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Old 10-10-2012, 09:45 PM   #270
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Join Date: Aug 2010
Location: Bay Area
Posts: 4,368
My Ride: X5, CT200h, CLK63 BS
Originally Posted by Bdave View Post
I thought 3 would be adequate, but its my thoughts that they are pretty maxed out on E85 at four digits. I personally would run a fourth pump or a different set up, just so the fuel system isnt strained. Its me being overly cautious I guess.

When just one of those three pumps starts getting weak you could run into problems fast. I like having a LOT of pump in reserve. I think its safer for everything in the long run. It doesn't break the ban to add a little more pump volume. That's all.
The way its setup in my car is additional pumps only come online at certain rpm's.. I cannot recall the rpm triggers at the moment.. but with the ProEFI I believe you can trigger secondary pumps based on fuel pressure (when fuel pressure drops turn on the secondary pump), boost or rpm.. maybe other variables as well.. you don't want to run 4 pumps (in parallel or series for that matter) at all times on a car that only needs them on occasion...

Maybe I'm completely off basis but regulating 4 pumps all the time seems like a bad idea.. you'd likely over run your fpr.

Last edited by MarcusLSB; 10-10-2012 at 09:46 PM.
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