the real ticket would be to do all these measurements on a dyno... then you take out the errors and changes in road conditions... then take the measurements... my head is rolling with the ideas I could muster up in my garage hahaha
Exhaust & Intake Pressure Measurements
- Thread starter Fix_Until_Broke
- Start date
Fix_Until_Broke
Top Post Dawg
Was the cat the OEM one or something aftermarket that came with the TT downpipe?vwdsmguy said:
Thanks for posting up the information.
I wonder if I'd see a higher pressure on the OEM DP if I measured before the cat instead of at the exit of the turbo?
Fix_Until_Broke
Top Post Dawg
I have a 600 HP infinately variable load - but it's not electric 
With a direct torque measurement all the intertial effects, drag, bearings, parasitic losses, etc go away because the torque cell doesn't know or care what the load is, just that there is one. Time/Torque/RPM is all you need.
Now - back on topic...
Does anyone have the exducer diameter of a 17/22 turbo handy?
The other piece of information I need is roughly the mass airflow going through the engine. I recall looking at some turbo compressor maps that it's around 25-30 lbm/min but don't remember off hand.
With this information I can start to determine the effects of my initial post turbo measurement location by getting an approximate velocity. Then I can start laying out my assumptions and then we can decide if it's worth continuing further down this path or not.
With a direct torque measurement all the intertial effects, drag, bearings, parasitic losses, etc go away because the torque cell doesn't know or care what the load is, just that there is one. Time/Torque/RPM is all you need.
Now - back on topic...
Does anyone have the exducer diameter of a 17/22 turbo handy?
The other piece of information I need is roughly the mass airflow going through the engine. I recall looking at some turbo compressor maps that it's around 25-30 lbm/min but don't remember off hand.
With this information I can start to determine the effects of my initial post turbo measurement location by getting an approximate velocity. Then I can start laying out my assumptions and then we can decide if it's worth continuing further down this path or not.
robnitro
Veteran Member
I just removed my muffler (A dynomax/walker 2.5 in/out super turbo muffler) and am amazed at how it cut down on the smoke. I am able to run a 4 IQ instead of previous 7, with minimal smoke. Stock DP, and 2.5 inch magnaflow diesel cat w VNT17. I didn't think backpressure affected smoke that much, but I guess with RC4 now, the flow is needed?
Fix_Until_Broke
Top Post Dawg
Added a re-formatted plot to Post 2 - Plotted everything vs RPM insted of time.
Not a large difference in how it looks, but a little easier to read and probably more meaningful.
Not a large difference in how it looks, but a little easier to read and probably more meaningful.
Fix_Until_Broke
Top Post Dawg
Added data to Post 3 - includes VagLogs, EMP/IMP/VNT Actuator Vacuum along with Dyno data.