![Photo](https://mazdaracers.com/public/style_images/infinite/profile/default_large.png)
90-93 Automatic donor swap
#1
Posted 02-05-2022 11:24 AM
![](https://mazdaracers.com/public/style_images/infinite/post_offline.png)
#2
Posted 02-06-2022 11:24 AM
![](https://mazdaracers.com/public/style_images/infinite/post_offline.png)
#3
Posted 02-07-2022 10:53 AM
![](https://mazdaracers.com/public/style_images/infinite/post_offline.png)
adding some additional detail since I had some automatic parts in my hands over the weekend...
The injector harness plugs are different between the auto and manual. The manual has a 6 pin connector at the main wiring harness that plugs into the injector harness while the automatic has 8 pins. So you need the main harness from a manual car to plug into the correct injector harness.
Also, the throttle position sensor is different. 4 pins for the automatic vs 3 pins for the manual. Not sure if the actual throttle body is different though.
Then of course, the camshafts are different on the automatic vs manual - and a few other changes that can be googled since I don't know them off the top of my head.
![Bona fide - A bonafide Spec Miata driver Bona fide - A bonafide Spec Miata driver](https://mazdaracers.com/uploads/awards/verified-driver.png)
#4
Posted 02-07-2022 03:29 PM
![](https://mazdaracers.com/public/style_images/infinite/post_offline.png)
#5
Posted 02-09-2022 12:03 PM
![](https://mazdaracers.com/public/style_images/infinite/post_offline.png)
I don't think the auto ECU provides 'better' low end torque. On the 1.6, I think that is from the different camshafts that the auto runs compared to the manual. Kinda how GM uses a different cam on their truck motors to improve low end torque vs top end power.
![Bona fide - A bonafide Spec Miata driver Bona fide - A bonafide Spec Miata driver](https://mazdaracers.com/uploads/awards/verified-driver.png)
#6
Posted 02-09-2022 02:51 PM
![](https://mazdaracers.com/public/style_images/infinite/post_offline.png)
I always heard that the engine in the NA auto cars had lower compression and smaller cams as the transmission used in the NAs were very weak.
#7
Posted 03-17-2022 02:27 AM
![](https://mazdaracers.com/public/style_images/infinite/post_offline.png)
1 user(s) are reading this topic
0 members, 1 guests, 0 anonymous users