the exhaust looks fairly closely mounted to the diff...or is it just the photo? looks good though...

my mate just got his exhaust done and the dodgy bastards actually moved his fuel tank to run the exhaust he wanted without telling him...2 weeks later driving to work his fuel tank fell out from under the car because the exhaust shop had done the dodgiest job placing and hooking the fuel tank back up... he is so lucky it didn't all light up!

 

Well if the diff was sourced from an NB, then its quite possible you do have the 4.30 instead of the 4.10. But if it came from any 1.8 NA, then for sure its a 4.10

 

Oooookay lets stop with this whole mis-information thing. Everybody seems to just be making things up...
The 1.6 came with a 6" differential that was either an Open or Viscous unit. Also, they had 4.30 gears.
The differential that Tabs604 blew was a Viscous 6".
The 1.8 NA (94-98) came with a 7" differential that was either Open or Torsen. These cars came with either 4.10 or 3.90 gearing.
The 1.8 NB (99+) came with a 7" differential that was either Open or Torsen and could come with a 4.30 gear.
The RX7 (specifically 83-85) came with a 7" differential and a Clutch type LSD.
NB diffs are rare - easily 90% of the Torsen diffs people swap into their 1.6's are from a 94-98 so they are not 4.30 geared. Most likely 4.10.
The only way that he could have a Clutch type LSD would be if there were an aftermarket unit (like Mazdaspeed's) installed or if the diff had come from an RX7. But, the RX7 came with I believe 3.90.

If you wanted the best setup (relative term I know) in terms of quickness you would get a 7" Open diff from an NB which would get you the 4.30 gears and then find a junkyard RX7 diff and pull the LSD out of that and put it in the NB pumpkin.

99% chance Tabs604 has a 94+ Torsen diff with 4.10 gears. And thats not a bad thing - its a great unit. The real LSD would be best though.

-Ryan

 

+1 to everything pass said.

 

Hey, Ryan, the RX-7 diffs. that people swap over are the '86-'91 S4 RX-7 diffs., not the '83-'85 ones. The '86-'91 ones are used because they have 7" guts that're directly interchangeable with the '94-'05 Miata diffs., plus the rear aluminum housings are interchangeable, too, along with the Miata diff. mounts. The '86-'88s are the ones most often used because they have clutch-type LSDs instead of the viscous LSDs of the '89-'91 cars. The '84 and '85 RX-7 diff. innards can be used, too, but they have different housings and axles.

 

The 4.30:1 came on the '99+ Miata (4.10:1 on automatic starting in 2000)
The 4.10:1 came on the 1994-97
The 3.909 came on the 99+ 6-speed Miata.
The 3.636:1 came on the 2001+ Austrailan 6-speed.

If you go with a torsen or clutch or viscous, you will get all the same strength but different characteristics. The strength is in the ring-gear.

The 84-85 RX7 LSD can be swapped into a miata 1.8 rear. The 86-88 has a carrier nearly identical to the miata 1.8 and can be used with miata pinon housing and gears.

The 84-85 GSL is a 3.909.

The 84-85 GSL-SE is 4.08.

The 86-88 BASE, SPORT, SE and GXL is 4.10 w/manual, 3.909 with auto.



BTW Tabs, I love the exhaust design...i just hate the tips.

 

I read in a post by dyna rocket that the ring gears are the same though. right? What Was changed to make the 3.9-3.6 ratios was it the ring and pinion or just the ring. I wonder if they just went with a ring gear with more teeth and left the pinion alone.

 

http://members.aol.com/solomiata/RingandPinion.html

Need to match the set, but looks like you can end up with a 4.0x gear ratio. (not much lower than the miata ring gear, and less work to pull the pinon gear form the housing.)

 

I dont know what you mean about "everyone" making things up, and misinformation. Look at my post WAYYY up there and youll see that I didnt make anything up. Thanks.

 

Andy, you are all about spreading bad inof and you know it :gay: