[Danspeed1]

Hello,

I am making my way down the rabbit hole of Modding my now 100k miles 2009 CTS-v. I've built many cars in the past (mostly corvettes). I hate replacing parts that don't work correctly, or doing it over again because I didn't buy a quality part the first time. So historically I have always sprung for the "most expensive" or highest quality part. My car has recently felt slower to me. I came to the incorrect conclusion that I was just getting used to it, as I've owned it for a couple of years and maybe it was time for something new. Ultimately I decided I love this car way too much to give it up and what it needs is more power. During the disassembly process I am doing currently I learned my Heat Exchanger Pump is done! It is DOA. The reason the car feels like its down 100hp is because it is. So my knee jerk reaction was to upgrade to the Varimax pump, but as I began doing some research I realized there were some other options. I checked out CWA, and the overkill option of the day was the CWA400 pump. At the cost of about 6 Bosch pumps it's certainly not cheap. And it's not going to plug and play in the stock location. Some how I found myself on some German website when I can to the realization that there is nothing special about this pump at all. It doesn't seem to be a supercharger specific pump; infact it has a BMW part number for a 2015 328i Xdrive 2.0 Turbo Engine.

So that got me thinking. Its technically a water pump. And its pretty rare for factory water pumps to go bad. So I would imagine a pump from Driveworks or SKP or Standard Motor Products would move the same amount of water for about 1/4 the price?

I'm going to post the part numbers I found. This might be a nice cheap upgrade to the stock Bosch pump. The only thing I need to figure out is where to get a pigtail for it, and how to run it 100%; its a PWM pump. I am sure someone on here has those answers. I am just looking for some input from anyone who has tried this pump out. Is it worth the effort. I am using an underhood water tank, ZZperformance Heat Exchanger, and a reinforced factory brick.

Specifications:

• Name: "Pierburg CWA400"
• Operation voltage: 8-16 volts
• Weight: approx. 2.15 kg
• Current consumption: 35.5A (36.3A max.)/ (approx. 0.2mA in standby mode)
• Nominal diff. pressure: 0.85 bar *
• Flow rate: approx. 150l/min @ 0.85bar / 220l/min @ 0.55bar
• Speed: approx. 5900 rpm
• Temperature range: -40°C – 128°C (water) / -40°C – 140°C (ambient)
• Protection: IP67

Part numbers:

• Pierburg: 7.03665.66.0
• BMW: 11517604027 / 11518625097 / 11518635089

Water Pump - 2012-2016 BMW 528i - Pierburg W0133-2040497

SKP SK1660E

STANDARD MOTOR PRODUCTS EWP101

PIERBURG 703665660
328i Base Model; Engine Code N26B20A; 40mm In/out; Plastic Impeller; Pulse Width Modulation Control

 

[SecondhandV]

That's exactly what I did. I purchased my pump from a euro parts retailer for significantly less than any performance focused retailer was advertising. It looks like there are a few, very similar, pumps out there, so make sure you're getting the one you need/want. The picture in the add you inserted doesn't look like an actual Pierburg CWA400 (Pierburg part number 7.03665.66.0) to me. The mounting feet are different, and the electrical connector is also different. It may be functionally the same though. I have no idea. I DM'd you the pigtail I purchased.

I am far from an expert, but that seems like too much pump for an under-hood tank setup. There are a lot of smart people here that can speak to heat exchanger efficiency, fluid volume, and velocity. I'm not one of them. I am installing the 400 with a trunk tank and lot of large diameter hose. I'm pretty sure there is a Pierburg pump that mounts in the stock location, outflows the Varimax, comes with nice pigtail that might be better suited for an under-hood setup. Are you planning to remove the factory hardlines?

As soon as I hit "post reply" there will probably be three people post that their CWA 400 under-hood tank setups are working great, and a trunk tank is absolutely unnecessary. I'll put my flame suit on haha.

 

[mememe123]

^^^ I was about to say that. 400 is the size of a small turbo. I think one might have overpressure/cap popping off issues in underhood configuration. Not to mention AMP draw, and factory wires.
Almost liken putting 10in intake on stock LSA.
May be you and I are both wrong ? Lol

 

[Danspeed1]

Thank you for sending me the link to the pigtail.

I'd be interested to hear if anyone has used on in an underhood tank application. I'm not really worried about finding a place to mount it. The wiring solution would be to use a high quality relay and the original output wire to control a higher gauge harness wired directly to the under hood power port. I'd also be interested in hearing more about the PWM function of the stock pump and why that would even be necessary. My thought process is to keep the heat exchanger as cold as possible for as long as possible.

 

[Danspeed1]

In the name of Hot Rodding I decided to give this one a try. For $126 I can always order a Varimax later if it doesn't work. I stepped down to a CWA200 on amazon with 134 positive reviews. If I can make it fit ill see how long it lasts and what my IAT temps look like.

 

[SecondhandV]

Be sure to post your results here. I haven't looked to see if anyone else has posted about using the CWA200 with an under-hood tank yet, but it'll be interesting regardless.

I ordered a couple of cheap PWM controllers from Amazon to play with. If I find I need high speed/low speed options, I'm hoping I can make that happen with a toggle switch.

Are you removing the hard lines?

 

[Danspeed1]

Be sure to post your results here. I haven't looked to see if anyone else has posted about using the CWA200 with an under-hood tank yet, but it'll be interesting regardless.

I ordered a couple of cheap PWM controllers from Amazon to play with. If I find I need high speed/low speed options, I'm hoping I can make that happen with a toggle switch.

Are you removing the hard lines?

I will post the results. The pump came in today and looks pretty decent. I was concerned it was going to be too big but I think with some creative mounting brackets it's going to fit in the stock location. I haven't decided what to do about the hard lines yet. Whatever I decide don't expect anything pretty or fancy, this is a daily driver with 99k I am trying to make fast. It just needs to work well.

 

[greenlal08]

This is OEM manufacture for BMW but without the BMW box price.

 

[RobF300]

someone had put up a picture of this pump in the trunk, looking at the size of it I dont know if youre getting this in the stock location

 

[Danspeed1]

I honestly think its going to be tight but I can make it fit. The whole front end is off the car right now so its the perfect time to make some adjustments.

 

[SofaKingSlow]

Before you get it put back together, would you mind posting a few side by side shots for us? Specifically the mounting base of the two pumps?

 

[Danspeed1]

Yes I can do that; after I make sure it fits

 

[RobF300]

you would want the front end intact when fitting this, but if you mean front bumper that wont really help you here.

 

[Danspeed1]

Sneak Preview.

I am not mounting this pump here. I will likely create a custom bracket to mount it in this location, but I have a good feeling it will fit with a little manipulation. I may even have to angle it. When I have it all put back together I will post some additional pictures of the completed result.