Aluminum suspension parts

[93redATX]

After fighting with rear suspension parts on Jason's (MilTownSHO) car today, I came up with an idea. How feasible would it be to make duplicate suspension parts out of aluminum for pieces that are discontinued by Ford? I am friends with a tool&die guy that can take precise measurements and things of that nature, as well as actually build the parts.

Moving along, I know of some cars that use aluminum extensively for suspension/subframe parts, with no ill effects to my knowledge. Granted, I'm basically just testing out this idea and haven't done really any research on it yet.

Does anyone have any input on something like this? If this would come to fruition, I would also like to know what any suggestions would be as to improvements over stock parts (in that sense, I wouldn't need any type of permission from Ford either if this came to be and parts were sold commercially).

Just guaging input; I'd really like to hear what you guys have to say

<small>[ December 31, 2003, 11:38 PM: Message edited by: 93redATX ]</small>

 

[MilTownSHO]

You know I'm interested after today!

 

[RJ-92]

Sure you could do it. But it would be rediculously expensive.

 

[Machspeed]

Not to mention the ride harshness.

 

[93redATX]

RJ-92:
Sure you could do it. But it would be rediculously expensive.

That's what I was thinking. I know the price would be up there, but once the R&D is done and there is a program for the machines to mill the aluminum parts, production wouldn't be nearly as time consuming. Then again, the benefits wouldn't be worth it to most people, thereby also ruling out any semblance of mass production (although I could see people who use their cars on the track springing for something like this provided it was well-made and reasonable for what it is).

Not to mention the ride harshness.

How would aluminum suspension parts affect harshness? It wouldn't change the ride vs. a stock setup, provided you were using the same type of bushings. For example, if you had all the stock steel control arms, strut rods, trailing arms, etc. with stock rubber bushings, and compared that setup with all aluminum parts while still utilizing stock rubber bushings, there shouldn't be a change in ride quality.


Are there any suspension/subframe parts, other than the knuckles, on Gen 3's that are aluminum?

<small>[ January 01, 2004, 08:19 PM: Message edited by: 93redATX ]</small>

 

[Hack]

Of course cost would be a factor, but I would probably be interested. I am all about lighter weight!

 

[gmorrell]

Are you thinking of making a billet Aluminum rear knuckle?

Interesting idea, there are some materials issues to consider:

The front (and rear) Nodular Iron knuckles use pressed-in wheel bearing races. Steel bearings and Iron knuckles have similar coefficients of thermal expansion, so you can press-fit bearing races and expect them to stay where they belong.

The '96 and up Aluminum front knuckle uses a wheel bearing assembly that's retained by a steel plate and three bolts. Reason being is that Steel bearings pressed into Aluminum substrates don't stay in place due to the different coefficients of thermal expansion.

Yaa, somebody is about to point out that the transaxle bearings are Steel races in an Aluminum case. Yep, you're right, but they're not pressed in, they're free flating in the case bores and the preload is set by shims: Different application, different thermal and mechanical loads.

Wheel bearings also see a lot of heat, much higher then a transaxle. In racing, its not unusual to see wheel bearing temperatures that will cook good synthetic grease. And unlike the transaxle, wheel bearings don't have circulating lubricant to remove the heat, the heat just sinks into the knuckle.

Not saying you can't do it, but there are some engineering and materials hurdles to overcome, and I doubt your tool&die friend has the finite element analysis skills for this project. You don't just take a high Nodular Iron suspension part and duplicate it, dimension-for-dimension, in Aluminum. It won't be as strong, you'll need to add a lot of material, and in the right places, or it will fail, and you'll be sued. eek!

<small>[ January 01, 2004, 10:01 PM: Message edited by: Gary M. ]</small>

 

[93redATX]

Gary M.:
Are you thinking of making a billet Aluminum rear knuckle?

Interesting idea, there are some materials issues to consider:

The front (and rear) Nodular Iron knuckles use pressed-in wheel bearing races. Steel bearings and Iron knuckles have similar coefficients of thermal expansion, so you can press-fit bearing races and expect them to stay where they belong.

The '96 and up Aluminum front knuckle uses a wheel bearing assembly that's retained by a steel plate and three bolts. Reason being is that Steel bearings pressed into Aluminum substrates don't stay in place due to the different coefficients of thermal expansion.

Yaa, somewbody is about to point out that the transaxle bearings are Steel races in an Aluminum case. Yep, you're right, but they're not pressed in, they're free flating in the case bores and the preload is set by shims: Different application, different thermal and mechanical loads.

Wheel bearings also see a lot of heat, much higher then a transaxle. In racing, its not unusual to see wheel bearing temperatures that will cook good synthetic grease. And unlike the transaxle, wheel bearings don't have circulating lubricant to remove the heat, the heat just sinks into the knuckle.

Not saying you can't do it, but there are some engineering and materials hurdles to overcome, and I doubt your tool&die friend has the finite element analysis skills for this project. You don't just take a high Nodular Iron suspension part and duplicate it, dimension-for-dimension, in Aluminum. It won't be as strong, you'll need to add a lot of material, and in the right places, or it will fail, and you'll be sued. eek!

Thanks. This is the type of input I'm seeking, since I don't know too much about metals and such. I wasn't thinking of making anything at this time, just what the feasability would be to create some aluminum suspension parts in general.

On the topic of knuckles, though, if a rear knuckle were fabricated, wouldn't it be possible to then use a similiar (to the front G3)setup where the bearing assembly has a plate that bolts to the knuckle? Also, would any design of the knuckle have to be radically altered due to the strength differences between aluminum and cast iron?

 

[Bizzy]

waht about taking rear knuckles off a gen 3 or 4? Are they aluminum like the fronts? I've never looked at a gen3 or gen 4 that close, but I would venture a guess that the might be aluminum only cause of ever increasing EPA MPG numbers. The AL are lighter and the lighter components mean better mileage right?

Anyone know if the rear knuckles of gen 3/4 disc could be used on a gen 2 if they are AL?

 

[93redATX]

netviper:
waht about taking rear knuckles off a gen 3 or 4? Are they aluminum like the fronts? I've never looked at a gen3 or gen 4 that close, but I would venture a guess that the might be aluminum only cause of ever increasing EPA MPG numbers. The AL are lighter and the lighter components mean better mileage right?

Anyone know if the rear knuckles of gen 3/4 disc could be used on a gen 2 if they are AL?

Gen 4 wagons are the only ones with rear discs, FWIW. The rear knuckles may well be aluminum, though, since the front ones are shrug

Maybe I'll jack my mom's car up tomorrow and pull off one of her rear tires and check it out thumb

 

[SHODWN]

93 to present rear knuckles are ALL the same. Made of 2 ton steel. If there was something else that was AL it too would be on the PLUS. Nothing really wong with them except they weigh a TON.

Seeing the we stole GTP arms why not the knuckles? are they lighter or better?

 

[Bizzy]

so you have a set of gen3 knuckles on your + already?

 

[Todd TCE]

Some of this just begs the question; why?

Speaking from someone with way too much aluminum on his hands I can tell you that the trade offs are not all you think they are. To get the strength you need you'll add in a lot of material and the weight will be at or near the stock part. And if you plan on welding any of it, well forget it unless you are prepared for constant inspection and repairs or properly heat treat it after welding.

If you really have the time and money to blow in such foolishnes why don't you consider buying a small race car like a FV, FF or something for under $8k and then you can play all you want. And if it breaks you can still drive the SHO home. Pulling the broken car on a small trailer.

 

[F-22 Raptor SHO]

The frames of Cannondale bikes are fatter than equivalent chrome Moly bikes for a reason...and its not for looks. Stick with the steel.

 

[billyshoe]

Has any body used a frt. alum. knuckle one a gen one? I realize it would require a custom lower arm. I have looked at the gen. 3 knuckles and found the dimensions have definite interchange posibilities with the exception that the balljoint designed into the knuckle is now inverted. This raises the center of the ball about 2". What effect would this have on geometry, and could it be delt with.? Would the gen 3 knuckle in be too much of a compromise in strengh? After all they applied it to the gen 3.

 

[gmorrell]

billyshoe:
Has any body used a frt. alum. knuckle one a gen one? I realize it would require a custom lower arm. I have looked at the gen. 3 knuckles and found the dimensions have definite interchange posibilities with the exception that the balljoint designed into the knuckle is now inverted. This raises the center of the ball about 2". What effect would this have on geometry, and could it be delt with.? Would the gen 3 knuckle in be too much of a compromise in strengh? After all they applied it to the gen 3.

First, read this thread.

I doubt raising the ball joint will noticeably alter suspension geometry; this is a Taurus, not a Formula 1 chassis. If anything, it might actually reduce the camber loss in bump a bit, which is an improvement. After the LCA goes level, camber starts to go positive as the suspension bumps further, which is bad, so reducing this effect is a benefit.

Strength won't be an issue. If you get to compare the Iron and Aluminum knuckles side-by-side, as I have, the Aluminum unit is much beefier. Sections are thicker and wider, there are more webs, more gussets, etc. Ford did their homework on the Gen 3 knuckle.

 

[billyshoe]

I understand all you are saying, these are basic answers I need to hear at this point. I have spent many hours figuring the factors involved involving brake component fitment, wheel fitment, ect...aside of other details, have still kept the idea alive alhough now inactive. I am not going to pretend that I know much about suspension set-ups. You mentioned "sued" in a privious message-it rang a bell. There are very expensive cars at those track events.