Aluminum spindles?

[Larry]

I'm considering purchasing either aluminum or steel spindles from colemanracing.com

The tech guy says they've used them in 2800 lb. cars. I'm a long way from completing mine, but I would roughly guess it will weigh in the 2200 - 2400 lb. range. I heard the C6 is using aluminum spindles.

This project will be both street-driven and track raced. Does anyone who has experience with aluminum spindles have any recommendations either way? Thanks.

[parsonsj]

Larry,
Aluminum is a marginal material for such duty. Aluminum fatigues very quickly compared to steel. My aluminum spindles passed an FEA test, but just barely. If I were to contemplate putting normal driving miles on the car (say 100,000 miles over 8-10 years) I would have switched them to steel.

Ask Coleman Racing how many cycles the part can endure before failure at 2800 lbs. Racing puts far fewer cycles on a part than street driving since cycles is a function of time under duress rather than the ultimate force it absorbs.

jp

[Larry]

That's good enough for me, not to mention steel being less than 1/2 the cost of aluminum. I'll use aluminum for UCAs/LCAs. Thank you.

[parsonsj]

I'll use aluminum for UCAs/LCAs.

That's actually a worse case for us hot-rodders. Making control arms usually involves welding. Welding aluminum will undo any heat treating leaving the strength of the resulting part somewhere around the normalized number. That can be a difference of a factor of 5 depending on the alloy.

If you want to have lightweight and strong control arms, use 4130 steel and TIG weld them.

jp

[MoeBawlz]

what about a CNC control arm? might that work out?

[stanglou]

cnc looked to be a god option for my front suspension until I started looking at the cost. The arms I designed were very strong, and light for how beefy they had to be. The problem was they were about 600$ a piece, and that was for a run of ten sets. needless to say it is possible, but expensive. if they are good enough for f-150 race trucks they are good enough for a 3000lb mustang...

Check out these guys 97 and up f-150 upper arms.
www.camburg.com (http://www.camburg.com)

[Steve Chryssos]

Well, I've got forged aluminum C4 vette spindles on my 3200lb car. My FEA computer was at the dry cleaners so I just slapped 'em on and went curb huntin'

So, I guess the first question is are the Coleman spindles forged?

[Mean 69]

No, the Coleman units are not forged. And that is a very big difference, whittling a critical part out of a billet of aluminum, is clearly not the prefered way to go, but it can be done (as John's project shows). The circle track guys expect to break parts, and the critcal parts are inspected closely on a regular basis. Most street cars don't have this as a normal process.

The steel spindles are very, very tough. We have one that we were considering using, but it was not worth the compromises in terms of geometry, so we are going a different direction. I will say though, you'd be hard pressed to make anything for anywhere near the low cost of the Coleman units.

Mark

[MoeBawlz]

Well, I've got forged aluminum C4 vette spindles on my 3200lb car. My FEA computer was at the dry cleaners so I just slapped 'em on and went curb huntin'

So, I guess the first question is are the Coleman spindles forged?


Yah I have the same as you. But as far as CNC peices they should be weaker than forged right?

And didnt Ford make CNC control arms to fix their problem with the Ford GT?

[Larry]

The UCAs I'm considering using have a steel BJ plate sold by hrpworld.com as "version 2". The only welded part (that I can tell) is the steel BJ plate. That's at least for the UCA. One LCA I'm considering is welded 4130. also sold by them.

[Mean 69]

The stuff Hoerr makes is probably just fine for the street. They predominantly make suspension systems for GT1 and Trans Am cars, which are basically the baddest boys in the front engine sedan road racing arena. Plus, they are terrific to work with, I bought my rear shocks from them, and also my front calipers. Their whole team is terrific, they are very helpful in one-off applications and try to point you in the correct direction.

The spindles they make are derivitives of the Sweet road course spindle, I am not sure Sweet even makes them anymore, but when I was inquiring about them, this is what they told me. I am pretty sure it is very much like the Coleman unit I have, and if so, it is really strong. I'd take a serious look at the LCA's, I have not seen them in person, I do know of the design, but the race car guys tend to make stuff that is "good enough," meaning as light as possible without breaking. No question, their stuff works on the track.

Mark