4.0 SOHC Rev Limiter

[Scotty J.]

For you 4.0 SOHC experts!

I got the headers and exhaust installed on my Ranger (02 Ranger, stock ECU) and now that I can hear it I've noticed that it seems to have a rev limiter at around 3k rpm.

Am I imagining things, am I crazy, or is this true? If it is, what may be some other things I may stumble across that seems odd about this vehicle?

 

[Red FX4]

If it is an automatic, you do have a rev limiter when in neutral or park. I don't think there is a rev limiter with the manual transmission. You also have a speed governor that kicks slightly over 90 mph and this exist on all Rangers after a certain year.

 

[Scotty J.]

If it is an automatic, you do have a rev limiter when in neutral or park. I don't think there is a rev limiter with the manual transmission. You also have a speed governor that kicks slightly over 90 mph and this exist on all Rangers after a certain year.

Thank you, that is exactly what I've been seeing.

Question is, why?? Is it to keep idiots for launching at over 3k (my Evo had a 3k rev limiter for that reason), and secondly if that's the only reason, can they be changed or disabled via the an ECU tune/flash? Also, any idea what the red line is for this thing, or is it 3k.

 

[Red FX4]

Revving an engine unloaded is bad for the engine but I think Ford uses the rev limiter on automatics to prevent damage to the transmission. I am not very familiar with automatics and why high rpm hurts them when not in gear. Hard launches may be the reason but I think even a 2500 rpm drop into gear would be bad for the transmission.

Yes, the ECU can be re-flashed to get rid of (actually raises) the neutral rev limiter and the speed limiter. The red line is around 6000 rpm and there is a rev limiter for that too.

 

[BRONCO 2]

2001 ranger SOHC 4.0 stress test. it passed. in drive to the floor