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Discussion in 'Classic Mustang Specific Tech' started by bnickel, Sep 12, 2007.
That is the funniest ***** I have seen in a while.
Caster change + or - would depend on ride height, and suspension compression or rebound, with the strut. So it would really depend on the car setup and dynamic situation as to whether the caster would increase or decrease from the static setting. For instance on the Mustang negative caster slightly increases as the front end lifts, and slightly decreases as the front end squats. Also on a stock upper Mustang control arm there is a slight caster change as the UCA moves through it's travel due to the threaded bushings. Again this causes caster to change both slightly less and slightly more depending on where the car is in the travel and where it's headed.
Depending on what CCP does with Anti-dive, this could also be a benefit for CCP. It really depends on their design.
cool, I was concerned I'd overstepped my bounds. Yeah, there are a couple of other things like the added ground clearance that sounds promising too. I missed that in my first read. It would be great if CCP could be allowed to post in this thread. It would certainly be great to have another good option for upgrading our suspensions.
The "plastic" I'm thinking of is a type of nylon product. For the life of me I can't remember the name. It's touted as "self lubricating plastic", I'll either remember what it's called or it will bug me so much I'll look it up. One of the downsides is it's thermal instability, this meant larger tolerances to compensate for growth and shrinkage. On the good side it is really cheap to make, as there is no machining. Stir up a mixture of pellets and dump it into the high pressure mold machine, and out pops a barrel full of bushings. They were also easy to change. Hopefully CCP does use either Delrin or a more thermally stable variation of what I'm thinking. That would be a big benefit.
honestly, i think it looks unnecessary, and i agree with the above poster(s) who said a good strut rod would take care of things. i'd prefer to either go full open tracker with the the spherical bearing LCA with heim jointed strut rod OR just go with a full bolt in coilover kit (tcp/RM/UP etc.)
funny you should mention that. GW has a new coilover kit for the 65-66 cars that is a very similar design to this with a one piece A-arm. it still uses the factory strut rod bracket however so you don't have to mount the 1/4" plate.
i see you keep saying that you'd rather use the Opentracker parts, like you feel that this is somehow going to affect John's business, i highly doubt that and he'd be the first to say that competition is good. i have a set of his roller perches on my car and absolutely love them, one of the best mods i've made to my stang.
if i do end up using this kit or something like it i can guarantee you i'll still be using some of John's product on the car somewhere. for sure a set of his full roller UCA's and probably his roller perches as well. i'm seriously thinking about getting him to build me a fully rollerized front end with some coilovers and maybe using the CPP kit on the bottom or more of his roller stuff for my 69 cougar project.
i can also 100% guarantee if John came out with something like this i'd buy it in a heartbeat.
Nobody seems to have any trouble with bolt-in sub-frame assemblys on production cars. They've been around for decades. And the last time I looked ALL the suspension parts that move are bolted in.
Besides, if you really are concerned about it coming loose you can always weld it after you install it.
exactly. you could also double nut the bolts, and use a proper lock nutas the second nut.
the cpp kit has the advantage of having a "0" caster curve, and a far more stable lower control arm mounting. that said, with the right parts the stock strut rod style suspension has few enough drawbacks, and the caster change in cornering is not a problem.
as for the bushing material, urethane is a solid, long lasting material whose only real problem is the lack of flexability
The stock LCA+strut rod is really a two piece A arm. After all, it's bolted together, so the strut rod doesn't work like a radius rod or something, and it doesn't pull the LCA forward (or backward). After all, that would require that the angle between the LCA and strut rod changes, and that is not possible.
So, in theory, neither the stock setup nor the CPP A arm change caster during suspension travel. In practice, the stock setup does reduce caster somewhat do the compressibility from the strut rod bushings, but that is a flex issue, not a geometry issue. Replacing the bushing with a heim joint or Maier Delrin bushing reduces it to near zero.
My biggest problem with this setup us the quality of the welds and setup that I see on the nova page the welds look to undercut the brackets and I would have boxed the front mounting point. I think it is a workable design I just have concerns of the quality of the materials and assembly. I would check as to where these are being fabricated before buying one.
The strut rod moves on an arch that is determined by the length of the rod. If it moves toward a 90 degree angle it will push the lower arm back and decrease the positive caster. If it moves away from a 90 it will increase the positive caster. It works just like the steering as you turn and the inside wheel turns tighter than the outside wheel because of the geometry (Ackerman) of the system. Think about what happens to your controll arm as it moves up and down...it pushes or pulls the spindle depending on where it is in its arch. This is also the same reason the universal joint bearings change speed as the drive shaft rotates. A constant velocity joint does not have that problem.
If you don't believe me go disconnect the rod from the arm and place a plum-line at the end of the rod and them move it up and down. It WILL move either towards or away from the plum-line based on the angle which makes this a geometry issue.
I saw one of these systems on a NOVA at Auto-Fair in Charlotte in April. It looks like a very good set-up. The owner loved it. Said he is building another one with the same system. According to him the understeer was greatly reduced and tracking was much better. For the $999.00 price I think it's hard to beat for a street car.....now if you are racing that might be another story.
Helmantel is correct.
I've been playing with Performance Trends Suspension Analyzer software lately to to evaluate modifications to the MII suspension. One of the examples included with the software is a 68 Mustang.
With all this talk about the caster change on a stock suspension I decided to investigate the 68 Mustang geometry. According to this example there is a total of 0.02* of caster change across 4" of vertical suspension travel. That is +/-2" from resting height. At +/- 3" it increases to 0.036*. These are insignificant changes. Of course this doesn't take into consideration deflection of the bushings.
A top view of the geometry explains the reason for essentially no caster change. The strut mounts to a point that is in line with the axis on which the lower arm pivots. This axis is in turn inline with the chassis. Picture a triangle and make the axis of rotation one side. Rotating the triangle on this axis has no effect on the length or orientation of the other two sides. Therefore the strut arm and LCA swing in exactly the same arc. To verify this I went to my garage where I have a 67 with no suspension and looked at the attachment points. Sure enough, if you look through the strut mounting hole you can see directly through the LCA bolt hole.
However, is no caster gain a good thing? Another example in the software is a 2001 Corvette. I think we all agree this car has very good handling characteristics. With +/- 3" suspension travel the Corvette caster changes from 6.5* to 11.5*. That's a very significant gain of 5*.
Very good point. Can you look at something like a Carrerra GT-3 to see what happens with it? THAT might be a telling bit of info. Apparently caster gain coulb be a good thing.
That's an interesting one to wrap the mind around. Caster is what brings the wheels back "on center" after turning and increased positive caster improves high-speed stability since it makes the car track straighter with less driver input. I noticed a huge difference at 90 mph in the blue '68 fastback after going from less than 2 degress to over 4 degrees of positive caster. So, perhaps the caster increase during suspension compression aids stability under very heavy braking? Perhaps it helps tracking when a large hit is encountered at speed?
Increased caster also provides the benefit of negative camber on the outside tire, albeit a very small amount, and in a turn is usually negated by bad camber curves in our stock suspensions. Camber gain, from the UCA drop plus the added negative camber from caster gain can't be all bad. However a sharp change in caster could cause some strange feedback at the wheel while driving at the limits.
But back to the kit.. It's hard to decide between a $270 set of bearings vs. $300 full a-arm conversion. Or is it?
Looks like the Nova site died on us. Was that bottom bolt on the arm the sway bar mount, or a possible mount for a coilover?
yes, camber gain is good. mostly what i was talking about with the stock strut rod setup was the camber deflection from the strut rod moving through it's travel AND the bushing squirming around.
helmantel mentioned the camber changes in 4 inches of suspension travel but the mustang suspension has a 7 inch travel stock and when you start getting closer into those last 3 inches the geometry goes all over the place. if you limit the suspension movement with super stiff springs, etc (the early T/A cars had cable limiters to eliminate too much suspension droop) then you can control the geometry changes better but you end up with a super stiff ride and the tire doesn't really follow the road. take a look at some trophy trucks sometime and watch the suspension travel on those things, some of them have almost 3 FEET of suspension travel and they look like a cadillac going over a bumpy street, the body doesn't move much but the suspension is moving up and down like a hyperactive kagaroo on a pogo stick .
if you eliminate that deflection you can run a softer spring and keep the full suspension travel, the you have a car that not only handles extremely well but has a pretty damn good ride as well. couple that front suspension with a good 3,4, satchell link or IRS rear suspension and you make the car that much better handling and softer riding.
personally i want to have my cake and eat it too, i want a car that can handle the twisties like a slot car and still have it ride like 86 town car (or at least a lot closer to both than stock)
here's my wish list for the 69 cougar project that i'll hopefully be starting this coming spring.
CPP A-arm subframe kit (lowers only)
Opentracker roller upper arms
either ORP roller perches or a custom coilover setup (if i can talk John into building it for me)
Degins' dropped spindles with his PBR caliper brackets
a nice 4 link like the TCP G-bar or a DVS cobra IRS conversion
Ultrastangs crown vic rear disc setup (if he makes it and i stay with a stick axle)
my TCP rack that is sitting in the garage awaiting install on the coug.
that's the big stuff, there's also a ton of other little stuff i want to do as well. and i'm also going to be using a 15" wheel instead of the 17's i have on the Stang now. i like a little more sidewall on my tires.
unfortunately the only bolt in 4 link i know of that will work on a cougar is the Rod and Custom kit but it looks flimsy at best so i don't what i'll do out back yet.
Exactly. To make it even simpler, imagine (or make) the following: cut a sheet of paper diagionally. Tape the long side to your desk. The long side presents the frame, the short side the LCA, the diagional side the strut rod and the ball joint sits at the tip. Moving the pointy end up and down shows exactly how the LCA+strut rod combo moves. I have to admit that I too thought that the strut rod moves in an arc, like a radius rod, so I can understand the confusion.
I assume you mean "is not caster gain a good thing?" The stock geometry already has some caster gain, due the angle of the upper control arm (anti dive geometry). The angle is about 5 deg., which means that the spindle gains approximately 1/2 deg of caster per inch of (upward) travel. I don't know how much is desirable though.
I can imagine that going over a bump with one wheel may give the same affect as having unequal (static) caster, so the car may pull to one side, but this effect is probably not as strong as for example a lot of bumpsteer, where the wheel actually turns when going over a bump.
the strut rod on vintage fords does move in an arc, but the strut rod is long enough that the arc is insignificant. as to caster gain, as long as it is in the right direction there is no problem with caster gain as it does help stabilize the steering geometry. it is when you lose caster that there is a problem. as i have said before though, the stock mustang front suspension is a good overall design, and with a little tweaking here and there, it becomes better. on vintage cars though the real gains in handling is going to be from the rear suspension.
bnickle, check out the air ride rear suspension for the 67-70 mustangs. i believe it will fit the cougar without a problem, and it is rather stout.
Yes, caster gain. The camber gain in the stock suspension is horrific.
My point is the CPP lower assembly doesn't do anything for caster change that a good ball joint strut rod won't correct. It may have other benefits such as a slight reduction in unsprung weight and improved rigidity. I've never liked stamped steel suspension components like the stock arms.
the air bar rear is EXACTLY the same thing as the TCP G-bar, in fact TCP sells them as both. the problem is that the cougar rear suspension is 3" longer than the mustang rear suspension and they say the G-bar or Air bar systems won't work because the arms are too short and the geometry is different.
if i had the money to waste, i'd be the TCP G-bar and see what it would it would take to modify it to work in the coug.
Here is some information from CPP. I have been asking them questions about their product. I thought that i would share it with you.
I am liking this kit more and more.
The Mustang kit is currently available for the 1964-1966. The 1967-1968 will be soon, with more to follow. We also have a kit for the early Falcon, Rancheros, etc. I am not exactly sure on the years of the Falcon/ Ranchero. We have done several all early 1960's I think the newest we installed a kit on was a 1964, and the oldest we installed was a 1962. The kit probably fits more years than that.
About the kit. We made a tubular upper and lower control arm. The strut rod and mount are removed from the car. The new crossmember bolts to the chassis with 12 bolts. The new lower arm uses the original mount for the rear of the arm, and the crossmember has the mount for the front of the arm. The cross member allows the front of the arm to become a caster adjustment. The upper arm is made 1/4" shorter. This allows a better camber curve, and allows you to pull the tire in from the fender. In order to get more room in the fender, you would need to slot the original lower arm pivot. We include a lock out kit that will hold the arm in its new position. In all this arrangement will let you align the car with the upper and lower arms. This lets you move the wheel in, out, front, or back; the advantage is the ability to run as large a front tire as possible.
These arms have sway bar mounts in the same position as the original arms. They offer more clearance for bigger brakes, tires, and wheels. They use a replaceable ball joint. The upper arms come assembled on new billet cross shafts. We use bushings made from a patented plastic material that will never squeak, works at temperatures above 400 degrees, has very little friction, has memory, and has an ultimate tensile strength just 10% less than aluminum. I stated using this in off road truck suspension about 5 years ago. It last longer than Delrin, and unlike Delrin it does not not squeak, break, crack or split. We do not like to mention it by name because then every one would switch. I spent many months researching and testing before I found this stuff. I have never seen a better bushing material. In testing we had urethane bushings fail, and split in half within 1 week of road use. The material we use has run more than 1 year in SCORE with no signs of measurable wear. Hope this answers all those skeptics questions about the bushings.
The biggest difference most people notice is how much more stable the car becomes, and how much better the steering feels.
I know some people say that the ONE suspension will work good if it is in good condition. It is no comparison to this kit though. We have sold thousands of these and not 1 person who installed and drove it could claim that it did not make the car better.
Here is a link to a Nova forum on the Nova kit. These are very similar to the Fords.
If you have more question you call or email
They seem very open to questions. I hope this helps and keeps this discussion going.