Pre turbo nozzle location ? in my cold air intake
07-22-11, 01:10 AM
#1
Pre turbo nozzle location ? in my cold air intake
I'm looking for a recommendation on where I should install the water injector in my cold air intake, pre turbo. AEM water injection kit, probably water only, T04R turbo. Please check out the pics below and more pics at http://www.flickr.com/photos/tom_truxell/ .
Should I drill and tap the straight pipe that connects in between my two 45 degree silicone elbows, it would be about 8" before the turbo. This would be the easiest place to put it, since my water line runs right in front of the passenger side strut tower so it would hook up nicely in this location. Would it really matter where the injector was located in my intake pre turbo, or what is the best location for it? I could think of reasons why it could be good or bad in any of the locations, and at any angle (left or right side of the pipe, top or bottom etc.) My air filter rest on the undercover below it at the base of the front bumper so I don't have room to inject into the front (bottom in my case) of the air filter.
I've seen a pic of dudemans... setup which is similar to mine and the injector is in the 45 degree bend that connects to the turbo.
Thanks for any thoughts or suggestions.
Should I drill and tap the straight pipe that connects in between my two 45 degree silicone elbows, it would be about 8" before the turbo. This would be the easiest place to put it, since my water line runs right in front of the passenger side strut tower so it would hook up nicely in this location. Would it really matter where the injector was located in my intake pre turbo, or what is the best location for it? I could think of reasons why it could be good or bad in any of the locations, and at any angle (left or right side of the pipe, top or bottom etc.) My air filter rest on the undercover below it at the base of the front bumper so I don't have room to inject into the front (bottom in my case) of the air filter.
I've seen a pic of dudemans... setup which is similar to mine and the injector is in the 45 degree bend that connects to the turbo.
Thanks for any thoughts or suggestions.
07-28-11, 05:03 PM
#5
About as much power as I can get safely with my current setup and I'm sure I'll have to put my 850 injectors back in the primary rail for more fuel. I wanted to start off testing with the small jet and probably end up with the middle size or large jet. I know many recommend a small jet pre turbo and others recommend a large jet pre turbo. Thanks
07-28-11, 06:06 PM
#6
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Iīm interested in your ignition setup? Iīve noticed that you mentioned loss of power on previous setup. Many people reported same, but by looking on old NACA studies, it all comes down to ignition. At usual water-fuel ratios used, it shouldnīt drop single HP - all other variables held constant.
Best of luck with new setup
Best of luck with new setup
07-28-11, 06:38 PM
#7
Before when I ran the water/meth pre throttle body I had a Jacobs fc1000 ignition with a fc leading coil, not sure which plugs were in the car at that time. Now I have a crane ignition and a twin post msd coil and the rotary racing plugs. So ya hopefully it works better with this ignition setup. Thx.
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08-07-11, 09:45 AM
#11
Around 500 HP, Idk I'll end up tuning up to about 25 psi probably so we'll see. I'm still tuning at 12 psi right now. I'm thinking adding a small jet to the greddy elbow too, t off my water line. I have a new aem 200 psi recirculating pump and the dual nozzle kit. .96 a/r and power fc
08-07-11, 10:43 AM
#13
I like it, I haven't turned up the boost high yet so full throttle is not comparable, but other than that it doesn't feel much different, it spools up about the same as the non sequential twins. At 10-12 psi with the 315 cc/min water injector with 200 psi full pressure, it definitely makes a lot more power with 11.5 afr compared to 11 or richer afr, and no knock. So I'm tuning for 11.5 afr for the boost rows above 10 psi with conservative timing right now.
08-11-11, 02:42 PM
#14
I added another nozzle post intercooler, as I wanted to do some experimenting and see if the extra water post intercooler helps. See pics attached. I chose to try it here for something a little different than most do for the rx7. One theory is that the water will have more time to mix with the air before it gets to the uim. I did some testing, I think it works pretty good, even with just a tiny 130cc/min at 150 psi injector I am currently using in this location, along with a 330cc/min pre turbo (200 psi aem pump so that ups the flow from the jets a little). ait temps stay steady during and after boosting (greddy elbow location fast reacting sensor), right around or just above ambient depending if it is after a heat soak. After I let it heat soak, the temps came down as I drove around and continued to fall to 30 degrees Celsius (close to ambient) as I boosted it. I did some 2nd and 3rd gear pulls, 10-13 psi boost, and then pulled over. My uim and greddy elbow were cool, not warm at all, cool like they were when I pulled the car out of the garage. Also importantly, the lim was cool too, even right above the point where my turbo heat blanket touches the lim the lim was not even warm at this location. When the car sits or idles for a few mins, the lim gets very hot, and the uim gets hot, as it was when I let the car heat soak before driving around boosting.
Now I know I am running low boost, and higher boost will make more heat, but then I will just put bigger water injectors in, I'll put the 550cc pre turbo and maybe 330cc post fmic or keep the 130cc there.
One thing I notice is that the fast reacting ait sensor reading does not change much at all, this must also mean that water is not soaking the sensor so it isn't giving a false colder temp reading. I don't like how it still heat soaks in the greddy elbow so I am going to move it back into the post fmic location that I had it in a few years ago, see pic attached. This location is just upstream of the water injector, so its pre water. I figure that the water will keep the air cool so the ait reading coming out of the fmic will be close to the temp of the air going through the uim where the sensor comes stock.
Although another theory is that the air could heat up by the time it gets to the throttle body so most recommend putting the nozzle in the greddy elbow or close to it, but I doubt the air will heat up since it's moving so fast through these pipes, and I plan to put some heat reflective tape around my intercooler pipe that goes to the greddy elbow, because that pipe gets warm from the hot air blowing from the radiator fans, that pipe was warm while the rest of the pipes from the fmic to the lim were not warm. So in my location post fmci there is more time for the water to mix with the air to provide a even water distribution to the uim.
Now I know I am running low boost, and higher boost will make more heat, but then I will just put bigger water injectors in, I'll put the 550cc pre turbo and maybe 330cc post fmic or keep the 130cc there.
One thing I notice is that the fast reacting ait sensor reading does not change much at all, this must also mean that water is not soaking the sensor so it isn't giving a false colder temp reading. I don't like how it still heat soaks in the greddy elbow so I am going to move it back into the post fmic location that I had it in a few years ago, see pic attached. This location is just upstream of the water injector, so its pre water. I figure that the water will keep the air cool so the ait reading coming out of the fmic will be close to the temp of the air going through the uim where the sensor comes stock.
Although another theory is that the air could heat up by the time it gets to the throttle body so most recommend putting the nozzle in the greddy elbow or close to it, but I doubt the air will heat up since it's moving so fast through these pipes, and I plan to put some heat reflective tape around my intercooler pipe that goes to the greddy elbow, because that pipe gets warm from the hot air blowing from the radiator fans, that pipe was warm while the rest of the pipes from the fmic to the lim were not warm. So in my location post fmci there is more time for the water to mix with the air to provide a even water distribution to the uim.
08-11-11, 02:48 PM
#15
I also just ran my water line through a rubber boot and through a passageway in the underside of the passenger fender above the plastic fender liner, see pictures below. This way the water doesn't get heated like it was when my water line ran through the engine compartment on the passenger side where it gets hot.
08-11-11, 11:22 PM
#16
My understanding is that you want the smaller nozzle pre-turbo since you don't really want water flowing through the fmic, as it will collect in there unless very finely atomized (which the turbo does help do). Also, large amounts of water sprayed onto the compressor blade at speed will erode/degrade the blade over time. So, you run the small nozzle pre-turbo, it atomizes the water nicely and pre-cools the air as well as increases the efficiency of the turbo allowing it to veer out of its efficiency range once you really push it, then you let the larger nozzle post-ic do the main cooling of the charged air. ie, the reverse of your setup.
08-11-11, 11:44 PM
#17
Many guys on here run large or even huge water injectors pre turbo, and I've seen some say to actually run the large one pre turbo and a small one after the ic, and they say the water does not make it to the IC, it evaporates in the turbo from all the heat and it lowers the temps coming out of the turbo. A fmic does a great job of lowering the air temps, so I think a big injector is not needed after a fmic and a small one post fmic combined with a larger pre turbo injector seems to work good. If it was a stock mount or similar IC under the hood, then yes a bigger water jet post ic would more than likely be needed.
08-12-11, 03:23 AM
#18
The larger the pre turbo nozzle, the less relevant the IC will become. This is because an efficient IC will start to condense the water back out of the air (to a point of 100% saturation at just above the ambient temp). The result is a net reduction in the IC's capacity to reduce the sensible temperature (e.g., what the IAT sensor measures) of the intake charge.
The math suggests that greatest power potential is achieved by reducing the sensible intake charge temp as much as possible with an efficient turbo and IC and then inject a modest amount of water downstream. This approach should generally result in maximum intake charge density.
That being said, it is possible to inject water pre turbo in modest amounts and still see some benefits without significantly reducing IC efficiency; which is a good tradeoff IMO. And this is the approach I take, primarily to aid turbo thermal management.
At normal and reasonable H2O flow rates, I would suggest starting with 30% pre-turbo and inject the balance post IC.
The math suggests that greatest power potential is achieved by reducing the sensible intake charge temp as much as possible with an efficient turbo and IC and then inject a modest amount of water downstream. This approach should generally result in maximum intake charge density.
That being said, it is possible to inject water pre turbo in modest amounts and still see some benefits without significantly reducing IC efficiency; which is a good tradeoff IMO. And this is the approach I take, primarily to aid turbo thermal management.
At normal and reasonable H2O flow rates, I would suggest starting with 30% pre-turbo and inject the balance post IC.
08-12-11, 11:17 AM
#19
Thanks for your thoughts and info. With my car's setup I'm getting reasonably low ait, the fmic outlet is cold and the intake manifolds are staying cool with the small post fmic injector, and knock is non existent or very low with conservative timing and afr 11-11.7, tuning trying to keep it close to 11.5 . therefore its pointless to inject more water post fmic, unless its needed after turning up the boost. But I ran up to 22 psi with stock turbos in colder weather and no water injection. And water just made it loose power, more water equalled more power loss.
10-02-11, 06:14 PM
#20
So my turbo impeller blades look to be getting damaged from the pre turbo water injection, see before and after pics below.
Before - http://farm7.static.flickr.com/6156/...c2bcc972_b.jpg
After - http://farm7.static.flickr.com/6018/...155e3b68_b.jpg
Thoughts?
I bought the turbo kit used and I think he also had pre turbo wi which might explain why it wasn't in perfect condition to begin with. I have been injecting water pre turbo with a 315cc aem nozzle with their newer 200 psi pump. I have not been injecting any post fmic lately because doing both I guess was too much water and I was losing power with both pre turbo and post fmic wi. Now I wonder if I should do only post fmic injection. I have a k&n air filter that is only 2 or 3 months old.
How much is this impeller blade damage hurting performance?
Before - http://farm7.static.flickr.com/6156/...c2bcc972_b.jpg
After - http://farm7.static.flickr.com/6018/...155e3b68_b.jpg
Thoughts?
I bought the turbo kit used and I think he also had pre turbo wi which might explain why it wasn't in perfect condition to begin with. I have been injecting water pre turbo with a 315cc aem nozzle with their newer 200 psi pump. I have not been injecting any post fmic lately because doing both I guess was too much water and I was losing power with both pre turbo and post fmic wi. Now I wonder if I should do only post fmic injection. I have a k&n air filter that is only 2 or 3 months old.
How much is this impeller blade damage hurting performance?
10-02-11, 08:34 PM
#22
The pump also primes for a couple seconds when I turn the key on, so it squirts in water, then that water will sit in the intake pipe until it gets sucked into the turbo, so if it doesn't get sucked in until enough suction is capable of pulling it in up over the lip of the turbo inlet then this could be a problem if it gets sucked in at boost when the turbo is spinning fast. Also I often times disconnect the battery, when I connect the battery the pump pumps in water, then it does it again when I turn the key to start it. I was a little worried about that being a problem, perhaps it Is?
Maybe this is one reason aem doesn't recommend pre turbo injection lol.
Maybe this is one reason aem doesn't recommend pre turbo injection lol.
10-02-11, 09:17 PM
#23
When I first installed this setup I had the little 130cc nozzle and was running about 18 psi and I remember checking after a few weeks and it looked good, no damage. Then I put in the 315 nozzle and running up to 24 psi boost, so ya the bigger nozzle and increased turbo speed could be a contributor. Maybe I'll put the 130 back in pre turbo and put in another 130 or the 315cc nozzle post fmic.
10-03-11, 05:54 AM
#24
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Or just simply one jet post IC and run just enough to suppress knock.