Hi there, for the next project my son & I are looking for info on the IRS under RX7 or aBMW.Anyone with experience or exposure? Is the RX7 a Ford 8.8 unit? The spline count on axles? Overall width? Bolt circle? Thanks any info on either setup is appreciated.

Forgot to state that the car will be a tube framed, widened & lengthened Series Alpine w a Volvo Turbo Ford 2.3-2.5 4 cyl & 5spd. I have a cple of jag rears but want to look at the RX & BMW onfo.Thanks, Will Potter

Wilfred, Here are pictures of Series II and Series III. Turbo models used 8" ring gear.  Or my idea of Toyota IFS for IRS:    
                     http://forum.britishv8.org/read.php?3,22861

Thanks Jim; interesting idea for the Toyota IFS. Is this the same diff as the trucks? They make tons of after market stuff for truck axles. WP

You can get an 8.8 irs from a mk 8? Lincoln. I was at the local pullapart about a month ago and there were 3. It looks likethe whole assembly would drop out but not sure how heavy it is or easy to mount.

Wilford, The link alongside the pictures tells everything about the Toyota 7.5. Robbie, the 8.8 is used by RX7 racers but the axles are custom and expensive.

Wilfred and clan, "if" you can use aftermarket,  930 Porsche CV's and axles, this saves $'s and opens-up length and strength possibilities.  Onward, roverman.

That's what I ended up using... 930 style CV's.  The Drive Shaft Shop in Salisbury, NC will do them any length and provide an adapter plate to convert to whatever your diff flange is.  They can also match most stub axle sizes and spline counts.