n8in8or
I never met a project I didn’t like
Ok, so I'm about 10 months late posting this info, but after seeing a conversation regarding this topic pop up on another thread I felt it was appropriate for me to share this info. I am trying to post this during my lunch hour, but if I don't finish I will just post what is complete and finish it at my next available moment.
Background: I went to the dyno Feb 10 2017 to see what my combo was putting out. In case my signature changes in the future my combo at the time was: 2004 Optimizer with home-ported heads, +.010 gaskets, -.010 pistons (~19:1 compression), Harland Sharp 1.6:1 roller rockers, homemade passenger side tube header, CKO HX40 turbo with Turbo Lab wheels, water-to-air intercooler, 4" exhaust, Raptor 100 lift pump and an Omega Plus Moose pump making 122cc of fuel at 3500rpm and Bosch marine injectors set to 2500psi pop pressure. I have attached the dyno charts from that day. Here is a video from the cab during the run.
During the summer of 2016 I had some hot start problems. To address these I got new batteries (I already had 1/0 battery cables) and installed a Power Master starter. The batteries didn't really help much; the starter did improve the problem due to the 30 additional cranking RPM, but didn't cure the problem. Conversations with Conestoga Diesel led to the conclusion that the high pop pressure was at least contributing to, and probably causing, the hard hot start problem. So after my dyno results I thought it was a good time to try lowering the pop pressure in anticipation of the summer of 2017 plus see if there was power in lowering the pop pressure. Conversations with Conestoga and Justin from R&D IDI plus some additional reading on the interwebs indicated there was some power to be had by lowering the pop pressure - due to the pressure/volume relationship (Boyle's law). This made sense to me and I was excited to try something that would not only improve my hot starts but also get me more power! So I decided to re-pop my injectors myself since I already had a pop tester that I had purchased while trying to diagnose some previous rough running. After considering all the info I had available to me, I decided to shoot for 1750-1800psi. Yes, this is lower than most people choose for an NA IDI, let alone a turbo application, but both Conestoga and R&D choose this pressure for their injectors which are intended for turbo applications so I figured I might as well go big (or little?) and try it.....let's really make it an experiment! So I went for it. Now I will admit that I'm not 100% confident in how accurately I was able to match the injectors to each other because the gauge on my tester is air filled and tends to chatter when popping injectors. I had to take my best stab at it and see how it went. Here's a video I took to show another guy the process. Note that I am popping the injector into the atmosphere.....in the future I will be adding a reservoir to pop into so I don't coat my lungs with diesel.
I went back to the same dyno Apr 21 2017. So what were the results? My butt dyno told me that it was an improvement. Take a look at the attached dyno charts and see what you think. Even though I changed the pop pressure 700psi, there was little to no affect on the power. Any discrepancy between the runs can be attributed to testing inaccuracies and the fact that I was at the point of changeover between winter blend and summer blend fuel (btw I run Stanadyne Performance Formula to the recommended ratio in every tank of fuel). Pretty shocking results I think (oh and more proof that butt dynos lie).
I will say that when I went to the lower pressure 2 other things happened: 1. the idle is a bit rougher. I gained a dash vibration that I didn't have before and you can feel the engine shake at idle most of the time. 2. The engine has become quite cold-blooded - below 50*F it will blow white smoke, with the volume and duration increasing as the temperature decreasing. Below 30*F it runs quite rough until I load it and get some heat into the precups. This isn't really what I want in a daily driver. I intend to re-pop the injectors again.
My next step: I have a good set of non-marine Bosch injectors that came with my Optimizer. I would like to pop them to somewhere in the middle, like 2100-2200psi and see what happens. I believe right now that there is little-to-no power to be had with pop pressure changes....now there are idle quality and perhaps efficiency/mileage changes (I haven't verified), but nothing really to be had in power. When I do this test I will go to the dyno once again. I am interested to see if Marine injectors make more power or not - I have yet to see PROOF that they do.....and it sure seems that a pump that puts out the volume of fuel that mine does would surely show whether they do or not. If I put in the standard injectors at a middle pressure and again see no change in power, then I will feel pretty confident that Marines don't gain much - again, as far as POWER goes. If I do lose power, then I will re-pop the Marine injectors to the same pressure as the standard injectors and hit the dyno again. This should give pretty conclusive results. Note that before I pop next time, I will be getting a quality liquid-filled gauge so I can achieve more accurate results.
I think that's it for now. I'm interested to hear comments and if I think of more info I will be sure to add it.
Background: I went to the dyno Feb 10 2017 to see what my combo was putting out. In case my signature changes in the future my combo at the time was: 2004 Optimizer with home-ported heads, +.010 gaskets, -.010 pistons (~19:1 compression), Harland Sharp 1.6:1 roller rockers, homemade passenger side tube header, CKO HX40 turbo with Turbo Lab wheels, water-to-air intercooler, 4" exhaust, Raptor 100 lift pump and an Omega Plus Moose pump making 122cc of fuel at 3500rpm and Bosch marine injectors set to 2500psi pop pressure. I have attached the dyno charts from that day. Here is a video from the cab during the run.
During the summer of 2016 I had some hot start problems. To address these I got new batteries (I already had 1/0 battery cables) and installed a Power Master starter. The batteries didn't really help much; the starter did improve the problem due to the 30 additional cranking RPM, but didn't cure the problem. Conversations with Conestoga Diesel led to the conclusion that the high pop pressure was at least contributing to, and probably causing, the hard hot start problem. So after my dyno results I thought it was a good time to try lowering the pop pressure in anticipation of the summer of 2017 plus see if there was power in lowering the pop pressure. Conversations with Conestoga and Justin from R&D IDI plus some additional reading on the interwebs indicated there was some power to be had by lowering the pop pressure - due to the pressure/volume relationship (Boyle's law). This made sense to me and I was excited to try something that would not only improve my hot starts but also get me more power! So I decided to re-pop my injectors myself since I already had a pop tester that I had purchased while trying to diagnose some previous rough running. After considering all the info I had available to me, I decided to shoot for 1750-1800psi. Yes, this is lower than most people choose for an NA IDI, let alone a turbo application, but both Conestoga and R&D choose this pressure for their injectors which are intended for turbo applications so I figured I might as well go big (or little?) and try it.....let's really make it an experiment! So I went for it. Now I will admit that I'm not 100% confident in how accurately I was able to match the injectors to each other because the gauge on my tester is air filled and tends to chatter when popping injectors. I had to take my best stab at it and see how it went. Here's a video I took to show another guy the process. Note that I am popping the injector into the atmosphere.....in the future I will be adding a reservoir to pop into so I don't coat my lungs with diesel.
I went back to the same dyno Apr 21 2017. So what were the results? My butt dyno told me that it was an improvement. Take a look at the attached dyno charts and see what you think. Even though I changed the pop pressure 700psi, there was little to no affect on the power. Any discrepancy between the runs can be attributed to testing inaccuracies and the fact that I was at the point of changeover between winter blend and summer blend fuel (btw I run Stanadyne Performance Formula to the recommended ratio in every tank of fuel). Pretty shocking results I think (oh and more proof that butt dynos lie).
I will say that when I went to the lower pressure 2 other things happened: 1. the idle is a bit rougher. I gained a dash vibration that I didn't have before and you can feel the engine shake at idle most of the time. 2. The engine has become quite cold-blooded - below 50*F it will blow white smoke, with the volume and duration increasing as the temperature decreasing. Below 30*F it runs quite rough until I load it and get some heat into the precups. This isn't really what I want in a daily driver. I intend to re-pop the injectors again.
My next step: I have a good set of non-marine Bosch injectors that came with my Optimizer. I would like to pop them to somewhere in the middle, like 2100-2200psi and see what happens. I believe right now that there is little-to-no power to be had with pop pressure changes....now there are idle quality and perhaps efficiency/mileage changes (I haven't verified), but nothing really to be had in power. When I do this test I will go to the dyno once again. I am interested to see if Marine injectors make more power or not - I have yet to see PROOF that they do.....and it sure seems that a pump that puts out the volume of fuel that mine does would surely show whether they do or not. If I put in the standard injectors at a middle pressure and again see no change in power, then I will feel pretty confident that Marines don't gain much - again, as far as POWER goes. If I do lose power, then I will re-pop the Marine injectors to the same pressure as the standard injectors and hit the dyno again. This should give pretty conclusive results. Note that before I pop next time, I will be getting a quality liquid-filled gauge so I can achieve more accurate results.
I think that's it for now. I'm interested to hear comments and if I think of more info I will be sure to add it.