[JTC1]

Originally Posted by OmahaDZL

Rob is like ABSCSU or something like that....he got flamed (not banned) for...umm..I cant remember but I had something to do with BPC vs JR... HP....dangerous tunes...timeslips...I cant remember.

I think his issue was that he got flamed for posting the Mexico videos. I think a member or two was giving him a hard time about it.

[ASBSECU E93]

Originally Posted by OmahaDZL

Rob is like ABSCSU or something like that....he got flamed (not banned) for...umm..I cant remember but I had something to do with BPC vs JR... HP....dangerous tunes...timeslips...I cant remember.

So, on injector placement are you saying that its better that the injector is further away? ie..the further the better?..... Rob seemed to be saying the closer the better (but maybe I misunderstood him)

As for placement of nozzle in relation to the temp sensor.... I was under impression that the benefit was direct. But you seem to be saying that its more for your monitoring than the DDEs.....so you can better monitor all of your info to get every last ounce of power out....

So to sum up...If I understand you correctly....putting it before the temp sensor helps in evaporation, but wont really help vis a vis the temp sensor.... So why not put it in the hard pipe on the upstream side of the IC? also would keep oil down in the IC

That's not exactly what I wanted to convey.

Is it more/less beneficial to place the nozzle after the sensor? Or, is placement prior to the sensor simply a function to get log data, but at some expense to functionality. Or does it really matter?

[TDIwyse]

Originally Posted by OmahaDZL

...
So, on injector placement are you saying that its better that the injector is further away? ie..the further the better?..... Rob seemed to be saying the closer the better (but maybe I misunderstood him)

So ... "better" is a term that could mean different things to different people with different goals (reducing certain emissions, increasing air density, etc.). If you want to fully maximize the density of the compressed air to maximize oxygen content, then you'd want all the fluid to fully evaporate in the intake to maximize the temperature reduction (basically a chemical intercooler). The closer the injection is to the cylinder, the less opportunity the fluid has to fully evaporate.

It would be really interesting to put multiple IAT sensors in the intake track and monitor the temperature along the intake to get a better idea of how the temperature profile behaves during high boost/rpm applications with varying injection rates. I've done this kind of measurement with the multiple EGT probes in my exhaust, and it's quite interesting to see how the EGT's drop along a relatively short exhaust path.

Originally Posted by OmahaDZL

As for placement of nozzle in relation to the temp sensor.... I was under impression that the benefit was direct. But you seem to be saying that its more for your monitoring than the DDEs.....so you can better monitor all of your info to get every last ounce of power out....

It appears our DDE's do not take advantage of the opportunity offered by the IAT to further tailor injection timing. Which is too bad, as it's a fairly important influence in combustion behavior.

I want to have a good idea of the IAT's so I can better understand what is going on in the system. It is an important parameter for knowing how much oxygen is going into the cylinders. Also, the enjoyment is more about learning than trying to get every last ounce of power ... which is why I've been slowly making limited changes over the years, doing one mod at a time and then measuring/analyzing/tweaking things. I had very little understanding when I first started playing with this platform. Experimentation and discussions with many people on here have significantly improved my understanding, and for that I am grateful.

Originally Posted by OmahaDZL

So to sum up...If I understand you correctly....putting it before the temp sensor helps in evaporation, but wont really help vis a vis the temp sensor.... So why not put it in the hard pipe on the upstream side of the IC? also would keep oil down in the IC

DWR and I have discussed putting a main nozzle pre IC on the hot side. The concern I have with this location is water pooling in the IC (the methanol would easiy evaporate, but the water "could" linger). This might not be a problem with a good solenoid setup extremely close to the nozzle, but if you use a check valve the slow shut off time and "dribble" could leave some water in there...

The only nozzle I've tried pre-IC is for pre-compressor injection. I measured no benefit from this, and in all cases for the numerous environmental conditions in my location, I measured a decrease in peak output capability (had an in cab switch that could turn on/off the utilization of the ~100 ml/min nozzle). The least negative impact was within the margin of accuracy of PerfExpert, and it was on a hot/dry day, but that's unusual environmental conditions for my geographic area (usually if its hot, it's also humid, and those conditions showed a negative impact, as did any kind of cool/cold condition). I've heard some people report a benefit from doing this, but I didn't measure any benefits. And the potential for compressor blade damage seemed like it's not worth the risk for my daily driver.

[nicklockard]

Originally Posted by TDIwyse

So ... "better" is a term that could mean different things to different people with different goals (reducing certain emissions, increasing air density, etc.). If you want to fully maximize the density of the compressed air to maximize oxygen content, then you'd want all the fluid to fully evaporate in the intake to maximize the temperature reduction (basically a chemical intercooler). The closer the injection is to the cylinder, the less opportunity the fluid has to fully evaporate.

It would be really interesting to put multiple IAT sensors in the intake track and monitor the temperature along the intake to get a better idea of how the temperature profile behaves during high boost/rpm applications with varying injection rates. I've done this kind of measurement with the multiple EGT probes in my exhaust, and it's quite interesting to see how the EGT's drop along a relatively short exhaust path.



It appears our DDE's do not take advantage of the opportunity offered by the IAT to further tailor injection timing. Which is too bad, as it's a fairly important influence in combustion behavior.

I want to have a good idea of the IAT's so I can better understand what is going on in the system. It is an important parameter for knowing how much oxygen is going into the cylinders. Also, the enjoyment is more about learning than trying to get every last ounce of power ... which is why I've been slowly making limited changes over the years, doing one mod at a time and then measuring/analyzing/tweaking things. I had very little understanding when I first started playing with this platform. Experimentation and discussions with many people on here have significantly improved my understanding, and for that I am grateful.



DWR and I have discussed putting a main nozzle pre IC on the hot side. The concern I have with this location is water pooling in the IC (the methanol would easiy evaporate, but the water "could" linger). This might not be a problem with a good solenoid setup extremely close to the nozzle, but if you use a check valve the slow shut off time and "dribble" could leave some water in there...

The only nozzle I've tried pre-IC is for pre-compressor injection. I measured no benefit from this, and in all cases for the numerous environmental conditions in my location, I measured a decrease in peak output capability (had an in cab switch that could turn on/off the utilization of the ~100 ml/min nozzle). The least negative impact was within the margin of accuracy of PerfExpert, and it was on a hot/dry day, but that's unusual environmental conditions for my geographic area (usually if its hot, it's also humid, and those conditions showed a negative impact, as did any kind of cool/cold condition). I've heard some people report a benefit from doing this, but I didn't measure any benefits. And the potential for compressor blade damage seemed like it's not worth the risk for my daily driver.

I did a detailed analysis of the potential for water pooling in an IC on tdiclub. I'll dig it up if I can. Short story is you'd have to flow an outrageously absurd amount at absurdly low engine RPM's to do so. For any reasonable set of conditions that warrant water injection, the air velocities (by volume and by mass) just won't support puddling. Droplet coalescence would be balanced by velocity shearing in the IC, and droplets would break up.

Plus there are videos of people literally pouring a garden hose worth of water stream into a diesel intake and not stalling it. IMO, people worry way too much about this remote possibility.

I also ran an analysis of when pre-turbo injection is beneficial and when not. I'll post links soon. It depends on the mixing ratio environmental factor.

[OmahaDZL]

Originally Posted by nicklockard

I did a detailed analysis of the potential for water pooling in an IC on tdiclub. I'll dig it up if I can. Short story is you'd have to flow an outrageously absurd amount at absurdly low engine RPM's to do so. For any reasonable set of conditions that warrant water injection, the air velocities (by volume and by mass) just won't support puddling. Droplet coalescence would be balanced by velocity shearing in the IC, and droplets would break up.

Plus there are videos of people literally pouring a garden hose worth of water stream into a diesel intake and not stalling it. IMO, people worry way too much about this remote possibility.

I also ran an analysis of when pre-turbo injection is beneficial and when not. I'll post links soon. It depends on the mixing ratio environmental factor.

Patiently waiting for that detailed analysis....this is coming up today on the FB page and something Id LOVE to get some consensus around.

[TDIwyse]

For the data nerds ...

This is for pure water, and shows how the evaporation time for a given mass of water changes vs the diameter of the droplets. A 2X increase in the droplet diameter increases evap time by 4X.

It also shows how a single injection of varying sized water droplets evaporate in a stream of hot air, which is very interesting.

If you know how much mass air flow your engine is flowing (OEM MAF clips at 44.1 lb/min, so you'd need an alternate way to measure air mass ... like this: http://www.e90post.com/forums/showthread.php?p=19151674 ) you can back out the CFM (if you have the correct logged parameters) and then calculate velocity in your charged air intake system, and then calculate residence time available for evaporation before the various cylinders ... Moving the IAT sensor from the charge pipe to the intake manifold would give a dramatically better and more accurate log of the actual air temps hitting the cylinders during conditions where injectioni s used.

As the charts show, it doesn't take long for the very fine droplets to evaporate (but if you do the above calculation you'll be astonished how little time exists for evaporation to occur), but it takes a very long time for increasingly large droplets to evaporate.

Adding alcohol to the water significantly reduces evaporation time, and also reduces surface tension, allowing for finer atomization for a given nozzle/pump combo. Both things are good for reducing time required for the state change from liquid to gas, where the big temp reductions and air density increase occurs.

I would think on our setups, with the incredibly short distance available for a nozzle to be used post compressor/pre IC, if you use a nozzle there that the chance of the liquid droplets having sufficient time to evaporate plummets, and will thus cause them to impact hard surfaces and coalesce/combine into larger droplets, which will dramatically increase evaporation time. The details on how significant, or insignficant, this will be will likely depend on specifics of the individual system.

[OmahaDZL]

Originally Posted by TDIwyse

I would think on our setups, with the incredibly short distance available for a nozzle to be used post compressor/pre IC, if you use a nozzle there that the chance of the liquid droplets having sufficient time to evaporate plummets, and will thus cause them to impact hard surfaces and coalesce/combine into larger droplets, which will dramatically increase evaporation time. The details on how significant, or insignficant, this will be will likely depend on specifics of the individual system.

So you are saying that going pre-IC, the droplets would come into contact with the surface of the intercooler too soon and would coalesce and collect.... Would probably be the same concept directly in the intercooler....thus the best place would be very low on the hard pipe coming out of the IC? Correct?

[TDIwyse]

Originally Posted by OmahaDZL

So you are saying that going pre-IC, the droplets would come into contact with the surface of the intercooler too soon and would coalesce and collect.... Would probably be the same concept directly in the intercooler....thus the best place would be very low on the hard pipe coming out of the IC? Correct?

Well, "best" is term that can change with perspective/intent/specifics... Really, if you want to find what's "best" for you, you should do some experimentation and measure behaviors and see how things change, so you can zero in on what's "best" for you :-)

I haven't specifically tried a nozzle between the compressor/IC, so I don't have any hard data to say if its better/worse than how I have things configured in my system. However, I tend toward the belief that positioning a nozzle in this location will not help atomization due to the very short distances involved with the way my 335d is presently configured. I think the droplets would coalesce more due to impacting surfaces, increase droplet diameter, and reduce evaporation. But again, this is speculation since I haven't done an actual test.

Here's a fun youtube video of a pre compressor injection setup that shows some behavior of coalescing droplets on the intake tube (skip to about the 1 minute point).

I got a good laugh when I first watched this as the dude almost had a pre-camera injection event during boost ... I don't think I'll try filming anything in my intake. I have, however, done injection/nozzle comparisons in PVC pipes with varying airflow and seen issues with coalescing droplet behavior with various vendors nozzles and pump pressures.

[OmahaDZL]

Originally Posted by TDIwyse

Really, if you want to find what's "best" for you, you should do some experimentation and measure behaviors and see how things change, so you can zero in on what's "best" for you :-)

I should have known better than to phrase it like that

[nicklockard]

Originally Posted by OmahaDZL

Patiently waiting for that detailed analysis....this is coming up today on the FB page and something Id LOVE to get some consensus around.

Post 146, 147, and 148 for how much flow is too much for water pooling in IC, here.

Post 213 for which ambient conditions it's beneficial to inject pre-turbo, here.

@TdiWyse: you can help ensure droplet distribution is more uniform (narrower bell curve) by addition of about 5 drops of high grade dish soap per gallon. That's a well known trick to reduce the mean diameter and tighten the distribution. Never use hard water--deionized is preferred.

Edit to add: if I were to repeat the analysis for how much water is too much for pooling in IC today, I'd just get to the point with graphs and tables and leave out the funny bits . And if I were repeating the analysis for when pre-turbo water injection helps with cooling intake charge, I'd just point you to the Vaisala humidity calculator and have you do it yourself. It's the best psychrometric software I've found that isn't a tarted-up, overpriced excel macro waiting the 'splode into bad VBA code.

[TDIwyse]

Originally Posted by nicklockard

...
@TdiWyse: you can help ensure droplet distribution is more uniform (narrower bell curve) by addition of about 5 drops of high grade dish soap per gallon. That's a well known trick to reduce the mean diameter and tighten the distribution. Never use hard water--deionized is preferred.

I had read a post of yours many years ago about using soap to reduce surface tension. That seemed like a great idea, so I tried it. However, every time I've tried this I shortly thereafter start having flow issues as measured by my in-cab flow gauge. It appears that the soap starts to foam inside the pump (I've tried 2 different pumps and both had issues) and causes priming/flow issues. I could crack open a fitting, then manually trigger the pump and get things to prime and start working again. For a short time ... and then the problem would come back.

Each time I've done this I end up having to flush/drain the system to return to proper pump/flow behaviors. However, just using a 50/50 or above ratio of methanol with the water significantly lowers surface tension as well, and I haven't had pump issues with this kind of combination.

Regarding pooling in the IC, this would actually be an easy test to implement. Hmmmm, I think I have my old OEM intercooler out in the garage somewhere. I might try to rig up a redneck test this weekend...

[TDIwyse]

Here was a good reference on soap/water surface tension reduction. This value is very close to methanol surface tension.

[TDIwyse]

Originally Posted by TDIwyse

...
Regarding pooling in the IC, this would actually be an easy test to implement. Hmmmm, I think I have my old OEM intercooler out in the garage somewhere. I might try to rig up a redneck test this weekend...

Got a test done using the OEM IC and my 6hp shop vac which can move air at up to ~180mph according to its specs. Results are ugly...I definitely won't be moving a nozzle into the pre-IC area.

First ~10 seconds show the pre test, and the close up of the outlet shows there's some residual oil left over from years ago that are the result of crankcase ventilation, but it's thick enough to not blow out the outlet. Then I turn on the 200 psi pump and full power and am using a small 2gph nozzle about 1 ft before the IC inlet, using 50/50 water/methanol. The nozzle produces a beautiful mist when injecting into the air. The results are pretty ugly, as atomization is destroyed and coalescing moisture becomes apparent.

[335dsleeper]

Thanks for performing and posting the test a video.

Do you think the volume of air would change the results? Would the compressed air leaving the turbo change the results? Would the post turbo air temp, air volume and velocity change how the water interacts in the intercooler?

[TDIwyse]

Originally Posted by 335dsleeper

...
Do you think the volume of air would change the results? Would the compressed air leaving the turbo change the results? Would the post turbo air temp, air volume and velocity change how the water interacts in the intercooler?

At high boost/rpm, the air temp and velocity would be higher than with this test, so that would be a difference which would likely help. However, the higher velocity would also give less time for evaporation to occur. And I was also using a small nozzle and high pump pressure to give excellent atomization for this test, and gave more physical distance from the inlet than what could be accomplished in the 335d . Based on what I was seeing, it confirms the concern about issues with coalescing droplets if the fluid isn't evaporated before hitting the IC.

[Bmwuk]

Just in process of setting up my devils own stage 2 voltage progressive controller install. Have people taken a signal direct from dde or from obd port? Whats the best option or are they the same result? Also, have people run piping under car or through interior?

[OmahaDZL]

Originally Posted by Bmwuk

Just in process of setting up my devils own stage 2 voltage progressive controller install. Have people taken a signal direct from dde or from obd port? Whats the best option or are they the same result? Also, have people run piping under car or through interior?

I think Andrew R just posted a video on the FB page (likely through youtube though so im sure its there) about how to tap into the DDE...

[Owen81]

@Ohiodiesel see post #7 from @TDIwyse here:
http://www.e90post.com/forums/showth...ght=hard+start

[DWR]

Originally Posted by 335dsleeper

Do you think the volume of air would change the results? Would the compressed air leaving the turbo change the results? Would the post turbo air temp, air volume and velocity change how the water interacts in the intercooler?

In a word, yes. Temperature drop due to evaporation does not depend on air temperature, as long as it is high enough, and there is enough time for all the liquid to evaporate. The intercooler's temp drop, on the other hand, does depend on the temperature difference. That difference will be greatest if evaporative cooling happens after the intercooler, not before. That means inject after the intercooler to maximize total temperature drop and maximum density.

[Bmwuk]

Finally installed my meth kit and wondering why i didnt do it sooner... pulls amazing even on a lower sized nozzle... getting a 400cc one installed soon but it has transformed it... highly recommend to anyone thinking about installing

[rkstar9]

Originally Posted by Bmwuk

Finally installed my meth kit and wondering why i didnt do it sooner... pulls amazing even on a lower sized nozzle... getting a 400cc one installed soon but it has transformed it... highly recommend to anyone thinking about installing

how do you know how many cc's a system puts out?

is it based on the nozzle or on the pump or a combination of the too?

i ask because i see pumps rated at 150psi or nozzles that say 3.61gpm@40psi so how many cc's is that?

hope i don't need an advanced degree to figure this out???

[Bmwuk]

I am sure a few more people on here will inform you better but it is a number of factors....

check out this thread for guidance...


http://www.alcohol-injection.com/for...flow-rate.html