I was wondering if anyone has or knows of someone who has dropped out the live rear axle out of an FB and replaced it with a half shaft system, in order to gain an indipendent rear end suspension system, reather then the stock semi-indipendent system?

 

Hey... if you want IRS, get an IRS car. The expendature of modding a FB so much isnt worth the resultant performance youd get out of it.

And, at any rate, you can make a live axle handle well with proper tuning.

 

It's funny, I was wondering the same thing, but you'll never get the right answer from the right person. You'll just get conjecture and opinions on the forums.

At any rate, I'm going to give it a shot with my SA and see if the donor pumpkin and subframe will work.

 

This has been talked about here before. Some people have thought about a miata rear end and that would be pretty easy if you are confident in your fabricating abilities. The FC parts could be made to work as well and might be easier because of only three mounting points if you don't count the shocks. You would just have to narrow things up a bit. If you are going drag racing don't bother but for anything else it would be pretty cool. You could end up with a car that feels better over bumps but as said above you can make a live axle work very well.

 

The main reason I need to swap out the rear end isn't so much for IRS, but because of a specific engine swap. I'm putting an engine in the SA that has the speed sensor in the rear diff. Without the diff the engine won't get a proper speed reading.

Hopefully, the donor sub-frame I have will at least help accomodate what needs to be done. Good thing the SA isn't my daily...

 

Depending on what you are throwing in the car a speed sensor should be no problem with any diff. Some ECU's use speed sensors on the input and output of the trannys and compare them. If there is no comparing going on any way of showing the ECU some kind of speed should work. It could be from a simple magnet passing by a sensor each revolution. If the ECU is using this for the speedo then you will have to get tricky. Find out what is being counted by the sensor and try to copy that signal. It may be wheel rpm it may be driveshaft rpm. If its driveshaft rpm then gear ratios need to be taken into account.
Is there an auto tranny in this plan? That is where most speed sensing becomes critical. The engine usually doesn't care if its spinning 3000rpm and going a certain speed but a tranny cares a lot. If not it could be simpler than a rear end swap. You could just adapt the sensors to the RX rear end. The