Raise rear up using different springs or 280z isolators better for geometry?

[briann510]

If one needed to raise the rear up of a 240z 1/2-3/4"" would it matter or one way be better than the other if longer 280z strut isolators were used or a different spring? Would the suspension geometry change be the same both ways (ie: halfshaft or cv angle changing with rear being raised).

 

Our car is lowered alot so the left halfshaft is bottoming out on hard launches (even when I had a cv shaft on left side it also bottomed out at full suspension compression) so im thinking to help solve the problem is to raise the car up some to correct the halfshaft angle to be a little more extended (doesnt have to be much). Im just not sure which way to raise it would be a better approach. The easiest ofd course is the longer 280z isolators which I have and would take about 10 minutes to change.

 

Ive also been talking to Unitrax about making some custom length billet halfshafts with Viper/equivelant Ujoints like they do for the Vipers and then not having to raise the rear up any.

[JMortensen]

Why not just shorten a stock halfshaft or have a custom CV shaft made? I had a plan to shorten a stock halfshaft and had it all planned out. Before I did it I decided to go with a CV shaft, but 2126 here did come forward and say that he had done pretty much exactly the same thing that I was planning on doing and had been running his car like that for years. If you look you may find that old thread, probably 3 years old now. Or you could PM 2126 and he might tell you what is necessary.

 

Alternatively you could raise the diff. Seen this done with nothing more than a custom front diff mount and a couple holes drilled in the mustache bar.

 

As a 3rd option you could install some longer control arms in the back. http://www.modernmotorsports.com has them, as does http://www.arizonazcar.com and others.

 

Putting 280 insulators on will raise the back of the car, but won't give you any more suspension travel. The better way to raise the car if you go that route is with a taller spring. I don't think I'd go that way though.

[johnc]

Our car is lowered alot so the left halfshaft is bottoming out on hard launches (even when I had a cv shaft on left side it also bottomed out at full suspension compression)

 

Known problem: http://www.betamotorsports.com/benchracing/R200handling.html

 

Shortenign the shaft as Jon suggested above is the ideal solution.

[briann510]

I have an old thread topic with pictures TonyD sent me of the details of shortening a stock halfshaft in below link, unfortunatly I cant find anyone to do it so far (I went buy a couple custom driveshaft places with the pictures and they said they wont do it) and I dont have the correct tools to attempt it myself.

 

Raising the diff would be easy enough but wouldnt give me enough extra travel for halfshaft I dontthink, but moving the diff to the right 3/4" or a tad more would let me do a custom front diff mount which I need and probably work ideal. My zxt cv shaft conversion didnt work well with this current problem of my now shorter drivers side distance for halfshaft travel, but i may attempt the 300zxt cv conversion since those shafts are much easier to modify and change diff splined ends.

 

Its my damn 4.38 gears again making this problem (carriers 10mm fat spacer has to be moved to opposite side) making drivers side available shaft distance 3/8" + shorter than original.

 

Thanks for the suggestions!

http://purplesagetradingpost.com/sumner/bvillecar/construction%20page-23.html

[JMortensen]

So you haven't found anyone to machine the new snap ring groove? That's an easy one to get past. My solution was going to be to tack weld the end piece on. It's not like you need to take it off to assemble the halfshaft, and that piece doesn't take a whole lot of beating either, it basically just makes sure that the balls don't roll off the end of the shaft. So then all you need is a bandsaw to cut the shaft and a welder to tack the end back on.

[briann510]

I just found an old post where you mentioned doing that and welding the end piece back on. Im gonna do it that way.

 

Thanks!

[JMortensen]

Hey no problem! Just one other thing, I wouldn't take too much off. I think 2126 said he took 5/8". Bottom line is you need it to extend far enough so that the strut extends all the way and the STRUT should be what stops the suspension extending. If you cut it too short then you'll have problems.

[briann510]

Im gonna cut off 7/8" and that should do it.

[blueovalz]

Could you weld a very small "stop" on the axle shaft to limit CV inner race travel toward center of the axle, and then simply peen the splines on the outside of the inner race once the inner race is set in place? Nissan only peens the outside on their ZXT shafts, so it should work here as well. This way, the inner race can be pressed off later if desired.