65 Falcon rear suspension suggestions.

[s.hembree]

Hi guys. been reading the forum for a while, but this is my first post.

I have a 65 Falcon with a Mustang II front suspension (don't hate, didn't know any better at the time), EFI 5.0, 4R70W, and a narrowed explorer 8.8. When I built the car a few years ago I moved the rear springs inside the frame and the rear axle back slightly to center the tire in the wheel well. Currently run 17 X 7 fronts and 18 X 8 rears with a 245 rear tire.

With the stock rear springs that are way too soft the car handles poorly and I literally can't have a rear seat passenger (suspension compresses and the tires rub). This car is a toy that sees some spirited driving, but also goes to cruises and I will be attending my first rally this summer. I would like to do some track days and parking lot autocross type events.

I'm looking for a recommendation for a rear suspension system. I bought a Heidts kit a while back, but after looking into it I would lose a ton of tire clearance, and that's not ok (I'll sell the Heidt's kit cheap if anyone is interested). I've heard good things about TCI's kit, but figured I would try to get some real world opinions on some others. I know there a ton of other kit's out there that fit the 65 era Mustangs and the suspension is similar, but I get conflicting information as to whether or not they will work in a Falcon, and the extent of modifications that would be required. I'm not afraid to modify something, but it doesn't make sense to spend 2k on a kit and cut it up to the point of damn near starting over.

Any experienced opinions?

[Red67Mustang]

I considered the various triangulated 4 links available but was concerned about what I considered the inherent bind in the design, so I opted for a 3 link with Watts link (by StreetOrTrack).

http://www.streetortrack.com/Street-or-Track-Rear-Bilstein-3-Link-Coilover-System-pr-24572.html

Call and talk to Shaun at StreetOrTrack, he's super helpful and I'll bet he can tell you what (if anything, given the chassis similarities) needs to be done to install on your Falcon.

As far as performance - AWESOME! This mod took my car from a twitchy over-steering mess to a a$$ hauler that is a thrill to drive at 10/10ths... I just ran it in an Autocross last weekend and was reminded again of how well this rear suspension sticks! That's my $0.02.

[BillyShope]

I had a '65 Falcon Sprint. (Superior to a Mustang, in my opinion.) First, I'll provide a cheap and effective trick. From J.C. Whitney, of all people, you can buy an overload leaf spring to attach below the stock spring. No, that's not all. I then clamped it at both ends and attached it to the stock spring with threaded rod. So, it didn't affect ride height, but definitely was an addition to the rear spring rate. Of course, you have the same effect...and it looks better...by paying a specialty outfit build you a higher rate spring. But, I have blood from a Scot.

Here's a better idea, but it means a whole lot more work (and expense). The plastic springs on the Corvette have been pretty much excluded from any control functions and act only as springs. OK, let's do the same with your Ford. If a second shackle is added, but to the front spring eye, the leaf spring can only handle vertical loads. But, unlike a coil spring, the leaf spring is like a solid extension of the axle housing. In other words, it acts like an "arm," a "torque" arm. See where I'm headed? By adding a Panhard and a couple of upper links, you have a torque arm suspension. With extra holes in the brackets, you have an adjustable torque arm suspension. And, looking at it another way, you have an adjustable 4link suspension. Those front shackles definitely qualify as "links." Remember: The instant center is at the intersection of the upper link line and a vertical line through the front spring eye. Finally, the upper links are carrying all the thrust loads, so NO spaghetti tubing!