fordfan1964

I'm replacing my LCA and UCAs with the Granatelli Motorsports Drag Package. It seems to be pretty inclusive kit.

What are the advantages and dissadvantages to Heim Joints?

I also really love rippin the twisties as well as straight line Drags. Any Recomendations?

Sleeper_08

A rod/heim joint LCA offers better articulation when the car rolls than a poly joint. This not important on a drag strip but is important on corners at the limit. The rod ends result in more NVH in the car and cheap ones can wear out pretty fast on the road.

I've ran poly/poly Steeda LCAs last year but this year am going to switch to the UMI poly/rod set as the back end just didn't feel right when at the limit. http://www.stranoparts.com/partdetai...D=99&ModelID=5

The poly end goes on the chassis and the rod end goes on the axle.

This is also a prettty good article to read http://www.cherod.com/mustang/HowTo/LCA%20_adj.htm

Texotic

The reason that Heim Joints feel better at the limit is because they offere a wider range of motion than rotation about one axis. All that means is that not only do they swivel like the poly bushings, but they have also have the ability to move side-to-side, eliminating bind. If your axle is being pushed really hard to the right side, the extra stresses on the sides of the poly bushings make it harder for them to move like they should, this makes it a bit more unpredictable at the limit since you never know when the lateral stress will decrease enough for them to move freely again. In a Heim Joint, however, there is virtually no rubber or plastic in between the sleeve and joint, so all vibrations are transmitted directly to the chassis instead of being mostly absorbed by a poly bushing. This makes them much less liveable on a street car since they are less forgiving and much louder.

For drag racing, poly bushings are fine since you aren't introducing lateral loads on the rear axle. Since you're getting a drag pack, that tells me you care a lot more about going in a straight line than turning, so the added benefit of a Heim Joint probably won't be able to offset the increase in NVH.

A lot of us use a combination LCA with Poly bushings on the chassis side and Heim Joints on the axle side. This allows half of the NVH shielded by a full poly/poly setup into the chassis, but that is still considerably less than a heim/heim setup. Also, since there's only one poly bushing, the bind that does occur isn't near as bad as with a poly/poly setup. The combo LCA's are a really good compromise for a street car.

Norm Peterson

I'll second (third?) the idea of poly/rod end LCAs. One rod end removes the "bind" caused by the body rolling over in a turn due to suspension compression on one side and extension on the other. It will provide a less "stiff-legged" ride and less side-to-side head toss going over one wheel bumps or other situations where the two rear wheels do not move up/down at precisely the same time.

A poly/rod arrangement gets rid of a lot of the "bind", though not all of it. But it's a good enough compromise for most applications and particularly so when street driving is included.


Norm