speedtigger

iTrader: (16)

Today I am installing the UMI Performance rear control arm braces for 64-67 Gm A-Bodies.

It seems to be a quality product and a great price, but during the mock-up, I noticed something that I think they should change for the better. I have attached a picture where the brace attaches to the upper control arm mount. In looking at this design, I cannot figure out why they did not locate the bar closer to control arm mounting tab. Having it a 1/2 inch away just ads addition leverage and invites extra stress from the resulting deflection.

I will ask them about this design and ask if this was intended for a reason.

UMI Performance

iTrader: (77)

To be honest from that picture I can't really see anything wrong at all. Bad angle maybe?

There will be slight variance from vehicle to vehicle, this was one of the main reasons we made them adjustable in length. We noticed during our design and the few sets we have installed that each car is a little different.

speedtigger

iTrader: (16)

The bar should be closer to the control arm mounting saddle. Instead, your design has the bar spaced out 1/2 -3/4". The further the bar gets away from the control arm saddle, the more leverage there is to put bending forces on the bolt. This, of course creates a weaker design that will inherently have more deflection and stress on the bolt. The worst case scenario eventual outcome could be bolt failure.

After noticing this, I started looking at some other brands pictures. What I found was that theirs seem to be correct. Here are a couple pictures of Hotchkis and Global West:





However, PMT Fabrication seems to have the same arrangement as your UMI braces:



My argument is that Hotchkis & Global West seem to have a design that is inherently stronger. Now, rather or not this strength difference is an issue in real world usage I do not know. But, having the bar closer to the upper control are mounting saddle is stronger and I would say superior.

I would also note, that there does not appear to be any interference issue that would prevent this design change. So, why not upgrade the design for the next production run?

bczee

iTrader: (12)

It took me a while to figure out what you were referring to (which part of the bar).. I finially figure it out. A picture or other image can help a lot. hope this one does help make the point..

speedtigger

iTrader: (16)

Thank you for creating that picture drawing bczee. That diagram is a perfect illustration. There is just one thing missing in that diagram. That is an arrow illustrating which side is closest to the upper control arm saddle. That way we can demonstrate that the current UMI piece is further from the support of the saddle bore.

bczee

iTrader: (12)

YW.. I have Hotchkis Myself. But I think UMI knows what you are getting to now.

I am really not sure that there is enough stress on the end points that would be worth to be overly concerned about. Might be a moot point ?.. maybe not.. ? Maybe the Guys at UMI could run some stress anlysis on it or something...? But I do get your point.

I guess this will help again. Sorry for the fuzzy picture..

speedtigger

iTrader: (16)

One of the V8Buick.com board members posted some pictures of some Global West Control Arm braces that he bought. They do not match the picture on Global West's website. I am speculating that he got an older design. But, it afforded me the opportunity to show these illustrated pictures of the design differences:

UMI Performance

iTrader: (77)

I looked into this a little bit. We have one car they fit good on and one has a little gap but fitment was good once the bolts were tightened down. We have a 67 Chevelle frame coming in soon so I will try a set on it as well.

I found a thread were others are having the same issue- http://www.chevelles.com/forums/show...=1#post3064927

speedtigger

iTrader: (16)

It is actually not a fit problem I was referring to. It was a design strength improvement. There are some illustrations a couple posts back the depict the exact area.

UMI Performance

iTrader: (77)

Yes I see now what you are referring to. I was a bit confused, we had a customer with a fitment/gap issue around this same time and I automatically assumed it was the same issue. We test fit a few sets and didn't experience any issues... but this wasn't your issue.

As for the design, I don't see this as any issue at all on this item. You may feel different and that is your opinion, no hard feelings. The Hotchkis center line based on the picture is only over a small bit more, the GW braces uses a much narrower piece of tubing forcing theirs closer.

Thanks,
Ryan

speedtigger

iTrader: (16)

It may not be any real world issue at all. I am running them and don't have any plans to replace them. I just felt the design could be improved and wanted to share the opportunity with you.

UMI Performance

iTrader: (77)

Thank you, I appreciate it... now that I actually know what you were explaining, lol.

Thanks again,
Ryan

speedtigger

iTrader: (16)

Recently, I installed my new exhaust system. This system fits in the factory location with offset-offset mufflers. I find that these control arm braces substantially restrict the area available for the cars mufflers. So, I will be replacing them with Edelbrock # 5212 units that more closely matches the original equipment control arm braces for the Grand Sport models.