'70 cuda, anyone have an offset upper 3rd link?

[bbs]

I'm far from done (see photo), but headed along the lines of Hot Rod Garage drift Cuda, except will install the upper 3rd link offset 6" to the passenger side. The chassis end will end up inside next to the driveshaft tunnel, so looking for lessons learned fabbing up mounts and a cover.



It won't have a rear seat, and it won't need a roll cage. The stroker 383 (496ci) is still in the machine shop, I don't expect it to have more than 600fwhp or get into the 10's, plus the nearest drag strip is too far. Might install a 6pt roll bar. It's not a daily driver. It's a play car, was 2bbl/383 Gran Coupe.



Also plan to use the QuickCar torque absorber. Lower links will be 28" long, upper will be 20". No I won't be using the air bags or helix parts in the photo.

[Cyclone03]

Can’t help with the install but I’m going to follow along.
I’ve been thinking about doing the same with my 64 Comet.
I have this dumb idea of making a Comet’s 114” wheel base and skinny track width go around corners .

[bbs]

That's awesome.

A Comet that flys around corners!

[416velle]

Looks like a really solid car, and I love seeing fab stuff like this, it just makes me happy. I built a 3 link/PHB setup for my chevelle that I'll be autocrossing, I'll give my 2 cents where I feel I can.

-Geometry measurements are only as important as your knowledge of their significance. Your suspension will require more measurement and theorizing than mine did because you don't have control arms from the factory, it definitely helps to maybe not know EXACTLY where/how things have to be, but rather a general direction of how/where things need to be. I say this mainly in regards to antisquat, but also for roll center height, sway bar rates, spring rates, etc. The intended use for this car (autocross/road course vs drag strip vs streetcar/show car) would determine some of the geometry in an ideal world. This isn't the first cuda with a 3 link so definitely do some research on what other people have done, it also is helpful to look at other cars that are similar size/weight, namely 1st/2nd gen camaros in this case.

-Theres nothing wrong with looking at pictures/videos of high-dollar aftermarket suspension systems and reverse engineering them to give you ideas or answer questions. I won't name names because I did a lot of this when putting my rig together

-IMO first order of business once you actually start to work on it is to set the axle in there WITH wheels/tires on it, put it it up under the car to determine your intended stance BEFORE DOING ANYTHING AT ALL. Take some rough measurements of where the axle is F-R, clearance to frame for bump, rough area of where control arms will go, shock crossmember/upper mount location, etc. I would do the coilover mounts first, find your ride-height shock eye-eye length from the manufacturer and drill some holes in some square stock at that length (mock up coilover essentially), mock up a mount on the axle and start looking at an upper mount crossmember location. When those are roughed in, the square stock can kind of act as a jig for the axle and allow you to work from there, that way you're working on it AT RIDE HEIGHT. (I learned this the hard way with my initial watts link i built, the ride height I wanted was far too low for the adjustment/link angles I had so the geometry was way off. Ended up scrapping it and fully redesigning EVERYTHING with panhard bar)

-I recommend having a fully assembled axle prior to starting building anything (with axles/diff, etc). Because the last thing you want is to have to redo stuff because the diff wasn't in there during mock up (suggestion from experience)

-Its fair to say a bunch of the floor will have to come out given the fairly long upper control arm length; some might suggest differently and they might be right given how mint the metal on that car looks, but once you start looking at upper control arm location my best advice is to cut out more than you think you will. You can visualize stuff a lot better when theres not floor obscuring the parts. Also you'll have more room to work around if/when you have to weld under there. Welds are always better when you're comfortable. Another thing; The bigger the pieces of floor you cut out at a time, the easier it is to re-use and weld back once its all done. Cutting as little as possible and trimming a bunch of times will result in very small pieces that wont weld back on.

-Buy as much off-shelf parts as you can. Control arm brackets, coilover mounts, panhard bar mounts, sway bar mounts, etc, because assuming your measurements are right when you're buying something and its precisely what you need with maybe a little massaging at most, prefabbed parts are WAY more precise than anything that can come from a cutoff wheel and grinder. Fabrication of custom parts is cool if you have a CNC plasma table, old fashioned hand tools only get you so far in terms of symmetry, tolerances, precision. Not having to mock stuff up out of cardboard is also a HUGE time and sanity saver.

-Try to make frame section crossmembers multi-use if possible (within reason) so that you don't have 6 different crossmembers under the thing all doing different things. IE, coilover crossmember doubling as sway bar upper mounts, etc.

-Don't move on and call anything "good enough" that you aren't satisfied with it. Because chances are, you WILL NOT be going back under the thing to redo stuff later on that you don't like the result of once the car is driving. Do it once, do it how you deem its right, and this leads into my last tip.

-TAKE YOUR TIME!! Prep, mock up, mock up some more, sleep on it a few days, mock up, don't final weld ANYTHING until the entire rear suspension is mocked up and you can do articulation checks with the wheels on, clearance checks, etc. Guarantee you'll have some sort of "aha" moment where you pinpoint a much better way of doing something, undoing things and is much easier if it isn't fully welded in. If you run into an issue, I cannot stress the importance of walking away from it and sleeping on it for however many days it takes til you resolve it.

Couple things off the top of my head. Will definitely be following this build!

[Cyclone03]

416Vell thanks for your insight. Using prefabbed brackets and mounts was my plan but my Google-foo is failing me on finding suppliers,can you point me in the right direction?

Im still in the education/research phase on my Silly Comet build and have actually been in FB contact with a guy who actually road raced one of the East African Safari 64 Comets prepped by Holman Moody Strope when the car was returned to the US. He has told me it’s a long row to hoe . The long wheel base,narrow track and weight over the smaller Falcon quickly had him changing cars. But I just love the 64 Comet body.

[416velle]

Ballistic fabrication, Artec and ridetech are good places to start. Youll find a LOT of what you need from offroad parts suppliers, so take your time and be creative with your search criteria. In regards to control arm axle brackets, rear end builders/suppliers like Quick Performance, Strange, Currie and Moser may have what you need. If they dont then consider using brackets from something like a chevelle/g-body because those are very common. Just some food for thought

[Cyclone03]

Thanks, I was also looks at off the shelf 4 link kits,not triangulated, for brackets and bars.

[416velle]

Definitely shop around before pulling the trigger on anything. One other thing you'll learn is a LOT of stuff thats labeled one thing can be used for something completely different. For example; coilover axle mounts can very likely be used as 4 link mounts if you grind down the half-moon/arch shape. I used this method for my upper coilover mounts on my frame. Another example; I used of all things a "ladder bar" crossmember for my 3rd link frame mount. It just so happened that the driveshaft-clearance arch in the middle worked with where I wanted to mount it between my frame rails, and I mounted my center link directly to the center of it. universal doubleshear mounts are how I mounted my sway bar to that same crossmember.
I have no idea what it would've costed to have the same crossmember built from a shop but its quite a timesaver to explore the internet because theres very likely something out there already that can be used for whatever you need. That's the best advice I can possibly give for custom fab stuff if you don't have solidworks or someone with CNC machines.

[bbs]

My build will take time. I spent the last few years replacing most of the sheet metal, patching holes, and primered with epoxy. I have a Ford truck dana 60 with limited slip and 4.10 gears which needs to be narrowed.

The ride height won't be crazy low, high capacity oil pans limit ride height. I'll be about this.


The lower mounts are set and use 1/4" plate for the 3/4" rod ends and for reinforcing the torque box. Lower bars will be about 29" long, I calculated minimum length for the upper bar at 70% which is about 20-1/4", but I could go longer. Fabrication for the interior is where I hoped to learn from other experiences.


The upper will be 6" offset to the right, but Ago416velle is right. I have to get the rear end in place before I can go much further. And it sounds like I should replace the upper crossmember, I have 2" square tube with 3/16" walls which is solid and pretty heavy. Again gotta stage the rear first. I do have to keep the offset of the driveshaft tunnel in mind when I have the rear narrowed.

[416velle]

Thats going to be one killer ride for sure.

In regards to interior stuff......I can't exactly speak from any experience on any other specific car than mine, but when you get around to cutting stuff out I would cut out a larger area than you think you would need to in order to negate as much trimming as possible. Because you can weld on a single section of floor easier than multiple smaller pieces.
BUT..theres multiple ways to kick the cat--skin the cat. There always better ways to do something if you dont like it.