PST 2" Drop Spindle

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TopherSM

TopherSM

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So I've been looking at suspension for my 69 Dart GT and wanted to go with the Pro-touring look. I found the 2" Drop Spindles from PST and was wondering if anyone has had any experience with them or if anyone knew of any other company that makes them. And if anyone has pictures of their cars that would be great also. Will also be going with Wilwood disk brakes all around. Thanks FABO!!!
 
Please let me know if there is anything that I can answer for you about our drop spindle. But do remember as a member of this forum you are eligible for 10% off your order. So for you the spindles would be $458 with free shipping within the US 48 States.

Thanks
James
 
PST said:
Please let me know if there is anything that I can answer for you about our drop spindle.

Thanks
James
Click to expand...

James, I myself am thinking about dropped spindles if use a FMJ suspension cradle on my 47 Dodge. Do they take standard Mopar caliper brackets or some other brand?
 
PST said:
Please let me know if there is anything that I can answer for you about our drop spindle. But do remember as a member of this forum you are eligible for 10% off your order. So for you the spindles would be $458 with free shipping within the US 48 States.

Thanks
James
Click to expand...

Awesome!!! Thanks for the info.

Chris
 
Sorry PST, but they're a waste of money. All due respect and all, I think most of your parts offerings are pretty great. But drop spindles are for coil spring type suspensions.

The correct way to do this is to use larger torsion bars. Larger torsion bars mean that the wheel rate (spring rate) is higher, so, there will be less suspension travel. You can then use the torsion bar adjusters to lower the car. That reduces the amount of available suspension travel, which is a problem if you don't install larger torsion bars.

But if this is a pro-touring style build, you ARE installing larger torsion bars. So, you can lower the car with the torsion bar adjusters. How much will depend on the the size of the torsion bars you install. The larger the bars, the more you can lower the car. You will also have to remove the stock lower bump stops, because you'll hit those pretty quickly when lowering. Replace those with a poly button style bump stop, and you're good to go.

The other thing is, the suspension geometry of these cars gets BETTER when you lower with the torsion bar adjusters. The ideal geometry for using modern radial tires is when the UCA is roughly parallel to the ground. At that point, you have the best camber gain curve. You also have less bump steer at that point as well than with the factory settings. Now, that's probably a little short of a full 2" drop. It's close, but it may be a little short. But here's the thing, that's also the point where ground clearance starts to become a real issue, even with the "good" header design (Doug's, TTI's). If you lower the car with 2" drop spindles, and don't actually lower the car a full 2" (remember you still have the torsion bar adjusters) you've actually raised the angle on the control arms. That means a worse camber curve than even the factory settings gave, same with bump steer.

I ran 2" drop spindles on my Challenger for awhile, before I figured some of this stuff out. I took them off, lowered the car just as much with the torsion bar adjusters, and don't have any problems. Like my Duster that is also similarly lowered, I run 1.12" torsion bars in that car.

The only purpose I see to the drop spindles is to lower the car without substantially increasing the wheel rate. Which is fine if you're just lowering for cosmetic purposes. But, if you're lowering the car because you want it to handle better, you're installing larger torsion bars. And if you really want it to handle well, you're installing bars large enough that you can lower the car as much as you can without starting to have other issues. Like running out of ground clearance on the headers, or even running out of suspension travel before the tops of the tires hit the inner fenders at full suspension compression. Which is where I'm at with my Duster. Were I to lower it any more, at full suspension compression my tires would hit the bottoms of the inner fenders. You'd have to raise the shelf on the inner fenders to lower the car more, at least safely.

So, if you're lowering the car for handling, you don't need drop spindles. If you're just lowering the car for looks, then the drop spindles are easy. But it's actually cheaper to buy larger torsion bars and better shocks and do it right.
 
Last edited:
OP,

I have the drop spindles on my car and am happy with them. I have for ages done as 72blu suggested and raised and lowered my car with torsion bar adjusters and torsion bar size. I’ve driven it that way for years, and he makes a few good points.

However, my reason for running the drop spindles is about suspension travel, with the car as low as I like I had about 1.25” of suspension travel with the “button bump stops”. With my personal preference Mopar .92 (or .96 can’t remember) torsion bars I was hitting the thin poly bump stops all the time. The thin bump stops are just that, thin, and very firm. Hitting the bump stops felt like I was gonna break something...

Thinner torsion bars was worse, and bigger bars I just find too stiff for my liking and had little to no twist in order to get the car where I wanted.

With the 2” drop I have the same fender height, and about 1.75-2” suspension travel with the SOFT factory rubber bump stop and much more twist on my torsion bars which helps increase spring rate some in my understanding.

It drives nice, and I stay off the bump stops unless I hit a BIG pothole on the highway or something. And the soft factory rubber doesn’t make it feel like I’m gonna knock my teeth out.

I will say, that with the drop spindles the car would bottom out with the wheel higher compared to the chassis putting my oil pan, headers, or trans pan closer to being “in harms way”... I haven’t had issues, but something to keep in mind.

Joe
 
Only pic with me... how it sits now.

CD9EEEEF-B9BF-4276-9F03-3DD545ABAE50.jpeg
 
I have 2" drop spindles (from Fatman and the only thing I could find in 2008), .89" torsion bars, and stock bump stops. I have no complaints but probably would have followed what 72bluNblu has suggested if I'd been more knowledgeable about it at the time. I assumed then that lowering via the bars would have given me a mushier ride. That was also just before the price of Mopar torsion bars skyrocketed. Would still have saved some coin.
 
72bluNblu said:
Sorry PST, but they're a waste of money. All due respect and all, I think most of your parts offerings are pretty great. But drop spindles are for coil spring type suspensions.

The correct way to do this is to use larger torsion bars. Larger torsion bars mean that the wheel rate (spring rate) is higher, so, there will be less suspension travel. You can then use the torsion bar adjusters to lower the car. That reduces the amount of available suspension travel, which is a problem if you don't install larger torsion bars.

But if this is a pro-touring style build, you ARE installing larger torsion bars. So, you can lower the car with the torsion bar adjusters. How much will depend on the the size of the torsion bars you install. The larger the bars, the more you can lower the car. You will also have to remove the stock lower bump stops, because you'll hit those pretty quickly when lowering. Replace those with a poly button style bump stop, and you're good to go.

The other thing is, the suspension geometry of these cars gets BETTER when you lower with the torsion bar adjusters. The ideal geometry for using modern radial tires is when the UCA is roughly parallel to the ground. At that point, you have the best camber gain curve. You also have less bump steer at that point as well than with the factory settings. Now, that's probably a little short of a full 2" drop. It's close, but it may be a little short. But here's the thing, that's also the point where ground clearance starts to become a real issue, even with the "good" header design (Doug's, TTI's). If you lower the car with 2" drop spindles, and don't actually lower the car a full 2" (remember you still have the torsion bar adjusters) you've actually raised the angle on the control arms. That means a worse camber curve than even the factory settings gave, same with bump steer.

I ran 2" drop spindles on my Challenger for awhile, before I figured some of this stuff out. I took them off, lowered the car just as much with the torsion bar adjusters, and don't have any problems. Like my Duster that is also similarly lowered, I run 1.12" torsion bars in that car.

The only purpose I see to the drop spindles is to lower the car without substantially increasing the wheel rate. Which is fine if you're just lowering for cosmetic purposes. But, if you're lowering the car because you want it to handle better, you're installing larger torsion bars. And if you really want it to handle well, you're installing bars large enough that you can lower the car as much as you can without starting to have other issues. Like running out of ground clearance on the headers, or even running out of suspension travel before the tops of the tires hit the inner fenders at full suspension compression. Which is where I'm at with my Duster. Were I to lower it any more, at full suspension compression my tires would hit the bottoms of the inner fenders. You'd have to raise the shelf on the inner fenders to lower the car more, at least safely.

So, if you're lowering the car for handling, you don't need drop spindles. If you're just lowering the car for looks, then the drop spindles are easy. But it's actually cheaper to buy larger torsion bars and better shocks and do it right.
Click to expand...


So ideally for those wanting to lower their car approx 2".....a 1" to 1-1/4" drop spindle would be a better fit to keep suspension travel and provide improved camber curve.

Who can we get to build them?
 
HemiDenny said:
So ideally for those wanting to lower their car approx 2".....a 1" to 1-1/4" drop spindle would be a better fit to keep suspension travel and provide improved camber curve.

Who can we get to build them?
Click to expand...

Yeah that would be a great idea. A 1" drop spindle would be the business.

Most people don't lower their cars a full 2", so a 1" drop spindle would ensure that at the very least you wouldn't have worse suspension geometry than stock. And if you lowered close to 2", you would be pretty close to ideal geometry but would still retain enough travel to probably keep your stock bump stops. Or at least taller than the 3/8" ones I run. And so you could be that low with 1.03" bars instead of the 1.12" bars I run, which would make a lot of people happy. You need 1.12's and the 3/8" bump stops to pull off my ride height with stock spindles and LCA's, and that's a little bigger than most folks want to go. 1.03's and 1" drop spindles would probably be the best of both worlds, better geometry, the right ride height, and suspension soft enough that most people wouldn't complain but stiff enough to still handle well.

Heck even the .92 to 1" torsion bars would work with that if you didn't lower a full 2". Improve the stance a little without buggering the geometry and still have pretty soft bars.

img_4427-jpg.jpg
 
...and have them make some decent sized torsion bars at the same time. :)

I'm in for a pair of 1.06" to 1.12"-ish torsion bars to replace my 1" bars, but the FirmFeel-price tag and costs of shipping overseas is holding me back.
 
BigBlockMopar said:
...and have them make some decent sized torsion bars at the same time. :)

I'm in for a pair of 1.06" to 1.12"-ish torsion bars to replace my 1" bars, but the FirmFeel-price tag and costs of shipping overseas is holding me back.
Click to expand...

It’d be nice, but I don’t think PST would sell enough bars in that diameter range to hit their current price point. Firm Feel is custom forging their own bars in fairly small batches, the price point reflects that. PST is having large batches forged, and 1.03” is probably pretty close to the largest diameter you could sell in large enough volumes to keep the kind of pricing they have.

The Firm Feel bars are absolutely worth the price too. The 1.12’s in my Challenger have gone probably close to 70k miles and been in the car almost 10 years, they’re still like brand new.
 
72bluNbu hit the nail on the head. The 1.03 bars satisfy the majority consumers. As the bar is a happy medium.

Thanks
James
 
So another question. Is there a complete kit out there that would be a better option? I'm just about to say screw it and just get a complete kit. Any suggestions?
 
TopherSM said:
So another question. Is there a complete kit out there that would be a better option? I'm just about to say screw it and just get a complete kit. Any suggestions?
Click to expand...

?

Spindle and brake kit? Full suspension kit?

The Hotchkis TVS is about as close as you’ll get for a torsion bar suspension upgrade kit, although it has some stuff you don’t necessarily need and is missing some stuff you do.

I have a complete list of upgrades I’ve done to my car with part #’s etc.
 
72bluNblu said:
?

Spindle and brake kit? Full suspension kit?

The Hotchkis TVS is about as close as you’ll get for a torsion bar suspension upgrade kit, although it has some stuff you don’t necessarily need and is missing some stuff you do.

I have a complete list of upgrades I’ve done to my car with part #’s etc.
Click to expand...
 
72bluNblu said:
?

Spindle and brake kit? Full suspension kit?

The Hotchkis TVS is about as close as you’ll get for a torsion bar suspension upgrade kit, although it has some stuff you don’t necessarily need and is missing some stuff you do.

I have a complete list of upgrades I’ve done to my car with part #’s etc.
Click to expand...

Honestly I want something that handles good and has a mean stance. So I'm open to suggestions. I haven't started buying anything yet so any and all info is appreciated. Thanks
 
TopherSM said:
Honestly I want something that handles good and has a mean stance. So I'm open to suggestions. I haven't started buying anything yet so any and all info is appreciated. Thanks
Click to expand...

The basic formula goes something like this...

1.06" (or bigger) torsion bars (Firm Feel)-------------$355 (if you want to go as low as absolutely possible, you'll need 1.12's)
Tubular UCA’s (PST, FFI, QA1 etc)------------------------$350
Adjustable strut rods (PST SR 14385)---------------$279
Solid tie rod sleeves (PST SAS 440S)----------------$49
LCA boxing plate (PST LCAPLTMOP621)-------------$14.50
Greasable LCA pins (FFI w bushings)----------------$135

Helwig tubular front sway bar 1 1/8” #55905 (73+ K)--$175
(#55917 for 67-72 K and large tires --- $263)
Solid rear 3/4” #6907--------------------------------$237

Mopar oval track springs
Zero arch- P4529414---------------------------------------------$232
1" arch- P4529415

Energy suspension 1" shackle bushings 2-2117G----$9
Bilstein RCD shocks(RCD-70-56663)------------------$410

Grand total on that is about $2,300, that's got a little extra built in depending on where you shop. And of course you can go crazy and buy Hotchkis sway bars. I'd stay away from their UCA's just because of the heim joints. If you want to go fully adjustable Bergman Autocraft SPC UCA's are the way to go.

In addition to that stuff, you'd need some chassis work. Basically you want subframe connectors, torque boxes, and a reinforced K frame (fully seam welded; steering box, LCA pins and strut rod mounts reinforced). Subframe connectors can be home made, I made mine out of 1.5"x3"x.120 tubing. Extra credit includes some kind of shock tower/firewall brace and a lower radiator support brace. Or you can go crazy and just buy the stage 2 US Cartool kit, unless you want a mini-tub too.

Some kind of steering improvement would be good, there are 16:1 boxes from PST and Flaming River, the Borgeson 14:1 power steering box (Bergman Autocraft), or you can have the stock power steering rebuilt at Firm Feel, as it's 16:1 already.

Real tires will mean 17's minimum, 18's better. With 18" rims on a Barracuda you could run 18x9.5's all the way around with 275/35/18's, backspacing dependent on your brake and rear axle set up. You can probably run 295/35/18's out back if you do a 1/2" spring relocation and are willing to do a little work on the quarter lip.

You can take a look at my build, I've got all of that stuff plus a some extra things, it's all in my build thread. My "new" '74 Duster- or why I need a project like a hole in the head

IMG_4756.JPG
 
I'm pretty sure Magnumforce makes the 2" drop spindle not PST. Frankly, I'm not sure if pst really manufactures anything. Jim? Can you elighten us? Sway away makes a lot of t bars too.
 
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