*NEW* DTT DSM/EVO 8/9 EGR Turbo Back Pressure Plate
Apr 15, 2013, 09:52 PM
#17
The barb will be located on the side facing the engine and NOT the firewall. This allows the barb to be connected to the air passage that goes through the cylinder head and connects to the exhaust gases.
The plate can be flipped so the barb is on the top or the bottom of the plate, as long as the barb is connected the the exhaust passage side of the EGR.
Apr 16, 2013, 09:10 AM
#18
nifty adapter. makes it much easier than putting a bung on the exhaust manifold. one thing i'll caution people about is that if a substantial leak develops at the end of the rubber hose where it attaches to the sensor, the flowing exhaust gasses will melt the hose and possibly kill the pressure sensor.
here are a two logs that i made with my setup using a bung attached my exhaust manifold. the first log is 2-3 psi lower boost at peak rpm than the second. note that the extra 2-3 psi in the second log jacked up the exhaust manifold peak pressure from 38 psi to 50 psi which shows that the turbo is totally maxed out. pressure ratio is a ridiculously high 2:1.
https://www.evolutionm.net/forums/ve...-toxicfab.html
https://www.evolutionm.net/forums/ev...tq-485whp.html
here are a two logs that i made with my setup using a bung attached my exhaust manifold. the first log is 2-3 psi lower boost at peak rpm than the second. note that the extra 2-3 psi in the second log jacked up the exhaust manifold peak pressure from 38 psi to 50 psi which shows that the turbo is totally maxed out. pressure ratio is a ridiculously high 2:1.
https://www.evolutionm.net/forums/ve...-toxicfab.html
https://www.evolutionm.net/forums/ev...tq-485whp.html
Apr 16, 2013, 09:47 AM
#19
We first tried it with 1 ft of coiled brass tubing, but we found the exhaust gas by the time it reaches the EGR is cool enough. We did back to back testing with both options and the high temp silicon hose stands up just fine and will not melt, we have a few Evo's with thousands of miles on it with zero issues.
Apr 16, 2013, 11:42 AM
#20
I've got a bit of background in IC & turbo design. That last post was pretty late at night, I think this'd be more accurate:
Load = (MAP(IAT) * (boost/backpressure)) * VE(rpm)
MAP(IAT) = manifold pressure corrected for IAT
(boost/backpressure) = operational pressure ratio
VE(rpm) = acoustically driven by manifolds, cams, ports, etc.
And no it's not directly from a book, but pretty much how I remember the concept as documented in a number of books; Heywood, etc.
Load = (MAP(IAT) * (boost/backpressure)) * VE(rpm)
MAP(IAT) = manifold pressure corrected for IAT
(boost/backpressure) = operational pressure ratio
VE(rpm) = acoustically driven by manifolds, cams, ports, etc.
And no it's not directly from a book, but pretty much how I remember the concept as documented in a number of books; Heywood, etc.
I understand what you mean about trying to use the ratio in a manner to show a difference in load but it wouldn't necessarily work out mathematically I think . Like you said, less back pressure than intake manifold pressure ensures the engines VE is working at its optimal potential without any post-engine restrictions. In theory, if there was much less back pressure than intake pressure, it would almost imply that more air is flowing through the engine than the maximum VE, even though that may not be actually happening. I could be wrong though. Was that a proven mathematical formula you have found of just something that seemed to make sense that you were thinking about? I wouldn't mind exploring that further.
-Jamie
-Jamie
Apr 22, 2013, 06:37 AM
#21
Well you want more exhaust velocity to drive the turbine, not more pressure even though they are functions of the same variables in PVT formulas. It is blatantly obvious that high ratio of psi indicates a restrictive hotside, but I don't think the pressure itself is the problem; it's more or less just the symptom?
To use this data, I would want to know what is efficient for my turbo and how to relate the sensor data to this turbine/hotside efficiency range. I am also interested in learning about this.
To use this data, I would want to know what is efficient for my turbo and how to relate the sensor data to this turbine/hotside efficiency range. I am also interested in learning about this.
Apr 22, 2013, 08:17 AM
#22
I've got a bit of background in IC & turbo design. That last post was pretty late at night, I think this'd be more accurate:
Load = (MAP(IAT) * (boost/backpressure)) * VE(rpm)
MAP(IAT) = manifold pressure corrected for IAT
(boost/backpressure) = operational pressure ratio
VE(rpm) = acoustically driven by manifolds, cams, ports, etc.
And no it's not directly from a book, but pretty much how I remember the concept as documented in a number of books; Heywood, etc.
Load = (MAP(IAT) * (boost/backpressure)) * VE(rpm)
MAP(IAT) = manifold pressure corrected for IAT
(boost/backpressure) = operational pressure ratio
VE(rpm) = acoustically driven by manifolds, cams, ports, etc.
And no it's not directly from a book, but pretty much how I remember the concept as documented in a number of books; Heywood, etc.
load = MAP/IAT*(1 + A*pr)*VE where A is an adjustable value and pr is the pressure ratio
I see your recommendation for Heywood. Anything else?
Apr 22, 2013, 12:08 PM
#23
This side of scanning a whole bunch of copyrighted texts, these two articles do a great job of covering how a turbine extracts energy from the exhaust. In short all turbine maps are in terms of pressure ratio, so that what you want to look at.
http://www.motoiq.com/magazine_artic...bine-maps.aspx
http://www.motoiq.com/magazine_artic...p-details.aspx
Something that's easy to forget, and ever harder to correlate in the data is that the turbine is attached to a given compressor that very often isn't the same as the one used on an aftermarket turbo. Aftermarket performance turbos typically run a bigger compressor and rely more heavily on the wastegate for exhaust flow, whereas OEM's design for more balanced compressor/turbine performance. This mismatch generally hurts turbine efficiency.
http://www.motoiq.com/magazine_artic...bine-maps.aspx
http://www.motoiq.com/magazine_artic...p-details.aspx
Something that's easy to forget, and ever harder to correlate in the data is that the turbine is attached to a given compressor that very often isn't the same as the one used on an aftermarket turbo. Aftermarket performance turbos typically run a bigger compressor and rely more heavily on the wastegate for exhaust flow, whereas OEM's design for more balanced compressor/turbine performance. This mismatch generally hurts turbine efficiency.
Well you want more exhaust velocity to drive the turbine, not more pressure even though they are functions of the same variables in PVT formulas. It is blatantly obvious that high ratio of psi indicates a restrictive hotside, but I don't think the pressure itself is the problem; it's more or less just the symptom?
To use this data, I would want to know what is efficient for my turbo and how to relate the sensor data to this turbine/hotside efficiency range. I am also interested in learning about this.
To use this data, I would want to know what is efficient for my turbo and how to relate the sensor data to this turbine/hotside efficiency range. I am also interested in learning about this.
Apr 24, 2013, 02:55 PM
#24
Evolved Member
iTrader: (4)
Join Date: Mar 2003
Location: South Jersey
Posts: 643
Likes: 0
Received 0 Likes
on
0 Posts
I like how this is tapped for 1/8 NPT. Perfect to mount my AEM 5 Bar Pressure sensor right into and log it thru the ECU as a 0-5V input. I will be placing my order shortly!
Apr 24, 2013, 10:38 PM
#25
I'm curious about the pressure ratio trim in your calculation. I did a quick search on Google and found no SD formulations that accounted for pressure ratio. I think it makes sense to include pressure ratio, and I will likely include it as an SD option in the ROM I'm working on, but I suspect the pressure ratio trim would be more like:
load = MAP/IAT*(1 + A*pr)*VE where A is an adjustable value and pr is the pressure ratio
I see your recommendation for Heywood. Anything else?
load = MAP/IAT*(1 + A*pr)*VE where A is an adjustable value and pr is the pressure ratio
I see your recommendation for Heywood. Anything else?
