the tack and speedo gear have nothing to do with each other, tach sould be electronic......

FWIW my tack reads high ex: my tach would say 4000 but on both my turbo timer and in MS it would read 3750....even before my 6 speed swap.

 

I did this swap the other week and this thread was very helpful.

- late model NB 6spd into '89 NA6CE Eunos Roadster.

I thought it was pretty easy although I took my time and spent around 5 hours, didn't change the clutch.

Everything on this page checked out, I used the NA trans plate with only two bolts. The switches on my 6spd didn't need changing but the reverse switch on my 5spd used bullet type plugs, not the spade type so I changed the ones on the 6spd trans for the bullet type.

Used the existing 6" 4.3 diff, the rpm's are a bit higher but not unbearable, I don't drive the mazda to work every day though. I think the 8/6 coilovers are less bearable than the revs.

Speedo drive taken from the 5spd, seems to read the same as before but I haven't driven with the GPS yet so it's difficult to tell if it's changed slightly.

Thanks for the help, it wouldn't have gone as smoothly without it.

 

sorry to hijak this thread but I'am looking for a 6 speed and was wondering what years of miata to get it from and what engine size is it only 2 litre on nb models that had the 6 speed or did the 1.8 have them as well reason being i phoned a junkyard and he asked me what engine is it off and what year?

 

it is only of the 1.8's in the US and it is 99-05 anything after 05 is an NC and a totally diferent drivetrain.

 

There has never been a 2l NB Model.

You're from the Uk, so you have 1.6l and 1.9l engines.

the 6Speed came in the 10th Anniversary and in the first NB with tan leather.

Otherwise, you'll find it in the NBFL Sportive Versions (1.9l)

No factory 1.6l with a 5speed

 

um there was nvr a 1.9 liter miata to my knowledge man. i am pretty sure it is a 1.8

 

we mean the same engine.

In Euro, we got two engines for theNB, a smaller 1.6l and a bigger 1.8l.

this engine however has more than 1800ccm and is therefore officially called 1.9l.

 

Nope, sorry. Unless you guys have something we haven't heard of, all of the 1.8 liter BPs put in Miatas from '94 to '05 are 1839cc, which is still considered a 1.8 liter motor. a 0.5mm overbore bumps it to 1862cc, which is then considered a 1.9 liter.