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N54 water to air intercooler street build

Discussion in 'N54' started by bantam, Jun 7, 2018.

  1. bantam

    bantam Lurker

    Messages:
    10
    Ride:
    2009 335i
    Hi all, I have been wanting to do a water to air street build for a while, I realize that this is not the best way to spend my money to make the most power per $. I am a mechanical engineer, and for whatever reason, this project interests me the most. I like the idea of having the output paths similar for both turbos and the other *potential* benefits that this system could provide. This is going to be a slow project, as my day job and marital obligations wind up leaving me with little free time. If you are a person or a vendor who wants to replicate the project, I may be able to provide some guidance, I have no intent to commercialize the design. If you do commercialize it and make a better design, all that I ask is that you give me a discount on the final product!

    Potential benefits:
    1)The reduced charge pipe volume will slightly improve throttle response
    2)The reduced travel distance, number of bends, and length of travel through the A2A intercooler may provide some marginal high rpm performance gain for stock turbos due to the reduction in pumping losses.
    3) Possible sub-ambient cooling at some point in the design

    Potential drawbacks:
    1) Weight
    2) System Complexity
    3) Cost

    My first selection was the intercooler itself. I searched far and wide for Water to Air intercoolers, and I was never really satisfied with my options. Out of sheer frustration, I decided to try the most obvious choice (OEM M3). I liked that it had dual inlets with internal turning vanes to guide the airflow, had demonstrated good performance, and was made to work on a car that had a similar engine layout.

    To my surprise, it was not a close fit, it was an exact fit! It neatly mounts directly to to the stock intake manifold with the same rubber shock-absorbing mounts that the airbox uses!

    But there is no way that the hood will close with that thing in there right?

    Wrong! Hood closes fine and with room to spare. Attached are some photos that I have taken showing the clearance remaining after shutting the hood. (this is for a LCI e90)

    As you can see, the OEM expansion tank will also not require any modifications. IMG_7746.JPG IMG_7744.JPG IMG_7743.JPG IMG_7742.JPG IMG_7746.JPG IMG_7744.JPG IMG_7743.JPG IMG_7742.JPG
     
  2. ShocknAwe

    ShocknAwe Sergeant

    Messages:
    260
    Location:
    SC
    Ride:
    N54 1er
    Interesting. Do you have any more pictures of how that thing sits in there?
     
  3. KevinC39

    KevinC39 Specialist

    Messages:
    67
    Ride:
    335i
  4. The Convert

    The Convert Lieutenant

    Messages:
    500
    Ride:
    335
    In for more pics! Best of luck man!
     
  5. Rcboosted2007

    Rcboosted2007 Sergeant

    Messages:
    377
    Location:
    Fresno ca
    Ride:
    07 335i
    I brought up the idea on a previous thread. The question i had was this.
    If we replace the existing transmission cooler with an air over cooler(wheel well) style. Does the existing water cooler have the capacity to cool a water/air intercooler?
     
  6. Rcboosted2007

    Rcboosted2007 Sergeant

    Messages:
    377
    Location:
    Fresno ca
    Ride:
    07 335i
    Also the camaro zl1 is a nice compact design
     
  7. MoreBoost

    MoreBoost Specialist

    Messages:
    71
    Ride:
    335i
    Everyone wants an N54 you can pour ice into before a big pull :D:D:D
     
  8. Rob09msport

    Rob09msport Corporal

    Messages:
    154
    Ride:
    2009 335i msport le mans blue
    Do you know what total cost would be I would do this just to look sick lmao
     
  9. MoreBoost

    MoreBoost Specialist

    Messages:
    71
    Ride:
    335i
    I like your thinking OP, doing it for fun and not worrying about costs too much.

    I found that on the rare occasional warm English day when I got to a drag strip that the IATs just rocketed from sitting in a queue to race. No airflow over the intercooler and heat soak under the hood often meant being most of the way down the track before the FMIC could do it's job. I considered a water system. I wanted to just spray icy water over the outside of the FMIC to keep things simple. I already use methanol injection for chemical IAT cooling under throttle. Which works great tbh. Spraying water on the outside of a FMIC seems to work quite well but it's obviously a big no no on a drag strip. The drops will pool on the rubber track and you'll be kicked off. It's fine spraying water during road use and you don't have the need to recool heated water. The cost being to replace the water or ice after each tank. With a pump system of course that then means monitoring the tank level and not letting the pump run when dry, burning itself out.

    So like you I went for a DIY project without worrying about actual expense. Just for fun more than anything. I got a CO2 tank, Nitrous solenoid, nitrous lines, switch and some wires and hooked it up to spray liquid CO2 on my intercooler.

    I haven't yet had the chance to dry it at the drag strip. I do actually need to make a slightly better outlet to hit more of the FMIC and distribute the cooling more effectively. It was fun. Should be potentially quite effective from the massive temp gradients but I doubt it is cost effective. I have the button in the cabin and pressing it simply opens the solenoid, spraying the gas.

    Test outside of the car:


    multiple nozzles:


    Single nozzle:
     
  10. Cornfed54

    Cornfed54 Private

    Messages:
    40
    Ride:
    E92 335
    ob
    Nice job! I have been contemplating making a setup similar to yours. It would be great if you could report back and give us some real world data on how much your CO2 setup can drop IAT’s. Did you use meth nozzles or what? Heat soak while sitting at lights and in traffic is very noticeable. I will often see IAT’s as high as 140F while in traffic, I’m sure the strip would be similar or worse!
     
  11. bantam

    bantam Lurker

    Messages:
    10
    Ride:
    2009 335i
    Sure, I can get more photos, what would you like to see?

    Thanks for the link, I had no idea, thought I was the first!

    The existing water cooler is the engine radiator system which targets a temperature of approx 200f. This actually serves the double function of heating the transmission fluid since the engine warms up more quickly than the transmission, and cooling the transmission when the fluid temperature exceeds the radiator temperature.

    I am hoping to target ambient +5deg through +15deg or whatever is the lowest feasible target given the system design currently.

    In short, no, the radiator will not work to cool the charge air.

    These are an interesting option, but I am desperately trying to design this system without compromising my AC system, it's just too hot for me otherwise.

    Really depends on your level of talent, and how many tools you have. I refuse to weld this project because I know that it will result in excessive build time, scrapped parts, and a crappy finished product.

    Budget for:
    Inlets~ $350
    Outlets~ $150
    Used Intercooler ~$350
    Custom Heat exchanger ~350-$600
    Pump ~$100
    Misc hardware/wiring ~$150
    Fabricator $$$?? hoping to get out for under $500?
     
  12. bantam

    bantam Lurker

    Messages:
    10
    Ride:
    2009 335i
    I like these projects too, just have to be careful that you are not creating a CO2 cloud that will rob your engine of horsepower. These systems used to be quite popular here among the turbo crowd but seemed to have fallen out of favor in recent years.
     
  13. MoreBoost

    MoreBoost Specialist

    Messages:
    71
    Ride:
    335i
    Yes that was my concern as well. So I'd only ever spray it before the run and not during. Luckily co2 is heavier than air and should fall away.
    The other option of course is to spray nitrous. There was a guy who posted a video where he has a double walled intercooler and he sprays nitrous around it. Looked good.
     
  14. aus335iguy

    aus335iguy Lieutenant

    Messages:
    612
    Ride:
    335i DCT 2009
    In for results.
     
  15. 9krpmrx8

    9krpmrx8 Corporal

    Messages:
    190
    Location:
    San Antonio, Texas
    N55 with a Speedtech kit IIRC but he used all OEM parts.

    [​IMG]
     
  16. ShocknAwe

    ShocknAwe Sergeant

    Messages:
    260
    Location:
    SC
    Ride:
    N54 1er
    Particularly interested in how the (is it the exchanger or the IC up top?) sits oriented to the intake manifold. A closer picture from over by the intake mount peg might help. Is that the N54 IM on there or did the S55 one fit? I'd also like to see a photo of how the IC outlet is oriented compared to the throttle body. Is it a straight shot, or offset? Obviously it's not going to be a straight pipe between the two but I'm sure you get my gist.
     
  17. Rcboosted2007

    Rcboosted2007 Sergeant

    Messages:
    377
    Location:
    Fresno ca
    Ride:
    07 335i
    Maybe you can look into the specs on the m4 gts cooler
     

    Attached Files:

  18. ShocknAwe

    ShocknAwe Sergeant

    Messages:
    260
    Location:
    SC
    Ride:
    N54 1er
    Do you see a difference? I was under the impression the biggest difference in that car was tuning and a "water injection" system.
     
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