Yup, You can't extend the shaft much beyond stock before you get into harmonic distortion and it will self-destruct. You'd have to increase the diameter of the shaft to be able to go longer - which won't work in the torque tube - so the carbon fiber deal is the only option.

That is good to know! I was relying only on the person who was going to be selling my the carbon fiber driveshaft so I felt that maybe he was just trying to sell me but this reassured me that he was telling me the truth. Thanks alot

Here's an online calculator:

http://www.wallaceracing.com/driveshaftspeed.htm

You can also hit the Dana corp web site for additional info.

http://www2.dana.com/expert/wc.dll?cvsp~Decrits~

PS, some call it 'driveshaft critical speed'.

do you have any detailed photos of the rear suspension rockers? Specifically how the pivot point is designed and how the rocker is attached at that point?

What is with all these cool trucks being built?
Maybe I am just jealous.:rolleyes:
Kevin

Keep the trucks coming, that should be a total bad ass when done looks awsum:thumbsup:

I don't have any pics right now of the rocker arms but i can try to explain how it works and how i have it setup. I designed the rocker arms to have right around 1.6:1 ratio plus you have the ratio of the lower control arm which puts me just under 2:1. I had to use short stroke shockwaves because i was limited with space since the rear rails were narrowed to accomodate the upper control arms. They have a 3.5" stroke so i am getting right about 7" of lift. The rocker arm pivots off a custom made rod end. The rod end screws into a welded in bung. The welded bung was reinforced with some 3/16 thick plate on top of the .120 tubing for some extra support. When you do a rear suspension setup like this you have to take into consideration your what your ratio is to what the shockwave weight capabilities. For example: a sleeve style shockwave has a 1500lbs per bag weight capability. So you take you ratio which in my case was 2:1 you have to divide 1500 by what your ratio is. So that left me with only 750lbs per bag which is a little close so that i why i decided to run convoluted shockwaves instead. They have a 2140 lbs per bag. I hope i answered some or your questions not sure if i did though. I will be out of town for the next couple weeks so when i get back i will try and get some pics for you if you still need them.

Josh

That is some great info! thanks alot

Josh

to have a pic of that would be nice, but not a necessity, so if it is no big deal to get a pic I would appreciate it.

There are more than a few rockers out there I have seen that didn't use some sort of heim/rod end and that is a big mistake (they just use a bolt thru a sleeve or something for pivot) and I am interested in seeing other's ideas when they "do it right". sounds like you did it right.

When i get back i will get some pics for you. The whole cantilever suspension setup isn't very difficult once you understand a few key points. When you deal with a solid axel rear end it is pretty simple because there isn't many variables but when you deal with IRS it becomes more complicated because you have to considers the limited space of the upper control arms, make sure you clear the rear axles, and that you take into consideration the angle of the lower control arm. I, by no means, am a expert with this type of suspension setups and suspension in particular and there might be better ways to do it but this is how i think it should be done and function properly. Anyways sorry for talking your head off.

Josh