Had some crappy performance a couple weeks ago. Hard tow up to a state park with 5th wheel (around 15 to 16K lbs plus the truck) As I got on it pretty hard to make the hill it seemed to die out and sputter a bit. I made it but got concerned. Since then I have tried to duplicate the problem with no luck. Still, with the trailer hooked on I seem to have less power than I expect. This is my third turbo diesel and it just doesn't FEEL right. So, I've been watching the boost gauge and I find that no matter how hard I stand on it I'm not getting more than 21 lbs of boost. I'm pretty sure the 7.3 and the 6.4 both pegged (40 lbs) on a really hard pull. So today I read that the 6.7L is limited by the PCM to 21 lbs of boost. Does anybody know for sure that this is true??? Thanks

 

Never have paid much attention to the numbers but mine approaches about half scale on the boost o meter. Not sure about the limit thing.

 

Yes, boost is limited and you are seeing results consistent with other 6.7's. No worries with the 6.7 making enough power. It doesn't need 40psi to make enough power.

 

Yep. All I can get is 21 PSI out of it as well... Hard to really tell, since the turbo gauge is mediocre at best.

 

I know a stock 7.3 only hits about 17-18 pounds.

 

I get a needle width past the midline so prob 21 -22 lbs. From your signature looks like you had a modded 6.4 and prob had one h*43ll of a chip and injectors and pump to get 40 psi in a 7.3. In stock form a 6.7 will outperform a 6.4 but with twin turbos the 6.4 prob responded better to mods than the 6.7. Your perception all depends where you are coming. If you expect the same or better performance from a stock 6.7 to a modded 6.4 or a heavily modified 7.3 I think that is unrealistic

 

The 15+ is higher with the bigger turbo. Pretty sure mine stock will hit around 27

 

OK guys, thanks for the replys. Not sure if I feel better or worse. It's good to know It's working as designed but the pull up that hill was a bit disappointing. I was in the Rockies last summer and had no problems with the passes. So, no codes and no way I'll duplicate the situation for a while so I guess I'll not worry about it.

FWIW the modified 6.4L was a pure beast tuned. Had a 4.30 RA and if I could have gotten tires that held it would have pulled that trailer up a pine tree. Of course the $5400 to replace the blown head gasket was a tough check to write.

Thanks again

 

According to ForScan, my '15 will hit about 29 psi absolute.

 

Now you are going to make me watch it more carefully... I thought it only went a little above the half way mark on the crappy, non-specific stock gauge. Need a scan gauge or Torque Pro to really watch it.

The reason the '15 got the bigger turbo was because of your issue StanleyZ - they ran of air at higher altitudes. Also if it is was hot out, it will detune to protect the motor.

 

Alllrigghhhttt then. Problem solved. I'll just trade in on a 15 or maybe a 16 or better yet a 17. The part about altitude and heat makes sense, I wasn't real high maybe 3200 feet MSL but it was above 90 degrees and I was at the end of a long climb. So, I guess it worked as designed. I know how to make it better if I want to blow off the rest of the warranty. Just saying

 

I think the 2011-2014/2015 are limited. My old 2011 never got above 20 or so. My 2016 I've seen close to 30 on occasion. But somewhere along the line I believe that the turbo changed too.

 

Possible derate due to high oil temp? When it's hot as hell out with a big trailer on a mountain pass the oil temp will climb fast. Doesn't take too long to get north of 240.


I ran 211 from Luray, VA west back to 81 over the blue ridge mountains on a 90 degree day with about 11K of trailer. Oil was 242 when I hit the top. Actually backed off it a bit toward the top.

 

The 2011-14 turbos have to be "nannied." Like most have stated, 20-22 is all you will get stock. Tuned will get you well past 30, but you are on borrowed time with these chargers. Order you a 2015 charger and pump and I'll swap it out one weekend for you for free!!! The swap can be done with stock tuning and emissions on the truck. A delete will obviously allow you max potential with the new setup.

 

I still think Stan has a turbo or waste gate problem.