Looks like all the same stuff is being debated as always. I've stayed out of this one for awhile, but the same claims are being made so I'll try to put up some relevant information. First, I see a lot of people saying you have to spend just as much to do a full rebuild and modernization of the torsion bar suspension. That's a joke. The price is no where near the same if you can intelligently make a list of parts instead of blindly buying a Hotchkis TVS and then filling in the gaps.
RMS Alterkation w/engine mounts and without brakes - $4,995
RMS Street Lynx - $1,995
Total:
$6,990 (keep in mind this doesn't include installing the street lynx, which takes welding)
This is everything I have on my Duster. It's not the cheapest way to do it, although it's not the most expensive either (ie, complete Hotchkis TVS).
Front:
1.12" torsion bars from Firm Feel: $355
Bergman Autocraft SPC UCA's:$395
Bergman Autocraft Delrin LCA bushings: $80
Firm Feel greaseable LCA pins: $135
Howe Racing upper ball joints: $130
Proforged lower ball joints:$80
QA1 LCA's: $395
Hotchkis Shocks: $475
Hellwig 55905 front bar: $175
Flaming River 16:1 steering box: $610
QA1 tie rod sleeves: $50
Proforged tie rods (all): $65
Moog pitman and idler arms: $80
Adjustable PST strut rods:$300
Rear:
Hellwig 6908 rear bar: $180 (this is the Ebody bar I run with my B-body rear axle)
AFCO 20231M springs: $320
AFCO leaf spring sliders: $200
Dr. Diff 1/2" spring offset:$150
Leaf spring perches: $15
Front suspension: 3,325
Rear suspension total: 865
Total:
$4,190
So, not even close on the price. $2,800 in savings, and I used most of the most expensive options out there for my car. You can do it far cheaper than that by boxing your stock LCA's, using regular upper ball joints, getting PST 1.03" bars, using a PST manual steering box, running Bilsteins instead of hotchkis shocks, etc. Just those by themselves drop over $1k from the total. So the idea that the torsion bar suspension will cost just as much to modernize is BS, you can do suspension for the entire car and still be almost a thousand bucks ahead.
The other thing I see talked a lot about is weight savings. HemiDenny was gracious enough to share a bunch of component weights here on another thread, which is here
Anybody running the RMS AlterKation? Was it really worth the cost? The link has all the component weights for those that are curious, they're not down to the ounce so you can assume they're probably within a few pounds but not exact. This comparison does not include brakes. There are a lot of options for both the coilover conversions AND the stock suspension, you can compare those on your own if you want.
The highlights are-
The HDK suspension with a manual rack is : ~31 lbs lighter than a torsion bar set up with manual steering, ~72 lbs lighter than a factory power steering, and about 57 lbs lighter than a torsion bar set up with Borgeson power steering
The HDK with a power rack is: ~50 lbs lighter than torsion bars with a factory power steering set up, ~35 lbs lighter than factory with a Borgeson, and less than 9 lbs lighter than with a factory manual steering box.
There are pros and cons to ALL suspension systems. Suspension is always a trade off. But adding coilovers to these cars is completely unnecessary if the end goal is handling performance. Case in point...
Hotchkis Challenger vs a 2010 SRT8 Challenger. The SRT8 lost on the skid pad to the Hotchkis Challenger. The Hotchkis Challenger pulled .93g on the skid pad. Not bad for "old tech".
2010 Dodge Challenger SRT-8 vs. 1970 Dodge Challenger | Edmunds
There's also a nice little video about the Hotchkis Taxi, a
4-door Plymouth Satellite, putting down better lap times at the TireRack test track than the 2012 3 series BMW's they usually use. With the same driver and same tires on both cars.
Remember folks, those "coilover systems" are just aftermarket Pinto suspension. Ain't nothing magic about it, and the design itself is just as old as the torsion bar design. If you absolutely need a rack and pinion and header space knock yourself out, the rest is just springs and shocks.
