Debating on leaf spring vs. 4-link

wicked93gs

15 Year Member
Sep 30, 2006
1,198
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Nashville TN
I am just wondering whether its worth it in the handling department to convert to a 4-link setup...I've been reading but seem unable to come to a conclusion here....I know to be able to handle well, I would almost certainly need different/better leafs...but I read from time to time about cars with leafs that are pulling close to a 1.0g on the skid pad(give or take a few tenths for that particular car) and mid to high 70s through the slalom and I see articles like that and wonder what the point of a 4-link system really is...or IRS for that matter....my goals are pretty simple....no wheel hop and good handling....will I be able to do that with leaf springs or will I need something else? currently I have leafs with a 8.8" setup, but since the car isn't yet running I haven't even tested this setup
 
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The stock quadra-bind 4 link suspension on Fox Mustangs doesn't handle as well as the leafs in classics, so a 4 link doesn't guarantee good handling. If you have a lot of power and sticky tires you can have problems with wheel hop caused by the leaf springs wrapping. However, using rubber bushings with a 4 link you can get just as bad wheel hop due to bushing deflection.

So, yes a link suspension (I wouldn't recommend a traditional 4 link) can outperform a leaf rear if you have a lot of HP and you want to have really good cornering grip. You might consider trying replacement springs with an extra leaf in the front to help limit leaf wrap before you completely throw the leafs away, though.

A 3 link with a pan hard bar is a nice setup if good geometry can be made to fit the car. Hopefully other forum members can give you feed back with actual experience with different suspension products.

My advice is to get the car running and try out what you have before deciding it isn't good enough. You might be surprised.
 
I have quite a ways to go before then...next weekend is the mustang II front suspension....and adapting the t5 to fit my DOHC 4.6L...still need to come up with a steering column and a driveshaft and a few minor things to finish it off...regardless, if I can get good handling with leafs I see no reason for the expense, depending on the limitations of my front suspension anyway, we'll see how much negative camber I can manage to get out of it
 
I'm a big fan of "if it aint broke, don't fix it" - also when it comes to leaf spring suspension. Leafs can go a looong way on the track with some help from a Panhard rod or Watts link. And if you run into leaf wrap problems as you up the traction or HP get this:
Total Control Products

On the track my old 69 hardtop pulls 0.96g in the turns on street tires. Leafs, HD schackles, SPAX shocks. No Panhard, Watts or torque arm. :)
 
a well set up leaf spring system is hard to beat. it is solid, reliable, and inexpensive. as for the fox body four link, it has two big issues;

1: the angles of the arms, and the length of the arms encourage suspension binding.

2: the bushings also encourage binding.

replacing the stock rubber bushings with spherical bearings, and installing a panhard bar, and the fox body suspension really comes into its own handling wise.

the key with any suspension design is elimination of suspension binding.
 
while leaf springs can be very capable they are 1850's technology...seriously they are that old!!!! i personally am planning on a TCP G-Bar setup for the rear of my cougar, for 2 reasons, first the G-Bar is nice system, especially if you go with the adjustable link setup, and secondly because it's currently the only rear suspension other than leaf springs available for the cougars.

the mustangs have a much larger array of suspension choices from really low-buck to extremely high dollar. with the mustang you can actually do a nice link suspension for about the same or not much more than a really nice leaf spring setup with Del-Alum bushings, traction bars, panhard, torque arm or watts link, etc.

i would stick with what you have for now and see how it works with your setup after the car is roadworthy and then decide if you even need a change. once you have some seat time in the car then start exploring and researching link type or independant rear suspensions and decide what the best solution, dollar for dollar, would be.
 
Leaf spring suspension is very capable. If you are going to drag race, I'd take leaf over a 4-link or 3 link or IRS any day. Now when it comes to the curves, I'd still take leaf over a 4-link. A good 3-link is a really nice setup and so is an IRS.

I'd say throw a watts link or a panhard in with the leafs and see how happy you are with it. They are capable of exceptional handling in their own right.
 
I was going to get the air ride triangulated set up, but after much research I am getting flex a form composite leaf springs along with cal-trac bars, about 650 bucks.

This is a great setup for drag or road racing, I have talked to a lot of people who use the composite mono leafs and they all claim huge improvement in ride, handling, road noise and it removes quite a bit of unsprung weight from the car. The other thing is you can route your exhaust in the normal location, with most of the 3 or 4 link setups you eithe have to run exhaust out the side or under your rear end.
 
I was going to get the air ride triangulated set up, but after much research I am getting flex a form composite leaf springs along with cal-trac bars, about 650 bucks.

This is a great setup for drag or road racing, I have talked to a lot of people who use the composite mono leafs and they all claim huge improvement in ride, handling, road noise and it removes quite a bit of unsprung weight from the car. The other thing is you can route your exhaust in the normal location, with most of the 3 or 4 link setups you eithe have to run exhaust out the side or under your rear end.

save your money and just get the fiberglass springs. they dont suffer from spring wrap like steel springs do so you really dont need the traction bars.
 
Good choice! :nice:

My choice of FAB9 with 5-leaf, torque arm and Panhard is after lengthy advice from the Chris Alston/TCP techs. They preferred it over the gBar for serious cornering with lots of available power and traction. I went 5-leaf instead of composite in order to be able to change spring rates between tracks (repacking the leaf sets).
 
Composite and fiberglass leafs?? Hum, I hadn't seen those.

I've got a set of the 4.5 leaf springs from Mustangs Plus. My car preformed really well on the autocross course, but is a bit rough on the street.

I changed my rearend pinion angle with a set of those shims (I can't think of what they are called for the life of me) and I now have light wheelhop. The other part I don't like is the fact that the rear of my stang likes to hop to the passenger side when I go over bumps and small potholes. I've been wondering if something is seriously wrong, but have no idea what it might be.

I wanna take my car to the next SCCA event, but I think we will take the wifes Camry so she can drive too.
 
The other part I don't like is the fact that the rear of my stang likes to hop to the passenger side when I go over bumps and small potholes. I've been wondering if something is seriously wrong, but have no idea what it might be.

I don't know if this is your problem or not, but I used to have the same thing with the rear end hopping sideways on bumpy corners. Mine went away when I added subframe connectors to the car. I see that your avatar is a convertible.. my '70 is a convertible as well.

edit: if that's happening during straight-line driving you might want to have the alignment checked - possibly something is wrong there.
 
Could be something wrong with the alignment. I've got subframe connectors welded on my stang. They made a huge improvement in the way my car handles. There is still some flex in the chassis though.
 
Could be something wrong with the alignment. I've got subframe connectors welded on my stang. They made a huge improvement in the way my car handles. There is still some flex in the chassis though.


i used to have that problem with my car when i had those damn extended shackles on it, but i also had worn out springs bushings as well, once i changed the springs, bushings and shackle kits out the problem was gone. is it possible that when you changed the springs you tightened all the bolts with the car in the air? i know when i had the extended we tightened everything with the car on the lift and the wheels hanging, when i changed the springs we tightened left everything finger tight and tightened it all up once the car was back on the ground.

so not sure what exactly fixed it or if it was a combination of everything but it rides smooth as it can be now and no funky rearend dances either. even though it has 5 leaf mid-eye springs now
 
Step back and consider what you plan on doing with the car. If you're going for a street/strip/weekend racer car then sticking with the leafs or going with one of the "bolt-in" link suspensions is best.

If you're going hardcore track day/autocrossing then you cannot beat a real 3-link with panhard/watts link. By real 3-link, I mean one that's got a sprung upperlink. You would not believe how good they work until you drive a car with one. Sadly can't really do this on a streetcar unless you want to give up your backseat...