I am considering installation of an Art Morrison tri-4 bar set up in my 69. Looking for any insight as to fitment to existing floor and trunk pans or any other comments about this set up.

TH

Are you planning on using our complete frame assembly, or just welding in a four link setup?

The complete triangulated 4 bar setup. I have a faxed layout of the whole clip, soon as I can find some time I hope that will answer most of my questions. Looks like this will allow a 345 rear tire too. I take it you work for AM, I have to say your tech / sales people are fantastic! Any pics of this install?

Tim

Yes, I'm an engineer for AM. The sales guys are just awesome, I can't say enough about them.

What aspect ratio do you plan on running for the 345 tire (and rim size)? If the sidewalls are too short, they can cause a severe oversteer condition.

Are you trying to find pics of this setup as installed in-car? I can probably find pics of that, but I can take a digital photo on Tuesday of one of the frames currently in the shop. Have seen our full chassis before? They're just awesome...

What aspect ratio do you plan on running for the 345 tire (and rim size)? If the sidewalls are too short, they can cause a severe oversteer condition.



Are you saying that a front tire 10cm narrower, assuming 245 tire, will not be overpowered by a 345 rear with AMs tribar and cause understeer? If that is the case than why spend the money and energy with the AM link suspension when leafs would be better?

Brian

I cannot say the fronts will be overpowered: the front is much heavier than the rear. The problem with an extremely short sidewall is that they have an increadibly stiff construction to handle the vehicle's weight (since the sidewall is so short). This gives the suspension an "added" spring rate, and hence the oversteer condition. BUT, keep in mind this is only if you are really performance oriented (this is something you'd only see on a road course, street applications would be just fine). I actually shouldn't really say anything, because I don't know what wheel size he's looking at. Yes, a properly sized 345 tire will cause the car to push through a corner.

Regardless, this is for any suspension type; ladder, 4-bar, tri 4-bar, hotchkis, 3-bar, etc. Any four bar with coilovers would be better than a leaf setup, hands down. Ride quality, driver control, tuning ability, are all benefits a multi-link has over a leaf.

If you are dead set on running a huge rear tire (keep in mind I don't know what tire size or wheel size you are looking at, spring rates, weight distribution, etc), you will be better off running a wheel that is 1" smaller (diameter) in the rear, to increase the sidewall height. Cosmetically, you can't really tell the wheel is smaller. There are actually many classes of road racing that take advantage of this trick. Again, for street/drag use, you'll be OK in whatever size you choose (within reason, of course).

Regardless, this is for any suspension type; ladder, 4-bar, tri 4-bar, hotchkis, 3-bar, etc. Any four bar with coilovers would be better than a leaf setup, hands down. Ride quality, driver control, tuning ability, are all benefits a multi-link has over a leaf.


Careful here Matt because that is far from the whole truth. I would hope you would know better than make such a blanket statement. A properly designed link style suspension can be better than leafs if it is designed and dialed in correctly. There are many ways to mess up the geometry of a link style suspension.

I understand you work for AM and would like to promote his product. That is fine and if tharber wants to spend his hard earned money on it, great.

Your reasons for going with a link style suspension are right on. Ride quality has me scratching my head though, but I guess it is all relative. Those and other reasons are why I am designing a three link for my 67.

Brian

Matt,

I doubt I would ever run that large of a tire. I have not decided on the exact sizes as of yet but it will more than likely be a 315/35 or 40 rear tire. I live in Central FL, so road racing will never happen. I'm not trying to build a max effort corner carver. 99% of the time the car will be a weekend cruiser with the occassional Mustang lunch light to light. I intend to have the new crate LS7 under the hood, so weight should not be an issue up front.

I have seen pics of the full chassis and it looks awsome, just overkill for my intended use. Do you guys manufacture the clips all the same, or are there differences depending upon rear tire, engine tranny combo. etc?

TH

TH,
Yes, the frames are all different depending on what you are planning on running. If the tire is wider than XXX amount, we have to re-design the general frame layout to accomodate larger tires. Each frame is custom made to the customer's desires.

If this is a street cruiser, you'll be in real good shape in whatever you decide to do.

Brian, yes that was a blanket statement. I could & should have justified/explained it more, but I don't want to write a whole book in these posts.