the best you can...do-able at most tracks.

I ordered just the diff Pedders bushings, and will let you know what they do.

Mine wheel hops like an SOB with just my few free mods and my bad-ass home made CAI.

If I could make these...nicely, I would put it up against any one out there.

[TheTugBoat]

wait till intense puts there g8 on the track for the first time...:poof:

[r33pwrd]

man ZF is one of my largest customers! I sell them electronics for the marine devision. I did not even know they did automotive stuff! I wonder if they can supply different gears for it?? i might have to make a phone call onthis one!

[-Ray-]

man ZF is one of my largest customers! I sell them electronics for the marine devision. I did not even know they did automotive stuff! I wonder if they can supply different gears for it?? i might have to make a phone call onthis one!

Call them now! :)

[GFORCE1320]

I would disagree, i have broke two posi and three axles in my street gto that i drove on the streets daily.The 7.5 and size of the case limits the ability of the small gto case.I see that you have had great results in your 9 second car that is stripped down ,modified to give you the best 1/4 mile time possible,using a 3 speed tranny with a trans break no swaybar etc,and thats great your also using a 15 inch tire maybe even a drag race slick ,which absorbes alot of the shock load .Your car is not the norm a progressive nitrous set up will ease the power in and save alot of shock on the drive train parts.I just wouldnt sugest to the guys in here that the rear will hold up in a car that the will drive daily ,weighing 4000lb plus with street tires in the 18-22 inch range..IT seems gm has made a great stride in the g8 over the gto size wise but if you need the $900 kazz,which is not recomended for drag racing and has to be rebuilt, along with a $600 rear gear and a $450 rear cover and just a few gear choices i like the idea of a 8.8 swap.

Wow, you must be bored this morning, LOL
I had great success on the stock dif and never spend the $ on all the crap you mention that everyone needs so I guess I wouldnt know what your talking about.
And yes the 8.8 is a good diff, cheap gears and plentiful.