Hello again all,
where is the best place to hook up a boost gauge on a 6.5 diesel express van? do i drill and tap into the maifold that connects to the turbo and goes to both sides of the engine or somewhere by the Map sensor? thanks for your input and pics would be great

 

I would remove the map sensor and tap the hole to install a pipe fitting and Tee with hose barbs on the outlets,one for the map with a vac line and the other to your gauge.

 

i took my plenum off and drilled/tapped a hole on the top and mine works fine.

 

ok i drilled and tapped my plenum and got it all hooked up but whats a normal amount of boost i should be getting?

 

Cruising could be 0-4psi and under heavy load you should see about 10psi.
Computer controlled boost is a moving target based on load.

Some people see spikes of up to 15psi under load-I think it depends on ECM programming.

 

you dont want to go over 15psi tho.

 

General rule of thumb but not a given, what you don't want is sustained 15+psi without preparing engine to do it, and GM's turbo efficiency really falls off at boost of 12+ psi, it can and will do it but IAT really climbs which causes higher EGT & overall higher temps as engine struggles to push more exhaust to get more boost through the restrictive waste-gated turbine section with the GM turbos

Health/age of engine also warrants keeping to the conservative side of boost pressure with the GM IDI.

For those new to the Diesel performance game; despite what you glean from reading in the different web sites and Diesel magazines more boost does not always equate to more power.

There has to be a choreographed blend of boost-fuel-timing-airflow in/out of engine to get max performance and sufficient cooling engine & trans to deal with increased heat from more performance. That said it is VERY doable to get more oomph out of a 6.5, but gauges like boost and EGT are IMO the 1st step (actually should have been stock gauges from GM when new IMO) in the performance and even great for daily driving as a diagnostic aid.

A good primer to Diesel know how can be found here: Banks Power | Technical Articles Banks is on the "high spend side" and really does not offer much for the 6.5 several vendors out there like Heath Diesel that do cater to the GM IDI enthusiast, I'm not a big fan of SS Diesel won't go into the whys here