Big Block Suspension Question

[abodyjoe]

I am actually running 225 60 15s on all four corners.

thats what we are running on our dart too.. rather have gone 17" but jamie wanted body color steel wheels and i couldn't find them in 17". have since saw someone makes them in alum but man are they expensive..

 

[72bluNblu]

yea but a tie rod has more a clamp then just a jamb nut.. just one of those thing that i don't like on a street car.. prefer only one side being able to move.

Not if you're running tubular tie rods...

Like I said, I kinda get it. But for me the utility of the adjustment far outweighs any concern about them coming loose. They'd have to loosen at both ends for the barrel to turn. And even then you still have the nut on the other side of the LCA. Not to mention if the length of the strut rod changed more than slightly it would start pushing or pulling against the LCA. Honestly the kind with the single through bolt at the LCA has more of a chance of coming loose, and if it does then the strut rod is totally free.

A drop of blue loctite and away you go

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.

Yeah I much prefer the QA1 style. They are also harder to install though, you have to slide the LCA back just like the stock strut rods. With the kind that has the bolt you can leave the LCA's in place (which also highlights how important that bolt is in that style).

I totally agree with the Duster comment too. It's one of the reasons I converted my Duster over to a Demon clone, the Dart bodywork is about 2" longer. On the '70-72 Dusters it's not as bad, I think with the '73+ dusters the bulge in the hood exaggerates the snub nose look.

You can see the difference in length here, Dart hood with Duster fenders...

And yeah, tires are everything. The more tire you run the more suspension loads you get with cornering, the more the suspension has to change to keep up with the tires. Especially when you go to 17/18" wheels. Not only can you fit a lot more tire up front, but the tire compounds available compared to what you have for a 15" wheel is night and day.

 

[abodyjoe]

Like I said, I kinda get it. But for me the utility of the adjustment far outweighs any concern about them coming loose. They'd have to loosen at both ends for the barrel to turn. And even then you still have the nut on the other side of the LCA. Not to mention if the length of the strut rod changed more than slightly it would start pushing or pulling against the LCA. Honestly the kind with the single through bolt at the LCA has more of a chance of coming loose, and if it does then the strut rod is totally free.

A drop of blue loctite and away you go

i'm not running those.. i'm running stock style.. and again i just don't like jamb nuts on a street car.. you can tell me you have 500,000 miles on your car with not issues and thats cool.. me personally i just don't like them..

 

[72bluNblu]

i'm not running those.. i'm running stock style.. and again i just don't like jamb nuts on a street car.. you can tell me you have 500,000 miles on your car with not issues and thats cool.. me personally i just don't like them..

Your car so do what you like. But the single bolt going through the LCA and straight into the strut rod tube is far more likely to loosen, and if it does it can fall out and immediately cause the strut rod to drop off the LCA.

On the style of adjustable strut rods with jam nuts, if one jam nut loosens nothing happens. The double adjuster is still torqued to the LCA and the other jam nut is tight so the barrel of the strut rod can't turn. If both jam nuts loosen, then the strut rod could change length if the barrel of the tube spun. But in order for the strut rod to come loose it would have to unthread off of the heim or the double male, which would be like a 1/2" or more of threads. And while that was happening, the strut rod would be being pushed backward the same amount. You'd notice that effect on the LCA long before you ran out of threads.

 

[abodyjoe]

like i said. they work fine for you.. i just don't like them for a street car.. i don't see why that is a problem.

 

[72bluNblu]

like i said. they work fine for you.. i just don't like them for a street car.. i don't see why that is a problem.

It’s not a “problem”. I have the PST style on my Duster right now.

All I’m trying to say is that if you’re worried about the strut rod coming apart, with the QA1 style you need a minimum of 2 things loosening up (both jam nuts) and then the adjuster has to spin off a ~1/2” of threads.

With the PST style, if that bolt through the LCA loosens the whole thing comes apart. So, if you’re worried about the strut rod coming apart you’re actually running the one that will come apart more easily.

But like I said, I’ve run both styles. And to be fair, neither will come apart if you install them properly.

 

[abodyjoe]

It’s not a “problem”. I have the PST style on my Duster right now.

All I’m trying to say is that if you’re worried about the strut rod coming apart, with the QA1 style you need a minimum of 2 things loosening up (both jam nuts) and then the adjuster has to spin off a ~1/2” of threads.

With the PST style, if that bolt through the LCA loosens the whole thing comes apart. So, if you’re worried about the strut rod coming apart you’re actually running the one that will come apart more easily.

But like I said, I’ve run both styles. And to be fair, neither will come apart if you install them properly.

and yet again.. i just don't like them for a street car.. use what you want, others can use what they want.. its my personal preference..

 

[72bluNblu]

and yet again.. i just don't like them for a street car.. use what you want, others can use what they want.. its my personal preference..

Right, run whatever you want.

But by saying you don't like them for a "street car" you're implying they won't hold up on the street. Which isn't true at all. I ran the QA1 style aluminum strut rods on my Challenger for 70k street miles. Summer, winter, snow, mud, gravel roads. Nothing ever came loose, the aluminum construction was never an issue, the heims held up, and other parts literally failed around them. Like the CAP tubular LCA's, but that's a different story. When my Challenger goes back on the road, they will be the only part of the suspension that's gone 70k miles that will go right back on with no modifications or replacements.

 

[abodyjoe]

Right, run whatever you want.

But by saying you don't like them for a "street car" you're implying they won't hold up on the street. Which isn't true at all. I ran the QA1 style aluminum strut rods on my Challenger for 70k street miles. Summer, winter, snow, mud, gravel roads. Nothing ever came loose, the aluminum construction was never an issue, the heims held up, and other parts literally failed around them. Like the CAP tubular LCA's, but that's a different story. When my Challenger goes back on the road, they will be the only part of the suspension that's gone 70k miles that will go right back on with no modifications or replacements.

holy **** man.. are you trying to convince me or yourself at this point? sure sounds like you are trying to convince yourself..

 

[RogerRamRod]

And the server space to store pages and pages of unrelated, unnecessary, irrelevant “arguments” over preferences. Oy!

 

[67BBCuda]

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.

Hey Jim, we're in southern CA. Now we're at a crossroads now with the k-member and wanted to use your expertise. We ultimately put in all new PST suspension parts (sway bar, t-bar, tie rods etc...) but kept the original k-member. After doing so and taking it to an alignment shop, they're telling us that the k-member is bent and needs to be replaced. When it comes to replacing the k-member with a QA1 tubular one, will I have any issues down the road going from my SB to a BB? is it just a matter of modifying the mounting points?

Thanks in advance.

 

[Jim Lusk]

Don't trust the alignment shop. They likely don't have a clue. I'd be happy to look at the k-member as I have a jig that will show whether it is straight or not. As far as QA1 I have no idea what works or doesn't work with them.

 

[72bluNblu]

Hey Jim, we're in southern CA. Now we're at a crossroads now with the k-member and wanted to use your expertise. We ultimately put in all new PST suspension parts (sway bar, t-bar, tie rods etc...) but kept the original k-member. After doing so and taking it to an alignment shop, they're telling us that the k-member is bent and needs to be replaced. When it comes to replacing the k-member with a QA1 tubular one, will I have any issues down the road going from my SB to a BB? is it just a matter of modifying the mounting points?

Thanks in advance.

I’m with Jim on this one, if the K member bolted up the chances of it being bent are pretty low, unless you’ve got a bent frame rail to go with it. There may be other issues with the K, like a cracked steering box mount or LCA tube that’s broken loose, but that’s not the same as “bent”.

More than likely the alignment shop if blaming the K-frame for their inability to do a proper alignment with aftermarket parts. Did they say why they think it’s bent? Or give you the alignment specs they have set?