Good friend of mine has a very good running 7.3 in his 01 f350. Makes 535 RWH on his dyno. Runs hard, well the darn thing whirls like a vacuum cleaner, and has low lowend boost. He has litterally changed out everything. He has a big ball bearing tubo on it, aftermarket plenum, couldnt tell ya what tunner, meth injection, blah blah blah, Well, this saturday we thought he might have a partially plugged intercooler or something, so we swapped the intercooler out, and still makes the noise,

Just sounds like wind blowing through a big tube, kinda echoes a bit.

It didnt do it untill he changed out this plenum, and went to the stage 2 injectors.

Sucker will black out a city block on the econo setting.

Im not very versed in the 7.3 department, but I told him in a week with his help I can make him a decent truck, I know of a 12 valve cummins just dying for a ford LOL.. he didnt like that.

Kasey

 

Low lowend boost is probably because of the big ball bearing turbo not being spooled up. The smoke is from getting too much fuel too early, and may be hurting the spooling of the turbo. Check the condition of the air filter too. If it is plugged, it will never get air right.

Look into the old plenum and see if it has vanes in it to help turn the air as it goes into the motor. If the old one had vanes and the new does not, the non-laminar flow in the new one could be where the noise is coming from.

 

Thats good advice Jstone. There are no veins in the factory plenum and the noise is most likely from the increased air flow of the after market plenum. Sounds like he is over fueling on the low end, have him try a different tune with less low boost fueling. He may actually pick up performance. Also what mods has he done to the HEUI system? Could be a culprit as well.

 

Ill have to ask him on the veined plenum. As for the turbo, his next step up is a t-4 setup with a s366.

So the setup he has now is not little , but not huge either. Ill talk to him tonight about the plenum idea, Thanks guys.

 

Have him go here thedieselgarage.com. It is an all brands site.

 

Boost may be leaking somewhere. Might wanna try a boost leak down check to see if that's it. What is the max boost it will hit? Double check and make sure his line going from the intake Y to the map sensor isn't cracked or anything. Some particulars like what turbo and tuner would be a little helpful. So....boost leak down check and check all boots for cracks. Next check for up-pipe leaks. Soot on the firewall is a good indication.