DIY DIY EKPM3 Active Cooling for LPFP

NoGuru

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Jan 9, 2018
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IMG_0803redu.jpg
IMG_0803redu.jpg
 

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rbryant

Lurker
Jul 26, 2018
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2008 e90 335i, 2007 e70 4.8i
The fan looks nice.

Are there holes for the hot air to escape? I saw more of your posts on another forum that show the added heat sinks but if the air can't blow into the case and escape somewhere then I don't see how the air will flow and cool things.

I agree with ajm8127 The bottom aluminum is really the heat sink here. Adding the small one on the top side chip isn't likely to do much when there is a 50x bigger one already on case bottom.

Has anyone tried a fan that blows air thorough a finned heatsink added to the outside of the case like ajm8127 but also with a fan? That would likely be much more effective.

The the more metal the air flows through the better it will cool.

-Rich
 
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NoGuru

Captain
Jan 9, 2018
1,206
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Just North of Detroit
Ride
BMW 335is
The fan looks nice.

Are there holes for the hot air to escape? I saw more of your posts on another forum that show the added heat sinks but if the air can't blow into the case and escape somewhere then I don't see how the air will flow and cool things.

I agree with ajm8127 The bottom aluminum is really the heat sink here. Adding the small one on the top side chip isn't likely to do much when there is a 50x bigger one already on case bottom.

Has anyone tried a fan that blows air thorough a finned heatsink added to the outside of the case like ajm8127 but also with a fan? That would likely be much more effective.

The the more metal the air flows through the better it will cool.

-Rich
Yes, there are a bunch of holes drilled in the side for the hot air to escape.
I have a Walbro 535 and Walbro 450 on this setup and ran some races last year, no issues at all.
 
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AndyW

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Jul 17, 2019
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2012 BMW 135i
Just wanted to say Thx for this thread. Gave me the confidence to put the thermal tape layers on and use thermal adhesive to put a heat sink on the mosfet. I also stuck some old finned heat sinks I had lying around to the back of the mount. Coded with Protool and we are running. Will have to see if the 6393 code comes back...(crosses fingers)
 
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AndyW

Private
Jul 17, 2019
34
23
0
Ride
2012 BMW 135i
Just wanted to say Thx for this thread. Gave me the confidence to put the thermal tape layers on and use thermal adhesive to put a heat sink on the mosfet. I also stuck some old finned heat sinks I had lying around to the back of the mount. Coded with Protool and we are running. Will have to see if the 6393 code comes back...(crosses fingers)

So far so good. No codes, car is running fine.
 

9krpmrx8

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Nov 5, 2016
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San Antonio, Texas
FWIW, my stock EKP3 (top) versus the $40.00 brand new Ebay one. Working fine so far on a PR 2.5 with a 535 pump. My original lasted 120,000 miles with a stage 2 PR running on it for the past 50,000 miles. The pic of the chip is the OEM.
 

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iminhell1

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Jun 17, 2018
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I've been thinking about this 'problem' for a little while.

I'm not going to go back and read but I'm fairly confident I know why they overheat. Our low pressure sensor is at the HPFP line. That's (guestimated) 20 feet from the fuel pump. That is around 28psi of pressure drop. Or the pressure at the pump output line is actually 70psi + 28psi (or whatever the pressure drop is). Look up on the fuel pump chart how many amps 98psi is (and flow to also understand why you need 2 pumps at such a low power level). I believe it's right on that 20 Amp line, which I believe the EPDM is rated for.
But then there's the Filter/Regulator that is rumored to be set below that, IIRC. So the target really can't be held and is only really reached when the HPFP demand isn't at peak ... once you grab 4th pressure crashes.

It all comes back to line size and pressure drop because of. Fans and the like, aren't going to fix the root problem.
 

SLOWESTN54

Captain
Feb 9, 2021
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B.C. Canada
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2007 E92 335i
I've been thinking about this 'problem' for a little while.

I'm not going to go back and read but I'm fairly confident I know why they overheat. Our low pressure sensor is at the HPFP line. That's (guestimated) 20 feet from the fuel pump. That is around 28psi of pressure drop. Or the pressure at the pump output line is actually 70psi + 28psi (or whatever the pressure drop is). Look up on the fuel pump chart how many amps 98psi is (and flow to also understand why you need 2 pumps at such a low power level). I believe it's right on that 20 Amp line, which I believe the EPDM is rated for.
But then there's the Filter/Regulator that is rumored to be set below that, IIRC. So the target really can't be held and is only really reached when the HPFP demand isn't at peak ... once you grab 4th pressure crashes.

It all comes back to line size and pressure drop because of. Fans and the like, aren't going to fix the root problem.
i just installed my upgraded line. I believe the sensor is no more than 10ft from the pump including the in tank lines.
 

Renzke

New Member
Aug 12, 2021
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Attached another / my solution:
I drilled holes in the holder bracket, added some longer screws (still a little bit short) and used thermal paste between the heatsink / EKPM3. (Besides this I exchanged the thermal pad in the module and added a mini heatsink on the motor bridge with thermal glue as already mentioned here).

The big heatsink dimension is 100mm x 100mm x 18mm. Clearance is not a problem. I did nothing with the cables behind the heatsink (not necessary, see pics). Car: E90
 

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