Coilovers on qa1 K-frame

[1973dusterkid]

Ok so I got to looking and seeing what I could do as far as installing coilovers on a qa1 kframe. Going in a 73 Duster gonna have a small block, mostly street car. I found some coilovers with a stud mount in one end, and was thinking with a properly braced upper fender well would they work? I have the qa1 tube frame with the tube upper and lower arms. I would probably brace the upper well with 1 1/2 in tubing and then make a beefer lower mount on the lower control arm. What do you guys think

 

[72bluNblu]

Why?

Trying to add coil overs to a torsion bar K frame using the stock suspension mounting points usually just results in poor geometry and a coil over that’s fairly short. Which limits suspension travel.

If coil overs are the plan, do it right with a full conversion.

For a “mostly street car” you can do a lot better with torsion bars than a cobbled together coil over set up.

 

[1973dusterkid]

Why?

Trying to add coil overs to a torsion bar K frame using the stock suspension mounting points usually just results in poor geometry and a coil over that’s fairly short. Which limits suspension travel.

If coil overs are the plan, do it right with a full conversion.

For a “mostly street car” you can do a lot better with torsion bars than a cobbled together coil over set up.

Well non of it would be cobbled up and the shock is very close to the stock ride height and travel as factory. When to comes to geometry well I am going to do my research and when I make the new mounts I can make that work.

And why because why not I have nothing better to do then burn wire and cutoff wheels if i can’t make it work oh well if I do well I got coilovers for a 1/4 of the price

 

[DrEamer]

The only consideration that I have heard about adding coil overs is that you need to add subframe connectors. Since all the weight that was supported by the torsion bars, and torsion bar crossmember is now supported in the front, versus in the middle with the crossmember. David Rea was talking about it in one of his videos, and makes sense to me.

 

[1973dusterkid]

The only consideration that I have heard about adding coil overs is that you need to add subframe connectors. Since all the weight that was supported by the torsion bars, and torsion bar crossmember is now supported in the front, versus in the middle with the crossmember. David Rea was talking about it in one of his videos, and makes sense to me.

I have subframe connectors and toques boxes I did just see the hdk bolt on kit

 

[72bluNblu]

Well non of it would be cobbled up and the shock is very close to the stock ride height and travel as factory. When to comes to geometry well I am going to do my research and when I make the new mounts I can make that work.

And why because why not I have nothing better to do then burn wire and cutoff wheels if i can’t make it work oh well if I do well I got coilovers for a 1/4 of the price

There’s a reason the high dollar coilover conversions don’t use the stock shock mounts. Just ask @HemiDenny about the amount of suspension travel you get if you use those suspension points.

As for “cobbled together”, yes, it will be. Regardless of how nice a job you do with the fabrication, just based on the suspension geometry you’ll end up with I’d still say you have cobbled together set up. Because the suspension geometry ends up being a mix and match game between stuff that was never intended for coilovers and the coilovers. Lots of compromises just to make it work. Maybe ok for a strip car, but generally not something I’d ever recommend for a street car.

You’re not the first person to try and set up a coilover suspension like that. I’m sure you won’t be the last. Lots of people have tried, with varying levels of success. Most of them never see the road, some have had serious issues and a couple have turned out ok, but still wouldn’t outperform torsion bars. Do a search, you’ll get a bunch of threads with the same idea.

As for “why”, I was asking because I wanted to see what you’re actually trying to gain. Because frankly, nothing you put together that way will perform better than properly setting up the torsion bar suspension. Even the high dollar, full coilover conversions that are fully redesigned around the coilover suspension are still, arguably anyway, no better than a properly set up torsion bar suspension. The clear advantages gained are limited to header clearance and the ability to use rack and pinion steering. Which isn’t nothing, for Hemi conversions and strip cars there are some advantages. But for a handling car you can still do better with torsion bars, and do it cheaper too.

 

[HemiDenny]

No secret, the reason why HDK does not use the top shock mount (or the factory LCA shock mount location) is simple. Coil spring / frame rail clearance.

Additionally, the re-enforced HDK upper shock mount is part of the 100 % bolt on chromoly support hoop package that has been utilized for over 20 years and hundreds of builds.....NO failures

I admire anyone who wants to build their own yet alone improve on anything.

 

[GMachineDartGT]

Why?

Trying to add coil overs to a torsion bar K frame using the stock suspension mounting points usually just results in poor geometry and a coil over that’s fairly short. Which limits suspension travel.

If coil overs are the plan, do it right with a full conversion.

For a “mostly street car” you can do a lot better with torsion bars than a cobbled together coil over set up.

 

[GMachineDartGT]

Agreed 100%.

I have no idea why anyone would buy the QA1 frame to begin with. We go from precisely mounted k with bolts with locating washers to a frame with long sloppy tubes to work the mounting bolts needlessly. It’s a poor design at best.