Lowering upper control arms -Shelby Mod

[Duncan Mach72]

Maybe. But it drives really well.

When people start talking of spending thousands on their Mustangs to replace the complete suspension because they 'want it to drive like a modern car' I feel very sceptical. I believe an upper & lower arm is better than a strut, if set up correctly, as that's what race cars have. I think a few well thought out mods + learning to drive the car is all that's needed.

What I would do is not believe what people say unless they have actually measured stuff. Remove a spring and figure out for yourself how the camber changes during full suspension movement, then work out what you'd like it to do. Maybe do some drawings or mock up with some pieces of wood or even computer simulation if you can.

If you do go ahead I would recommend a kit for the hardware because of the time it will save.

At the moment I'm wondering how best to positively locate the rear axle as i know that will yield big gains in cornering control and feel.

By the way, there is another downside common to any lowering mod, it bump steers when braking. I'm definitely going to buy a kit to fix that!

 

[Total Control Products]

So as I understand it today' date=' everything you did should not have been done given the car vintage. Not picking on you at all but just hoping to land on THE answer as I start to tweak my '73 Mach 1.[/quote']
Right. Compared to the early cars it already has improved upper control arm mounting position. Lowering will increase the amount of camber gain/the angle of the tire under compression. With a stock width tire, or slightly more than stock, it might be okay.

The issue that arises when moving the upper arm pivot down too far is that it begins to affect the roll center height with a negative effect to overall handling. In a nutshell, the stock position is fine and the biggest improvements aside from spring rates comes from minimizing play in any suspension pivot point.

IMPORTANT NOTE: It’s imperative that the balljoint angle be adjusted so that it will not bind at full compression.

At the moment I'm wondering how best to positively locate the rear axle as i know that will yield big gains in cornering control and feel.

If you want to stick with leaf springs the simplest option for improved lateral location would be to just pick up a panhard bar from your favorite supplier.

By the way' date=' there is another downside common to any lowering mod, it bump steers when braking. I'm definitely going to buy a kit to fix that![/quote']
Some bump-steer is inherent to the stock suspension design but it can be improved or exacerbated. Simply lowering the car’s ride height does not, in and of itself, change the bump steer characteristics of the suspension design. The pivot points are still all in the stock position. Often bumpsteer is more noticeable at the extreme ends of suspension travel. When the car is lowered, it’s closer to full compression and therefore closer to the bad part of the bump steer curve.

The stock strut rods play a big part in the bump steer tendencies of the car; the bushing deflects all over the place during compression and extension/braking. Theoretically, having too much camber gain could make the B/S numbers worse, too, but probably not enough to notice the change. Our front suspension system lowers the car about two inches AND improves the bump-steer through geometry tweaks and the reduction of deflection.

Looking at your pictures, it appears that the UCA mounting position has also been moved slightly forward in the car. This will reduce the amount of positive caster that can be set in the alignment. This also will make the car feel more twitchy. Maybe it’s the just the angle of the image; I have obviously never seen the car in person.

My suggestion for the short term would be to simply get a pair of bump-steer adjustable tie-rod ends, LIKE THESE, and then have the car aligned at a race alignment shop. This is not a ten-minute process, but it will pay dividends.

 

[1972MustangSVH]

Ok, I have to ask a dumb question. I see all the sparkle and gloss and find myself thinking this would be a good idea. However, I have to wonder how this stuff performs in the real world. I live very, very, rural. It's a couple of miles to very unimproved chip n seal black top, then 6 miles to the next one and another 5 to a highway. Going to the highway to get anywhere around here is considered "taking the long way around." Granted my car (and me) are long past our Dukes of Hazard days. But the facts remain, I have to think that my car will have to travel on less than good roads to get anywhere. How can I expect these Mods to perform under less than ideal conditions?

 

[Total Control Products]

Ok, I have to ask a dumb question... (snip)... How can I expect these Mods to perform under less than ideal conditions?

The only dumb question is...well that's a crock. I answer dumb questions all day long. Haha! But, at any rate, this isn't a dumb question.

Since you ask, our stuff is super durable. I have had people race it in La Carrera Panamericana. That's a pretty stout test, in my opinion. Parts eventually wear out, just like the stockers, but on a street car they last for years and years. There are still people running around on the racetrack with the original parts built by TCP in the 90s. If you think you're putting an excessive amount of abuse into anything then it should be inspected.

Obviously I'm not suggesting that our parts are designed for off-road racing, but they're beefy and definitely the strongest in the aftermarket.

 

[Duncan Mach72]

So as I understand it today' date=' everything you did should not have been done given the car vintage.[/quote']

Right. Compared to the early cars it already has improved upper control arm mounting position.

I will believe this when I see pictorial evidence

Lowering will increase the amount of camber gain/the angle of the tire under compression. With a stock width tire, or slightly more than stock, it might be okay.

Well it's certainly better than the 65-70 stock camber loss, that really chews up the tire's outer edge!

If you want to stick with leaf springs the simplest option for improved lateral location would be to just pick up a panhard bar from your favorite supplier.

I live in the UK. Probably not as easy as you might think

I'd like a panhard rod but there will be issues with the exhausts. I might engineer some struts to triangulate the axle to the leaf springs. I had a kit like this on a European Capri that I bought from the Caprisport club & it worked wonders.

Looking at your pictures, it appears that the UCA mounting position has also been moved slightly forward in the car. ....Maybe it’s just the angle of the image; I have obviously never seen the car in person.

Actually moved rearward as I made my template with the new holes projected out at 90 degrees to the original UCA axis.

My suggestion for the short term would be to simply get a pair of bump-steer adjustable tie-rod ends and then have the car aligned at a race alignment shop. This is not a ten-minute process, but it will pay dividends.

A good idea but getting anything like that done here is a ridiculous drama like you wouldn't believe

I'm really happy with how it drives except for the bump steer and having to continuously correct the steering. I'm sure it needs more caster dialling in, which I will get done with the bump steer kit & hopefully some stiffer springs as I now have a 429 in place. Then there is the total lack of traction in first gear to resolve...

It's all fun, eh?