Miata trans swap auto to manual

Just ran across what looks to be a very clean 1992 Sunburst Yellow Miata. Sadly it has an autotragic...

Car is under 3k, how tough is it to correct the trans issue? Of course a 1.8 torsen diff would also have to added...

Not difficult to swap. Just remember, that 1.6 (behind the auto) is only 100hp. Weaker cams than the five-speed motor.

But, it's a sunburst, so it's probably worth doing.

So swap cams too? I knew they were weaker, but didn't know how they did it.

Ah, just do a full-on 1.8 swap I think there's a compression difference as well, I'll have to go back to my notes.

The Miata.net Garage has an article on what's involved with an autoectomy. It's easier on the 1.6 cars. If you do decide to go with a 1.8 swap, you won't have to change the throttle body so it's an easier thing to do.

Actually that would make more sense. Find a good 1.8, 5-speed torsen car and swap everything. (Then put the 1.6 etc in the other tub and sell)

Mazda lists different part numbers for the pistons depending on transmission type. That'll give you the compression ratio difference right there. Camshaft part numbers are different too.

Also, since it's lower compression, you could benefit from tarbo after the manual swap. I'm sure Keith can tell you all about those.

Also, if you want to get rid of that automatic transmission and you don't mind sticking it on a pallet and shipping it, my folks may buy it from you. They've got an auto NA and they're sort of looking for a spare.

ACTUALLY, now that i think about it I've got a 1.6 five speed parts car that I have no designs on the transmission stuff in. Wanna work a trade?

psteav, is your parents' car a 1.8? Different trans.

Some people like the 1.6 auto engines for turbo use - partly because they use a real TPS (better for aftermarket engine management), partly because of that low compression. Although it's more typical to go for a 1.8 than a 1.6 these days.

Keith Tanner wrote: psteav, is your parents' car a 1.8? Different trans. Some people like the 1.6 auto engines for turbo use - partly because they use a real TPS (better for aftermarket engine management), partly because of that low compression. Although it's more typical to go for a 1.8 than a 1.6 these days.

You got me Keith, it is a 1.8 How different are we talking? And what's market value for a 1.8 automatic in usable-but-not-rebuilt condition?

Hey gearhead, where are you located? You could just sell me the sunburst and buy a manual car Seriously.

Keith is right, they had lower compression and less aggressive cam profiles. I swapped my auto motor out for a fresh manual motor, and noticed a huge difference.

Minor thread jack - Keith, I'm installing the Jenvey IRTBs on mine and was planning on adding the Webcam 505s, but they no longer offer them from billet - just mail in mine, hard weld, and regrind. Being horribly impatient I'm now on the search for a similar set, any ideas?

thanks, mark

Finally got to see the car in person today. In my first post I said "Looks to be" a clean car.... looks were deceiving. Car has poorly repaired rocker panel and fender rust. Even the vent window frame on the drivers door is rusted clean through. How does that happen? I did not drive it, hear it run, or even look under the hood. Guess I'm so project hungry that anything looks good at first.

I'm running away. Should anyone else wish to temp fate here's the CL link

http://detroit.craigslist.org/mcb/ctd/3561207190.html

1.8 autos were electronically controlled, 1.6 weren't. That's the big difference I know of. Honestly, it's not an area I've paid much attention to, but Mazda felt they had to detune the 1.6 auto engine but didn't on the 1.8 - which was rated to at least 133 hp (1996-97).

Mark, what engine? I might have a few interesting cams sitting around, old stuff from Integral. I not looked for a 505 alternative, but odds are that Toda has something worthwhile in their massive collection.

Keith, it's a 1.6 spec Miata race engine that I bought from a guy who was retiring from racing. Bear in mind that I still use the auto trans and would like mid range power and torque as opposed to top end.

thanks for anything, mark

Sorry, the 505 is the only one I've spent much time with. I wouldn't call it a mid-range cam, it's pretty sleepy until 4000. Some of those "stock" Spec cams are pretty healthy. Maybe ask Rebello?

I don't know if this is helpful or not, but I swapped my 1991 VW JETTA from auto to manual in a weekend. The hardest part was taking the dash out & putting it back in (necessary to swap the pedals)

See what went into the VW swap here:

http://grassrootsmotorsports.com/reader-rides/5506/

Thanks Keith. I'll check with Rebello.

mark