new from indiana

[Dune junkie]

Cool. I wasn't really thinking about that but sounds like a good idea. Thanks for the advice.

[fabr]

Depends on car/design. Ya gotta clip wherever it takes to prevent what carl described.

[D Walker]

That's the rub right there. If the car is not built right, the axle c as n't be clipped on both ends. If the axle is long enough to not pull apart at full down travel it will surely bang the cups at full up travel.

A arm rear takes care of most, if not all of the problem.

[fabr]

Just another reason I use a arm rear suspension. For nearly all of us the use of trailing arms is not needed,they are cheaper though,  as we "only "want 20 or so inches of travel and just about any rear suspension design will work well. For MASSIVE travel ,then ta's are maybe the only way possible.

[D Walker]

 Zero plung... At that point I would probably move to u joints drivelines. Much cheaper, stronger and less maint.

[fabr]

You can't get a true zero plunge due to deflection of all sorts of things during operation unless it is so overbuilt/heavy it would be useless from a performance point of view.. Some plunge will occur even with zero design plunge. But the very small plunge provided by a cv @ near zero plunge prevents most ,if not all, heat and migration of lube that is the true killer of cv's. IMO. Cv's are plenty reliable if lube and heat is controlled.

[Dune junkie]

By plunge you mean how they float back and forth?

[Carlriddle]

Yes, trailing arms or semi trailing arms.  The distance between cv cup changes as wheel moves from full droop down to where its level with center.  That change is called plunge

[Carlriddle]

Just another reason I use a arm rear suspension. For nearly all of us the use of trailing arms is not needed,they are cheaper though,  as we "only "want 20 or so inches of travel and just about any rear suspension design will work well. For MASSIVE travel ,then ta's are maybe the only way possible.

Travel numbers are limited by axle length and cv angle.  Trail or A arm shouldn't matter as long as TA are set correct, straight across at full droop.  Or did I miss something

[fabr]

No Carl,I missed something.I meant to say that a arms will change rear track a lot and at massive travel  ta's will be a better choice. I have 18" + a bit  actual on new car with a arms and IMO that is about the limit unless building a huge/very wide car. Due to the A arm track change as the wheel "tucks under/in" you lose available cv angle as the track narrows .Ta's don't have that issue .

[Dune junkie]

Very helpful advice so far.

[D Walker]

No Carl,I missed something.I meant to say that a arms will change rear track a lot and at massive travel  ta's will be a better choice. I have 18" + a bit  actual on new car with a arms and IMO that is about the limit unless building a huge/very wide car. Due to the A arm track change as the wheel "tucks under/in" you lose available cv angle as the track narrows .Ta's don't have that issue .

Very true, but TA cars have their own problems. At mid travel the cv's, while straight accros have the front to rear offset. The axle is at its shortest at that point and its strongest.

It's been said before, but people put much importance or value on big travel numbers. Give me a well designed, built and sprung 16/18" travel car, and i will beat a poorly built 24" travel car without damaging parts.

[fabr]

+1 for sure.

[D Walker]

+1 for sure.

With all that said, I am planning on 30+" of rear travel with 0 cv problems.

 

[fabr]

Well,we're glad to hear that..............................