Are lowering blocks a viable option?

SadbutTrue · Nov 23, 2004

My issue is fairly simple... I want to upgrade my suspension but already have nice enough shocks and I have these brand new (pretty much) 4.5 leaf, standard height leaf springs in the back of my car. They are a nice level of stiffness and would go well with a set of sway bars and some new coil springs up front. I know several companies sell handling kits that include lowering blocks... are these viable options? If my leaf springs weren't new I would probably just throw them out, but the fact that they are new causes me to wonder... if I install leaf springs will the performance and ride quality be comparable to a 4.5 mideye leaf spring (mideye springs produce roughly the same drop as these blocks)? Or are they not worth looking at? Are they reliable?

Also, you think I could convince a vendor to take out the shocks in one of these handling packages and save me some money?

rbohm · Nov 23, 2004

lowering blocks are a good way to lower the rear end of your car, just keep in mind that 2" is about the limit you want to set. more than that and you run into a couple of problems like;
1: pinion angle tends to change a bit too much leading to accelerated u-joint wear.
2: the connection between the axle and the spring becomes somewhat unstable as you have u-bolts that are getting rather long and flexible.

HistoricMustang · Nov 23, 2004

Mine is dropped about 2 1/2" in the rear using reverse eye and a 1" polycarbonate (of my own design) lowering block. I added the shim for the pinion angle. No problems with this set up. Will try to put up a picture.

I have seen aluminum blocks crack so if you decide to use this type check them often as there is a lot of flex in the rear leaf springs.

HistoricMustang
www.historicmustang.com

WORTH · Nov 23, 2004

Another thing to keep in mind is LEVERAGE, the higher the block, the further away from the spring the axle is so the torque on the springs is multiplied which equals more spring flex.

Mosse · Nov 23, 2004

WORTH must mean that the higher the block? Which is correct yes. I was thinking this the other day when makin my shelby bars: Should I take it lover in the back end to compensate the 1" blocks I have? I decided not to

SadbutTrue · Nov 23, 2004

Is there any way to avoid them breaking? So would they be a good idea for me, all things considered, if I decide to mess with the rest of the car's suspension? I'm also not sure I understand the comments regarding the leverage and such, if anyone could clarify that I'd be grateful.

HistoricMustang · Nov 24, 2004

There are some steel lowering blocks out there.

The only concern I had is that the springs do actually have a "curve" in them when in the shock mounting plate so I am not sure they are actually ever flat. This is what cracks the aluminum type.

Here is a pic of my set up with the polycarbonate blocks.

HistoricMustang
www.historicmustang.com

HistoricMustang · Nov 24, 2004

A little better pic.

HistoricMustang
www.historicmustang.com

Hack · Nov 24, 2004

In my opinion, Opentracker's method is better than most other options. He uses old sets of leaf springs and repackages them to get the leafs to be flat rather than arched. I haven't done it yet, but I'm going to this spring, and Opentracker has done it several times on different cars. If you enjoy doing the work, this is very inexpensive and very functional. You could also have a shop de-arch your springs.

http://forums.stangnet.com/showthread.php?t=506466&highlight=leaf+rear

Check out this thread. Also consider that a spring curved like a smile will induce oversteer (oops this should read UNDERSTEER) when the car rolls. This is safe, but not good for performance. Ideal is a flat spring, with the front and rear mounts level. This setup is neutral handling when the car rolls, meaning that the rear end won't affect the car's steering.

HistoricMustang · Nov 24, 2004

I actually try to induce as much oversteer as possible to negate the horrible understeer in the early models.

HistoricMustang
www.historicmustang.com

CochinoFilipino · Nov 24, 2004

Right now you know how your car sits with the springs you have. If you want it one inch lower, simply use one inch blocks. If you buy new springs, you really don't know where you'll end up. And what if the new springs set you too low? I'd go with the blocks if the springs you have are in good condition.

GT2K · Nov 24, 2004

If you need a visual comparison (5 leaf springs with standard eye):

HistoricMustang · Nov 25, 2004

GT2K.....................very nice!

HistoricMustang
www.historicmustang.com

Hack · Nov 25, 2004

Hack said:
In my opinion, Opentracker's method is better than most other options. He uses old sets of leaf springs and repackages them to get the leafs to be flat rather than arched. I haven't done it yet, but I'm going to this spring, and Opentracker has done it several times on different cars. If you enjoy doing the work, this is very inexpensive and very functional. You could also have a shop de-arch your springs.

http://forums.stangnet.com/showthread.php?t=506466&highlight=leaf+rear

Check out this thread. Also consider that a spring curved like a smile will induce oversteer when the car rolls. This is safe, but not good for performance. Ideal is a flat spring, with the front and rear mounts level. This setup is neutral handling when the car rolls, meaning that the rear end won't affect the car's steering.

Ooops I said that wrong. The standard configuration induces understeer when the car rolls. That's why the factory set it up that way - for safety.

For performance it's preferred to get rid of the understeer and shoot for neutral handling.

I apologize for the mistake.

DJ Mustang · Mar 28, 2015

I lowered my Mustang with lowering springs. The front looks mean and aggressive. The rear although is lower, still is higher than the front. I don't know what to do

Are lowering blocks a viable option?

SadbutTrue

rbohm

HistoricMustang

Active Member

WORTH

Mosse

SadbutTrue

HistoricMustang

Active Member

HistoricMustang

Active Member

Hack

HistoricMustang

Active Member

CochinoFilipino

GT2K

HistoricMustang

Active Member

Hack

DJ Mustang

New Member

Similar threads

Are lowering blocks a viable option?

Active Member

Active Member

Active Member

Active Member

Active Member

New Member

Similar threads

Privacy & Transparency

Privacy & Transparency