Art Morrison C-5 IFS
 

Hey All! I'm building a '66 nova and have been going round and round on the suspension issue for some time now. I had finally decided to have Wayne Due do a full chassis for me but that doesn't look too likely now that his shop is closing. I am also considering Art Morrisons C-5 IFS but Kevin Kosier is telling me that it won't work and that I should go with their own brand of IFS. As much as I'm sure theirs will work fine I just love the way those C-5 Control Arms look and I would really like to try and get them to work. Here is what I am figuring and please tell me if I am in error anywhere in my calculations. Car will be low, probably around 5" at its lowest point. Don't want to bag it. Wheels I would like to put on are 18 x 8's with a 245/18/40 BFG KDW on the front. AM makes a C-5 clip with a 57 1/2" Hub to Hub. I figure with the backing plate and disc brake plate it should add another inch on each side bringing total width to 59 1/2". With the 8" wheels I'll probably backspace it 4 1/2". I figure the center section of the rim will add another 1/2" on each side bringing the total track width, including wheels with backspace, to 66 1/2". The ID fender to fender is 70 1/2". This should leave at least 2" between fender and wheel. Isn't this enough to still have a decent turn radius? Why is Kevin Kosier from AM telling me I will have rubbing issues? Can anyone explain? He says one of the factors is the shape of the opening of the wheel well on the front fender of the '66-'67 models. Anyone? :question:

Nova,
Hopefully I can shed some light on this.

With that size tire & wheel, along with the 5" ride height, you'll want to shoot for a tire bulge-to-bulge of 63", not 66.5" like you had mentioned. As you lower the car (especially down to the point you mentioned), you need to suck the tires in quite far. Don't worry, it doesn't look goofy.

With our narrowed C5 suspension, the "hub-to-hub" of 57.5" that was told to you was actually a bit misleading. That measurement includes the stock rotors, so 57.5" is the "wheel mounting width".

So, a wide hub track and a narrow bulge-to-bulge requires lots of backspace. Assuming a 9-7/8" sidewall width, you'll need about 6.38" of backspace on a 8" wide wheel. Shop around to see if you can get the style of wheel you like in that offset.

Another issue that Kevin may have brought up is engine set-back. The C5 suspension is designed to have the engine set far back from spindle C/L, just like a production C5. That feature has been maintained with our suspension due to the positioning of the rack and pinion. However, we are nearly complete with a re-design that places the rack in a much more favorable location that will require little to no engine set-back for small block engines, all while maintaining excellent geometry.

We've done C5 IFS on a Chevy II before, but it's a squeeze. But as you know, it looks great and handles awesome.

Matt Jones
Mechanical Engineer, Art Morrison Ent.

Read your post in Pro-touring........