Attention: TDR Forum Junkies 
During a massive clean-up at work a couple of weeks ago, a collegue suggested that the 6. 7L fresh air intake system we were about to scrap, would likely fit in my 06 and provide some flow improvement.
Although the air cleaner mounting points are the same and the turbo inlet OD is the same at the same location, none of the 5. 9 and 6. 7 parts interchange accept the catches for the filter box and the restriction indicator. The 5. 9 element will fit the 6. 7 box but not vice-versa.
The 6. 7 system was designed to provide the same or lower level of restriction as the 5. 9 but at a higher flow value and the dust capacity was increased. This was accomplished by the following.
Element depth was doubled but pleat count was reduced considerably. This required a new lower shell. The 5. 9 element still fits in the new lower shell.
Upper shell outlet increased diameter from 3. 5" to 4". This accommodates the Mass Air flow sensor that was added for the 6. 7 but is not required for the 5. 9. This required a new upper shell.
The outlet was tucked into the air box upper and the accordian section of the upper elbow was removed to allow smoother bends for the clean air ducting. However the tucking in of the outlet required the outlet to extend into the air box to provide a straight section for the MAFS which leaves a lip extending into the flow path. This as well, required a new upper shell.
In the process of creating a new upper and lower shell, the hinge between upper and lower was moved to the opposite side so upper shells won't interchange.
I revised as follows.
MAFS had the sensing element cut-off and cavity filed with a JB weld type material. I cut the connector off the outside as well. So it is now just a plug
I removed the lip extending into the box and provided a nice smooth radius into the remaining portion of the outlet.
I switched the charge air temp sensor over since the wiring connector for the 5. 9 will not fit the 6. 7 sensor. The 6. 7 uses only 1 screw to mount the CAT.
I gutted the clean hose resonator which is real easy to do.
I plugged the hose coming off the inside of the lower clean duct elbow.
This system installed with no issues. Everything fits with acceptable clearance.
I think I wanted to notice better spool up but there is certainly no increase in turbo whistle over my gutted 5. 9 system. My test drive was just after a snow storm so I didn't have a chance to really try it. I don't drive it enough to have an idea of mileage improvement and I am not yet instrumented to know if EGT's are affected.
There should be more 6. 7 systems around from those that have replaced with an aftermarket system so this should provide a very cost effective performance improvement. The PSM style mod should fit exactly the same. I have this ready to install as soon as the weather gets decent.
I apologize for the long post.
Regards, John
Although the air cleaner mounting points are the same and the turbo inlet OD is the same at the same location, none of the 5. 9 and 6. 7 parts interchange accept the catches for the filter box and the restriction indicator. The 5. 9 element will fit the 6. 7 box but not vice-versa.
The 6. 7 system was designed to provide the same or lower level of restriction as the 5. 9 but at a higher flow value and the dust capacity was increased. This was accomplished by the following.
Element depth was doubled but pleat count was reduced considerably. This required a new lower shell. The 5. 9 element still fits in the new lower shell.
Upper shell outlet increased diameter from 3. 5" to 4". This accommodates the Mass Air flow sensor that was added for the 6. 7 but is not required for the 5. 9. This required a new upper shell.
The outlet was tucked into the air box upper and the accordian section of the upper elbow was removed to allow smoother bends for the clean air ducting. However the tucking in of the outlet required the outlet to extend into the air box to provide a straight section for the MAFS which leaves a lip extending into the flow path. This as well, required a new upper shell.
In the process of creating a new upper and lower shell, the hinge between upper and lower was moved to the opposite side so upper shells won't interchange.
I revised as follows.
MAFS had the sensing element cut-off and cavity filed with a JB weld type material. I cut the connector off the outside as well. So it is now just a plug
I removed the lip extending into the box and provided a nice smooth radius into the remaining portion of the outlet.
I switched the charge air temp sensor over since the wiring connector for the 5. 9 will not fit the 6. 7 sensor. The 6. 7 uses only 1 screw to mount the CAT.
I gutted the clean hose resonator which is real easy to do.
I plugged the hose coming off the inside of the lower clean duct elbow.
This system installed with no issues. Everything fits with acceptable clearance.
I think I wanted to notice better spool up but there is certainly no increase in turbo whistle over my gutted 5. 9 system. My test drive was just after a snow storm so I didn't have a chance to really try it. I don't drive it enough to have an idea of mileage improvement and I am not yet instrumented to know if EGT's are affected.
There should be more 6. 7 systems around from those that have replaced with an aftermarket system so this should provide a very cost effective performance improvement. The PSM style mod should fit exactly the same. I have this ready to install as soon as the weather gets decent.
I apologize for the long post.
Regards, John
