I am looking to do a front coil over conversion on my 73' Javelin.  I have received a ton of valuable information from Forum member "Mopar_guy" (many thanks again!)....But I'm looking for someone who has put either (Ride-tech or QA1) coil overs on and has utilized the factory upper control arm and upper shock mount.  I am curious what part numbers(either Ride-Tech or QA1) were used for the actual "shock" component.   I have the part number for the (tapered) spring, but I'm curious what shock worked in conjunction with the spring?  Looking to lower the factory stance by 1"-2" up front.  The rear will have to have the springs de-arched to get the lowered (dead level) look i'm going for.  

There's a ton of knowledge in here, I figure i cant be the only guy who has wanted to do this.  

Thanks again everyone.

Dave

In addition to bump steer type or related issues. 

don't forget these are unibodies, monocoque designs where sheet metal constructs are taking loads. no AMC shock mount is able to support the car's weight on any corner. the front inner fender, spring tower, and the connection up to the firewall are designed for the vertical load. the shock mounts are not. (many folk who put air shocks in the rear of and AMC experience a punched-through upper shock mount.)

up front the only chassis member designed and able to support the weight is that upper spring socket. the AMC front suspension design is very clever and technically sweet -- the static load is directly over the "king pin" (virtual) and wheel upward impulses directed straight up into the socket. the upper arm is under nearly zero load oif any kind and mostly keeps the knuckle vertical. the lower arm of course deals with all of the horizontal forces (parallel to the road), bumping curbs, braking, cornering, etc.

the AMC spring-over-knuckle has the best features of a McPherson strut without the dynamic geometry changes. camber in turns can be (but isn't :-) precisely controlled. the downside for AMC was, it's really tall! it really hurt styling choices early on.

a GM system transfers the static load to the lower control arm, so the lower arm is very stiff and heavy (high unsprung weight), and the upper end of the spring can be tied into the frame since it's so low. this allows for a lot more flexibility in styling the car. it has the terrible feature of a radically changing "leverage" over the spring, in turns. it is LOUSY handling by design. AMCs is flatly superior.

the common Ford spring in the upper arm isn't bad but has some dynamic (roll) spring-leverage changes.

AMCs system is very nice. i think product-engineering-wise, the older Nash type trunnions were more labor intensive (63 Classic...). the AMX type trunnion is a no-brainer -- it's very nice to work with! it has a bit of mass though (not that it would matter in Ramblerdom).

i would imagine that late 60's AMC suspensions have less unsprung mass than GM, for sure, and likely Ford. the early Americans have good geometry, but bizarre and terrible construction details.  but those are extremely light weight! and AMC fixed all that crap starting with the 64 Americans.

AMC suspension design is good, not junk at all. certainly late model stuff is superior -- it has 50 years of experience and now, computer design and simulation. but Ford, GM crap from the 70's and 80's is in no way "superior". the mustang 2 stuff is mainly easy to bolt on. it doesn't automatically work better.

as always, modifications depend entirely on what you expect to do, and get out of it. i'm no purist, and it's your car, do what's the most enjoyable! i'm no stranger to heavy mods for fun and the challenge of it.

All he's trying to do is replace the stock springs and shocks with a coilover setup just like the CF conversion but without the control arms and the high price tag. He's going to keep his stock control arms and the springs will sit in the stock spring pockets. The shock is still a shock and will hook to the stock shock bracket with no extra load on it. The load is carried the same way as it was designed.

There was a guy who use to make a conversion as I'm describing. (don't remember his name) I called him years ago to get one but he quit making them since the sales fell off. I got tired of guessing what springs to use and wanted the adjustability that a coilover will give you in both ride height and rebound. Lowering the ride height an inch or two is not going to kill the geometry. What happened to all the cars that were driven thousands of miles when the original springs sagged out? They kept driving them! Most restored cars now a days aren't driven a few hundred miles a year so it's a non issue.

Take a Porsche 911 or 924/44/68. Torsion bar rear, where the bar is effectively isolated by bushings, as is the very rigid crossmember. The loads from the spring into the chassis are very well isolated and well distributed into the chassis. The shock is separate, and fed into the unibody in another mount. People circumvent all that with a simple and effective coilover. It solves a few things, but my point is that all the spring and shock loads AND vibration now pass through a weak body point and with a small rigid spherical or shock bushing. Sometimes the unibody will break, depending on spring and shock rates used. Mostly for track use so vibration takes a back seat (literally).

Tom’s points, to me, are well put. 

And I stand by my comments in geometry. Particularly when I say that when roll centers are altered for the worse, your need for excessively high spring rates kills compliance and ride. 

As for worn out hoopties and cars driven a couple hundred miles, and it being a non issue. Ok. Sure. 

Mopar_guy wrote: All he's trying to do is replace the stock springs and shocks with a coilover setup just like the CF conversion but without the control arms and the high price tag.

oh -- spring in the AMC position, just with a shock up inside it? if so, sorry, i misunderstood the plan, man. y'all have my apologies. but if the shock is up inside the spring, how can it be using the stock shock mounts?

what advantage does putting the shock inside provide? since there's no change in geometry, there's no handling/ride difference from stock (other than spring rate and shock rate changes you might make). how's it better than just good OEM style replacement parts?

from what i can see, the main reason for the CF system is that those offset spindles clearance for huge wheels and tires up front (though why you'd want huge tires up front is beyond me). it doesn't offer, say, adjustability. the shock does (you can buy bolt-in QA1's) but with springs, you're left winding and cutting and shimming, like the stock system.

looking at the AMC CF setup, it don't see how it handles even as good as AMCs stock setup.  it appears to me that they essentially lowered the upper arm's outer pivot, switching to that spindle setup. to fix AMCs inherent understeer, you'd want to *raise* that ball joint, or lower the inner pivot (look up the "Shelby drop" fix for Mustangs; i did that to my '61 American and the result major).

the CF stuff looks great. AMC's (and everything from that era) is bulky stamped rough sheet steel; not pretty.

I have QA1 double adjustables on my 70 Challenger and love them. It's not rocket science, just need to figure out some dimensions and message QA1 or maybe someone on here has been down this road and can save us some time with some part numbers? 

This should be useful for determining a starting point for spring rates.....

https://www.ridetech.com/info/tech/spring-rate-calculator/" rel="nofollow - https://www.ridetech.com/info/tech/spring-rate-calculator/

https://www.freakride.com/product/amc-front-coil-over-conversion-systems/" rel="nofollow - https://www.freakride.com/product/amc-front-coil-over-conversion-systems/

The coilover conversion kits all have added strengthening plates/mounts that address that issue. Not just replacing the shock. All that I've seen mount the coilover in place of the spring.

Theoretically the stock suspension is superior to something like a Mustang II... depending on the Mustang II type used. The cheaper aftermarket kits still use some original MII parts such as the lower control arm, the better ones (like Fatman) are improved with a real lower A arm rather than an arm and strut (like the 62+ AMC big car, 64+ small). The late AMC suspension is about on a par with the MII EXCEPT for the superior spring location. The high spring has a lot of advantages, as TomJ pointed out.

BUT... there are some issues. It could use the "Shelby drop" to improve anti-dive characteristics for one, though the high spring helps with that. They were sprung rather softly for rougher roads of the day, so they can use a 10-12% spring rate increase. More and the ride starts to get a bit harsh, but I'd go 15% for a road racer/autocross car.

Mopar_guy, I suspect you're comparing a well worn original suspension with the Fatman conversion. In that case the Fatman BETTER be much improved over the original! A fresh AMC suspension shouldn't be much different, especially if the springs are changed with a slightly stiffer rate. In the long run it's cheaper to rebuild the AMC suspension with slight improvements rather than swap it out, but there are many reasons to swap it out -- I'm not trying to invalidate your decision to do so! AMC parts aren't going to get cheaper or easier to find for one thing. I'm not real worried about having the rebuild mine 20-30 years or more from now though. Someone will have to, just not likely me!

The next car I'm planning will likely have the front suspension swapped because it's a 62 American and I don't think I have all the front suspension parts in good enough condition to use or refurbish. I have a front suspension from my engine donor car that might work, will look into something else if it won't. Might end up gather original parts, we'll see... maybe. It's a long put-off project that might never get done... no point in kidding myself!

Here's two examples of what I'm talking about.

The main reasons for doing this as I said before to set ride height and have an adjustable shock. It's pretty much that simple! Most of the stock replacement stuff is iffy at best and you end up guessing what springs to buy and hope they work. I know this because I went thru 3 sets years ago trying to get the ride height I wanted and not have it ride like a truck. Once you have a good coilover setup, you won't go back.

FYI.... I emailed CF and they replied quickly , they say with the coilover kit you use your stock AMC spindles/brakes etc.., with the IFS kit they supply Wilwood Pro Spindle which is a pinto styled spindle. Then you choose what brakes you want( wilwood has mulitple options) if you like Wilwood stuff...

Nope! Not at all! My front end was completely rebuilt with a quick ratio box and a Larry Mitchell sway bar kit on it and my Fatman IFS out rides it and out handles it. It's like driving a new performance car. I'm back to using the original stock sway bar and the car corners more flatly than it did with the big bar. I did it because I needed to the steering box space for the a/c compressor on the Hemi and the strut rods were in the way of the exhaust. With those gone, that opened up everything.    I don't advocate doing this for everyone but it was something I had to do in order to get where I wanted to be but I wouldn't hesitate to do it again now that I've seen/felt the difference.

Mopar_guy -- got it. that looks pretty nice. i get it now.

More track oriented tires, even street versions will ride Way way harder than your average tire. Same with any size. One just has to have compliance somewhere or you get the vibes. I don’t mind them, but some do. 

I understand everyone's concern regarding ride height and geometry.  I have an 06' Mustang GT as well that I put lowering springs in. Had to put an adjustable pan hard bar and caster camber plates to compensate for the lower stance and to keep the toe and alignment correct.  If I understand the AMC geometry (and I completely admit, I am a novice at best) .... By putting coil overs in and utilizing the factory (upper) spring pocket, I agree...you are affecting the geometry of the control arm positions, but if you can adjust alignment and toe in to keep the specs correct...where is the problem?..   

Has anyone tried Dairyland Fabrication's coil over set up? = just type in dairyland fabrication for pictures etc.

Oldamcnut

Well, after reading more I see Steve from Dairyland has posted here but I would still like to know if anyone has used it.

Oldamcnut

Thanks for the information, it is totally helpful.  Yes, you are correct....looking to just have a just a street car.  No auto cross or even what would be considered "aggressive" driving.  Looking primarily for the lower stance.  Max drop will be 1.5" more likely 1"  I have seen Eaton lowering springs available for both front and rear which may also fill the need.  The adjust-ability of the coil over is the primary reason I'm considering it.  Smoother or stiffer are good options to have...if I did just a shorter spring, I don't gain the adjust-ability, but that comes with a price tag.  I just need to weigh out the cost vs. benefit.  In talking with many, many of the guys who have done the swap to coil overs...they all agree their car handles much, much better.

Thanks again for the tech advice.

Lowering plates are the shortcut. 6 cylinder springs also work well.

Personally I think the CF setup is overpriced either way but it's the only bolt in option out there for the big body cars.  Replacing the stock springs and shocks with coil overs is the most cost effective way. A quick ratio steering box is a must to really get it to drive better  There's a lot of reading on this topic if you do some searching. I'm not a fan of lowering plates and wouldn't use them.

If all you're after is handling, then a set of front and rear sway bars, a quick ratio steering box, adjustable shocks and some good tires will get you there. Some of this depends upon how you're defining the term "handling" and how deep you wallet is.   If you want the car to ride nice and handle better, you're better off with the full on CF setup because it cures one of the nasty parts of the front end - the strut rod. The main reason for this thread was he wanted to be able to adjust the height of the front end and have it ride nice as well. The selection of stock coil springs is pretty slim and for what Eaton wants, you can do a coilover setup for close to that cost and have adjustability that you can't get with a stock spring.

Another issue is shocks. The stock suspension wasn't designed for gas shocks and when you put those in, it's going to ride a bit rougher. A nice set of adjustables is pricey so it depends upon what you plan to do with the car and how much you're going to drive it. There's several threads on this subject as well.

I had most of the stuff I mentioned and my car did handle way better than stock. In fact I autocrossed it a while till I took out the main bearings in the motor. When I was researching my options for the front end to do the Hemi swap, I opted to use a Fatman IFS because it has the correct geometry but at half the cost. It has to be welded in but it was totally worth it because the car rides and drives like a modern car. It's light years ahead of the stock suspension and after 8,500 miles of driving last summer, my front tires (255/45/17) are wearing almost perfectly flat. That's something the stock suspension will never do with that wide of a tire. You can see pictures in my build thread. There's a link in my signature.

Are you talking about a Pre-1970 or the later 1970 and beyond.

I build the Dairyland Fabrication Kits and I created it because I was not satisfied with the performance of the Stock trunnion suspension when Auto-Crossing my car. The stock geometry is a disaster. I can now keep up with late model mustangs in lap times for example. That would not have been possible with the stock suspension.

As for the 1970 and later stuff, It's not too bad. The geometry has been corrected by the factory. That said you still can't dial-in the Caster of a modern car, so it's still somewhat limiting.

Coil-Overs are great because spring rates, ride height, and damping can be easily (and inexpensively) changed to dial in the desired suspension behavior. Springs for QA1 coil overs are only $100 a set.

Have fun

Michael

Fitting a universal adjustable coil-over on a 1970 or later Javelin/AMX would be a great upgrade.

Would be pretty simple to fab up the required brackets to get it to work.

You would need to know the needed compressed/Extended dimensions. And how much you want to spend. I would recommend bearing mount (not bushing).

Box the control arms, and fabricate mounts. I think the 70 TA cars had basically a coil-over setup.

Here is a link to the Custom Mount QA1 web site. https://www.qa1.net/automotive/suspension/shocks-struts-coil-overs/custom-mount-coil-over-shocks" rel="nofollow - https://www.qa1.net/automotive/suspension/shocks-struts-coil-overs/custom-mount-coil-over-shocks

Good info here on the Penske/RWR cars. http://www.camaros.org/forum/index.php?topic=9285.0" rel="nofollow - http://www.camaros.org/forum/index.php?topic=9285.0

The lower control arm should be strong enough. 343sharpstick hasn't mentioned anything about strengthening his....  

You might want to box it to make it more stable, but that also take some of the flex out of it and moves all flex to the bushing. The arm is designed to flex just a little front to back to keep it aligned with the strut rod. People have boxed the arm for decades, so it won't hurt, but I'd use a rubber control arm bushing if boxing and not a poly so it won't add strain to the boxed arm.

The lowering plates are limited to about 1-5/8" drop. There are a few who have made them so that the lower holes on the spindle match the upper holes on the steering knuckle, but that's a bit drastic to me, but shouldn't be an issue for a cruiser with 3/8" cold rolled steel plates (the one I remember doing this used 1/2" plate). Splitting the difference should be more stable. The plates maintain stock suspension geometry while still lowering the car. Using shorter or softer springs changes the suspension geometry. You can get by with a 1" drop without affecting it much, but much lower and it does. Stiffer short springs minimize the effects, but make for a much harder ride.

Not sure how accurate Wayne Davis' T/A replica is to the original, but in his build thread he does show coil overs. Upper control arms look to be stock. Couldn't tell from the photos about lower control arms, but sway bars were torsion bars with splined links, which I'm pretty sure how the real T/A cars were done. Mods were limited by SCCA rules, though some brake changes were allowed in the interest of safety. SCCA also gave AMC a waiver to run dry sump after continued engine failures. 

I did have WSC coil-overs on my car, but have since replaced them with a spring/shock combination similar to the original Trans Am Javelins.  The coilovers were fine for the street and some track time, but not stout enough for serious track time.  The biggest issue was that I couldn't get a stiff enough spring for the coil over.  Attached are a couple photos of what I have now.  The photo with the blue spring is a more modern spring design, and a shorter spring height that requires a spacer to get proper ride height.  The photo with the black spring is a more period type spring, although both springs are rated at 900#.  I had to convert to a Mustang spring perch given that no one makes a race spring to fit the AMC perch size.  The Mustang perch fits a 5" spring diameter.  I also am using Vari-Shock dual adjustable shocks that allow track tuning and have the appropriate upper and lower mounts.  The other picture of a spring on a bench is a photo of one of the actual springs from the real Trans Am Javelins.  I boxed the upper and lower control ams and replaced all the bushings with spherical bearings.  I also have lowering blocks.  The front sway bar is a torsion bar with end links attached to the upper control arms rather than the lower control arms in the stock application. 

https://public.fotki.com/Coloradoamx/ta-javelin-suspension/be355a65-06e3-4e97-.html" rel="nofollow"> https://public.fotki.com/Coloradoamx/ta-javelin-suspension/31bfdf98-dec0-418d-.html" rel="nofollow"> https://public.fotki.com/Coloradoamx/ta-javelin-suspension/4e148a37-be58-42ff-.html" rel="nofollow"> https://public.fotki.com/Coloradoamx/ta-javelin-suspension/278cd831-ddf8-49e4-.html" rel="nofollow">

If you want to read more about Wayne's Javelin here's a link to the rest of the story.

http://theamcforum.com/forum/penskedonohue-javelin-replica_topic78747.html" rel="nofollow - http://theamcforum.com/forum/penskedonohue-javelin-replica_topic78747.html

The workmanship on this car is absolutely awesome.

It really is a work of art. 

Thanks Wayne for the explanation and photos of the front suspension.  I had always wondered what Penske did to the Javelins back in the day.  I've read The Unfair Advantage several times (Donohue was my boyhood hero) but was never sure about how far the Javelin suspension deviated from stock.

https://www.summitracing.com/parts/qa1-gd507-10500c" rel="nofollow - https://www.summitracing.com/parts/qa1-gd507-10500c

Turned down slightly the stock shafts to fit the QA1 bushings then added  these to the shaft to position the coil over on the shaft

https://www.princessauto.com/en/detail/3-4-in-shaft-collar/A-p3871340e" rel="nofollow - https://www.princessauto.com/en/detail/3-4-in-shaft-collar/A-p3871340e

How about posting a few pictures? I'm only using a 450 lb springs in my front end and my car weighs about 400 lbs more than a stock car so be careful in using higher weight springs.

Been a while since I've come full circle on this post.  Many, Many thanks to Mopar_guy (Keith) for all of his assistance with this project.

I installed Ridetech coil overs on my 73' Javelin and they work extremely well.  Great control and a fantastic ride, as well as lowering the vehicle. 

I removed the pivot axle that is inside the original spring perches and took it to a machine shop to turn down the axle so it would slide through the eyelet on the bottom of the Ridetech Coil over.  I had the machine shop turn the axle down to 5/8" and cut way about 2/3rds of the whole axle.  I slid a Delrin washer on, then one of the aluminum bushings that came with the coil-over, then the coil-over itself, then the other bushing, another Delrin washer and then a lock collar with set screw.  

I ordered QA1 springs through Summit, Ridetech does not offer a tapered spring.  So if you haven't taken yours apart yet, I'll explain it a little here.  The coil spring you need to use will taper from the bottom size of (2.5" collar on the shock part of the coil-over ) up to (3.5") at the top (the size of the spring pocket on the vehicle).  The shock part of the coil-over comes with a "stud" attachment at the top, much like a regular shock absorber, only hard plastic bushings rather than rubber.  I utilized the factory shock mount on the top as the mounting point for the shock portion of the coil-over.  

Part #'s are:

Ridetech 24149905  Shock absorber, 4.1" travel for 2.5" I.D. Coil, single adjustable. Stud Upper and bearing lower mounts 10.5"(compressed)/14.6"(extended).  Approximately $250.00 each, depending on where you source them.

QA1 tapered springs QA1-10HTSP450  This is a 10" tall, High Travel Spring rated at 450 per spring. (Summit sells these at $72.95 each) More than enough spring for my A/C equipped 360

You will also need the Ridetech spanner wrench to adjust the collar that the spring sits on.  

So I ended up lowering the front suspension by 1-3/4" You could very easily raise or lower it depending on how much you adjust the collar up or down.  Car has since been aligned and is within specs and no irregular wear on the tires.  I have 225/60R15 tires on mine and I think the stance is spot on (personal preference)  Attached are some photos of the project.  For the rear I had a local spring shop "de-arch" the leaves 1" and install new rubber isolaters Note: Brakes are Scarebird big disc brake conversion.

  

I would but can't figure out how to on this site? Thanks for your help with the coilovers also member  Dmack 

I see it's offered in a 450 lb spring as well. https://www.summitracing.com/parts/qa1-gd507-10450c" rel="nofollow - https://www.summitracing.com/parts/qa1-gd507-10450c

FWIW, QA1's only have a one year warranty vs a million mile warranty on Ridetech's plus the Ridetech's are all made in the USA rather than parts of them and assembled here.

I hear ya, good point. I've had double adjustable QA1 shocks on the 70 Challenger for almost 10 years now with no issues. 

Also, why 450 lb springs when the originals were only 307 lb?  Not being critical, just trying to understand.

Does seem like a good way to test the waters with coil overs without having to hack the car up.

So, if I have this right, here's what I'd need:

Ridetech 24149905 Shock

Viking 10SP450 Spring

I'm not quite clear on details of turning down the axle in the spring perch, but I suppose it would become clearer once I'm looking at all the parts.  Does the spring perch go away entirely then except for saving (and modifying) the pivot axle out of it?  If that's the case, it seems like the lack of the rubber bushing in the spring perch might transmit more road noise?  Would not otherwise break my heart to get rid of the perches since they're now made of unobtanium.

What amazes me is that right now my '73, on its worn-out factory suspension, rides pretty well with modern 17" tires and wheels... better than my '72, which has 14" tires and wheels.  The '72 front end was rebuilt using Moog 3112 front springs and I suspect that's the problem.

I'm a little afraid to mess up the '73, since it drives so nicely, so I'll probably use the '72 as my guinea pig.  I'll be pulling the 360 out of the '73 after I get back from Kenosha so it might be a couple months until I get back to the springs.

Been there, done that, Alex!