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Boxing in Lower control Arms.

PostPosted: 01 Mar 2007 20:19
by 98Hawk
Going to help my brother on his suspension project. He is getting all new bushings and such. I have an article (if I can still find it) on boxing in the lower conrol arms. Car is a 70 challenger with a 440. Is it worth doing this or should be just change the bushings and be done?
Thanks
Brandon

PostPosted: 01 Mar 2007 21:01
by dave-r
I really don't think it is worth it. In fact it probably adds unsprung weight.

There is a lot of business these days in beefing up old cars so they handle well.
90% of it is Bull.

All you need is to use uprated springs/torsion bars and especially sway bars front and rear. Then add chassis connectors and if your car did not come with them you should also add the plates that box in the corners of the chassis as shown in this diagram below. You can get them from Auto Rust Technicians.

Finally use poly bushes all around the car. The trans mount is optional (if the engine is not ballanced well) but don't forget the rear spring bushes.

PostPosted: 02 Mar 2007 15:18
by Eddie
I wondered about that as well. A lower control arm is a pretty stout piece of metal. I would think many other places would "flex" before they would.

PostPosted: 03 Mar 2007 11:54
by 98Hawk
I know it would add unsprung weight, but there is always a trade off. I will be doing subframe connecters as well. The car does have a front sway bar but I don't know how big it is, I don't even know about the rear. But all of this is in the plan

PostPosted: 07 Mar 2007 16:34
by Eddie
Cool, keep us posted! I "beefed" up the suspension on my R/T and it was well worth it. I remember driving my friends 71 383 Cuda back in the seventies and it handled terribly with a lot of body roll, mushy suspension, loose front end ect.. It was fast in a straight line but you had to slow down for the curves! The trade is slight and those lower control arm reinforcement plate weighs maybe 10 oz. not a lot to worry about, hell my wife weighs lierally 500x that amount!

PostPosted: 07 Mar 2007 16:59
by dave-r
My LCAs are not boxed and nor do I use the thicker tie rods that the performance people selling you these things claim you need. And I bet my car would corner as good as the best Challengers out there.

According to the people pushing these daft ideas you need their parts because tie rods break and LCAs flex every time you go to the shops in the car. Probably true if you push the car hard off-road on dirt and rocky tracks. But not on pavement for christs sake.

Your main problems with the LCAs is controling movement at the bushes.
The ONLY way you could stop the LCA moving around would be to use a solid bush at both the pivot and the end of the strut at the K-frame.

Without doing that you are completely wasting your time boxing the already strong LCA.

But you cannot use solid bushes if you want to actually use the car. The best you can do is fit poly bushes to the strut and pivot as well as the UCA.
They are very firm but there will always be a very slight movement. Boxing the LCA will not stop this movement.

So don't believe everything you read in the American press. The people pushing these ideas are PAYING the magazines to publish this tosh.
Think for yourself and think like an engineer.

PostPosted: 07 Mar 2007 18:11
by Eddie
Dave, dont hold back, tell us how you really feel! Sometimes I read these explanations and just laugh because he is right you know, I am laughing at myself because I am an addict and like all with an addiction anything to enhance the buzz is justifiable, even if it's all in your head. I envy those that make do with little and have the same enjoyment as those that have the best of everything. :lol: MoPar Actions Green Brick was the epitome of Dave's theory on the suspension. It was almost all stock Valiant. They beat a lot of high dollar cars with it.

PostPosted: 07 Mar 2007 18:12
by dave-r
That is called a "Robson Rant" that is. :lol:

PostPosted: 14 Mar 2007 11:28
by 98Hawk
OK. I guess that all makes sense. Just how well can you get these cars to handle? I think he wants it to corner like a new sports car. I'm not talking about a Corvette or anything, just wants it to more than hold it's own and make everyone ponder the "Old muscle cars can't turn" mentality.
Thanks guys.

PostPosted: 14 Mar 2007 12:13
by dave-r
My car corners better than a BMW 3-series. Not bad for a 440. All I have done is what I have advised you. The only othere thing would be to fit 17" wheels with low profile tyres.

PostPosted: 14 Mar 2007 16:13
by Eddie
Yeah, wheels and tires make a huge difference don't they Dave? You could even make a Ford product handle well with bigger wheels and tires! :biggrin:

PostPosted: 14 Mar 2007 19:28
by dave-r
Anything but the new Mustang that is. :lol2:

PostPosted: 14 Mar 2007 20:06
by Eddie
The 500 H.P. GT is pretty nice. I think this is the last year for the real GT-40, shame. The new Viper is gonna be the standard!

PostPosted: 14 Mar 2007 21:09
by dave-r
The 500hp job is only OK in a straight line. It has a normal axle for gods sake.
I can't believe than in this day and age they are trying to sell a performance car with a truck axle instead of independant rear suspension.

Every European test of it gets the same bad press. It is all over the road on a circuit. It is giving American cars an even worse press over here than they normally get. :(

Aparently Ford wouldn't fit IRS because it would have put the price of the car up??? :hmmm: :bonk:

PostPosted: 14 Mar 2007 21:41
by christer
dave-r wrote:I can't believe than in this day and age they are trying to sell a performance car with a truck axle instead of independant rear suspension.

Every European test of it gets the same bad press. It is all over the road on a circuit. It is giving American cars an even worse press over here than they normally get. :(


You better get your Chally in running condition soon, Dave. Your comments give me the impression that you almost have forgotten that you own one of these babies yourself. :p:

PostPosted: 14 Mar 2007 23:06
by Eddie
That's weird, doesnt Ford's Sport Utility Truck Like vehicles use IRS? So, Ford found it "better" to equip their trucks with the latest IRS but give the performance car an old Hotchkiss Truck Rear? What will the new Chally have? The Benz sourced 8.8? which is a CV jointed rear I think. Same as whats used in the 300C and Dodge Chargers.