Ride quality even worse than expected. Advice welcome.

-
When the car impacts a pot hole for instance a 1.14 T bar will deflect the lower
control arm less than say a 1.03 T bar under the same conditions. That shorter
deflection will transmit more of its force thru the chassis than the longer deflection
The bump stops hitting is another issue, chassis reinforcements make a big difference
in making a old unibody car feel more solid.
 
A lot of guesses about bump stops but QA1 LCA have neither the same issues as a stock LCA nor the same remedies.



Probably a good idea to make sure your Qa1 actually have bump stops at all.

upload_2019-5-20_14-24-9.png


Or if it DOES, is it adjusted properly???
This one here is set WAY TOO HIGH

upload_2019-5-20_14-26-59.png
 
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That's why I drive a Chevy truck, runs like a top, all I do is change the oil never have a problem, never make any noises at all

A guy at my church is haveing trouble w/ his 5th chevy trans , in 3 diff p/ups , he`s always bad mouthing dodges. I wonder if his his little alum boat is heavy, I drove an 02 quad cab for 15 yrs. , towing my car trailer by itself weighs more the his boat and trailer loaded.
I told him to go buy a dodge , shoulda seen the look on his face! LOL
 
My son's Barracuda has 1.14" torsion bars, big sway bar front, 3/4" bar out back, heavy rear springs (cobbled up at home), short bump stops, and KYB shocks. It also has 235-60-15 tires on all four corners. Ride is great, even on bad roads. Last time I rode in the car it felt great. The tires probably do a lot to help the ride characteristics. This is also with an all-iron (except for the intake) 383 and four speed. I don't think his Barracuda rides as stiff as my 2004 330Ci with sport suspension. Then again, the BMW has extremely short sidewall tires.
 
I have been focusing on handling parts for my Dart. This virtually always means a serious ride penalty but that roughness can also improve the sense of connection with the car in addition to better handling manners and predictable limits. I have done complete suspension setups in several cars (late model Mustangs, Miatas) so I was pretty well prepared for some "harshness" but this just doesn't quite feel right.

I'm wondering if my setup is just suffering from being too low (lacking travel) or of something else is going on but the car basically rides like crap. It bangs and shudders over bumps and feels just jittery but still lacking any sense of satisfying feedback.

I have chassis reinforcements still sitting in a box, waiting to go in the car (torque boxes and subframe connectors) so I haven't even dreamed of pushing it through any corners yet but nothing about the driving characteristics inspires confidence.

QA1 Upper and lower control arms
QA1 Dynamic adjustable strut rods
1.14" Torsion bars
Mancini camber spacers (may remove if not needed)
Hotchkis/Fox shocks (non-adjustable)
Helwig front sway bar
16:1 manual steering box
Fresh ball joints
Hotchkis rear lowering leaf springs
1.5" lowering blocks
relatively light aluminum wheels
225/60/15 front, 255/60/15 rear tires (poor performance tires but they should only help the ride quality, no?)

Anything inherently wrong with that combo?
Looking at the car, it doesn't strike me as being extremely low...

(Yes, I know the hood is still crooked...It still working on that. I just got impatient and wanted to go for a drive :D)

View attachment 1715337830

A few questions you still haven't answered-

What are your current alignment specs? "Feeling jittery" could easily just be an alignment issue. But there's a few things in that list of parts that really makes me scratch my head.

Why the camber spacers? With the QA1 UCA's you shouldn't need them at all. With 15's and lousy tires on a street car you wouldn't even want a full -1° of camber. The Mancini spacers add -2°. With those UCA's you shouldn't have any problems running close to -1° of camber with +4° or more of caster without any additions at all. If you haven't aligned the car, stop and do that.

Why the lowering blocks? The hotchkis leaf springs should sit the back end of the car pretty low. As in, lower than your car appears to be sitting right now. And that's without the lowering blocks. Seems to me like something is going on there. The only time I've seen anyone use lowering blocks of that size to end up at a similar ride height they were using super stocks. Are you using the Hotchkis front hangers? Or something else with multiple spring bolt locations?

You have adjustable strut rods. How did you set the length? Did you check for binding through the entire range of suspension travel? If the mounts aren't clocked correctly at the front, the heims will bind. If they're not the right length, the LCA's can bind.

The QA1 LCA's come with rubber LCA bushings. So, they MUST be torqued while the car is sitting at ride height. Before the car is on its wheels they should only be hand tight. If that wasn't done, you may have torn the bushings on your first drive, and the noise you hear is because your LCA bushings are toast again. I don't know why QA1 doesn't install poly or Delrin bushings, but they don't.

Any marks on your tires? Or on the wheel wells? You could be getting tire interference too. The tires aren't the absolute biggest you can run on a Dart Sport, but they're still more than big enough to cause issues if the backspace isn't close.

Banging and clunking means something is loose, interfering with something else, broken, or you ran out of suspension travel. At the ride height your car is at, you can't use any of the stock bump stops. Period. They were designed for the stock height and nothing else. The upper bump stops (the ones for the UCA's) need to be taller. The 1.14's don't twist much and have almost no built in clocking, so fully unloaded you can drop the LCA's off the adjusting bolts. So, you usually need to add a taller bump stop. You're re-centering the bump stops around the new ride height. The lowers have to be shorter. But you have QA1 lowers, so....

A lot of guesses about bump stops but QA1 LCA have neither the same issues as a stock LCA nor the same remedies.
Probably a good idea to make sure your Qa1 actually have bump stops at all.

View attachment 1715338057

Or if it DOES, is it adjusted properly???
This one here is set WAY TOO HIGH

View attachment 1715338060

This!

QA1 LCA's are one of two versions. The early ones don't have any bump stops at all. None. So unless you mounted the stock lower bump stops somehow/somewhere, there's no bump stop. Now, with 1.14" bars and that ride height you shouldn't actually have an interference problem. The bump stop-less QA1 LCA's have a lower profile height than a stock LCA, and because of that they add almost a full 1" back into the suspension travel. That's a 2" height drop at the wheel. That's the kind I run, and that's why. I did add bump stops back onto my frame stops, but just the little poly disks shown in the linked threads above. Just to keep from going metal on metal.

The latest version of the QA1 LCA's has a bump stop. A pretty large poly bump stop. I haven't laid hands on one of those yet, but just based on the pictures I'd wager they actually reduce travel with the bump stop they come with. So if you have those, you could be sitting on the bump stops at your ride height. And those are poly stops, so, unlike the stock rubber bump stops there's little to no cushion. If you're bottoming those out the ride quality will be terrible.

With a 1.14" torsion bar, you'll need close to 1" from the bump stop to the frame at ride height if you intend to stay off the bump stops most of the time. I run just under that with my 1.12" bars, so you may get away with a little less, but it depends on the weight of your car too. You still have all the stock '74 stuff up front, so you're hanging more weight off the front of that car than I am now.

So-
  • Inspect your LCA bushings
  • Check your LCA bump stop to frame distance at ride height
  • Inspect your rear suspension, because you should't need blocks with Hotchkis leafs
  • Get a proper alignment if none of that turns up anything
This is my set up. Notice the really tall upper bump stops, and the really short bump stops on the frame stop. This is obviously on jack stands, the UCA is on the upper bump stop. My typical ride height puts just under 1" between the bump stop on the frame and LCA.

img_4412-jpg.jpg
 
Bump stops would be the first place I'd check. I think Energy Suspension sells replacements, I'd get those and trim them as needed of you find your riding on them. Secondly I'd check shock travel. You may be out of their range or simply got the wrong pair. On your sway bar, does it pivot freely? I've found I needed to shim some sway bar mounts to keep them from clamping he bar too tightly. I've seen hollow bars break from the mounts being too tight.

Nice looking car BTW.
Energy suspension sell the lower bump stops you can get 2 lower than factory. Go on their site great people to deal with .
 
Lots of good info here. Your 1.14 should not produce poor ride, especially with a decent shock. The fox shocks that hotchkiss sells are rebound only adjustable. Their is always limited information around what spring rate the shocks are designed for. This relationship is critical and usually mismatched to some degree.
The bumpstop issue is easy enough to check at ride height. I run thr 11/16 without issues or poor ride quality.
I was never a fan of the qa1 lower arm. The cantilevered attachments can't be as stiff as the originals. Besides, the inboard only sway bar mounts and rubber bushings don't make any sense to me. An oe arm, my delrins and box plates, your in business. Add a hotchkiss sway bar with the beefed up oe style weld on brackets and all fits perfectly.
Chassis stiffness is also a great point. However, most make the mistake thinking the frame connectors are most important. The twist comes from the motor compartment, where reinforcements are the most critical. We developed the rad supports and inner fender bracing at XV. USCT has adopted those designs today.
 
Lot's of excellent suggestions/observations, @72bluNblu . Thanks!
Just to cut to the easier to respond to points while I'm still at work ;)

...

So-
  • Inspect your LCA bushings
  • Check your LCA bump stop to frame distance at ride height
  • Inspect your rear suspension, because you should't need blocks with Hotchkis leafs
  • Get a proper alignment if none of that turns up anything
...


- Based on your suggestion in an earlier thread, I was sure to torque the LCAs with the car’s weight on the wheels so that shouldn’t be an issue. I could always try loosening/re torqueing if the symptoms warrant it.

- My QA1 control arms do have bumpstops. The 1” guideline is very helpful and I’ll take a look at that tonight.

- Proper alignment has not happened yet... that certainly could contribute to "jittery" feeling.

- I’m confused about the rear ride height. There’s not a whole lot involved in installing leaf springs…I have the Hotchkis body mounts, stock shackles. After the install, the car was higher than it was with the original (very tired) springs.

This is the ride height comparison before/after the lowering blocks...in fairness, they were brand new in the first picture so perhaps they had yet to settle? That still doesn't explain why I needed lowering blocks to get where I am.

Dart lowering blocks.jpg
 
Lots of good info here. Your 1.14 should not produce poor ride, especially with a decent shock. The fox shocks that hotchkiss sells are rebound only adjustable. Their is always limited information around what spring rate the shocks are designed for. This relationship is critical and usually mismatched to some degree.
The bumpstop issue is easy enough to check at ride height. I run thr 11/16 without issues or poor ride quality.
I was never a fan of the qa1 lower arm. The cantilevered attachments can't be as stiff as the originals. Besides, the inboard only sway bar mounts and rubber bushings don't make any sense to me. An oe arm, my delrins and box plates, your in business. Add a hotchkiss sway bar with the beefed up oe style weld on brackets and all fits perfectly.
Chassis stiffness is also a great point. However, most make the mistake thinking the frame connectors are most important. The twist comes from the motor compartment, where reinforcements are the most critical. We developed the rad supports and inner fender bracing at XV. USCT has adopted those designs today.

All great info here.

In terms of stiffening, I already have subframe connectors and USCT torque boxes waiting to go in.
Would you say that the rad support/inner fender braces should come first?
 
Personally, any person running t bars over an inch is probably applying principles that they wish they could apply to their dick.

I get a kick out of all the stiffening people do to their chassis after they run the biggest t bars and thickest leaves on the market cuz you know....

Bigger is better.

Like maybe the chassis doesn't need to be rock hard and rigid if their suspension on their STREET car has some compliance.

If you don't want a lumber wagon, stop building a lumber wagon.

And yes, I'm ready for the hate. Bring it.
 
Personally, any person running t bars over an inch is probably applying principles that they wish they could apply to their dick.

I get a kick out of all the stiffening people do to their chassis after they run the biggest t bars and thickest leaves on the market cuz you know....

Bigger is better.

Like maybe the chassis doesn't need to be rock hard and rigid if their suspension on their STREET car has some compliance.

If you don't want a lumber wagon, stop building a lumber wagon.

And yes, I'm ready for the hate. Bring it.

I hear what you're saying (even if nobody asked :D ) but you have to hear something: Not everyone just wants to go to car shows and the drag strip.

We each have a vision for our cars and for most of us, we do the best we can and get there step by step. I have wanted to make my Dart into a competent handling car since I got it when I was 17 (23 damn years ago).

An A-body isn't a terrible place to start for a handling build. They have some limitations but their simplicity, well engineered suspension design, relatively light weight offer some respectable potential and it can be done without drastically altering them away from being the lovable, honest, practical 60s/70s cars that they always have been.

You say "lumber wagon" in a derogatory way but maybe you don't appreciate that there is a reward for giving up plush driving comfort. Stiff/rough ride is fine so long as the car turns-in and behaves in a way that justifies it. I know the second part is achievable. I'm just not there yet.
 
I hear what you're saying (even if nobody asked :D ) but you have to hear something: Not everyone just wants to go to car shows and the drag strip.

We each have a vision for our cars and for most of us, we do the best we can and get there step by step. I have wanted to make my Dart into a competent handling car since I got it when I was 17 (23 damn years ago).

An A-body isn't a terrible place to start for a handling build. They have some limitations but their simplicity, well engineered suspension design, relatively light weight offer some respectable potential and it can be done without drastically altering them away from being the lovable, honest, practical 60s/70s cars that they always have been.

You say "lumber wagon" in a derogatory way but maybe you don't appreciate that there is a reward for giving up plush driving comfort. Stiff/rough ride is fine so long as the car turns-in and behaves in a way that justifies it. I know the second part is achievable. I'm just not there yet.

Well I gotta say, I'm the first one to jump on "big wheels suck and low cars suck" bandwagon, but I have to admit here, your car LOOKS great. To ME. Wheels, tires, stance and all. So consider yourself privileged. LOL I don't think your problem is going to be torsion bars too big, or something that you're going to have to unlock the space time continuum or the secrets of the universe to find out. It's something stupid simple. You've got a LOT of high quality parts on your car.

Therein lies some of the problem. WHen you change a LOT of stuff, sometimes you run into things like this. It's sorta like a race car. All my life I've heard the old guys say "change one thing at a time" and it's true. If you shot gun it and the car slows down, what caused it? You won't know.

But sometimes with some of these kits, you don't have a choice. You have to change a lot of things at once and sometimes you're left with having to diagnose a new problem. I wish you were local, I'd come over and help you out. This is right up my alley. I did alignment and suspension work for years. I'm good at findin stuff. I know that's no help, but the sentiment is there. LOL I bet when you find it, you're gonna kick yourself.
 
I'm not knocking the well handLing car, that's what I built for myself.

That said, just because someone MAKES huge springs for your car doesn't mean you NEED huge springs (or anything else) for your car. If you make it, someone, somewhere, is gonna buy it whether they need it or not.

Have you stroked your shocks to see if they're smooth and balanced? The jounce bumper is, as mentioned, a good place to start for harsh ride but here's a fun fact: if your jounce bumper is bottoming, all those handling mods are an absolute waste of time and money, so let's hope that's not the case. Bottomed suspension equals slide off road during corner and indicates a fundamental misunderstanding of suspension function.
 
Personally, any person running t bars over an inch is probably applying principles that they wish they could apply to their dick.

I get a kick out of all the stiffening people do to their chassis after they run the biggest t bars and thickest leaves on the market cuz you know....

Bigger is better.

Like maybe the chassis doesn't need to be rock hard and rigid if their suspension on their STREET car has some compliance.

If you don't want a lumber wagon, stop building a lumber wagon.

And yes, I'm ready for the hate. Bring it.

Hate? No reason to hate. It's pretty obvious you don't have the foggiest idea what you're talking about though.

First off, the problems that mrGTX is describing aren't an issue with 1.14" torsion bars. He has an install or alignment issue. I know that because my car with 1.12" bars doesn't have any of those issues. So, right off the bat I know the problem isn't just that he's running large torsion bars. There's no reason a car with 1.14" bars has to ride like a "lumber wagon". Mine doesn't. Set up properly a car with torsion bars that size should ride similarly to a modern performance car. After all, most modern performance cars run a wheel rate similar to what you get from a 1.06-1.14" torsion bar.

Second, if it was just a "bigger is better" deal, we'd all be running 1.24" bars. You can get them from Firm Feel or Sway Away. So really your logic doesn't apply. Heck, if we really were just working off of "bigger is better" we'd all install C-body torsion bar anchors and adjusters so we could go BIGGER than 1.24". That is after all what they did on the NASCAR and oval track Mopars back in the day. A-body anchors are only 1.25", so they limit the bar diameter to 1.24". The C-body anchors are larger, so you can go even bigger- all the way up to 1.40" if you wanted. And Firm Feel will custom make the bars for you if you want.

Finally, I've run 1" bars on the street. Even the 225/60/15 Falken Ziex's I ran for awhile were more than they could handle. The ride was still too soft and the suspension travel needed for that wheel rate precluded lowering the car much at all from stock. I couldn't lower the car enough to get the best suspension geometry for radials. When I went to 275/35/18's up front they simple couldn't deal with the amount of grip the tires had. Sway bars weren't enough, the torsion bars had to go larger.

Bottom line is, there are several members here that frequently put their cars on road and autoX courses. Most of them quite successfully. They all run 1.06" or larger torsion bars.

AutoXcuda- 1.14" torsion bars
GmachineDartGT- 1.06" torsion bars
Tomswheels- 1.06" torsion bars
"Redbrick"- 1.20" torsion bars - formerly lilcuda's car, it is a well documented performance road racer [SOLD] - 1968 Valiant road racer

Both the Hotchkis Challenger and Taxi run torsion bars in the 1.1" or 1.12" range. The B/E torsion bar spring rates are slightly lower than an A-body bar in the same diameter (B/E body bars are longer), but they're still more than what a 1.06" bar would give you. Their exploits are well documented. And Hotchkis does their homework.

So yes, there is a reason why the best handling Mopars are all running 1.06" to 1.14" torsion bars, even on the street. And it has nothing to do with "bigger is better". It has to do with matching your tires and traction levels to your suspensions capabilities.
 
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That's why I drive a Chevy truck, runs like a top, all I do is change the oil never have a problem, never make any noises at all

Ignorance is bliss I guess..
 
All great info here.

In terms of stiffening, I already have subframe connectors and USCT torque boxes waiting to go in.
Would you say that the rad support/inner fender braces should come first?
You will notice the biggest
All great info here.

In terms of stiffening, I already have subframe connectors and USCT torque boxes waiting to go in.
Would you say that the rad support/inner fender braces should come first?
yes.
 
I have had a pile of people ride in my car through the years and no one ever mentions it’s stiff with 1.14” bars... in fact it rides better than my .840” bars, which just blow through the travel and bottom out on any decent bump.

68F10648-E206-47E0-8C3A-346EC4C9A278.jpeg
 
...I've run 1" bars on the street...

So yes, there is a reason why the best handling Mopars are all running 1.06" to 1.14" torsion bars, even on the street. And it has nothing to do with "bigger is better". It has to do with matching your tires and traction levels to your suspensions capabilities.

Ah man, now I feel all inferior and wimpy with my .99 TB's. And I thought going from .87 TB's was a jump. I gotta get the biggest I can!!! :rofl:

I will say, with the .99's and RCD's it sure rode nice on the one drive I've had. Had'em for years, came in a parts car, and glad to finally have them in the car.
 
Ah man, now I feel all inferior and wimpy with my .99 TB's. And I thought going from .87 TB's was a jump. I gotta get the biggest I can!!! :rofl:

I will say, with the .99's and RCD's it sure rode nice on the one drive I've had. Had'em for years, came in a parts car, and glad to finally have them in the car.

I don’t think there’s anything wrong with running 1” bars. But it depends on the whole build. Ride height plays a big part of that. The tires being used are a big part of that. For a car relatively close to the stock ride height and using 15” rims and the street legal tires that are available for those, 1” torsion bars with aftermarket sway bars will work well and you’ll have a car that handles far better than they ever did stock. I think the 1.03” PST bars are a great choice for a street car with some mild updates to tires, braking, etc.

But it does depend on the build. Lower the car significantly to take advantage of better suspension geometry and you need larger bars to increase the wheel rate to deal with the loss of suspension travel. Improve the tires by running wide, high performance compound modern tires and you need more wheel rate to deal with the added suspension loads that come with those tires. Run shocks with modern technology and vast improvements from what was available even 10 years ago and the larger bars have much less of an impact on how stiff the ride quality is. There isn’t a new car on the market that rides like one of these cars did back in the 70’s, and that’s a GOOD thing.

Suspension has to be matched and tuned to work properly. That can mean large changes to the suspension components with relatively minor changes in application. I’m not saying everyone should run 1.12” bars on their street car, they shouldn’t! I usually recommend not going bigger than 1.03” for guys that are keeping 15” rims. You just can’t get street tires with enough performance in those sizes to need bars much larger than that. But that also doesn’t mean a car that’s been set up for more aggressive handling can’t use them successfully.
 
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Ignorance is bliss I guess..

Ha Ha, You guess ?? Your the one that had to apologize for driving a Ford!

So I drive a 2014 F150 with an ecoboost. Why the fekk does that matter to you?
 
...
Therein lies some of the problem. WHen you change a LOT of stuff, sometimes you run into things like this. It's sorta like a race car. All my life I've heard the old guys say "change one thing at a time" and it's true. If you shot gun it and the car slows down, what caused it? You won't know.

But sometimes with some of these kits, you don't have a choice. You have to change a lot of things at once and sometimes you're left with having to diagnose a new problem. I wish you were local, I'd come over and help you out. This is right up my alley. I did alignment and suspension work for years. I'm good at findin stuff. I know that's no help, but the sentiment is there. LOL I bet when you find it, you're gonna kick yourself.

That makes perfect sense...and while it's not a surprise, the suspension always seems like it should be simpler than it is. In reality, it's a system and each component contributes a new set of dynamic variables...messing with any one thing affects everything else and reminds us why it costs so damn much money to engineer a car from the ground up.
 
I don’t think there’s anything wrong with running 1” bars. But it depends on the whole build. Ride height plays a big part of that. The tires being used are a big part of that. For a car relatively close to the stock ride height and using 15” rims and the street legal tires that are available for those, 1” torsion bars with aftermarket sway bars will work well and you’ll have a car that handles far better than they ever did stock. I think the 1.03” PST bars are a great choice for a street car with some mild updates to tires, braking, etc.

I put 245/45R17 on it at the same time I put the .99 TB's in. Ride height probably isn't as low as some, but not as high as stock either (based on how my stock LCA bump stop is just touching or close to touching the frame rail).

IMAG0778.jpg


But enough about me. Hope MRGTX can get his issue solved.
 
Yeah, I am wondering if I am on the bump stops...but the car really doesn't seem that low. Cutting the bump stops doesn't seem like the best idea but there must be some way that guys are able to drive around lower than my car.



It certainly could be step 1. I don't see why I has to be. I the flex would definitely be bad for handling (I haven't gotten to that point quite yet) but if anything, I would guess that the flexibility in the chassis could soak up some of the bumps and reduce harshness. I have heard that this is why Chrysler preferred to leave the front/rear subframes disconnected in the first place as it made for a smoother ride. Seems ridiculous.
Not at all...a flexible chassis acts like a soft spring...
 
Not at all...a flexible chassis acts like a soft spring...

I totally agree. However I have always heard that one reason for the lack of connection between the front and back of these unibodies was for a more compliant ride. No, I don't have a source on that...just tribal knowledge, I guess. Maybe that was just an excuse for cheap-o chassis design? In any case, they obviously didn't plan for the grip capability of the tires we have today.
 
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