Login Register Sign up for the GRM e-newsletter

Login to post Forums » Grassroots Motorsports » Early Miata Option Package Question
  • Woody

    Jan. 21, 2010 7:58 a.m. Woody SuperDork

    This morning, I looked at a ratty but completely original 91 Miata as a parts donor. It's got alloys, but manual windows and a non power antenna.

    There's no way that this car would have been equipped with a viscous LSD rear, correct?

  • unevolved

    Jan. 21, 2010 8:09 a.m. unevolved Reader

    It could... I found a LSD in one of my track cars at work (92) that we all thought was stock. Only thing that makes sense was it was stock.

  • jrw1621

    Jan. 21, 2010 8:10 a.m. jrw1621 Dork

    Reference for this and future:
    http://www.miata.net/faq/miatachanges.html
    http://www.miata.net/faq/america/index.html

  • Keith

    Jan. 21, 2010 10:02 a.m. Keith SuperDork

    The viscous LSD was a stand-alone option. You can't tell if it's in the car by looking at other things. But you can spot one visually - look at the stub shafts coming off the diff. If they're different on each side, it's a VLSD.

  • splitime

    Jan. 21, 2010 10:09 a.m. splitime Reader

    Keith wrote:

    The viscous LSD was a stand-alone option. You can't tell if it's in the car by looking at other things. But you can spot one visually - look at the stub shafts coming off the diff. If they're different on each side, it's a VLSD.

    You can also call mazda directly and they can use the VIN to check if it was on the car originally, but this doesn't confirm if it is STILL on the car.

    But Keith's way is the simplest... of course it doesn't tell you if the vlsd is still working... but it'll confirm what it is.

  • Keith

    Jan. 21, 2010 11:51 a.m. Keith SuperDork

    To confirm if it's working - and that diff was designed with only about a 40% torque split in the first place, so I think more of them work than people assume - do the standard LSD test. Wheels on surfaces with different traction levels, nail the gas. Works on all LSDs, is quick and easy to perform on a test drive without the need to marque-specific minutae.

  • White_and_Nerdy

    Jan. 21, 2010 4:39 p.m. White_and_Nerdy Reader

    I was going to answer but Keith pwnz.

    Though I will point one thing out... Even the stubs don't tell the whole story. There are different stubs and axles specified for LSD and non-LSD applications. However, when I installed a VLSD into my 91 Miata, I reused the original axles and stubs. So if you look at my car, it'll appear to have an open diff - until you mash the gas on corner exit. They're not awesome LSDs, but they're a lot better than open. And legal in stock class, which is why I got one instead of a later Torsen.

  • Keith

    Jan. 21, 2010 4:46 p.m. Keith SuperDork

    You managed to use open stubs in a VLSD? From what I recall, the VLSD ones are different lengths.

  • Josh

    Jan. 21, 2010 4:53 p.m. Josh Dork

    Justin, we definitely did not use the open diff stub axles in your vlsd. You car wouldn't move under it's own power if we had.

  • willy19592

    Jan. 21, 2010 5:50 p.m. willy19592 Reader

    hehe I just got a good lesson in the stub shafts. I was told (incorrectly) that the ones that had ears were vlsd, and the rather sqaure ones with no ears what so ever were open. a customer wanted a set of open stubs, and I went thru 20 diffs to find a pair. When I took them out they sure looked like ls to me, but didnt think to question, and sent them out. Of course my customer said these were wrong. doh, egg on my face ;) I did more research and found that the "ears" on a viscous are not symetrical, and the opens have symetrical ears. I then took another set out and compared them. I sent out the corrected shafts of course free of charge, and didnt ask the guy to send my mistake back. just having gone thru this with them sitting on the desk next to each other, there is no way in hell that the open stubs will work in a vsld diff, no way. LOL I just seen Josh responded and corrected the story WINK

 
Tire Rack- Revolutionizing Tire Buying

You'll need to log in to post.