Can I cut here? (QA1 upper control arm issue)

[72bluNblu]

the directions don't say anything about notching that area? thats pretty lame.

I agree

It should probably be included in the instructions. I've seen worse instructions than what QA1 provides though. All of these cars are a little different, and how much you need to notch that mount depends on your ride height, alignment, and whether or not you've modified the bump stops any. The QA1 instructions kind of make it sound like an easier operation than it really is, "bolt it on and go" kind of deal when adding tubular control arms is really a pretty big modification to the suspension. It's a relatively simple addition, but it changes a lot of other things, especially clearances.

Hotchkis includes the info in their instructions, even though the Hotchkis arms are probably less likely to need the mounts modified than the QA1's because of their design. You can actually see that in the picture, the UCA is actually lower than the clearance they cut on theirs.

 

[MRGTX]

Mopar put out a Technical Service Bulletin for the '73 models for a fix if a car suffered from a loss of alignment. The dealer-fix was to weld a gusset on the UCA mounts if cracks were noted.
So "in general" it could be assumed that some reinforcements in this area is recommend, especially when the car is used on a more performance orientated way.

Has anyone found cracks on the UCA mounting points? My car was a relatively early build (October 72) and I’m not even sure what to look for.

 

[72bluNblu]

Has anyone found cracks on the UCA mounting points? My car was a relatively early build (October 72) and I’m not even sure what to look for.

I haven't found any myself, but there was a thread on it here not that long ago Cracked UCA mounts

 

[RustyRatRod]

I would have fixed that a different way and not cut the CAR, but you got it done and that's all that counts.

 

[MRGTX]

I would have fixed that a different way and not cut the CAR, but you got it done and that's all that counts.

Usually, I agree with this. I go to pretty great lengths to only modify my car in ways that could be put back to stock if I decide to go that way 20 years from now. In this case, it was a tiny piece of sheet metal to trim. There’s no way to safely modify the control arm itself...

 

[72bluNblu]

I would have fixed that a different way and not cut the CAR, but you got it done and that's all that counts.

Usually, I agree with this. I go to pretty great lengths to only modify my car in ways that could be put back to stock if I decide to go that way 20 years from now. In this case, it was a tiny piece of sheet metal to trim. There’s no way to safely modify the control arm itself...

Exactly. The metal trimmed off the car is non-load bearing, it’s a purely cosmetic change to reshape that corner. Changing the control arm to leave that little corner in place, without seriously compromising the strength of the UCA, would be pretty difficult.

I wouldn’t say it’s impossible to modify the UCA safely. Some would be harder to change than others. But you’re messing with a part that can cause a catastrophic failure and loss of control. No thanks.

If a future owner wants the return the car to 100% stock, welding a little chunk of 16 gauge metal onto the car should probably be something they can do. Lot easier than fixing the damage from a failed control arm.

 

[RustyRatRod]

Usually, I agree with this. I go to pretty great lengths to only modify my car in ways that could be put back to stock if I decide to go that way 20 years from now. In this case, it was a tiny piece of sheet metal to trim. There’s no way to safely modify the control arm itself...

Oh yeah there is. But like I said, you got her done man. It's all good now!

 

[RustyRatRod]

Exactly. The metal trimmed off the car is non-load bearing, it’s a purely cosmetic change to reshape that corner. Changing the control arm to leave that little corner in place, without seriously compromising the strength of the UCA, would be pretty difficult.

I wouldn’t say it’s impossible to modify the UCA safely. Some would be harder to change than others. But you’re messing with a part that can cause a catastrophic failure and loss of control. No thanks.

If a future owner wants the return the car to 100% stock, welding a little chunk of 16 gauge metal onto the car should probably be something they can do. Lot easier than fixing the damage from a failed control arm.

I just don't like hackin on the car unless I have to. I know, what he removed is probably miniscule.....never be missed. I would have marked the control arm, removed it, cut a "window" out of that front arm above where that bracket was it was hitting, flipped the "window" around backwards and welded it back in. That would make the control arm convex in that one area and would have cleared the bracket. Again, a LOT more in depth than cutting a small part off, but it would have worked and not compromised the integrity of that control arm.

 

[72bluNblu]

I just don't like hackin on the car unless I have to. I know, what he removed is probably miniscule.....never be missed. I would have marked the control arm, removed it, cut a "window" out of that front arm above where that bracket was it was hitting, flipped the "window" around backwards and welded it back in. That would make the control arm convex in that one area and would have cleared the bracket. Again, a LOT more in depth than cutting a small part off, but it would have worked and not compromised the integrity of that control arm.

Reducing the cross sectional area of the control arm that close to the mount by doing what you suggest would absolutely reduce the strength and integrity of the UCA.

That’s EXACTLY why I wouldn’t suggest modifications to the UCA. That’s not the place for shade tree fixes.

 

[RustyRatRod]

Reducing the cross sectional area of the control arm that close to the mount by doing what you suggest would absolutely reduce the strength and integrity of the UCA.

That’s EXACTLY why I wouldn’t suggest modifications to the UCA. That’s not the place for shade tree fixes.

Well we'll have to agree to disagree. Pretty much why I hesitated to even bring it up. Not everybody does things the same way. When I want to be insulted, I'll start something next time.

 

[RustyRatRod]

Reducing the cross sectional area of the control arm that close to the mount by doing what you suggest would absolutely reduce the strength and integrity of the UCA.

That’s EXACTLY why I wouldn’t suggest modifications to the UCA. That’s not the place for shade tree fixes.

And what if it was made that way originally? Would your internal abacus and slide rule still disagree? I've seen stuff like that done on dirt track cars that see way more stress than his part would ever see and never failed. It's simply all in how you look at something. Not everybody does things the same way.

 

[72bluNblu]

Well we'll have to agree to disagree. Pretty much why I hesitated to even bring it up. Not everybody does things the same way. When I want to be insulted, I'll start something next time.

And what if it was made that way originally? Would your internal abacus and slide rule still disagree? I've seen stuff like that done on dirt track cars that see way more stress than his part would ever see and never failed. It's simply all in how you look at something. Not everybody does things the same way.

Rob, I try not to start crap around here, I really do. But you’re 100% wrong on this, and I’m not going to let it slide just because you think you have more experience and don’t respect my education and background. It’s a safety issue, and you are wrong.

It’s not about “everybody doing things the same way”. What you suggested would reduce the strength of that UCA. Period. It’s not “all in how you look at something”. It’s Physics. It’s metallurgy and materials science. Bottom line is, it’s engineering. Cross sectional area is a basic principle in structural analysis, and if you don’t understand that you’re not informed enough to have the opinion you’ve got.

If something was “that way originally” then somebody figured out it was strong enough for that application. Different applications and suspension designs can have very different strength requirements.

Guys with a high school education don’t design cars anymore for a reason. Experience alone can only take you so far.

 

[RustyRatRod]

Rob, I try not to start crap around here, I really do. But you’re 100% wrong on this, and I’m not going to let it slide just because you think you have more experience and don’t respect my education and background. It’s a safety issue, and you are wrong.

It’s not about “everybody doing things the same way”. What you suggested would reduce the strength of that UCA. Period. It’s not “all in how you look at something”. It’s Physics. It’s metallurgy and materials science. Bottom line is, it’s engineering. Cross sectional area is a basic principle in structural analysis, and if you don’t understand that you’re not informed enough to have the opinion you’ve got.

If something was “that way originally” then somebody figured out it was strong enough for that application. Different applications and suspension designs can have very different strength requirements.

Guys with a high school education don’t design cars anymore for a reason. Experience can only take you so far.

I hear you guy. But your condescension reeks. You're not right about everything. I'll tell you what too, I can call what QA1 did there shade tree. Look where the control arm post is welded to the bushing shell. Were it centered up, instead off to one side BADLY, it would have stood a chance of clearing and no mods to the car might have been necessary. THEY don't get it 100% right either.

And I never bragged about experience here. I simply said people do things different ways man, that's all. DO YOU have a physics and metallurgy meter handy? Probably not, so you're really talking out of your back side here, just as much as I am. You didn't design the control arm anymore than I. You don't know the variances (and there are some) anymore than I. I don't really know who in the world you think you are being so condescending here. I have not done that to you. Were we standing side by side, you'd be missing some teeth right about now. So, with that, I'll put you back on ignore where I had removed you because I really do respect your knowledge, which you have vast amounts of. And you're probably right here, I agree 100%. But your delivery stinks and I don't have to put up with it.

 

[MRGTX]

...
Guys with a high school education don’t design cars anymore for a reason...

Ohhh wait until you drive a Mitsubishi Mivec...