Meth/water just before supercharger
03-29-2016, 05:06 PM
#1
Pro
Thread Starter
Meth/water just before supercharger
I haven't found much info on this subject. I'm designing/building my on Meth/water injection system. I will be using multiple nozzles. I am considering using one of the nozzles as a fogging nozzle to inject some amount (?) of the total meth/water charge just before the supercharge intake - this should allow denser charge, increase the efficiency of the charger and help with lower IAT's.
Problem is I can't find much info on the proper methods and amount to inject before the charger. Have any of you FI guys experimented with this or tuned such a system? If so can you give me input as to amount to inject, beginning injection PSI, etc. Or point me to info on the net that will help me design. I have found some fogging nozzles that I think will do a much better job of atomizing/breaking up the charge compared to most of the nozzles now in use. I think this will work well but I have no experience.
Please let me know what you think/know about this method.
Problem is I can't find much info on the proper methods and amount to inject before the charger. Have any of you FI guys experimented with this or tuned such a system? If so can you give me input as to amount to inject, beginning injection PSI, etc. Or point me to info on the net that will help me design. I have found some fogging nozzles that I think will do a much better job of atomizing/breaking up the charge compared to most of the nozzles now in use. I think this will work well but I have no experience.
Please let me know what you think/know about this method.
03-30-2016, 04:09 AM
#2
Drifting
I considered doing this, and tried to find information on it some time ago. If you search the web, you'll find SOME information about injecting water/meth before a turbocharger, which is functionally basically the same as a centri supercharger in this case. I know I've heard that some rally teams (Subaru) do pre-turbo water injection, but, they're not concerned about the longterm life of their turbos.
Most sources say that you need to inject very small amounts of meth/water (like 3 GPM) and ensure its fully atomized before hitting the compressor or else you can damage the fins. I've also heard that there's a danger of water accumulating in the housing which can damage the bearings.
Most importantly the meth/water changes the characteristics (compressor Map) of the turbo/supercharger. You're effectively changing the air density, which affects the efficiency, boost level, etc. etc.
In short, its more complicated than you would think and can dramatically effect the way your supercharger behaves. I don't know much beyond this, but its probably not a good idea.
Devil's Own has a small blurb about it on their website. Its pretty much the only source I've found on this subject that isn't random people on a Subaru forum.
http://www.alcohol-injection.com/en/...jection-nozzle
Most sources say that you need to inject very small amounts of meth/water (like 3 GPM) and ensure its fully atomized before hitting the compressor or else you can damage the fins. I've also heard that there's a danger of water accumulating in the housing which can damage the bearings.
Most importantly the meth/water changes the characteristics (compressor Map) of the turbo/supercharger. You're effectively changing the air density, which affects the efficiency, boost level, etc. etc.
In short, its more complicated than you would think and can dramatically effect the way your supercharger behaves. I don't know much beyond this, but its probably not a good idea.
Devil's Own has a small blurb about it on their website. Its pretty much the only source I've found on this subject that isn't random people on a Subaru forum.
http://www.alcohol-injection.com/en/...jection-nozzle
Last edited by PhysicsDude55; 03-30-2016 at 04:11 AM.
03-30-2016, 05:50 AM
#3
Use an M3/M4 nozzle if you want to, anything more is too big...
There is zero chance of damaging any bearing...
Injecting it there vs the intake tube itself, it the same thing only your trying to cool down the head unit itself a little bit, that's it..
Real racers been doing this for years with no ill effects what do ever.
There is zero chance of damaging any bearing...
Injecting it there vs the intake tube itself, it the same thing only your trying to cool down the head unit itself a little bit, that's it..
Real racers been doing this for years with no ill effects what do ever.
03-30-2016, 08:05 AM
#4
Pro
Thread Starter
Meth/water prior to supercharger
First, thanks for the reply. I think some of your negative points are very valid. But, I also think part of the solution is a fogging nozzle at a reasonably high pressure (250 - 300 PSI) - as opposed to a misting nozzle. The smaller droplet size is more likely to make it through the head unit with out coming out of suspension. If you look at the pattern of the smaller fogging nozzles (videos are online) you will see the difference. The output of the fogging nozzle is reminiscent of a morning fog.
Combine that with a only small portion of the total water/meth would be injected prior to the head unit. I'm guessing but probably on the order of .5 - 1.0 GPH ( calculations need to be done). The remainder would be injected in the traditional manner just prior to the intake in a second nozzle tied to the same water/meth source and connected to the same pump. However, using flow control, the head unit supply could come on sooner - maybe as soon as boost is seen. That way you don't abruptly change the head unit behavior after boost is initiated.
Small droplets, decent pressure and small amount might work. I also understand the pressure map would change to a degree but I don't think it will make a particular head unit unusable in it's intended application. I only see benefits. Cooler charge = more charge = more charge sooner & lower IAT's (I think
). One might have to "pulley" around the performance of the meth/water injection if the use of it prior to the head unit if it substantially changes the map. I've also received another reply indicating this is "old hat" in some racing circles and is safe and effective.
Watch the thread. With your screen name I am assuming you may be able to contribute as the discussion develops. Thanks again.
Combine that with a only small portion of the total water/meth would be injected prior to the head unit. I'm guessing but probably on the order of .5 - 1.0 GPH ( calculations need to be done). The remainder would be injected in the traditional manner just prior to the intake in a second nozzle tied to the same water/meth source and connected to the same pump. However, using flow control, the head unit supply could come on sooner - maybe as soon as boost is seen. That way you don't abruptly change the head unit behavior after boost is initiated.
Small droplets, decent pressure and small amount might work. I also understand the pressure map would change to a degree but I don't think it will make a particular head unit unusable in it's intended application. I only see benefits. Cooler charge = more charge = more charge sooner & lower IAT's (I think
). One might have to "pulley" around the performance of the meth/water injection if the use of it prior to the head unit if it substantially changes the map. I've also received another reply indicating this is "old hat" in some racing circles and is safe and effective.Watch the thread. With your screen name I am assuming you may be able to contribute as the discussion develops. Thanks again.
I considered doing this, and tried to find information on it some time ago. If you search the web, you'll find SOME information about injecting water/meth before a turbocharger, which is functionally basically the same as a centri supercharger in this case. I know I've heard that some rally teams (Subaru) do pre-turbo water injection, but, they're not concerned about the longterm life of their turbos.
Most sources say that you need to inject very small amounts of meth/water (like 3 GPM) and ensure its fully atomized before hitting the compressor or else you can damage the fins. I've also heard that there's a danger of water accumulating in the housing which can damage the bearings.
Most importantly the meth/water changes the characteristics (compressor Map) of the turbo/supercharger. You're effectively changing the air density, which affects the efficiency, boost level, etc. etc.
In short, its more complicated than you would think and can dramatically effect the way your supercharger behaves. I don't know much beyond this, but its probably not a good idea.
Devil's Own has a small blurb about it on their website. Its pretty much the only source I've found on this subject that isn't random people on a Subaru forum.
http://www.alcohol-injection.com/en/...jection-nozzle
Most sources say that you need to inject very small amounts of meth/water (like 3 GPM) and ensure its fully atomized before hitting the compressor or else you can damage the fins. I've also heard that there's a danger of water accumulating in the housing which can damage the bearings.
Most importantly the meth/water changes the characteristics (compressor Map) of the turbo/supercharger. You're effectively changing the air density, which affects the efficiency, boost level, etc. etc.
In short, its more complicated than you would think and can dramatically effect the way your supercharger behaves. I don't know much beyond this, but its probably not a good idea.
Devil's Own has a small blurb about it on their website. Its pretty much the only source I've found on this subject that isn't random people on a Subaru forum.
http://www.alcohol-injection.com/en/...jection-nozzle
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tysmith45 (05-27-2020)
03-30-2016, 08:11 AM
#5
Pro
Thread Starter
water/meth prior to head unit
Tanks for the reply Big Jt. Please hang around and watch the thread. Sounds like you may have some good information. Also pleas read my reply to PhysicsDude and see what you think.
Use an M3/M4 nozzle if you want to, anything more is too big...
There is zero chance of damaging any bearing...
Injecting it there vs the intake tube itself, it the same thing only your trying to cool down the head unit itself a little bit, that's it..
Real racers been doing this for years with no ill effects what do ever.
There is zero chance of damaging any bearing...
Injecting it there vs the intake tube itself, it the same thing only your trying to cool down the head unit itself a little bit, that's it..
Real racers been doing this for years with no ill effects what do ever.
03-30-2016, 07:40 PM
#6
Drifting
Use an M3/M4 nozzle if you want to, anything more is too big...
There is zero chance of damaging any bearing...
Injecting it there vs the intake tube itself, it the same thing only your trying to cool down the head unit itself a little bit, that's it..
Real racers been doing this for years with no ill effects what do ever.
There is zero chance of damaging any bearing...
Injecting it there vs the intake tube itself, it the same thing only your trying to cool down the head unit itself a little bit, that's it..
Real racers been doing this for years with no ill effects what do ever.
Just because racers do it doesn't mean I'd want it on my street car.... racers also use anti-lag systems ("bang bang" systems), but probably results in very short turbo lifespans for street cars.
You can find a few videos of pre-trubo injection systems. Once the throttle lets off, you can see that water flies all over inside the turbo. Its probably less violent for a centri, and I don't know that the water would really damage anything, but its something to consider. I mean, its not like it will rust inside, and the intake is exposed to humid air all the time.
I'm guessing but probably on the order of .5 - 1.0 GPH ( calculations need to be done). The remainder would be injected in the traditional manner just prior to the intake in a second nozzle tied to the same water/meth source and connected to the same pump. However, using flow control, the head unit supply could come on sooner - maybe as soon as boost is seen. That way you don't abruptly change the head unit behavior after boost is initiated.
..I only see benefits. Cooler charge = more charge = more charge sooner & lower IAT's (I think). One might have to "pulley" around the performance of the meth/water injection if the use of it prior to the head unit if it substantially changes the map. I've also received another reply indicating this is "old hat" in some racing circles and is safe and effective.
..I only see benefits. Cooler charge = more charge = more charge sooner & lower IAT's (I think
). One might have to "pulley" around the performance of the meth/water injection if the use of it prior to the head unit if it substantially changes the map. I've also received another reply indicating this is "old hat" in some racing circles and is safe and effective.Might be kind of like a really big cam... yes could technically get a lot more power, but on the wrong setup it could actually hurt performance. I'm not saying it will hurt your car, but its more complicated than just more meth = more power.
If you're spraying less than 3GPM I say go for it. I don't know that it would help to start spraying pre-head unit earlier than pre-throttlebody. I'm curious to see how it turns out anyway.
Intuitively, I think you're on the same thought that I had, that spraying earlier lets the water/meth atomize better and have better distribution and thus better cooling. According to a lot of stuff I've read, that might not actually be beneficial. Port injected meth supposedly is a lot more effective than pre-intake injected meth, and port injected meth certainly will atomize less well than pre-intake injected meth.
I would take the advice of someone who does racing over what I say. I just know a few equations, doesn't always directly relate to real life.
03-30-2016, 09:05 PM
#7
Why are you even talking about turbos? is says in the title "superchargers"..therefore, whatever you say about turbos are irrelevant and basically a waste of time.. they are two different things all together..
I use an M3 and everyone else do too that runs it before the blower..You want to know what works..listen to a grudge racer or read on yellow bullet.. Saying that what racers do is not relevant for this thread is hog wash..other wise why would he want to do it before the blower anyways... hes trying to get every little bit of of the setup..exactly what grudge racers do..
I use an M3 and everyone else do too that runs it before the blower..You want to know what works..listen to a grudge racer or read on yellow bullet.. Saying that what racers do is not relevant for this thread is hog wash..other wise why would he want to do it before the blower anyways... hes trying to get every little bit of of the setup..exactly what grudge racers do..
04-05-2016, 04:31 PM
#8
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Some info here: http://www.aquamist.co.uk/forum2/vbu...read.php?t=531
http://www.aquamist.co.uk/forum2/vbu...read.php?t=251
http://www.aquamist.co.uk/forum2/vbu...read.php?t=251
Last edited by bogor; 04-05-2016 at 04:40 PM.
04-05-2016, 09:55 PM
#9
Pro
Thread Starter
Injection
Thanks for the reply. Lot of good info on that site.
04-28-2016, 09:55 AM
#10
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One reason WMI usually takes place after the compressor is because hot air can hold more moisture before condensation takes place. Air coming into the compressor may be nearly saturated. And depending on where your water/meth tank is located, you may actually heat up the air with the spray.
Supercharger inlet air temperature and ambient air temperature should be pretty similar, correct? If your water/meth reservoir is in the trunk, it could still be hotter than the outside air, especially if the car has been sitting in the sun all day. So the question to ask is, what sort of temperature drop do you expect with the water/meth spray before the supercharger?
Supercharger inlet air temperature and ambient air temperature should be pretty similar, correct? If your water/meth reservoir is in the trunk, it could still be hotter than the outside air, especially if the car has been sitting in the sun all day. So the question to ask is, what sort of temperature drop do you expect with the water/meth spray before the supercharger?