Wow, the educational post has now turned into the same old BS which is not what it was intended to be at all!
Goat1 To Address Your and PIG's Statements or Questions.
"There's no question that solid is usually stronger than tube.
As a fair comparison use real world DOM yield strengths. The mill certs on our tubing is often in the 85-90 ksi range. That puts 2 x .250 DOM at F=45,650, not as much difference now, your 2" solid is still stronger, 20% more, but still more than twice the weight. You use solid because is cheap and you can just thread the end and not weld a threaded bung. Like they say in racing, you can have cheap, light and strong, pick any two.
When I look at stock JK's I notice how light some of the components are, the bumpers don't weigh any thing, there is a cast magnesium spare tire mount, the body panels are very thin, etc. Jeep engineers went to great lengths to keep the weight down. There must be a reason?? We do nothing but add weight to our modified jeeps, I just try to keep it to a minimum. 2 x .250 DOM lower control arms are a good compromise of weight and strength IMO, see I have this annoying tendency to engineer things.
When our 2dr JK had stock axles, short arm suspension, light wheels and tires, it would haul ass in the desert and would climb very well, it was really fun to drive, pretty amazing how well it worked with 4" lift and 35's. Now it has Rock Jock 60s, 40's, heavy bead locks and it is a dog, not nearly as much fun to drive any more."
First to address your strength of material concerns. Your Poly Performance website states that your lower long arms are made from 1 3/4" O.D. .188 wall 1026 DOM tubing.
Copied right off your website:
•Poly Performance Front Long Arm Lower Control Arms for 2 Door & 4 Door Jeep JKs
•Suspension components feature an abrasive resistant powder coat finish for maximum durability and corrosion resistance
•Made from high quality crush resistant 1 3/4" X .188 Wall 1026 DOM tubing
•Arms are designed and manufactured to maximize ground clearance
•The arms will allow the use of OEM wheels with larger tires without the requirement of an additional wheel spacer
•Features an OEM style bushing for extended permanence & minimized road vibration
•Incorporates the tried and true Currie Enterprises Johnny Joints® for paramount performance
•Poly Performance Double Adjuster Sleeve & Pinch Bolt Assembly: allows for adjustment of control arm length without removing control arm mounting bolt
•100% bolt on components assures an easy, trouble free installation with the use of basic hand tools
•Sold in pairs
The 2" O.D. 1/4" wall thickness will be a conciderable improvement over your current offering if you are indeed upgrading or changing the material. The yield strengths that we posted are all based off ASTM standards. Sure, there are going to be mill runs where it will run higher, that statement goes for all materials, but the ASTM standards are the minimum! That is why we posted those numbers and it can be quickly referenced through matweb. Again, this was done for the people. Not to have a pissing contest. We have also seen some rediculous numbers on our 1018-1020 CR during our mill runs, but we are not going to base anything on that knowing that does not have to be the case! You have no control over that. Especially if you do not order mill runs of material.
To address your concern over weight. Weight is always a concern. You are talking about your JK handles poorly now because it is heavy! You probably added over 1500 pounds to your JK in axles, going with 40" tires, your long arm suspension, all of your Poly Body Armor, Bumpers, etc. Alot of things will contribute to the poorer handling. Could be suspension related? We would imagine a huge effect would be the rotational inertia and mass of the 40's from 35's? Another huge effect will be all the weight you added up top further raising the CG of the vehicle with all your armor, roll cage, etc.
If you want to bad mouth us for our system being a little heavier, on a relative scale we are talking what here, 70 to 80 lbs, call it at worse 100 as the difference between our full long arm system and your Poly kit! To put it into perspective for the average consumer, that is the equivalent of approximately 12.8 gallons of fuel at most. That certainly won't make your JK handle like crap! Not to mention, this weight difference is down low where it actually aids in lowering your vehicles effective CG. When we come out with our body armor if we do, it will be all aluminum. Nice and light weight up top designed to protect! In our opinion, in some places it is ok to add weight and in some cases better methods should be sought out!
What are we seeing JK 4 Doors tipping the scales at these days on 40 or 42" tires all armored up and accessorized. Say 5500 pounds plus? That will contribute significantly to poorer handling, acceleration loss, but if that is how the consumer wants his or her rig, then the basic equations above apply and if you want it move faster, then you will have to have great Force. This is why hemi swaps are so popular and almost needed at that point in our opinion. Power adders are certainly nice for a JK tipping the scales in that range!
Sure Jeep tried to save weight where they could on the JK. Look how much heavier they are than a TJ. They had to do something where they could to help out their fuel economy numbers someplace. The new frames are stronger and heavier, the axles are larger, the brakes are bigger, the body is physically bigger, so sure. Chrysler designed a few parts that were hopefully based on weight savings. Notice, all their weight savings was mostly on the body and accessories. They did not skimp on the frame or major structural components!
"Originally Posted by GOAT1
You use solid because is cheap and you can just thread the end and not weld a threaded bung. Like they say in racing, you can have cheap, light and strong, pick any two.
If solid is cheaper, why don't more of the inexpensive kits on the market use solid?
Very good question"
PIG, really is that your arguement? That is a poor way to judge just about anything. You guys do some things that other companies do not do.
We own all the machines to manufacture all of our arms and components in house! We are a machine shop by nature, we own all the lathes, bending equipement, welding equipment, and even in house powder coating equipment. We also manufacture for other companies. That is how we are set up as a company. Most other suspension "manufacturers" really don't manufacture anything. They might design it, then they source all the parts and put them into a box, not really manufacturing anything. We would imagine the up front costs keeps this process away from alot of other manufacurers.
Sure solid alloy steel is more cost effective. Not by much for us! We order mill runs of material since we manufacture in house! We own all the machines to perform the work and since we own the machines and equipment it is easy for us to simply machine the ends of the bars, bend them and weld a tube on for the bushings! It is strong, which cannot be denied, however it is also a more robust and a cost effective process. We do not have to machine a threaded bung, we do not have to fixture and weld in a threaded bung, so two hole operations are ommitted where a possible mistake could be made. This creates a more robust and cost effective product! In the end, in our opinion, the consumer wins! They get a very robust product as cost effective as possible!
The above reasons is probably why not alot of other companies do it! The capital required to buy all the equipment neccessary to perform all the operations would be a major hinderance! And, like most, if the components are simply designed then sources (and especially if they are coming from over seas), the shipping of the components in would be a major overall expense and a significant cost of the bill of materials relative to the raw cost of goods!
Now, to help out those that actually tried to bring some relavent information or offer good questions!
Yes we are concerned about the corrosion causing issues. On things like bridges and stuff, zinc blocks are used for sacrificial anodes. Our first thought is that the zinc plating on our joints will hopefully act like that sacrificial anode and prevent the joints from freezing into the aluminum material. We are in the perfect enviroment to test this out. In NY, our roads are covered with salt from Oct some years all the way through April.
For those questioning the welding of 7075; it is similar to that of welding heat treated chromoly. It can be done, but you must be concerned with the change in material properties in the "heat effected zone", so if you are at home triing to weld any high strength material, be aware of that and make sure it will not be a cause for concern.
Sorry for all of those who are actually triing to learn something and educate themselves on the basics of materials, process, etc. We hope you can read through alot of the BS, take in the facts, and think for yourself. We truely started this post to help educate and help out the entire JK Community.