onepointone

i was reading a grassroots mag. that was laying in the back of my friend's car. they had an article on junkyard finds. i was reading the mazda section, and they said something along the lines of "although no we dont know of anyone doing this, messurments show this swap holds promise" i remember reading something about it, but couldnt find the post. has anyone messed around with this idea? i dont know if miata's have lsd's or not, but wouldnt the IRS make it worth it? any thoughts on this?

Manntis

I'm looking into this as well. I've heard complaints that the miata diff is a bit weak, and not a lot of shops want to do the fabrication required for the install, but it sounds like a fun project nonetheless

onepointone

well arent the diffs. interchangable between miatas and rx7's? i met a guy at the local autox with a turbo miata. he showed me a time slip that he ran a 12.6 (forgot the mph) and he was running the stock rear end. i think thats pretty impressive for a stock rear end to take that much abuse.

Manntis

I can't see diffs being interchangeable between an IRS and Live Axle pumpkin... but stranger things have happened.

fatboy7

IIRC the 2nd gen 3rd member can be swapped over to a miata with some fabrication, and that they take a lot more abuse. I'm sure if you were going to swap the entire subframe from the miata, it wouldn't be too hard to do.

Defprun

This swap would be a wet dream. I know the solid rear axle "teaches" drivers how to dance on the edge of losing control...but having actual increased control of the rear-end would be a welcomed change from spinning out all the time.

inittab

Here's a little howto on swapping in a Miata Torsen diff into a 1st Gen live axle.

I saw that article too and recently I peeked under a Miata and I must say, it looks pretty similar to the 1st Gen construction under there. The IRS is a frame construction that mounts to the unibody. Without taking any measurements it looked pretty doable to me.

--Bob

Defprun

Are we talking about the fully independant susp from a miata? Or just the diff?

inittab

both actually.

You can swap in a Miata Torsen diff fairly easily (see link) OR for those that are more adventurous swap in the whole IRS. I've never seen the IRS swap but like I said it looks like a reasonable job for someone with some welding gear.

--Bob

toxic_d

anyone wanna send me an IRS rear end from a miata and i will do it and let you all know how it goes...

toxic_d

what no takers???

RE Matsuda

I saw that RE Amemiya had done the Miata LSD swap into their SA. This also opens up the options of getting the KAAZ or Cusco LSD for the Miata, which are much better quality than the factory units, with a larger diameter clutch, more pinions, and better oil grooves. Plus you can get 1.5 and 2-way locking abilities.