Big Block Suspension Question

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Ottmundr said:
I can't remember, have you run a QA1 K member before the alterkation?

My plans call for the QA1 front end setup with torsion bars. I want to keep my cg as low as possible and torsion bars help with that.
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I did run the QA1 setup in my current car before going to the AlterKtion. It's better, but still not comparable to the AlterKAtion. Also, it only comes with small block mounts
 
The weight savings is less than people think. There was a thread where HemiDenny provided a bunch of weights for his coilover conversion and I weighed a bunch of stock parts. After everything was said and done we determined that a HDK coilover conversion was-

50 lbs lighter than the OE K member and suspension with factory power steering (vs HDK w/ power rack)
35 lbs lighter than an OE K member and suspension using a Borgeson power steering box (vs a power rack)

31 lbs lighter than an OE K and suspension w/manual steering (vs a manual rack)

And yes, if you go OE K and OE power steering to a manual rack the savings is about 70 lbs. But that's because the OE power steering is such a turd, even going from OE power steering to OE manual steering saves 40lbs. If you compare the OE K and manual steering to an HDK and power rack it's only a 9 lb savings.

A more detailed break down is here Anybody running the RMS AlterKation? Was it really worth the cost?

That also doesn't include any weight savings on the OE parts. If you run tubular LCA's and such you can shave some weight off the OE side too. It's not much, but if you care that much about a few lbs it can be done. On that note, my OE numbers are with 1" torsion bars.

roccodart440 said:
Header fitment
Handling
ALignment
Looks
weight loss
oil pan fitment
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Ok, let's get real. Half of that is BS.

Header fitment- yup, that's true. Much easier without torsion bars.
Handling- 100% false. You can handle just as well with torsion bars. Hotchkis cars have handily beaten RMS equipped cars. There's nothing special about the MII suspension from a handling standpoint.
Alignment- What does that even mean? I bet I'm running more extreme alignment numbers on my torsion bar car than you are on your RMS car. -1.1° camber, +6.5° caster, 1/16" toe
Looks- If you're buying suspension for looks, you get what you deserve
Weight loss- 31 lbs manual to manual. Ain't that much.
oil pan fitment- I suppose? There are plenty of aftermarket pans that fit the stock K. Or mostly so. I'm ok with the small notch I knocked out of the engine mount for my Milodon road race pan. Lots easier than a $5k hit for pinto suspension.

Let's not forget the loss in turning radius when you do a coilover conversion. Or, the additional frame stiffening needed to account for the fact that the Mopar chassis was supposed to carry its suspension loads in its crossmember and K frame, not on the frame rails/shock mounts/firewall.
 
72bluNblu said:
The weight savings is less than people think. There was a thread where HemiDenny provided a bunch of weights for his coilover conversion and I weighed a bunch of stock parts. After everything was said and done we determined that a HDK coilover conversion was-

50 lbs lighter than the OE K member and suspension with factory power steering (vs HDK w/ power rack)
35 lbs lighter than an OE K member and suspension using a Borgeson power steering box (vs a power rack)

31 lbs lighter than an OE K and suspension w/manual steering (vs a manual rack)

And yes, if you go OE K and OE power steering to a manual rack the savings is about 70 lbs. But that's because the OE power steering is such a turd, even going from OE power steering to OE manual steering saves 40lbs. If you compare the OE K and manual steering to an HDK and power rack it's only a 9 lb savings.

A more detailed break down is here Anybody running the RMS AlterKation? Was it really worth the cost?

That also doesn't include any weight savings on the OE parts. If you run tubular LCA's and such you can shave some weight off the OE side too. It's not much, but if you care that much about a few lbs it can be done. On that note, my OE numbers are with 1" torsion bars.



Ok, let's get real. Half of that is BS.

Header fitment- yup, that's true. Much easier without torsion bars.
Handling- 100% false. You can handle just as well with torsion bars. Hotchkis cars have handily beaten RMS equipped cars. There's nothing special about the MII suspension from a handling standpoint.
Alignment- What does that even mean? I bet I'm running more extreme alignment numbers on my torsion bar car than you are on your RMS car. -1.1° camber, +6.5° caster, 1/16" toe
Looks- If you're buying suspension for looks, you get what you deserve
Weight loss- 31 lbs manual to manual. Ain't that much.
oil pan fitment- I suppose? There are plenty of aftermarket pans that fit the stock K. Or mostly so. I'm ok with the small notch I knocked out of the engine mount for my Milodon road race pan. Lots easier than a $5k hit for pinto suspension.

Let's not forget the loss in turning radius when you do a coilover conversion. Or, the additional frame stiffening needed to account for the fact that the Mopar chassis was supposed to carry its suspension loads in its crossmember and K frame, not on the frame rails/shock mounts/firewall.
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Thanks for the in depth reply, that gives me a lot of confidence in my decision to stick with t-bar suspension.
 
67BBCuda said:
Thanks for the in depth reply, that gives me a lot of confidence in my decision to stick with t-bar suspension.
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What part of California are you in? I've done a lot of A-body suspension work over the years as well as big block conversions. I'm in Fresno.
 
72bluNblu said:
Ok, let's get real. Half of that is BS.

Header fitment- yup, that's true. Much easier without torsion bars.
Handling- 100% false. You can handle just as well with torsion bars. Hotchkis cars have handily beaten RMS equipped cars. There's nothing special about the MII suspension from a handling standpoint.
Alignment- What does that even mean? I bet I'm running more extreme alignment numbers on my torsion bar car than you are on your RMS car. -1.1° camber, +6.5° caster, 1/16" toe
Looks- If you're buying suspension for looks, you get what you deserve
Weight loss- 31 lbs manual to manual. Ain't that much.
oil pan fitment- I suppose? There are plenty of aftermarket pans that fit the stock K. Or mostly so. I'm ok with the small notch I knocked out of the engine mount for my Milodon road race pan. Lots easier than a $5k hit for pinto suspension.
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Keep in mind I was comparing stock suspension to the alterK. Now 100% of what I said is true.

I'm personally very happy with the AlterKation. I agree stock suspension can be upgraded, to get the job done, or even do it better. In regards to looks, why do people paint or powdercoat suspension parts?

Now here is the part that gets me...we are here talking about QA1 setups and other aftermarket parts. Some of these setups, while retaining the torsion bars, replaces every part of the stock system. Some guys go one step further and replace the stock steering box too.

Another thing I despised about the stock setup was the early style biscuit mounts. They left alot to be desired, especially after hacking the drivers side mount for the schumacher conversion mounts. YEs, you can make your own DC K-member or get yourself a 73 and newer K-member. Maybe i'm just lazy but parts are harder to find and my time is valuable, so again, for me, I like the alterKtion.

If you are going this far, I preffer the ALterKtion. THat is my opinion based on my experience.
 
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For what it's worth if you are looking for examples, I'm running a 440 in a 69 Cuda with .890 NOS bars.. ( I believe that's what came in a factory big block a bodies) front sway bar and 16:1 manual box with manual disc brakes conversion. I absolutely love how the car handles it feels really good on the road in comparison to others I've had. Bear in mind I'm running aluminum heads Aluminum Intake aluminum radiator and 2in TTI headers. If you ask me, it's probably no heavier than a factory small block car. Just my 2 cents though.
 
67BBCuda said:
In the very early stages of resto right now, putting new brakes in to get it road safe.

But in doing the brakes, the suspension might as well be changed. We plan on doing a 440 swap down the road. On a scale of "almost useless" to "absolutely necessary", where does changing the torsion bar suspension to a coil over conversion lie?

For information, it's a 67 Barracuda that will be almost exclusively street driven, with occasional track days.

Thanks in advance.
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67BBCuda said:
In the very early stages of resto right now, putting new brakes in to get it road safe.

But in doing the brakes, the suspension might as well be changed. We plan on doing a 440 swap down the road. On a scale of "almost useless" to "absolutely necessary", where does changing the torsion bar suspension to a coil over conversion lie?

For information, it's a 67 Barracuda that will be almost exclusively street driven, with occasional track days.

Thanks in advance.
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i have QA1 tortion set up on my 68 with small block. They have a new set up with coil overs and it is awesome. Set up for big block too. Now a rear coil over is available from them.
Just installed it and love the performance and tuning capabilities.
Not cheap though.
 
When I switched out the all iron 340 (including exhaust manifolds) to a 400/468 stroker with Aluminum intake/heads/water pump housing, and tube headers I scaled them both on the chain falls, the lightened BB weighed 70 lbs. more than the small block. Both were fully equipped with alternator/power steering/belts/and fan. I installed 1.03 bars and the car handles better than it did with the SB and stock .875 bars although there is still some push in high speed turns, most notably left turns under power. 1.20 bars would likely get rid of the push but might also make it loose. Pick your poison, but loose can bite you by surprise and put you into the weeds before you can let off.
 
I know its a bit off the actual topic but,
Everyone mentions Headers when speaking of weight reduction. I swear the TTI's I currently have are probably every bit as heavy as the manifolds I took off. Manifolds with 3' of pipe MIGHT be a different story, but I wouldn't put money on that either. A set of Hedmans or something could be a fair weight reduction though, I don't know.
 
67BBCuda said:
In the very early stages of resto right now, putting new brakes in to get it road safe.

But in doing the brakes, the suspension might as well be changed. We plan on doing a 440 swap down the road. On a scale of "almost useless" to "absolutely necessary", where does changing the torsion bar suspension to a coil over conversion lie?

For information, it's a 67 Barracuda that will be almost exclusively street driven, with occasional track days.

Thanks in advance.
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Personally I would stick with a potent small block stroker big blocks are nose heavy, a friend on mine had a 67 dart with a 440 it did not handle all that well your call
 
roccodart440 said:
Keep in mind I was comparing stock suspension to the alterK. Now 100% of what I said is true.

I'm personally very happy with the AlterKation. I agree stock suspension can be upgraded, to get the job done, or even do it better. In regards to looks, why do people paint or powdercoat suspension parts?

Now here is the part that gets me...we are here talking about QA1 setups and other aftermarket parts. Some of these setups, while retaining the torsion bars, replaces every part of the stock system. Some guys go one step further and replace the stock steering box too.

Another thing I despised about the stock setup was the early style biscuit mounts. They left alot to be desired, especially after hacking the drivers side mount for the schumacher conversion mounts. YEs, you can make your own DC K-member or get yourself a 73 and newer K-member. Maybe i'm just lazy but parts are harder to find and my time is valuable, so again, for me, I like the alterKtion.

If you are going this far, I preffer the ALterKtion. THat is my opinion based on my experience.
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See, that is exactly the problem I have with the coilover conversions. People always do what you suggest, which is compare their brand new coilover conversion to the worn out stock suspension that was on their car before and say "it's a night and day difference!!!"

Well of course it is! You're comparing worn out factory stuff to brand new aftermarket parts. It's also a "night and day" difference if you rebuild the torsion bar suspension with aftermarket parts and compare that to the original worn out suspension.

Would you do a front suspension swap with a Pinto and use all the components you got out of the wrecking yard? Of course not. And I don't see anyone comparing their stock Mopar suspension to stock Pinto suspension and using that as the reason they're doing a suspension conversion. But if you replace all the original Pinto components with aftermarket parts, well, you basically have an Alterkation don't you? It's just a Mustang II set up with a custom crossmember. Coilovers are just a spring and a shock. Torsion bars are just a spring and a shock.

You can in fact replace everything in the torsion bar suspension system with aftermarket parts, this is no different than using an AlterK with completely aftermarket parts. The parts aren't hard to find, I can give you a list with everything you need. Even if you replace everything and replace the stock parts with improved aftermarket stuff you can do it for significantly less money than what a AlterK will cost you. And when you're done you'll have a more adjustable system that works better with the chassis. I know because I have done it. Coilover conversions have a couple of "pros", but so do the torsion bars. Every suspension system has pros and cons, they're all a compromise and they all have trade offs.
 
I'd agree with all of that, and I know you know your stuff with suspension. I'm still happy with my choice. I like Bill's system. I'd probably go that way in the future, but a rebuilt or upgraded factory style setup would also serve anyone very well
 
When weight goes up, spring rates and shocks just need to be stiffer, whether coilover or torsion bar; either system will do the job.

I have 1.14" Sway-A-Way torsion bars in my Duster and it handles like a modern car. Definitely stiffer ride than stock but not harsh, it's a really nice feel. Like in the old GTX Car and Track road test on YouTube, "The suspension has a big, beefy feel that invites hard cornering." I can whip the steering wheel around at highway speeds and the car goes exactly where I point it with no loss of grip, pretty amazing tbh. Every time I go to a time-trials event people are impressed with how it handles around a tight track-day course. And I'm currently only running cheap garbage parts-store shocks and the rear leaves could be quite a bit stiffer (pro tip, Hotchkis springs are not nearly as stiff as they should be!)... quite a bit of room for improvement.
 
roccodart440 said:
I'd agree with all of that, and I know you know your stuff with suspension. I'm still happy with my choice. I like Bill's system. I'd probably go that way in the future, but a rebuilt or upgraded factory style setup would also serve anyone very well
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I’ve got no problem with people using the RMS or other coil-over conversions. They do have their advantages, just like any suspension system. If you’re happy with it then that’s all that matters, your car, your choice.

The part that bothers me is the exaggerated benefits and unfair comparisons. Other than the rack and pinion steering and header clearance, there’s pretty much nothing the coil-over conversions will do that the torsion bar suspension can’t also do. And in most cases do a lot cheaper, even with a full aftermarket upgrade of the torsion bar suspension. There’s nothing magic about coilovers, and there’s nothing special about the MII suspension the conversions are based off of.

There are pros/cons to both systems if you consider everything. If someone considers all the pros/cons and decides to go to a coil-conversion that’s their business. But no one “needs” one to get their car to perform its best. You can get equal or arguably better performance in some applications while still using torsion bars if you set up the suspension properly for what you’re using your car for.
 
Going to purchase strut rods and upper control arms soon. Have a Hotchkis front sway bar and boxed lower control arms. Running 73 up spindles and brakes. Plan on increasing current .920 bars. Any manufacturers have an edge there? Thoughts?
68 Dart, B engine aluminium top end.
 
The 1.08 bars look like a good size for my application. Will likely go that route. I think I will go with a basic tubular upper A arm with built in caster. My K has been re welded and powder coated.
How long do the heim joints typically last in the strut rods versus bushings?
A lot of options to make the old suspension look and drive better.
Will likely have a few more scratches in the TTIs and cus words during install of OEM based suspension than if I ran one of the Coil over conversions. LOL
 
mine have been in since 2014 and are still good.. one of these days i'll actually buy soem real shocks for it and het rig of that kyb junk..lol

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Cool. Does RMS build OEM style components too? Looks like the adjustable strut rods are mostly identical among manufacturers. Is the extra adjustment in the upper A arms very beneficial? I have the KYBs too. Many years ago they were very popular. Lots has changed. LOL
 
DC Dart said:
Does RMS build OEM style components too? Looks like the adjustable strut rods are mostly identical among manufacturers.
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those are RMS upper arms and strut rods. they do carry some stock style stuff.... pst sells rms strut rods just with pst decals on them..

Is the extra adjustment in the upper A arms very beneficial?
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sure.. can help dial things a little more.. where the directions say to put them usually gets you where ya want it.


.
 
DC Dart said:
The 1.08 bars look like a good size for my application. Will likely go that route. I think I will go with a basic tubular upper A arm with built in caster. My K has been re welded and powder coated.
How long do the heim joints typically last in the strut rods versus bushings?
A lot of options to make the old suspension look and drive better.
Will likely have a few more scratches in the TTIs and cus words during install of OEM based suspension than if I ran one of the Coil over conversions. LOL
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I put 70k miles on the QA1 style adjustable strut rods on my Challenger, the heims are still good. There really isn’t much load on them there. I like the QA1 style better, they’re easier to adjust.

Now, the heims on my Hotchkis UCA’s on the same car have only been lasting about 7 to 10k miles. I would keep bushings there.

DC Dart said:
Cool. Does RMS build OEM style components too? Looks like the adjustable strut rods are mostly identical among manufacturers. Is the extra adjustment in the upper A arms very beneficial? I have the KYBs too. Many years ago they were very popular. Lots has changed. LOL
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Extra adjustment at the UCA can be handy, but it depends on the use and set up of the car. For example, on my Duster I run 275/35/18’s on the front, and overcoming the tires tendency to self steer takes more caster. I actually run +6.5* of caster on that car, and you’re not going to get that much out of most non adjustable tubular UCA’s. But if your plan is to run 225/60/15’s you don’t need that much either, so a set of non adjustable UCA’s with some extra caster built in would be fine.

With 1.08” bars you will definitely want to ditch the KYB’s. Bilstein RCD’s or the Hotchkis Fox’s both work well.
 
72bluNblu said:
I like the QA1 style better, they’re easier to adjust.
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i prefer only having the one side that can move.. yes i can see the qa1 style is easier to adjust i just never liked both sides needing jamb nuts like the qa1 strut rods.. just a goofy fear of them both loosening and losing the strut rod all together..lol
 
abodyjoe said:
i prefer only having the one side that can move.. yes i can see the qa1 style is easier to adjust i just never liked both sides needing jamb nuts like the qa1 strut rods.. just a goofy fear of them both loosening and losing the strut rod all together..lol
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It’s the same idea as a tie rod.

I like them because they’re basically the same set up as the stock strut rods with how they’re attached to the LCA. You have the threaded end that goes through the LCA and gets a nut, as opposed to the RMS or PST style that has a bolt that goes through.

Way easier to adjust too so there’s less of a chance you end up with any binding on the LCA. Just turn the tube like a tie rod end and set the locks. With the bolt style you set the length but then have to torque the bolt. If you haven’t pre-set the length perfectly tightening the bolt can change the overall length and move the LCA. Obviously it’s not impossible but I’ve found it takes me more trial and error to get it all assembled the way I want.

And yeah, 70k miles on the ones on my Challenger and nothing ever came loose.
 
Hotchkis is similar to PST except it attaches to the lower control arm like QA1 and OEM. I have been pondering the differences that have been mentioned.
QA1 adjustment would be way easier but the simplicity of one threaded end is nice. The bolt on the lower control arm end may get rid of dealing with the taper while adjusting?
I am actually running 225 60 15s on all four corners. Bought 10 + years ago. Last 15 inch wheels I will ever likely buy.
On kind of different note. I always felt Dusters where not proportional. Large rear area small front clip. A friend installed 17 or 18s on front similar to 72bluNblu. Looks awesome fixed that in my mind. So the adjustments of the aftermarket suspension components may be a plus when maximizing tire width up front. And the type of tires to play a big part in suspension set up I suppose.
 
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