Ya, dem Specialty Products arms are spendy.
67 Barracuda- Brakes and suspension on a 5000 budget- advice needed
- Thread starter SeattleQQ1Fish
- Start date
-
autoxcuda
Well-Known Member
- Joined
- Apr 6, 2007
- Messages
- 8,812
- Reaction score
- 3,748
They should because you are not going over 4” backspacing on the rims. If you have rear mount factory type calipers check caliper to UCA clearance or ask someone with that combo. When the arm swings out in the back there can be an issue
I know with Hotchkis UCA rear mount factory calipers are an issue
Funny you said that, I was just thinking about it. I don't have the ability at home to swap Kmembers, but I know of a shop that could probably do it. Plus I could paint it properly and maybe assemble some of the suspension before it goes in the car. Could you explain more about why the 67 only idler arm setup is so hated?
autoxcuda
Well-Known Member
- Joined
- Apr 6, 2007
- Messages
- 8,812
- Reaction score
- 3,748
It’s not supported on both ends. Like a door with one hinge. And the idlers are expensive and harder to find.
if you were going to change the suspension and torsion bars yourself at home, you can change the k-member. It’s about 6 more bolts. Then you put a wide wood block (2x6) elevated under your oil pan to support your motor.
And/or you can run a 4x4 across the engine compartment from fender bolt lip to fender bolt lip. Then take off carb and put threaded rod into manifold carb boot holes. The the motor will be supported by itself.
Last edited:
67autocross
A new iron curtain drawn across the 49th parallel
Last year on Christmas day we drove form Austin to San Antonio while I was down there for vacation...hooked up with a couple of other guys and drove in a 3 car pack at around 100mph the whole way! Good times...
That’s not uncommon to see down here, but it’s a little unnerving when you’re cruising along in an old car with a 50 year old suspension. Just yesterday a guy was racing a Mustang in his Challenger and they had to have been going over 100
512Stroker
We are all here because we are not all there.
Just for the hell of it I contacted the Tech Support at QA1 and the Tech Guy said
" If your setup worked with the factory UCA's it will work with our UCA. Rear mounted factory disc brakes will not matter".
I have my new QA1 UCA's in hand and over the next couple of weeks we are going to find out, after I finish a little prep and paint on the rest of the componets.
Wish me luck
67autocross
A new iron curtain drawn across the 49th parallel
Everyone was go at least 80-85 minimum so it’s not like we were going much faster... plus on Christmas Day the traffic was next to nothing
I love that Texas allows us to drive as fast as we need to. I don’t know that I’ve ever seen anyone pulled over for speeding on 35 and it seems rare on the other big roads around here too. The toll road around here is 80mph and some of the rural highways are 85! Hard to imagine there were 55mph limits at one time..
67autocross
A new iron curtain drawn across the 49th parallel
I love a good brisk drive once and awhile... a few years ago on the west coast of Canada I was driving the Coquihalia Highway with my wife in her Lexus GS when a bunch of Nissan 350 Zeds and Japanese cars flew past me... we ended up in a 10 car pack going as fast as 120mph at times...funniest part was when they all pulled into a town for gas I stopped as well... they were all laughing when I got out of the car as they assumed I was another Asian from Vancouver... and not some cracker from Winnipeg
Last edited:
This is a great list, and is in no way overkill for a good handling street car. If “amateur racers” aren’t running this level of equipment they’re not really trying to be competitive. Which is fine, but they’re not gonna be competitive with less than that.
The original strut rod design with its giant, soft, floppy rubber bushings causes alignment changes. Period. The harder you brake, accelerate and corner the worse these alignment changes become. The factory got away with it because of lousy tires and overall too soft suspension. Throw some 245’s up front with big brakes and that lower control arm will start moving around with the slack in those bushings. That does not provide precise or consistent handling.
And honestly, all the OE replacement rubber bushings out there are trash at the moment. Moog rubber is hot garbage. Their ball joints and tie rod ends aren’t good either. Their production changes have made them a product to avoid. I’ve put 100k street miles on adjustable strut rods on my mopars. And I wouldn’t use factory strut rods on anything meant for the street with decent tires.
There’s fancier stuff out there, I run it on the street and love it. But you don’t need SPC UCA’s or tubular LCA’s for what you want. The rest of the stuff, the sway bars, springs etc are what you need. And really, there isn’t much in the way of cheaper stuff that will do the job. Hellwig is a little cheaper than Hotchkis, but not by much. Most of the things are pretty comparable. You can definitely spend more money than that.
I would run at least 17x8’s all around. In the front with 5.5” of backspace, in the back with around 4.5” if you stay with factory width A-body rear axles. If you go to a B-body 8 3/4 you’ll need more backspace. In the front with 17’s I’d go 245/45/17 like I said before. In the back you can go up to 275/40/17 if you want, you’d need a 17x9 for that. A 245 or 255 would be easier though.
Last edited:
autoxcuda
Well-Known Member
- Joined
- Apr 6, 2007
- Messages
- 8,812
- Reaction score
- 3,748
There was an issue with 5.25”-5.5” backspacing 17” rims and QA1 UCA’s. The raised area behind the ball joint interferes with inside of rim.
Here:
Qa1 uppers. With 17x8. 67 dart.
I was suggesting running factory strut rods with poly bushings. Then the SPC arms could be used for the added adjustment. And then adjustable strut rods aren’t necessary since you can adjust the UCA so much.
I’m seeing the SPC arms and the QA1’s for same price $349 but you need to buy UBJ’s for the SPC’s ($36/pr Proforged or less $ others on rockauto)
I’m trying to cut to stay within the $5000 budget. $150 here and there...to pay for K-member, rims, and/or rear end.
Last edited:
512Stroker
We are all here because we are not all there.
Well everyone is entiled to their opinion. I just express mine alot less snarky.
Sure its a great list and also true is that you can do pretty well with alot less on the street. As far as track time go back to the Trans Am racing series those teams would get amazing handling with very few trick suspension component's .
67autocross
A new iron curtain drawn across the 49th parallel
Just in case you run out of budget before you get to the wheels and tires you could throw some Cooper Ultra Touring CS 5 tires on your cop rims... they are a decent modern tire for a daily driver... way better than a cobra or BFG
autoxcuda
Well-Known Member
- Joined
- Apr 6, 2007
- Messages
- 8,812
- Reaction score
- 3,748
Very cool. But when I went to the copper website they didn’t list that size. Google only popped one person selling them close out
Cooper CS5 Ultra Touring | 225/60R15 | Mavis Discount Tire
67autocross
A new iron curtain drawn across the 49th parallel
I picked some up in Canada in the last year...dropped the wheels off at my local tire shop and they called me about 10 days later to come pick them up...they are best tire I have used in that sizeVery cool. But when I went to the copper website they didn’t list that size. Google only popped one person selling them close out
Cooper CS5 Ultra Touring | 225/60R15 | Mavis Discount Tire
67autocross
A new iron curtain drawn across the 49th parallel
I looked and you are correct they seem to be discontinued... I might stop at the tire shop and see if they have any left in the system up here.
Actually that thread raises the question of clearance, but only one member said he had actually done it and it worked with minor clearancing of the large QA1 upper cup, and that was with a full 5.5" of backspace.
Adjustable strut rods are necessary, especially with poly or delrin LCA bushings, and the reason has nothing to do with adding caster. I would definitely not use poly strut rod bushings, they're counterproductive. First, you have the issue of the strut rods not being the right length because of the differences between the poly bushings compared to the factory ones at both the LCA and the strut rod. Second, they add binding. The strut rod bushings acts in two different planes. You want them to be stiff under braking and acceleration to keep the LCA from flexing forward and backward, BUT, you don't want them to be stiff when the strut rod is moving up and down with the suspension travel of the LCA. The poly strut rod bushings will actually add binding into the system by resisting the LCA moving up and down with suspension travel. That is why adjustable strut rods are ideal. Not only do they keep the LCA from flexing forward and backward, but they move freely up and down.
And, you can actually make them the right length, which further reduces binding in the suspension. Stock strut rods will NOT be the right length if you're using poly or Delrin LCA bushings. My adjustable strut rods have been adjusted so there's no binding in the range of suspension travel of the LCA. When I was running factory LCA's with poly bushings I can tell you the length of the adjustable strut rods was different than factory (shorter). With the tubular LCA's I run now with Delrin bushings the length was different again to produce free travel on the LCA.
Good grief. The Trans Am cars used all kinds of tricks in their suspension. Only the very basic components remained stock, and even those were modified. They did everything they could within the rules to improve the suspension geometry.
And then, yeah, the rules. What the Trans Am did and didn't do with their suspension was just as much dictated by rules as it was performance. And that was the 70's, so straight back to tire technology too. I love the Trans Am cars, but I wouldn't for a second use them as a blueprint for how to set up suspension for a street car now. Tire technology is better, there are a host of aftermarket parts available that they couldn't use, and frankly if they'd had free reign on suspension components they'd have done different stuff. I mean they acid dipped the chassis' they used. No tricks my foot.
512Stroker
We are all here because we are not all there.
What to you so long to respond?Actually that thread raises the question of clearance, but only one member said he had actually done it and it worked with minor clearancing of the large QA1 upper cup, and that was with a full 5.5" of backspace.
Adjustable strut rods are necessary, especially with poly or delrin LCA bushings, and the reason has nothing to do with adding caster. I would definitely not use poly strut rod bushings, they're counterproductive. First, you have the issue of the strut rods not being the right length because of the differences between the poly bushings compared to the factory ones at both the LCA and the strut rod. Second, they add binding. The strut rod bushings acts in two different planes. You want them to be stiff under braking and acceleration to keep the LCA from flexing forward and backward, BUT, you don't want them to be stiff when the strut rod is moving up and down with the suspension travel of the LCA. The poly strut rod bushings will actually add binding into the system by resisting the LCA moving up and down with suspension travel. That is why adjustable strut rods are ideal. Not only do they keep the LCA from flexing forward and backward, but they move freely up and down.
And, you can actually make them the right length, which further reduces binding in the suspension. Stock strut rods will NOT be the right length if you're using poly or Delrin LCA bushings. My adjustable strut rods have been adjusted so there's no binding in the range of suspension travel of the LCA. When I was running factory LCA's with poly bushings I can tell you the length of the adjustable strut rods was different than factory (shorter). With the tubular LCA's I run now with Delrin bushings the length was different again to produce free travel on the LCA.
Good grief. The Trans Am cars used all kinds of tricks in their suspension. Only the very basic components remained stock, and even those were modified. They did everything they could within the rules to improve the suspension geometry.
And then, yeah, the rules. What the Trans Am did and didn't do with their suspension was just as much dictated by rules as it was performance. And that was the 70's, so straight back to tire technology too. I love the Trans Am cars, but I wouldn't for a second use them as a blueprint for how to set up suspension for a street car now. Tire technology is better, there are a host of aftermarket parts available that they couldn't use, and frankly if they'd had free reign on suspension components they'd have done different stuff. I mean they acid dipped the chassis' they used. No tricks my foot.
I work for a living bud, I just finished a 72 hour shift at work. Sometimes I get a minute or two to make a couple quick posts from my phone while I'm at work, sometimes I don't.
autoxcuda
Well-Known Member
- Joined
- Apr 6, 2007
- Messages
- 8,812
- Reaction score
- 3,748
I own some of the original Trans Am engineering design notes. All the suspension parts were moved around. Nothing stock about those.
but I do think you can get dramatically improved handling with a few simple things. I ran half the stuff on that list for 15+ years and it was night and day difference than stock. Drove 80 miles round trip to work over heaviest trafficked stretch of highway in the world (405 sepluveda pass).
the other parts listed are better. No doubt. Just trying to stay in budget and most bang for buck.
I’m afraid we are going to bust past his $5K.
but I do think you can get dramatically improved handling with a few simple things. I ran half the stuff on that list for 15+ years and it was night and day difference than stock. Drove 80 miles round trip to work over heaviest trafficked stretch of highway in the world (405 sepluveda pass).
the other parts listed are better. No doubt. Just trying to stay in budget and most bang for buck.
I’m afraid we are going to bust past his $5K.
Last edited:
autoxcuda
Well-Known Member
- Joined
- Apr 6, 2007
- Messages
- 8,812
- Reaction score
- 3,748
Just when you start going more than 4.5-4.75” backspace, you’re above the ball joint. I don’t like limiting my future rim choices when there are other UCA options for similar price.
what about just running rubber LCA bushing and cutting 3/16” off the rear strut bushing?
The LCA bushings are so thin in these cars, they don’t move around like other makes rubber bushings.
I think the would help road noise and vibration for daily driver too.
also... a 65-67 B-body rear is 2 3/8 wider than an Abody. That’s 1 3/16” wider on each side.
so a 5.5” backspace rim on rear puts you in almost same place as 4.25” backspace rim on A-body rear with LBP axles.
that would save ~$700 over typical LBP Abody 8 3/4.
Man I would love to see those design notes!!!
I don't disagree, a few things can really improve handling. The Green Brick formula basically, you can do a lot with that.
But when the 15" rims go away, the improvement in rubber, the additional width of tire, etc, means that more is necessary. More caster than you can get with the stock arms. Less binding and slop than you get from the stock strut rods and LCA bushings, etc. The tires really make all that stuff apparent.
I also don't think we've totally busted his budget. His list was still under $5k, and he went with a 13" brake kit up front.
I don't see this. PRC literally said he had 17x8's with 5.5" of backspace with the QA1's and only a minor clearancing on the outer corners of that raised cup (which wouldn't hurt anything). That backspace gets you 255's up front if you want them. If he wants wider tires than those, he needs to go 18's anyway, and they will also clear the QA1 UCA.
I just don't see the point of cutting up bushings and trying to tune strut rod lengths with factory parts. The bushing needs to be thick to allow for the vertical movement without hitting hard parts since nothing else bends. You can get a part that works better for $230. By the time you've modified the bushings, checked for binding, modified the length of the strut rod, checked for binding, modified it again, etc, etc you could have paid for the stuff that works.
And the strut rod length isn't about gaining caster (like you would with a shorter bushing), it's about getting everything to move without binding through the whole range of travel. The stock stuff has rapidly increasing resistance especially as it gets toward the limits of travel.
No disagreement there, a 65-67 B rear basically lines up the backspace front and rear using 17" rims and their backspace limits up front.
To save on rims, I'm going to find a cheap pair of 17" Mustang wheels to use as a placeholder until there's more money later this year. They seem plentiful; hopefully I'll find something with an offset that works for now. My wife wants quieter tires for her Acura and they just happen to be 245/45/17s with plenty of tread left. Sounds like a good time to take care of that for her.
With suspension and brakes, i'm under budget, mainly because i've opted to take on the bulk of the work myself.
What's holding things up is the rear end and k member. i'm loathe to do all the work and then have to go back and replace the k member later. There aren't any 68-76 a-body Mopar k-frames changing hands in Central Texas right now. I look at Craigslist daily and there's not much of anything partswise, just the same old overpriced stuff that's been there for weeks. FB marketplace doesn't have much either, plus I have very little trust in strangers from that group. Ebay is pretty dry right now too. It could be because it's the dead of winter.
I'm starting to think, by the time I spend the time and money finding a k member, ship it across the country, blast it, powder coat it, have someone reinforce it for me, and figure out how to mount my 273 (i have to keep it for one more year,) I could pay for part of a Qa1 member and have it in my garage in a week. it's only 600, and I could get the family CFO to approve a few hundred additional budget because I'm calling it a "safety issue."
Have any of yall used one of these k members? Looking through threads, many say it's a reasonably straightforward bolt in.
Am I getting too far over my head with all this? If I go tubular, I'll have replaced almost everything on the front end of my car with aftermarket parts. The Circuit of the Americas is close to here, maybe I can go racing this summer...
Questions:
Can one convert a slant six k member to V8? There is a NOS one on Ebay right now
Do B-body 8 3/4s bolt directly into our A-bodies, or do they need to be modified?
Thanks to everyone for the Mopar A-body suspension education
1- slant 6 to V8 requires conversion engine mounts. Schumacher was making them, they are not anymore. US Cartool has advertised them, but they're not selling them yet.
You may be right on the K member. Typically they cost at least a couple hundred bucks, and if you have to ship it figure at least another hundred. You can do the seam welding and reinforcing yourself, but it does take time. I would say you'd be pretty close to a QA1 K-member in cost by the time you locate a K, pay for it, modify it, etc. A friend of mine has the QA1 K frame, they're pretty easy to deal with. There's a couple things I can't say I like about them, but at least you know for your money that you're getting a straight K frame with the right engine mounts. You may not get that buying a used original. I prefer the originals, but, I had what I needed already for all of mine. The Qa1 isn't necessary, but there's definitely an argument for getting one if you don't have one you can use.
On that note, you already have a '67 V8 K frame? The only real issue with the '67 K is the idler mount. That can be retro-fitted for the later style idler with some welding. Someone that can reinforce an original K should be able to make that conversion as well.
2- B-body 8 3/4's have the perches in the wrong place. To use them you need to weld a new set of spring perches on. That's also a great time to install a 1/2" spring offset kit so you can run more tire out back, only thing needed is to move the perches (which you already have to do) and get the offset hangers and shackles (DoctorDiff).
-
