New Art Morrison IRS

[Nothingface5384]

Yes

Talk about unbeatable lol
Best setup for the best driver :-)

[j-c-c]

From what little I can see from the brochure, it looks robust, I like, not sure why the the 9" was not the base rear end, maybe offered later, the Heidts etc rears always seem more for looks then function, and anyone in the high HP drag rears is not going IRS anyway. $8k will sell a lot IRS, $13K not so much. Are brakes inboard? Sway bar?

[David Pozzi]

From what little I can see from the brochure, it looks robust, I like, not sure why the the 9" was not the base rear end, maybe offered later, the Heidts etc rears always seem more for looks then function, and anyone in the high HP drag rears is not going IRS anyway. $8k will sell a lot IRS, $13K not so much. Are brakes inboard? Sway bar?

Brakes are outboard, same as a fifth gen Camaro. I wouldn't get one if it had inboard brakes, - too hard to cool. Sway bar is adjustable, three holes, I think.

[andrewb70]

Ultimately, the customers will decide if the $13k price is too much or not, but here is how I see it. The only fair way to compare this rear end is to compare with a solid axle suspension system that has similar features.

The Speed Tech Chicane solid axle is such a system. It uses a floating axle design with ZR1 hubs on a 9" housing. It retails for $5500. To it you must add a carrier, diff, and gears. Let's say another $2000. So we are up to $7500.

Now we need to add a suspension system. There are a dozen options but for the sake of comparison let's use the DSE Quadra-Link. It sells for $2725 with the sway bar option. So that's a total of $10,225.

Now you have to ask if having an IRS is worth an extra $2775...

One thing that I would want to know more about is how the handling characteristics change with rear end width. Is wider better for handling?

Andrew

[David Pozzi]

Andrew, wider track width is better for handling on a road course for sure. It also is for autocross but extra width can make it tougher to clear the cones in the tighter turns.

[Whistler]

This is true , but keep in mind the considerable amount more that a 5th gen weighs in comparison to the cars these rear diffs will be used in. Thats huge when debating the amount of power it will take before needing an upgrade.

The stock 5th gen camaro diff is not as strong as some think. A lot of 5th gen owners replace the stock diff when they add any real tq/hp to the car.

Overall, the rear looks very promising.

[David Pozzi]

Here's a quick shot of it.

[killer69]

Ultimately, the customers will decide if the $13k price is too much or not, but here is how I see it. The only fair way to compare this rear end is to compare with a solid axle suspension system that has similar features.

The Speed Tech Chicane solid axle is such a system. It uses a floating axle design with ZR1 hubs on a 9" housing. It retails for $5500. To it you must add a carrier, diff, and gears. Let's say another $2000. So we are up to $7500.


I just want to clarify......... the 5500.00 INCLUDES the Center section with a Trutrack and Gears. Lets keep the information correct when doing comparisons so that people can make informed buying decisions .

thank you

[jtwoods4]

Here's a quick shot of it.

that's great thank you David! would you mind taking photos of the installation process and any issues you encounter?

[David Pozzi]

Mary will write up an install feature with photos for Super Chevy. I need to see how that impacts what I post here.
With some other chassis companies offering IRS, it's a smart move for Art Morrison to have it as an option on their chassis line.

[killer69]

Cant Be any good it doesn't have a watts link!!! lol

[j-c-c]

I'm sure there is a clearance reason, but why are the UCA bent, what do they need to clear? Same for upper rear cross member? Is there a swaybar in this package, and any pics from the rear?

[andrewb70]

[QUOTE=killer69;1049878]

Ultimately, the customers will decide if the $13k price is too much or not, but here is how I see it. The only fair way to compare this rear end is to compare with a solid axle suspension system that has similar features.

The Speed Tech Chicane solid axle is such a system. It uses a floating axle design with ZR1 hubs on a 9" housing. It retails for $5500. To it you must add a carrier, diff, and gears. Let's say another $2000. So we are up to $7500.


I just want to clarify......... the 5500.00 INCLUDES the Center section with a Trutrack and Gears. Lets keep the information correct when doing comparisons so that people can make informed buying decisions .

thank you

My apologies. Your website wasn't super clear on whether the carrier was included or not, or I just missed that point.

Andrew

[killer69]

[QUOTE=andrewb70;1050098]

My apologies. Your website wasn't super clear on whether the carrier was included or not, or I just missed that point.

Andrew

no big deal just trying to keep it real.

[CTSV]

AM sent me a catalog last week and I saw this system on the cover, it does look nice and very well built but a few things i do not like. In their catalog they mention that the design was influence by the Infiniti, BMW, Ferrari etc but after watching the video Popular Hotrod did it seems its clearly based of the 5th Gen Camaro.

I had owned 2, 5th Gen Camaros and i will tell you one car was a flat our track car and the other was a Zl1. I hated both cars because on the standard not ZL1 car the rear geometry is crazy and you always have badly pitched CV joints when you lower the car down. We tore up axles, CV and differentials like crazy. We then switched to the Ford 9 inch and we still kept breaking CV because there was no way to take the negative CV angle out when the car was at ride height. Another characteristic of the 5th Gen is the back end would bounce often under load and even with tripple adjustable Eibach or Kw coilovers we never were able to dial this out. We worked with lots of aftermarket companies and it just was a inherent design of that rear IRS. My ZL1 was much more planted and GM changed a few things around by moving to a new rear housing which helped with the CV angles and the Mag shocks on the Zl1 were incredible. I got tired of breaking parts everytime i drove the car hard and now moved on. You gotta wonder why so many low mile 5th Gen that are modified are for sale any given time. Speak to the guys who race the 5th Gen in the Rolex series and they will confirm all the parts failures after each race.

this IRS stuff is cool but still nobody really has proved this to be better than the DSE Quadralink or other stuff on the market for our cars and still DSE cars seem always at the top of the list at every event. Until results are really proven id stick with a 4 link for now because the investment is serious do so one of these kits.

[Cdog]

Here's a quick shot of it.

Where do the shocks mount?

[David Pozzi]

I'm sure there is a clearance reason, but why are the UCA bent, what do they need to clear? Same for upper rear cross member? Is there a swaybar in this package, and any pics from the rear?

The uppers are bent to clear the factory frame rails in bump.
There is a sway bar, we don't have it yet.
The dip helps support the rear diff mounting.

[David Pozzi]

AM sent me a catalog last week and I saw this system on the cover, it does look nice and very well built but a few things i do not like. In their catalog they mention that the design was influence by the Infiniti, BMW, Ferrari etc but after watching the video Popular Hotrod did it seems its clearly based of the 5th Gen Camaro.

I had owned 2, 5th Gen Camaros and i will tell you one car was a flat our track car and the other was a Zl1. I hated both cars because on the standard not ZL1 car the rear geometry is crazy and you always have badly pitched CV joints when you lower the car down. We tore up axles, CV and differentials like crazy. We then switched to the Ford 9 inch and we still kept breaking CV because there was no way to take the negative CV angle out when the car was at ride height. Another characteristic of the 5th Gen is the back end would bounce often under load and even with tripple adjustable Eibach or Kw coilovers we never were able to dial this out. We worked with lots of aftermarket companies and it just was a inherent design of that rear IRS. My ZL1 was much more planted and GM changed a few things around by moving to a new rear housing which helped with the CV angles and the Mag shocks on the Zl1 were incredible. I got tired of breaking parts everytime i drove the car hard and now moved on. You gotta wonder why so many low mile 5th Gen that are modified are for sale any given time. Speak to the guys who race the 5th Gen in the Rolex series and they will confirm all the parts failures after each race.

this IRS stuff is cool but still nobody really has proved this to be better than the DSE Quadralink or other stuff on the market for our cars and still DSE cars seem always at the top of the list at every event. Until results are really proven id stick with a 4 link for now because the investment is serious do so one of these kits.

Thanks for the info. Were you running the Driveshaft shop axles & CV joints, or stock parts? If this rear had stock 5th gen stuff I'd not be doing it.

Staying with the tried and true is probably best for most people out there. We have done very well against the DSE cars but want to see if IRS can do any better. It has the potential to be a little better so we will find out soon & let you know.

Maybe more anti-squat would have helped the rear end bounce.

[David Pozzi]

Where do the shocks mount?

Shocks mount to the rear of the lower control arms, the top mounts to the frame rail.

[CTSV]

Thanks for the info. Were you running the Driveshaft shop axles & CV joints, or stock parts? If this rear had stock 5th gen stuff I'd not be doing it.

Staying with the tried and true is probably best for most people out there. We have done very well against the DSE cars but want to see if IRS can do any better. It has the potential to be a little better so we will find out soon & let you know.

Maybe more anti-squat would have helped the rear end bounce.

We broke factory parts and every part from the aftermarket, Frank at DSS became my buddy after all of this. We also dealt directly with Riley Tech who builds the Grand Am cars and even used some of their stuff but even they said its just a bad design from GM to fit that rear suspension and driveline under that Camaro body. Who knew but you gotta realize the Camaro was the GM bailout savior vehicle. Have you viewed alot of videos of heavily modified 5th gens online? Peter at Pedders also was very helpful as well,

I think GM and the aftermarket is better off to copy the CTSV platform because my CTSV is bulletproof and I kill the car daily and never broke a single part.

David Pozzi I thought I'd better insert an update here. Today is July 30, 2017. Mary has run the car extensively including a lot of Goodguys runs in first gear, SCCA National autocross Championship at Lincoln NE. Many Many regular autocrosses, some with me as co-driver. We have experienced NO failures at all which is GREAT! We did have some issue with the left inboard CV bolts backing off. It was probably due to my not being able to keep the CV joint grease from getting onto the threads during assembly and contaminating the loctite. I finally used Stage 8 bolts with lock tabs and not more troubles.