Will lower rear axle gearing effect the ECM?

[dla]

07, 2.3L, 5spd and I'm changing from 3.73 to 4.30 in the rear axle. Will the gearing change effect the overall performance from the ECM?

 

[jax4bangin]

ur ecm wouldnt know the difference wat gears are in the axle. at 2500 rpm in 5th ur truck wud think its at 70 mph but ud really be around 45-50 mph. stock tires of course

 

[locovaca]

ur ecm wouldnt know the difference wat gears are in the axle. at 2500 rpm in 5th ur truck wud think its at 70 mph but ud really be around 45-50 mph. stock tires of course

Not true. It will affect your speedometer and the PCM will think you're not going at the speed you are.

Check the library:

http://www.therangerstation.com/tech_library/Speedogear.html
http://www.therangerstation.com/tech_library/speedometer.htm

 

[jax4bangin]

i recently switched from 3.73 gears to 4.56. and from 27" stock tire to 30" bfg. the only thing that is different is my speedometer. when my dash says 72mph the actual speed is 65

 

[Ferris Bueller]

Why are you doing this ratio swap? If your engine and tire sizes are stock this ratio change will probably make its accelleration slower.

 

[dla]

Why are you doing this ratio swap? If your engine and tire sizes are stock this ratio change will probably make its accelleration slower.

Why do you think that?

 

[jax4bangin]

Why are you doing this ratio swap? If your engine and tire sizes are stock this ratio change will probably make its accelleration slower.

i think it wud be quicker.. it wud just be at a high rpm on highway..

 

[Ferris Bueller]

My 2004 2.3 5 speed Ranger has the 3.73 rear in it. The engine winds out rather fast with the factory axle ratio it already has. I could be wrong but if you measure its accelleration before and after ratio swap and your truck is quicker with 4.30 gears I will be surprised.

 

[Rifleman]

Its top speed would be lowered, but it could reach that top speed faster.