I've just replaced my Hotckis units that were heavy as hell. 10lbs each or more for one. Swapped in some adj tubular double rod end Comp Engineering alum LCA's that weigh 2lbs each.

Is there any benefit to having a lighter LCA? Is that considered unsprung weight? How will it affect wheel hop as I had none w/ the boxed units, haven't driven yet w/ the new pieces (down for the winter). Just wondering as I see many folks go to tubular I guess for clearance purposes.

Thanks.

 

Well the overall weight and unsprung weight reduction is a benefit.

However, your major improvement is lack of bind in the rear suspension during cornering. While your car has a "live" axle, it still needs to be able to articulate some (each side of the car needs to be able to move somewhat independently from the other). Did you notice that the stock rubber bushings were not solid, but appeared star shaped, so that the arms did not bind? Those poly bushings in the Hotckiss rear LCAs don't like it when the car leans some under heavy cornering. Where it get nasty, is when you are corning hard and then hit a bump. The bushings bind and the rear of the car immediately tries to come around on you.

With spherical bearings or rod-ended links, there is no bind. Did you say 2lbs for each arm? Sound very light. I certainly would want the rear LCAs to be very strong. My tubular Global West rear LCAs with spherical bearings probably weigh about 8lbs each.

 

Thanks for the info. 2lbs each. Well I took one off to weigh it again and the scale reads 2.89lbs. They are really light. They came of my partner's car we traded. LS1 w/ 500fwhp w/ the a 150 shot.

Won't be able to try them out til spring though. But when in his car they were quiet and didn't bind for nothing. That may have been a problem w/ him and launching.

Thanks again.

 

Anyone have a picture of the spherical bearings and the rod ended links? I know what the rod ends look like but the bearings?

 

Go to Global West Suspensions at "http://www.globalwest.net/". They have some photos of the rear LCAs with spherical bearings.

 

Cripes! 8, 10 lbs each? What a waste of metal! (I won't even mention the obvious lack of Engineering in the designs.)

My 2 lb aluminum LCA's were strong enough to bend my axle when I crashed backward into a hillside at the track this summer. How much stronger do they need to be?

 

Small off topic here - hey Jon, how did you manage to register for this forum before PCs were even invented?

 

LoL, now that is odd... Must have been on a DEC PDP machine back then, or maybe the same Honeywell that Al Gore used to create the internet with.

 

Jon A,

Sorry to hear you crashed your car and bent the axle. I guess the aluminum LCAs are pretty strong when subjected to compression forces.

The estimate of 8lbs each for the GW LCAs was probably too much. 5lbs each is probably more accurate. I handled Hotckiss LCAs and the Metco solid aluminum boxed LCAs and both of these were much heavier than the GW LCAs.

On a vaguely related subject, I had an intake valve snap on me on a BME aluminum rodded Pontiac Super Duty 455 years ago. The rod as completely unaffected and was flexible enough to save the crankshaft and bearings! However, the iron head was complete toast. It is amazing what aluminum can do to steel, under compression forces. Unfortunately, good alloys are required to hold up under repeated stretch cycling from tensile forces.

Rick R

 

Don't you guys know I'm on the cutting edge of technology? I never get credit! For example, Al Gore would not have been able to invent the internet had I not first invented the home PC!

Rick,

These are 6061-T6511 and are actually stronger in tension than compression (assuming both ends pinned for a buckling calculation). Did you read the links? You could chain 15 F-Bodies together and hang them from a set of these. With about .85" or so of thread protrusion the pullout of the rod end is about equal to the ultimate tensile strength of the arm. Strong enough...and much, much stronger than the stock LCA's.

 

I have the LG aluminum LCA's and PHB with double rod ends, and they survived a laterat trip across the rumble strips at MSR yesterday.

 

Just for reference my stock LCA's weighed 4.25lbs each and my G2 poly/rod LCA's were 3.75 lbs each.