73C34me

Anyone drill holes in an effort to reduce the weight of stock upper control arms? They appear beefy, thinking of using a 1-1/2"ish hole saw to drill an area out of the center of the horizontal triangular area. Then perhaps. Couple of 3/8" holes int the vertical lip area close to the cross shaft. I have seen this done years a ago and wouldn't do it on a daily driver. The aftermarket lite weight arms seem slightly flimsily and expensive for the minimal savings in weight. I have tubular lower arms with the mono spring conversion.

cagotzmann

Anything you take out of the control arms you will never be able to notice or measure anything in performance gains. You will get more performance saving running 1/2 tank of gas. Its a waste of time thinking this one change would be helpful. What is your final weight you want to reach, and where are you at now ?

flyeri

Or just take the spare change out of your pocket.

cv67

Heck no I wouldnt do that.
Bet GM put just enough metal there to be stable thats it
Not to be sarcastic but youll never see anyone do that to their roll bars, scattershields etc. Look somewhere else for weight, some of it is "good"

Alan 71

Hi,
Probably the most famous of the Pontiac Catalina "Swiss Cheese" Super Stock cars…. note the control arms!
Regards,
Alan

Strokemyaxe

Are you not worried about reducing the structural integrity? Seems to me, if you are going to such extreme measures to reduce weight, you are likely pushing this car to its limits. But if you are pushing this car to the limits, would you really want to chance the arms buckling/breaking?

MCMLXIX

When drilling holes in sheet metal, drill a smaller hole and flange it.
It makes it lighter and stiffer.
Two smaller flanged holes in the indented center part between the legs might even make the A arm stiffer.
Drilling holes in the leg part of the arm seems like a bad idea.

diehrd

I would just buy a set from TRZ , lighter by 12 pounds , stronger and better camber specs .

And weight loss is incremental I saved 100 pounds on breaks and control arms .

MotorHead

Lay off the Twinkies over the winter months and you won't have to drill any holes

BOOT77

TRZ upper I think are about 6lbs each and stock are 9lbs, so they save you about 6lbs total for both uppers.

AW IR C3

The trouble with the catalina and all copycats of this is that the holes are not considered in the engineering process. I'm sure whoever came up with the idea back in the day worked on aircraft during WW2 and saw the structural air-frame with holes in ribs to reduce weight. 2 differences here; 1. the air-frame is designed that way 2. the holes have a ridge line around them which actually makes that structure stronger than if there were no hole in the first place as the stress load is distributed *360 instead of linearly. Just drilling holes weakens the structure tremendously.

See the difference with the ridges

7t9l82

I know lots of guys waay back that swiss cheesed parts on drag cars some would pull the front wheels on every run ,do it dozens of times then a suspension part failed or a frame would fold up.any of those guys today would tell you find a better way.
The little weight saved is minimal a set of aluminum calipers from will wood bolt right on and one caliper will save more weight than all your holes.

73C34me

Great responses guys thnx. I tend to overthink sometimes & always budget focused!

diehrd

That's why you do upper and lower

BOOT77

lower is less loss

diehrd

I weighed them on our digital nos bottle scale . Old vs new TRZ was 12 pounds total all 4 if i remember right plus the aerospace breaks lost me 88 ,I pulled 100 lbs total on those 2 mods.

73C34me

Very nice are the brakes for drag use only?

diehrd

Nope they are slotted vented rotors for street use. 4 piston calipers and they stop the car at least twice as well as the stock set up.