Drop spindle question
- Thread starter dgibby
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All of the drop spindles out there at the moment are based off of the dimensions of the '73+ disk spindles, which have a larger bearing diameter than the stock SBP Kelsey Hayes disks. So, I would say that's a "no".
I know SSBC offers dual pattern disk kits that have both the large and small bolt patterns, but I think all of those are intended to work with drum spindles, not '73+ disk spindles.
And then of course, there's the small matter of drop spindles being an expensive waste of time. You'd be far better off keeping your stock spindles and stock SBP disk brakes, buying a set of 1.03" torsion bars, and using your torsion bar adjusters to lower the car. Since the larger bars will result in less suspension travel, you can "give up" some of that travel to lower the car with the adjusters.
I know SSBC offers dual pattern disk kits that have both the large and small bolt patterns, but I think all of those are intended to work with drum spindles, not '73+ disk spindles.
And then of course, there's the small matter of drop spindles being an expensive waste of time. You'd be far better off keeping your stock spindles and stock SBP disk brakes, buying a set of 1.03" torsion bars, and using your torsion bar adjusters to lower the car. Since the larger bars will result in less suspension travel, you can "give up" some of that travel to lower the car with the adjusters.
Was thinking the torsion bar route but wasn't sure if they would lower the front out of the box or have to be cranked down. Mine are cranked down now and the ride is terrible. Tried low profile bump stops and it still sucked. Don't really want to buy new torsion bars, crank them down to get the front in low and have it ride like crap.
autoxcuda
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Just adjusting the ride height does not change the ride/spring rate.
Sounds like it's bottoming out.
What front torsion bars do you have now?
How much space between your short lower control arm bump stop and the frame with the car at the lowered ride height? Or/and how low is your K-member to the ground when you lower it? Just trying to get a measurement of how high you want the body when it's lowered.
What is your front tire size?
Sounds like it's bottoming out.
What front torsion bars do you have now?
How much space between your short lower control arm bump stop and the frame with the car at the lowered ride height? Or/and how low is your K-member to the ground when you lower it? Just trying to get a measurement of how high you want the body when it's lowered.
What is your front tire size?
Changing the ride height doesn't change the spring rate. Your "ride is horrible" because you're constantly hitting the bump stops, your torsion bars need more suspension travel than your lowered car has. Even with low profile bump stops and the stock bars you don't have enough room to lower the car much before you start hitting the stops. At the factory stock ride height, the bump stops were intended to be used as part of the suspension travel. That's why they're triangular, they act progressively. So, changing to low profile bump stops with the stock bars was probably even worse that the stock bump stops. It delays when the bump stop first comes into play, but makes the "hit" more harsh. The stock bars have a wheel rate around 100 lb/in. That's it. You need pretty much every bit of the designed suspension travel with those bars, and then some, in the form of the stock progressive bump stops.
The "trick" to lowering your car is to match the wheel rate of the torsion bars to the amount of suspension travel you're going to have at the lowered ride height. The lower you want to go, the stiffer the torsion bars will have to be. And the stiffer the torsion bars get, the better your shocks have to be. But it's still cheaper to buy a set of 1.03" bars and a good set of shocks than it is to buy drop spindles.
I run my Duster at 25" from the ground to the top of the wheel opening in the front. That translates to about 1" of suspension travel between the frame and the low profile bump stops. With the 1.12" torsion bars I run (300 lb/in), I almost never hit the bump stops, just on really big potholes and the like. I also run it with Hotchkis Fox shocks. I think the ride is great, very much like a modern performance car.
I have .890 bars on it now and the tire is a 225/45R17. I have not measured the k-frame but the wheel lip to the ground is 25 inches and is right on the stock bump stop. Had it down to 24.5 but ride was too harsh. With the low pro stops it had about an inch of clearance but it really banged hard on bumps. Right side seems worse for some reason... If I bounce the car hard I can get it to bottom out but that is not the feeling I get when driving, it a very harsh, bang, like no shock absorption at all.
autoxcuda
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That tire is 25" diameter. I run 24.5" diameter tires which is only 1/4" more on the radius.
I'm 24" to the top of the front fender lip to the ground. Really stupid low.
But I have 1.14" torsion bars that are almost 3 times as stiff and Bilstein RCD shocks.
You are bottoming out. And check your welds at the lower control arm stud hole on the K-member and check for cracking around the K-member bolt on the frame.
I think you need bigger T-bars or go with dropped spindles if you like the ride of the .89" torsion bars.
I'm 24" to the top of the front fender lip to the ground. Really stupid low.
But I have 1.14" torsion bars that are almost 3 times as stiff and Bilstein RCD shocks.
You are bottoming out. And check your welds at the lower control arm stud hole on the K-member and check for cracking around the K-member bolt on the frame.
I think you need bigger T-bars or go with dropped spindles if you like the ride of the .89" torsion bars.
I'll check for the cracks.
Was thinking of going with the 1.03 bars but like I said, I don't want to buy them and still have a poor ride. I don't mind a firm, modern car feel, its the harsh banging that I want to avoid.
Was thinking of going with the 1.03 bars but like I said, I don't want to buy them and still have a poor ride. I don't mind a firm, modern car feel, its the harsh banging that I want to avoid.
Holy crap! .890 bars? That's only a 130 lb/in wheel rate. No wonder you're bottoming out at that ride height.
Like I said when I gave you my specs, I only have about an inch of clearance to my low profile bump stops. And my tires are 25.6" tall, so I have to lower my suspension more to put my fenders in the same spot. I still, although only very occasionally, touch the bumpstops going through potholes etc.
But my wheel rate is 300 lb/in. That's 230% higher than yours. You need more than twice as much available suspension travel as what I run, not the same. Your car is pretty much always on the bumpstops, which gives it that harsh ride and banging. You basically have 0 suspension working for you at that height.
Spot on. Banging the bump stops all the time could easily damage something, especially with an unreinforced K member. Stock welds on the K members break all the time, especially at the LCA mounts, even with stock bars and factory ride heights.
If you want to keep the .89" bars, you'll have to use drop spindles. Otherwise, I would suggest getting torsion bars that are at least 1.06". Your car, at your current ride height, would sit about a 1/4" higher than mine with the same size tires. Realistically, I would say you need 1.12" bars to stay off the bumpstops at that height, and I'm talking about the low profile bump stops.
So, either
1. Buy the drop spindles, which will give you about 2" of suspension travel compared to what you have now (which is about what you need with those bars).
2. Buy 1.06 or 1.12" bars and a good set of shocks and swap the low profile bump stops back in (or get 1.03's, but be aware you might still need to raise the car up a little from where you are now to stay off the stops)
3. Raise the ride height back to factory levels and keep all of your current parts.
Good info. Thanks!
Just to make sure I understand...
I can't use the drop spindles with my current small bolt pattern? I don't want to change bolt pattern.
Could use 1.03 bars but might have to raise front end a little to make them work? I don't want to go any higher, would like to go a little lower.
That leaves 1.06 or 1.12 bars with good shocks and low pro stops. The torsion bars are pretty much the same price so is there an advantage or disadvantage with either? Car is only street driven, no track, but it is driven on a regular basis.
Just to make sure I understand...
I can't use the drop spindles with my current small bolt pattern? I don't want to change bolt pattern.
Could use 1.03 bars but might have to raise front end a little to make them work? I don't want to go any higher, would like to go a little lower.
That leaves 1.06 or 1.12 bars with good shocks and low pro stops. The torsion bars are pretty much the same price so is there an advantage or disadvantage with either? Car is only street driven, no track, but it is driven on a regular basis.
I have heard of people cutting and rewelding the lower control arm to raise the position of the spindle relative to the t-bar clocking and adjustment. Raising the spindle lowers the car (same as the "drop" spindle).
What I'm curious about is how this would affect suspension travel -- does it act exactly like a drop spindle, or more like cranking down the adjuster?
What I'm curious about is how this would affect suspension travel -- does it act exactly like a drop spindle, or more like cranking down the adjuster?
Changing the ride height doesn't change the spring rate. Your "ride is horrible" because you're constantly hitting the bump stops, your torsion bars need more suspension travel than your lowered car has. Even with low profile bump stops and the stock bars you don't have enough room to lower the car much before you start hitting the stops. At the factory stock ride height, the bump stops were intended to be used as part of the suspension travel. That's why they're triangular, they act progressively. So, changing to low profile bump stops with the stock bars was probably even worse that the stock bump stops. It delays when the bump stop first comes into play, but makes the "hit" more harsh. The stock bars have a wheel rate around 100 lb/in. That's it. You need pretty much every bit of the designed suspension travel with those bars, and then some, in the form of the stock progressive bump stops.
The "trick" to lowering your car is to match the wheel rate of the torsion bars to the amount of suspension travel you're going to have at the lowered ride height. The lower you want to go, the stiffer the torsion bars will have to be. And the stiffer the torsion bars get, the better your shocks have to be. But it's still cheaper to buy a set of 1.03" bars and a good set of shocks than it is to buy drop spindles.
I run my Duster at 25" from the ground to the top of the wheel opening in the front. That translates to about 1" of suspension travel between the frame and the low profile bump stops. With the 1.12" torsion bars I run (300 lb/in), I almost never hit the bump stops, just on really big potholes and the like. I also run it with Hotchkis Fox shocks. I think the ride is great, very much like a modern performance car.
at the risk of taking this well off track, I have a 1972 Chrysler Valiant Charger (Australian built 2 dr coupe) that shares A Body platform history. I have 2" drop spindles for this (not yet installed) and am looking to upgrade T bars (currently 0.870) and shocks. I was lookig at Hotchkis 1.1" bars and Hotchkis or Bilstein shocks.
I'd be very interested to hear your opinion on what may work. I am looking to get more of a drivers feel happening plus eliminate potential bump stop impacts. Car is running a 300hp 265 inline 6cyl and 4spd manual. I will be running 18's on front with 40/45 profile.
Cheers
Dion
Sent you a private message (PM). Easier to discuss your particular situation without taking the thread off track
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