FMX Shift Point Adjustment

7173Mustangs.com

Help Support 7173Mustangs.com:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
Joined
Jul 6, 2015
Messages
4,345
Reaction score
207
Location
Iowa
My Car
1973 Mustang Grande 351C 2v
Is there a way to adjust the shift points on an FMX? I would like it to shift later (at higher rpm). Currently under WOT is shifts from 1st to 2nd at 3,800 to 3,900 RPM and from 2nd to 3rd around 3,700 rpm. This seems crazy low to me. Is there a way to adjust the shift points? Thanks in advance. Any help would be appreciated.

 
you can adjust the shift points some what with the vacuum modulator.

if you get an adjustable modulator for the FMX you can turn the adjuster clockwise to lengthen the shift points.

you can also adjust the modulator using different length pins.

here are the factory shift points

2eztzip.jpg


you are column 5 or 6 depending on tire size

 
remember to match the chart to your engine vaccum. if your engine has a new cam or some other modifications or is very worn out you would have low vacuum which would throw the modulator out of adjustment. you need 17" HG of vac to match the chart above.

 
I will be grabbing a vac gauge before the weekend. The engine is bone stock and has never been rebuilt. 69k miles. It runs great but I will check out what it is pulling for vac. I assume this is 17" at idle with engine warm and manifold pressure?

 
Back
Top