Falls off at WOT near governor....normal?

[whiteboyslo]

OK, newb question, but I am curious since I haven't ridden in any other IDIs...

My truck seems to run strong enough all the time. Not a speed demon, but once it builds some boost (non-WG Banks Sidewinder) it trucks right along. But, one thing it seems to have always done since I've owned it (few years now) is to fall pretty flat on its face the last couple hundred RPM up to the governor. When it gets toward the end of the range, the power drops off significantly, the smoke picks up (only a light haze up until the end), and the boost drops quite a few PSI. Admittedly, I haven't played with the timing or fuel a ton to try to alleviate this, but I also don't want to spend a ton of time trying to eliminate something that might just be 'built in' to the truck. Is this just a characteristic of the IP timing, or should I try playing with the timing a bit?

The truck only has 90K miles, runs just fine, starts great, and otherwise does the job I need. I have timed it in the past (cannot remember what I set it to, but I used Gary's rental setup to do it), but since I've timed it, I have added the Facet fuel pump and also dialed the fuel screw back a bit to turn the smoke down to reasonable levels.

Mike

 

[lindstromjd]

In my experience, the governor doesn't do anything other than stop delivering extra fuel. So no matter how much more you're asking for, it just can't deliver it. It should run strong all the way up to the governor and sit there all day long without losing power.

 

[cpdenton]

From Mel on another thread.



All of our fuel ratings are guaranteed spot on at 1400 RPM. As the RPM's climb, the fuel curve does start to drop off after 3000 RPM. Most pumps will make within 5cc of the advertised spec at 3000. Once you get to 3300, it starts to drop off sharply by design. This is to keep the engine from blowing up if you ever got into a full throttle no load situation. By 3600 RPM most of the fuel is gone.

 

[rhkcommander]

From Mel on another thread.



All of our fuel ratings are guaranteed spot on at 1400 RPM. As the RPM's climb, the fuel curve does start to drop off after 3000 RPM. Most pumps will make within 5cc of the advertised spec at 3000. Once you get to 3300, it starts to drop off sharply by design. This is to keep the engine from blowing up if you ever got into a full throttle no load situation. By 3600 RPM most of the fuel is gone.

This 110%. A semi-easy workaround is to play with the screw on the throttle plate on the IP so you can't get full RPM range