Lateral-g Forums - Art Morrison IRS, 73 Camaro

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Thanks David. Great to see a straight up review.

How's the First Gen coming? I think we need a project thread on it :thumbsup:

Quote:

Originally Posted by David Pozzi (Post 546934)

I don't have the roll center height data but they say it's very stable which is the main consideration, it moves 1:1 with the body.

We are starting from scratch on spring rates and shock valving. The motion ratios are different from the stick axle we had, more like the front now. We are at 450 in spring rate which is what Morrison runs on their 69 Camaro. It works very well, I doubt we will be far from that in a year from now, but time will tell.
We started with an aggressive toe steer setting (toe out in bump) we found that to be too much and backed it down to pretty close to what Morrison runs on their 69 right now. We will experiment further.
I'm not much up to speed on the "numbers" yet, we have been so busy just getting it into the car. I'm not sure my Performance Trends software can even handle this type of suspension. I kinda doubt it.

Thanks David. I use Performance Trends for various IRS designs. The data enters like a double a-arm front suspension with X,Y, and Z measurements of the pivot points. It will yield moment center, instant centers, camber gain, and the like. I am anxious to see Mary's car perform in person.

Pappy

Quote:

Originally Posted by Ron in SoCal (Post 546939)

Thanks David. Great to see a straight up review.

How's the First Gen coming? I think we need a project thread on it :thumbsup:

Ron,
I have my rear IRS in the shop for my 67 Camaro & will begin the install within the next week. I've been told there is very little cutting needed compared to a second gen. My engine should be done in a month so I can start building my headers then. It's a tall deck RHS block. I think I'll get it running before doing the body work, then finish the fenders to suit my wheels and tires, then tear it down over winter and paint it. Autocross is ending at Marina by the end of the year and I'd like to run the car a few times locally & work on the setup before I have to start towing longer distances to events. If I don't get it running by late year, I'll just paint it, then run it next year. I'd love to have it in good shape for the USCA events next year.

I'll start a project thread when I make some progress on the IRS install. Not much to see right now except the junk I'm throwing out/moving in my shop, I'm making room so I can move my Camaro around.
The nice thing is, our cars will be the same under the skin, Although I'm running the LG drop spindles and Mary isn't.

Morrison recommended I get new frame rails with my IRS. They make their own first gen frame rails. The assembly comes as shown below and I was advised to fit it in the car as a unit. They recommend cutting out the factory frame rails but leaving the spot welded flanges in place. This gives a thicker area to weld the new rails to. I'll sand blast the stock rails before cutting. The paint on Mary's frame rails was tough to remove, it's whatever JCG used.

The suspension comes aligned so you can measure from the hubs to the fender openings to get it centered up.
My IRS:

Quote:

Originally Posted by mfain (Post 546946)

That's encouraging, I have to get all the measurements for it.

Quote:

Originally Posted by David Pozzi (Post 546968)

Autocross is ending at Marina by the end of the year and I'd like to run the car a few times locally & work on the setup before I have to start towing longer distances to events.

HOLD THE PHONE!

WHAT?!?!?!?!?!?

I'm speechless. What an intense set up. :thumbsup:

Quote:

Originally Posted by Damn True (Post 546972)

HOLD THE PHONE!

WHAT?!?!?!?!?!?

FAA is tightening security. I guess Autocrossers are a risk. There is SO little going on at that Airport it's pathetic!

Quote:

Originally Posted by David Pozzi (Post 547054)

FAA is tightening security. I guess Autocrossers are a risk. There is SO little going on at that Airport it's pathetic!

What a load of crap!

What's left? Oakland, GG Fields, SJCF and Mather?

I haven't been down there in over a year but $1 to a bag of donuts there are houses going in near that parking ramp sometime soon if construction hasn't already begun.

I can't figure out how to get ahold of Jesus Villareal, thinking maybe you and Mary know him. At any rate, Tesla now runs the old NUMI plant in Fremont. They aren't using the big North lot. Might be a chance they'd be amenable: https://www.google.com/maps/place/45...6e26a14c243e97

Pacific rail depot in Milpitas (pretty sure this is still in use though): https://www.google.com/maps/place/65...8e66bfd64ef337

Also in Fremont, this lot isn't far from NUMI and IIRC used to belong to NUMI as well. Access appears to be via the wrecking yard property to the North: https://www.google.com/maps/place/67...6db48f4e2af05f

The holy grail is of course Moffett Field. Now that Google runs it perhaps there might be a chance?

Marina city wants us, FAA which is federal does not. The city makes some money off autocross, FAA doesn't make a dime & could care less what we want.
Houses will be built closer some day, but it's a long way off.