I blew a boost tube off and was reading 2.8 lb boost at idle with torque pro. is it reading a command signal? 02 LB7. Bear with me as i am as dumb as a box of rocks when it comes to a dmax.
Boost tube blew off, 2psi at idle, why
- Thread starter bigboybuilder
- Start date
Welcome to the page! Was this reading before or after the tube blew off? Were you reading MAP or BARO (barometric/atmospheric pressure)? What kind of tuning device is on the truck? IIRC the banks 6 gun in your sig is an interference/intercept style module so it may be displaying a false boost reading in the efforts to gain low end fueling. Try unhooking the 6 gun from the engine bale connectors and see if it goes to zero.
Torque doesn't correctly read boost on the LB7. The LB7 has a MAP (Manifold Absolute Pressure) sensor, and it has a barometric pressure sensor. It doesn't expose a true boost PID to read. The correct way to determine boost (how EFILive & the Edge CTS do it) is to read MAP and Baro, then report Boost = MAP - Baro.
Torque, on the other hand, never seems to be able to do that on the LB7. Instead, it reports Boost = MAP - (some value it thinks is baro) which is usually wrong. You can go into the settings and adjust what it thinks the barometric pressure is to get your boost reading accurate, but then as you change elevation or weather, it is wrong again.
I'm 99% sure that is what is happening to you here.
What I do on torque is just directly display the MAP value, as kPa. 100 kPa ~= 1 atmosphere at sea level, so if you see MAP = 100 kPa you have no boost at sea level, or a little boost at elevation. 150 kPa means 1.5 atmospheres, so in theory your engine is making 150% the power it could without a turbo. And so on. It might take you a little time to get used to seeing pure MAP, but once you are used to it, I find it is a more meaningful number, as it correlates to engine power output regardless of elevation. With boost, you need to factor the elevation in to get a feeling for power output, because 10 PSI boost at sea level is way more power than 10 PSI boost at 7,000 feet. In fact, it takes 3.2 PSI of boost at 7,000' to just equal the power of no boost at sea level. With a MAP reading, you can glance down and see 80 kPa and know you have 80% the power available as you would at sea level, no mental math required.
Torque, on the other hand, never seems to be able to do that on the LB7. Instead, it reports Boost = MAP - (some value it thinks is baro) which is usually wrong. You can go into the settings and adjust what it thinks the barometric pressure is to get your boost reading accurate, but then as you change elevation or weather, it is wrong again.
I'm 99% sure that is what is happening to you here.
What I do on torque is just directly display the MAP value, as kPa. 100 kPa ~= 1 atmosphere at sea level, so if you see MAP = 100 kPa you have no boost at sea level, or a little boost at elevation. 150 kPa means 1.5 atmospheres, so in theory your engine is making 150% the power it could without a turbo. And so on. It might take you a little time to get used to seeing pure MAP, but once you are used to it, I find it is a more meaningful number, as it correlates to engine power output regardless of elevation. With boost, you need to factor the elevation in to get a feeling for power output, because 10 PSI boost at sea level is way more power than 10 PSI boost at 7,000 feet. In fact, it takes 3.2 PSI of boost at 7,000' to just equal the power of no boost at sea level. With a MAP reading, you can glance down and see 80 kPa and know you have 80% the power available as you would at sea level, no mental math required.
It was after, before it read 0 at idle and went up based on load/throttle and is back to as before. Torquepro says boost so im not sure what it reads. Learning as i go. torque is not worth the$ "at the current time" no fuel prssure, ballance rates are -390's, no data for throttle demand along with other's. That may change as i learn. Love the truck i hit the hiway with camper and turned on cruse at 74 and the only guage moving was boost and stayed dead nut on 74 my gas truck would have blown the rods out trying to do half that.