To lower or not to lower???

-
72Valiant4Door

72Valiant4Door

Trouble Maker
Joined
Sep 20, 2015
Messages
980
Reaction score
241
Location
Chattanooga
Been thinking about lowering my survivor 72 an inch and maybe spacing the wheels out a little, to change and modernize the stance.

After a chat with my speed shop tech, i was wanting to know what you a-body experienced folks thought.

Will i be putting too much wear on the suspension and geometry with just a 1 inch drop and little wheel spacing?

Will these require me to start upgrading the stocker suspension?
 
I'd at least get an alignment after the drop. But I lowered my car with no issues so far. Soon to have spacers and wider wheels as well.
 
Just be sure you have enough suspension travel, esp. in front. Bottoming the suspension is hard on things. I ain't familiar, you can get dropped spindles for some of 'em I think.
 
If you're only lowering it an inch, you can do drop the front by turning down the torsion arms a little, and get some lowering blocks for the rear. If you use wheel spacers, you might need longer studs. Or you could get wheels with more negative offset.
Get an alignment when you're done
 
lowering will improve handling if you have suspension clearance.
..most guys seem to like the 'jacked up' rear look.
i like them a hair low or stock height.
 
I lowered my dart now I scrape my headers on pretty much everything lol
 
You won't be able to lower the car a full inch without making some changes to your suspension. To be successful, you'll need to do at least a couple of things:

- Bigger torsion bars. When you lower the car, you reduce the amount of available suspension travel. With the stock torsion bars and bump stops you're pretty much stuck with stock ride height unless you don't mind hitting the bump stops ALL the time. If you increase the size of the torsion bars, you reduce the amount of suspension travel needed, so you can lower the car accordingly. For example, if you double the wheel rate, you can roughly halve the amount of suspension travel. The stock torsion bars are almost inadequate for even the stock ride height, which is why the stock bump stops are progressive, they were part of the suspension travel design.

-Offset UCA bushings. Changing the ride height in either direction changes your alignment. In order to maintain a proper alignment with a lowered car, you'll probably need offset UCA bushings. Those will allow you to adjust for the changes that occur when you lower the car, as well as to use more modern alignment specs (NOT the factory specs, which were intended for bias plys and are WRONG for radials).

Lowering the car actually improves suspension geometry. It results in a better camber curve and reduces bump steer, which was pretty good originally. So, not only do you get better handling because of a lowered center of gravity, you get better performance from your suspension as well. As long as you take the necessary actions of replacing your torsion bars and getting a proper alignment.

Avoid drop spindles, especially to lower the car only 1". The drop spindles available are all a 2" drop, which, when used to lower the car only 1", will actually make the suspension geometry worse than stock. The resulting geometry of using a 2" drop spindle to lower the car 1" is essentially the same as RAISING your car an inch in terms of the control arms angles, etc. Using a 2" drop spindle to lower the car 2" maintains the factory control arms angles/geometry, which negates the improvements that lowering the car has on the suspension geometry. Not to mention that for the price of any of the drop spindles available you could buy a new set of torsion bars, better shocks, pay for your new alignment, and have a MUCH better handling car when you're done.
 
My 75 is lowered 1.5" in the front (done with torsion bar adjustments) and 2" in the rear (done with lowering block).
I don't have any problems with hitting bump stops.
When I was done with the lowering, I had the alignment done and they were able to get it all into spec.
Handles well (for a 3400 lb 4 door) and has a bit more 'Stance'
Also, have 15x8's front (225/60-R15) and rear (245/60-R15).
Take a look and see what you think.
Personal preference plays a lot here.
What do you want the car to look like?
 

Attachments

  • 0514152047a.jpg
    59.8 KB · Views: 514
What Blu said . Post #8.

Mines lowered quite a bit. It flies nice. It was a lot of money and a ton of work to get it right.
If you're looking to fill the wheelwells, bigger tires is far far easier and cheaper.

Now here's my opinion on T-bars; the 1.03s are NOT too stiff, and are the minimum, if you are into spirited driving. On a stocker, the 383 bars ain't that bad, but the teener bars suck for anything but old-man driving. Hey, it's an opinion.
 
I dig the look swies.

I was not really wanting to get new wheels or tires, as the stock rims had brand new tires put on them before I purchased the car.

72blu... do you have the specs i should have the car set to with the offset bushings?

I should say, this is the first torsion bar vehicle I have worked with, so advice is appreciated. I was under the impression my stocker's 318 tbars were adequate.
 
swies, what's your backspacing on the front 15x8s?
 
72Valiant4Door said:
I dig the look swies.

I was not really wanting to get new wheels or tires, as the stock rims had brand new tires put on them before I purchased the car.

72blu... do you have the specs i should have the car set to with the offset bushings?

I should say, this is the first torsion bar vehicle I have worked with, so advice is appreciated. I was under the impression my stocker's 318 tbars were adequate.
Click to expand...

-.25 to -.5* camber, +3* caster for manual steering, as much +caster as you can get for power steering, and 1/16" to 1/8" toe in. That's what you should be running with radial tires, regardless of the rest of your suspension set up.

As far as the stock torsion bars go, IMHO they're not adequate for anything. I would recommend upgrading to at least 1" torsion bars, and I totally agree with AJ that 1.03" bars are better. I had 1" Just Suspension brand bars on my Duster for a bit, they were still too soft for me. But my cars are set up more for handling, with a focus on autoX. That said, my Duster and my Challenger are my only running cars, so, they are my daily drivers. Both have 1.12" torsion bars. The key to running larger torsion bars is buying a good set of shocks. Bilsteins are good especially for 1.03" bars or smaller, the Hotchkis Fox shocks are better and work great even with my 1.12" bars.

Swies- I'd bet money you bottom your suspension more than you know if you're lowered that much with stock torsion bars and bump stops. If you don't believe me, put a small dab of grease on the top of your bumpstop and go for a drive around town. My money is on there being a dab of grease on your frame by the time you get back. The stock bump stops act in a progressive fashion, it's not super easy to tell when they start touching the frame. Now, swap them out for little polyurethane bump stops and it gets pretty obvious.
 
I always enjoy reading the advice / comments from 72bluNblu , IMO...he knows his sh*t.
 
And if you lower the front, and install the offsets, and set the specs to what Blu recommends(and I concur), you will very definitely get into an odd camber curve,and bump-steer. This may take your alignment guy several hours to correct. If you don't correct it, the alignment will only be correct in the straight ahead course and only over a very small amount of vertical travel.
When I set up my car I was a well seasoned tech, in an alignment shop.I had unlimited use of the bay during off hours. I could tell you how many times I put the sensors on my wheels, but then I'd have to hang myself, cuz it was criminal.
Also, be advised that once the front end height is chosen and set up, mostly it becomes written in stone.If you later decide to change the height, you will be looking at another alignment session.
Unless you need to lower the car, as opposed to want to;Wheels n tires are easier, and may be cheaper too. If you currently have good parts and good camber curves, 1 inch should be okay; but I would then forgo the offsets.As soon as those go in and you start cranking in the caster, the fit hits the shan.
Your results may vary.
 
Well sounds like I am now searching for an affordable set of thicker torsion bars before I touch anything.
 
I vote lower it, but it is important to replace worn parts while you are there. Mines about 2" front and 1" rear. Bigger torsion bars help, I have .930 or something in mine but most guys go bigger... Also there are shorter button style bump stops for the front that give you back a bit of travel.

Joe
 

Attachments

  • image.jpg
    66.1 KB · Views: 390
Pst 1.03 torsion bars are around 200 shipped if you use the members discount. Don't know if you can find any for cheaper than that unless you go used
 
Here's my setup. About 2" lower in the back with blocks and 1.5" inches in the front by adjusting the torsion bars. I've done the grease on the bump stop trick that Blu talked about (I actually used toothpaste) and I managed to drive around for a couple days without kissing the bump stop. Blu is absolutely right about the bumps stops being progressive; there were times when I thought I didn't touch but was close to touching it, but the toothpaste was all over the frame rail proving me wrong. Still, for the cost of a couple lowering blocks and a front alignment I have a much better handling car.
 

Attachments

  • IMG_20151003_115137.jpg
    42.6 KB · Views: 351
  • IMG_20151003_115207.jpg
    48.1 KB · Views: 339
I feel like I'm missing something here, how can you lower the front theses cars 1.5 to 2 inches and not be on the bumps stops?
 
67autocross said:
I feel like I'm missing something here, how can you lower the front theses cars 1.5 to 2 inches and not be on the bumps stops?
Click to expand...

You just missed the part where you remove the stock bump stop and replace it with a low profile poly bump stop. ;-)

I use Energy Suspension 9-9132G. They're .375" tall.

ens-9-9132g_ml.jpg


That's also why you need the larger torsion bars. You don't want to be hitting that small of a bump stop all the time, because they are definitely not progressive like the stockers. And if you lower the car that much, your available travel is reduced to a bit more than an inch before you hit even the smaller bump stop, so your wheel rate has to increase accordingly.

On my car, my 1.12" torsion bars have a 300 lb/in wheel rate, which is 3x what the stock wheel rate was. So, I will only use about 1/3 of the suspension travel, which means I can lower the car so my available travel matches what I'll actually be able to use. Stock cars had about 5" of total suspension travel, mine has about 2". But since the wheel rate is so much higher, even if I raised the car to have more travel available I wouldn't ever use it.
 
72bluNblu said:
You just missed the part where you remove the stock bump stop and replace it with a low profile poly bump stop. ;-)

I use Energy Suspension 9-9132G. They're .375" tall.

ens-9-9132g_ml.jpg


That's also why you need the larger torsion bars. You don't want to be hitting that small of a bump stop all the time, because they are definitely not progressive like the stockers. And if you lower the car that much, your available travel is reduced to a bit more than an inch before you hit even the smaller bump stop, so your wheel rate has to increase accordingly.

On my car, my 1.12" torsion bars have a 300 lb/in wheel rate, which is 3x what the stock wheel rate was. So, I will only use about 1/3 of the suspension travel, which means I can lower the car so my available travel matches what I'll actually be able to use. Stock cars had about 5" of total suspension travel, mine has about 2". But since the wheel rate is so much higher, even if I raised the car to have more travel available I wouldn't ever use it.
Click to expand...

I know that you have big torsion bars and low profile bump stops, but you seem to be the only one that does in this thread,all the other must be sitting on the factory rubber stops if they are that low.
Most of the cars I have had the front was only about an inch off the factory bump stop before lowering. I'm a bit surprised that they had 5" of travel stock, I would have guessed about 2"s before they would touch the factory stop.
I'm going to go out to the shop and stick a factory stop on the car and see how tall it is...
 
You're only considering half of the travel. At the stock ride height there should be about 2.5" to the bump stop. The other 2.5" is before the UCA hits the upper bumpstop at full extension. I only have ~1" from the frame to the .375" tall bump stop on the LCA. I also use a taller bumpstop for the UCA, because otherwise the LCA drops off of the torsion bar adjuster at full extension.

Stock lower bump stops are 1.4" to 1.5" tall btw.
 
I have not had one at stock height for any longer than an hour after I buy them so I never put much thought into the overall travel.
Interesting about your upper bump stop, I guess it would depend on the clocking of the torsion bar if it could fall off the adjuster bolt.
 
You must log in or register to reply here.
-

Back
Top