99 Throttle Body - Auto vs Manual
 

Currently building a 99 engine to swap into my 90 shell. It's currently running on the stock ECU with a FM throttle body adapter.

I have a DIYPNP on the way, so I'd like to ditch the 90 TB in favor of one with a VTPS. It looks like any TB 94+ will work, but I'd like the 99+ for aesthetic reasons - the IACV draws from the intake tube rather than it's own pipe.

Regardless, I'm wondering if there is any functional difference between the auto and manual 99+ throttle bodies, as parts houses seem to list them differently. I'm guessing the throttle rotor is probably different, but not much else.

I had always assumed that only the 1.6 cars had different throttle bodies. Now that I look closely, however, the Mazda parts book does indeed list different throttle bodies for AT vs. MT in the '99. I can't figure out why- they have the same TPS and IAC valve, and the intake manifold itself is also the same for MT and AT cars. Same throttle cable as well.

The only other part in the whole system I can find that discriminates between AT and MT is a tiny little mounting bracket which secures the throttle cable near the end. That part is listed for AT only (no MT equivalent), but I can't see how that would affect the throttle body.

I would suspect that it doesn't matter which one you use.

For what its worth, the 1.8 NA lists the same TB for all applications.

Well, that certainly answers the question! That was what I suspected as well, thanks!

I suspect you'll find the difference is the throttle wheel which for a '99 and up is not easily removable. The AT has two pick up points and guides for cables where the MT has only one guide.

The 1.6 throttle cable will be the wrong length but the end of the cable will fit into the throttle body thing.

All you'll need to for proper tension is fab a bracket out of sheet aluminium (4 holes?) or put some sort of spacer on the pedal-end of the cable.

Also even the NA 1.8s have different style throttle bodies.
e.g. this
https://www.miataturbo.net/attachmen...ine=1314581622
I have one of those lying around. Came from a japanese BP engine I bought off ebay. The cable I had on my car (a 96) wouldn't fit length-wise (was too short I think)

Not to whore the thread, but I've got an '01 MT TB sitting in my parts bin if anyone wants it.