DIY : PTFE line- tank to HPFP + inline fuel filter upgrade

Dec 16, 2016
14
If you guys are adding the filter, why cant we delete the filter from the driver side of the tank?
 

doublespaces

Administrator
Oct 18, 2016
6,854
AZ
If you guys are adding the filter, why cant we delete the filter from the driver side of the tank?
You probably can, but that thing is more than just a filter. It also routes fuel back over the driveshaft tunnel to the LPFP side, fuel level sensor, etc. The filter is integrated and not serviceable if I recall.
 

Vitan

Specialist
Nov 20, 2016
66
Pilsen, Czech Republic
You probably can, but that thing is more than just a filter. It also routes fuel back over the driveshaft tunnel to the LPFP side, fuel level sensor, etc. The filter is integrated and not serviceable if I recall.
Thats true, filter is not servicable. Its paper filter, after 50k miles is in very bad condition. I opened it at 50k, so I know it. You can bypass it quite easily, but you have to cut plastic housing. Filter housing has three outlets, one to hpfp and second to pressure regulator and third to venturi on driver side. Output from regulator leads to fuel pump bucket, over the driveshaft tunnel. Maybe I have some photos, I'lI try to find it. So you need 10micron filter and ideally aftermarked pressure regulator to eliminate this bottle neck and dirty filter. Also paper filter is not ideal for e85...
 
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doublespaces

Administrator
Oct 18, 2016
6,854
AZ
For anyone interested, here are my 6AN PTFE with olive to 5/16 crescent locking EFI fittings that will hook onto the stock lines:
upload_2018-8-21_13-1-35.png


This eliminated a fitting by using just this one piece, instead of a 5/16 efi fitting to 6AN and then a 6AN female to PTFE hose end.

I could only find them from the Racetronix link posted earlier:
https://www.racetronix.biz/product.asp?ic=fit-p6qdf56cl
 
Dec 16, 2016
14
Thats true, filter is not servicable. Its paper filter, after 50k miles is in very bad condition. I opened it at 50k, so I know it. You can bypass it quite easily, but you have to cut plastic housing. Filter housing has two outlets, one to hpfp and second to pressure regulator. Output from regulator leads to fuel pump bucket, over the driveshaft tunnel. Maybe I have some photos, I'lI try to find it. So you need 10micron filter and ideally aftermarked pressure regulator to eliminate this bottle neck and dirty filter. Also paper filter is not ideal for e85...
https://www.ebay.com/itm/Fuel-Filte...mBbaR-t:sc:ShippingMethodStandard!11428!US!-1

I wonder if its worth grabbing that and modifying it for science.
 

NoQuarter

Lieutenant
Nov 24, 2017
876
Indiana
No need since PR already has a billet regulator with serviceable filter
That looks really nice! I want to do more on my intank setup but my I can't find the desire to get in there. On the Z4 it is upside down under the car! Between the draining and laying under the car/open fuel tank, and the smell that permeates everything... ugh... no thanks :anguished:
 
Aug 11, 2017
1,732
Virginia
Thats true, filter is not servicable. Its paper filter, after 50k miles is in very bad condition. I opened it at 50k, so I know it.
And yet BMW considers it a lifetime filter ... ?!

On any standard BMW this is a moron simple replacement job. On the E89 Z4, a total pain in the ass that makes replacing the usual log filters under the old BMWs seem like an oil change (also a pain in the ass). One has to jack the car up, drop the exhaust, pull the shield, drain the tank, pull the filter out of the tank (which will still drip gas, I guarantee it). As a bonus the tank is double hump - very hard to tell which side one is draining (ask me how I know) and Murphy's Law is in full play.

When I did my Fuel-It LPFP, I spent the $110 and replaced this filter with the service kit, even though my car had 30k miles. Don't place to do it again.

Filippo
 

NoQuarter

Lieutenant
Nov 24, 2017
876
Indiana
Bringing this topic back...

looking at the dual HPFP pumps from the S55, there are no filters.

Do the M3/M4 cars have a fuel filter somewhere else in the system?
 

NoQuarter

Lieutenant
Nov 24, 2017
876
Indiana
Apr 26, 2018
13
Sacramento
Great thread! I plan to do PTFE 6an from the pumps(dual 450s) all the way up to the hpfp. Let me know if anyone needs any pictures
 
Apr 26, 2018
13
Sacramento
You might as well upgrade to an 8an fuel line, 6an is stock
i believe that someone said -8an would be too large to fit between the fuel tank and the body. Any opinions on this? I wouldn't mind going 8an, it shouldnt add much cost.
 
Apr 26, 2018
13
Sacramento
I run 8an kryptalon which is like 10an in size. I believe the upgraded lines from Fuel it are 8an
I believe the fuel-it lines are a 3/8"/6an. After pricing the difference I will probably step up to a 8an, however I cant locate a fitting for the connection to the HPFP
 
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