Miata rear suspension installed

The last while has been spent building the bridge from the Miata subframe to the Triumph frame.  Capped off the widened and moved inboard, Triumph frame rails.  Then added gussets to the top and capped that off as well.  Then started welding in the finished floor.  

Then took the time to do the fun part.  Bolt in the control arms and wheels.  Checking for clearance it looks quite good.  may need to clearance the flange at the rear part of the wheel a bit.  I had left them long when redoing the fender so no problems taking a bit off.  It will depend on where the actual max upper position is.  Still have to check on that.

From inside looks about the same as factory :-)

But underneath it's a whole different structure.  Have the front floor pretty much welded in.

Don't have the shocks and springs in at the moment so I can move the wheel up and down.  The upper and lower mount for it are same as when it was in the Miata so it's simply bolting them in.  Also will probably fit it with a roll bar. Will try to narrow the Miata one.  Will see how that goes.

Differential In The Car

Feels like a big accomplishment to have the differential and suspension mounts (Miata subframe) all in the car. Wasn’t that long ago I was just trying to get the diff into the subframe. It’s not completely finished but the first test fit is looking really good. 

One of the funny things is the Miata brace that goes under the subframe. Once narrowed it looks laughable. I often feel like I am working on a toy car. 

Not a lot of in process pictures. Was just trying to make progress. Can take pictures later. 

Might add that the differential is an E36 medium case. Was looking for something that was a clutch or torsion limited slip that had a ratio of 2.98 or 2.67 ish so it would match well with the transmission I was using (a BMW 5 speed). I do not want it to be revving like crazy at freeway speed. It'll have more than enough HP to start off from the line. I didn't find many differentials in this ratio with an OEM LSD. There were a few but decided to go this way. Wasn't the best fit but oh well. 

One benefit of using the BMW diff is I can buy one driveshaft and get the right ends and just lengthen or shorten it. I had one of these differentials with the clutch LSD in my BMW with a LS1 (400 hp) and I quite liked it. Sadly finding a LSD version proved to be difficult and I settled on a Welded diff for now. Can switch out the guts later if need be.

Subframe About Done

 Has been a month since my last update. Been working to finish up the subframe and some of the body structure. Both are about done. The subframe needs the front mount designed and fabricated to hold the differential and a few tweaks.

Testing the differential

Looking at the subframe from the rear

Looking at the rear diff mount from the front.  With it so narrow there is little room for anything.  A different differential may have fit better.

More work needs done on the body side so it's not ready for show and tell yet. For now here's a few subframe pictures.