Classic Mustang Suspension stuff

I posted this in my build thread for Susie, but I didn't get much traction, so I figured I'd post it in the open.

In addition to the below, I've been thinking about doing the Upper Control Arm relocation mod since I've got nothing else to do here at home.  Instead of spending $15-20 to order a steel plate from someone online, I was thinking of just 3D printing one  using these measurements.  Any thoughts on that?

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Been catching up on Roadkill Garage.  Watching Freiburger and Dulcich wrench on the Disgustang.  Some stuff he said about the handling made me start to think about how I should probably revisit my suspension plans as the last time I had anything resembling a coherent plan was maybe 10 years ago?  Figured I would check in and see what sort of insights I can glean from the groupmind.

The only motorsports I've ever done with this car is AutoX, would potentially be interested in some actual road course stuff, but I'm not at all interested in drag racing.  I also want to be able to drive her daily if I want to (although I probably wouldn't unless work's parking changes somewhat)

So, handling is the primary concern, but semi-closely behind is comfort.  With that being said, I do drive with no AC in Florida, so my comfort needs are pretty lax already.  I guess to quantify it when I talk about that, I don't want noise from the suspension, and I don't want a lot of harshness when I hit a pothole driving around on the surface streets.  Maybe adjustable shocks will be part of the solution to that?

There are fairly standard upgrades for the front end as well as fully custom stuff like welding in a Mustang II setup, but I think I want to avoid permanent changes like cutting out shock towers.  That being said, the rear end might be the biggest cost area to look at.  The two main options are a live axle with a 3 or 4 link, or an IRS from a late model Mustang or other car.  It seems like everyone is still focused on the Cobra IRS from the early 2000s, but I know the '15+ cars also had IRS.  Maybe it's not being swapped in because its too wide?  Something to research at least.

I'm also wondering about secondary help for the handling, how much stiffness I want to put into the car with underbody braces and whatnot.  I don't have any info on how that will affect any sort of harshness/comfort concerns as I outlined above.  

This feels like its petering out, so I'll leave it at that and go work on something while I think on it more and let you guys do your thing

When I did the shelby drop to my 63 Falcon i made my template from a piece of 16ga steel. 

I measured the existing upper control arm bolt spacing and scribed it onto the steel then scribed a line 1 inch down and IIRC 1/8" back (it has been a few years and I know the early cars have a slightly different relocation spec than later mustangs) and bolted the plate to the existing studs and used it to drill pilot holes for the new location.  

Moving the mounting points down changes the camber curve and moving them back adds caster.  

It was about a two hour job to make the template and do the mod. Handling was improved but the inherent bump steer issues with the chassis still left me wanting more. I wound up going so stiff with springs to limit wheel movement to the point bump steer wasn't much of a problem anymore.  I never did get to the point of doing something with the steering to fix it.

Also, knowing what I have learned doing suspension modeling with Ransom since then I find myself wondering if the angle of the upper arm could be changed at the same time when doing the shelby drop so that one could dial in a bit of anti-dive geometry. 

Holy run on sentence Trent!

I just posted in your build thread.  I own a '69 Cougar and am updating all the systems now.  
 

I would suggest that you contact the following vendors for input:

Street or Track

Opentracker Racing

Global West

Maier Racing 

Mike Maier Racing

Detroit Speed

All are focused on vintage Mustang suspension except Detroit Speed who are relatively recent suppliers to Mustang owners though they have an impressive front suspension offering.

In reply to Mr_Asa :

I used the same template from Tony Branda about 20 years ago on my '65 Fastback. I made a paper template, transferred it to a piece of thin aluminum and used that. After doing the first side of the car, flip it over and use the same template for the other side of the car.

Dis it make a difference? For my purposes (street use only), probably not much, although it should give you a little more fender clearance to run wider front tires. You may not need that on a '67-68. And if you don't lower it in the first place, you may not have a clearance issue anyway.

Even the best of these cars don't handle all that well anyway.

Opinion:

Anything you do to a car of that vintage that doesn't update the whole suspension will improve a wee bit, but it will still drive like a buckboard wagon.  I updated my 67 Camaro to 78 spec front clip, which at least gets it to a radial tire setup.  I really lust after the DSE setup, but it's way, way too many dollars.

Lose the spring towers, and buy the aftermarket setup that best matches your budget and desires.  

I've been there. 
 

The ride comfort is not going to be negatively impacted in anyway by improving the suspension geometry. So go ahead with the Shelby drop and a modern alignment.
 

Spring rate and shocks will make the biggest difference on ride quality.  The good news is that you don't have to go crazy with spring rates or shocks to get good handling. My pro touring Camaro and road race Mustang ride similar to modern sports cars. And a whole lot better than a family member's Mini Cooper S. 
 

I suggest a high quality single adjustable shock like the ride tech. 
 

Above someone suggested some brands to look at. I agree with all of those. I'd also add TCI Engineering to the list. I have it on my Camaro and after killing it on the autocross with their parts as well as driving two TCI equipped Mustangs I'm in the middle of installing it on my Mustang. Though TCI, SoT and DSE are pretty extensive on the mods and allow deletion of the shock towers.  
 

I had a killer setup with shock towers on my Mustang. Similar to the Maier parts but mostly homebuilt. I'm switching to fit 315 and 335 front tires. The spindle design on most early Mustangs really restrict tire width due to the upper ball joint location. 
 

if you really want to keep the shock towers then give Mike Maier a call. 
 

On the rear id go torque arm or 3 link for handling. I'm not a big fan of the 4 link designs. They work but just not as well IMO.  That's based on driving a bunch of different pro touring muscle cars.
 

I've driven every major brand.  TCI, DSE, Maier, Speedtech, Art Morrison Global west etc. haven't driven SoT though. 

I have never devised it myself, but I have wondered if there is an "off the shelf" way to upgrade these cars.  What if you used a strut from an Accord and something else to tie it together.

Accord suspension

The strut/spring goes where a spring and shock lives anyway.  Instead of making the upper control arm support the weight like the original let it go through through the upper arm and attach to the lower arm  like Honda does.  Since the lower arm would now support the weight instead just holding the bottom of the knuckle in place you may have to box the lower arm for strength.  This is all dead reckoning theory, so take it as you may.

Another idea is since the shock/spring tower holds the top of the spring and shock, maybe try some SN95 knuckles and lose the upper arm altogether.  This would need a pivot bearing for the strut to turn on so you could steer.  And maybe a rear sump oil pan and mount a SN95 rack in front of the control arms.

I am rambling.  lol

I've been very happy with my Street or Track stuff so far.  Shaun, the owner, is a solid guy to work with.  He tracks his car and understands what works.  He also worked on data collection during system development with a guy I know at GM.   Systems he designed performs very well on my old cat!  No shock tower cutting either.  Lot of vintage Mustang guys on vintage-Mustang forum use his stuff.  He's also local to me so I got to meet with him before my purchase.  I can heartily recommend him and his stuff!

That looks great.  

That's exactly what I installed in my Cougar!  Finished it off with steering and big front brakes.

I've been following Opentracker Racing for a while.  I remember when they first started, were big into getting feedback from forums and people that used the products.  I've still got some stuff bookmarked from them from probably 10 years ago.  The Street or Track stuff also grabs my eye for some reason.

Price point seems fairly standard throughout, with the exception of one or two of those companies, but those kits look to be full replacement cradles and everything.

I'm going to have to do some talking with them as the I6 is lighter than the SBF and the weight sits differently, so it should affect some of the handling.  Nothing that can't be dialed in, but it should affect spring rates

Anyone have any thoughts on whether I should play with an IRS?  I have an 8" in the car right now, but most of the rear end modifications seem to require weld on mounts.  Not sure how much sense it would make to stick with the 8" if I'm doing such permanent modifications.

noddaz said:

That looks great.  

That's pretty much the setup I had on my Mustang. I bet they purchased the coil over kit from SoT but boxed the oem control arms and installing bearings in the cross shafts instead of bushings. 
 

worked great. Would of left it if the tire clearance worked how I wanted. 
 

i must of been thinking of another setup earlier when I mentioned SoT having to cut the towers. 

I have a 67 Falcon so basically the same suspension, but a different body. What I admired about that RK garage episode was how well Freiburger stuck to his guns about keeping it street-oriented and reasonably priced. The Opentracker/Street or Track/Meier Racing stuff is really awesome looking and I bet it makes sense if you plan to run hard at the track and want to get the most out of these old cars.  

Problem is I’m not made of money, and I mostly drive on the street, so when I rebuilt my front suspension a few years back I could not afford ultimate performance, but I also couldn’t live with the bad handling of the factory setup. With this in mind here are some things that I thought worked well:

Upper control arm drop (Shelby drop) - Definitely plan to do this, it’s almost free, except the time invested, and it does so much to address the built-in factory flaws. You can immediately feel the front is more firmly planted after this mod. Unless you’re a spaz you really don’t need a metal template, I used a paper copy of the Shelby drawing and took my time to measure and drill and that was just fine. 

“Roller” spring saddle - This made a surprising difference in freeing up the bind created by the factory style firm spring perches. I added some cheaper ones “while I was in there” to adjust coil spring height, and was shocked at how much better the suspension articulates and conforms to the road. You can sink some money into the expensive roller bearing perches but I got a pair of these simple ones (greaseable poly with a zerk) and they spin easily and work great! Scott Drake Coil Spring Seats C4DZ-3388-HP

Adjustable shocks - I feel like I need these real bad and I’m thinking you will want them too. I’ve tried a few different non-adjustable shocks but they have ended up feeling either too soft or too firm, so adjustable seems like the way to go here. I’m still researching but plan to make this one of my next purchases.

Aftermarket strut rod - Freiburger decided to splurge with a tube style upper arm, but I’d rather spend my money on a better strut rod. I added new rubber bushings to the factory strut rods to save money,  but precisely locating the lower control arm are just not their strong suit. I’ve heard poly bushings just add bind and can stress the factory rod to the point of failure, so I think a nice well engineered part here is probably money well spent. It’s on the list...

Rear Suspension - I have not messed with mine yet so I have a lot of the same questions do, but I think rebuilt leaf springs with a panhard bar and adjustable rear shocks is where I will go next. I can’t afford to adapt an IRS or 4 link (I have a wagon so Mustang stuff will not work without a lot of fab) but I’d sure like to get there one of these days.  Given how much I can feel the rear shifting around corners, I’m sure nailing down the axle location will do wonders just by itself.