I'm putting in a turbo pressure gauge and looking for some advice on where to get the air pressure. A forum member sent me a photo of his (thanks, Barry) but I don't have the same fitting on mine. The only 1/8" plugs I see in the air system are the two on the "air horn" attached to the turbo (arrow in photo #1). Is it possible to use that as the source? The second photo shows the air pipe on its way to the CAC. Do I have to drill it? Thanks.
jor
On the intake side of the engine there is 1/8th pipe plug above the fuel shutoff solenoid, that is where I put mine.
I'd be buying this product, used them for years: ISSPRO.com - Quality Gauges, Tachometers, Speedometers and more! (http://www.isspro.com)
That would be good to use at the fitting at the arrow.
The pressure anywhere on the outbound side of the turbo is about the same psi, that is from turbo to intercooler or intercooler to intake manifold. So your plug is a good place for connecting a hose to an pressure sensor that converts psi to electric signal to feed a dash boost gauge.
We recently drove at or just below sea level and our max boost hit 30 psi.
Do you not have some kind of fitting in the intake manifold itself? Some pipe plug you could remove and install a adapter if needed? That would give you a more accurate reading. In the event your CAC ''Charge Air Cooler" started leaking you will see the drop in boost.
That's a real good point Stumps makes.
I also would consider mounting the sensor off the engine and running hose or tubing to it. Electronic sensors don't like heat or vibration and heat can especially affect accuracy too. I would check out the temperature rating of the sensor. The location of the turbo outlet elbow (in photo 1) will be the hottest. On newer engines the turbo outlet air temperature can reach over 400 F meaning you would need to use silicone or soft copper tubing. Note that the hump hose is silicone (judging by it's color) and gives you an idea of how hot it gets. Cummins recommends silicone to OEM installations when temperatures exceed 250F.
If it were me, I would use soft copper. The best practice is to run the copper from the fitting on the engine through a tube clamp somewhere else on the engine, then across to the chassis with another clamp on the chassis and then into the sensor. Without the clamps on each end, the tube will flex at the fitting which can loosen it or cause fatigue cracking. A nice loop or two between the engine clamp and the chassis clamp is good to reduce the bending stress. I would also used rubber cushioned clamps.
Finally finished up my turbo and pyrometer gauge project. For the turbo I ended up using my original location for the turbo air source (1/8" pipe plug just past the turbo). I couldn't find another place on the air pipe nor the intake as a couple guys suggested. For the pyrometer I used the downpipe from the turbo.
As I often do, I pretty much knocked off Barry's installation and used VEI Systems gauges. I also used a special clamp from Glo Shift for the pyro sensor. Someone else on the forum suggested it but I can't find the post so no attribution. :)
I used four of the my six extra wires which were located just under the hydraulic reservoir.
I bought the gauges directly from VEI. Neal is very helpful.
jor
VEI Systems: 561-713-8344
Turbo Gauge Kit: V1K-BHEP-MRB $148
Pyro Gauge Kit: V1K-PYF-MRB $178
Pyro Sensor Clamp: GS-EGT-Bracket: $25
Keep in mind the 300 to 500 deg. difference between pre turbo and post turbo for safe egt.
EGT Probe Location: Pre-Turbo or Post-Turbo? – GlowShift Gauges Blog (http://blog.glowshiftdirect.com/2013/06/27/egt-pyrometer-probe-location-pre-turbo-or-post-turbo/)
Exhaust manifold [pre turbo] is usually cast or mild steel, so pretty easy to drill and tap. Some use grease on tap and drill bit, some actually run engine when drilling to blow out metal. Have done it more than a couple of times and just used shop vac after drilling with no problems.
John, Neat job especially with the mounted VEI components. Your muffler connectors also look very sharp. Let us know how it all performs when the wheels are turning.
Yea, I thought about that. Thanks for the link. I just figure once I have a baseline I will be able to note aberrant readings.
I am sure you are correcto but I couldn't talk myself into it. I have an unreasonable fear of messing around with the exhaust manifold due to a couple instances in my yoot of broken bolts and the resulting nightmare.
jor