ARJ Posted April 17, 2015 Share Posted April 17, 2015 Does any one know what the fuel pressure should be for a Subaru RX turbo EA82 .I have a complete motor all attatchments ,ECU and wiring harness plus a new never used 5 speed hi low range box to suit 3.7 ratio which I wish to test run on the garage floor . I either need the fuel pump to suite or to know the required fuel preesure. Can anyone help ARJ Quote Link to comment Share on other sites More sharing options...
jono Posted April 17, 2015 Share Posted April 17, 2015 ARJ, it'll run at 10 psi but 36 is better for boost and best spray mist from jectors Quote Link to comment Share on other sites More sharing options...
wagonist Posted April 17, 2015 Share Posted April 17, 2015 Almost any external EFI fuel pump will have enough pressure. These engines aren't the most powerful in stock trim... Quote Link to comment Share on other sites More sharing options...
naru Posted April 17, 2015 Share Posted April 17, 2015 Almost any external EFI fuel pump will have enough pressure. These engines aren't the most powerful in stock trim... No they won`t. You need a pump strong enough to have decent flow at 42 psi for a road test under boost. A lot of EFI pumps are not strong enough. Stock fuel pressure ratings are not directly related to stock horsepower ratings. If they were,those old CIS injected VWS w/80 psi would have been real powerhouses. Quote Link to comment Share on other sites More sharing options...
naru Posted April 17, 2015 Share Posted April 17, 2015 Does any one know what the fuel pressure should be for a Subaru RX turbo EA82 .I have a complete motor all attatchments ,ECU and wiring harness plus a new never used 5 speed hi low range box to suit 3.7 ratio which I wish to test run on the garage floor . I either need the fuel pump to suite or to know the required fuel preesure. Can anyone help ARJ You need 36 psi above manifold pressure. So,28-29 at idle 36 engne stopped 42 at full boost. I used an Airtex E8312 in my car. Quote Link to comment Share on other sites More sharing options...
ARJ Posted April 18, 2015 Author Share Posted April 18, 2015 Confused ?? different answers without a pressure regulator on the outlet side of the inlet manifold it would seem you rely on the pump pressure I dont think the ECU controls the pump pressure as there doesn't appear to be a sensor there . Think I'll look for a rx fuel pump or as I was told a pump from a twin tank F100 . Can't see how you can get higher pressure on boost without a sensor control to the pump as increased flow would result in pressure drop pure physics ,Capacity is litres per minute at rated pressure increase flow results in pressure drop to maintain pump capacity . Thanks for advice This is interesting and fun to test these theories Quote Link to comment Share on other sites More sharing options...
naru Posted April 18, 2015 Share Posted April 18, 2015 I don`t know what you are talking about,but,your motor has a mechanical fuel pressure regulator Quote Link to comment Share on other sites More sharing options...
jono Posted April 18, 2015 Share Posted April 18, 2015 (edited) ARJ, if you are still located in Oz, get onto Nardek - they used to do a standard generic efi fuel pump external, with 12mm input, 8mm ID output, 12V as a direct replacement for a plain jane VL Commode. Our Subes ran same part number fuel pump whether NA or turbo. Also get a fuel pressure gauge - I used an oil pressure gauge strapped on windscreen to watch as I drove and diagnosed. It is T'eed into fuel line to get correct reading .Three or four different makes have idled with as little as 10 psi - too low for fpr intercept - just would not take the load for a drive or boost, They were all very terminal pumps. One mechanic diagnosed his own truck as engine stuffed, so bought and paid for another engine to be fitted - same problem New fuel pump fixed it VL Commodore is about all I quoted to them to be able to supply me back in 2006 or 7. Went like a rocket after ! Edited April 18, 2015 by jono Quote Link to comment Share on other sites More sharing options...
jono Posted April 18, 2015 Share Posted April 18, 2015 Contact Details Nardek Pty Ltd PO Box 427 Frenchs Forest NSW 1640 Australia Phone: (02) 9984 9984 Overseas Phone: +612 9984 9984 Website: www.nardek.com E-mail: nardek@nardek.com.au Copyright © 2014 NARDEK PTY LTD Quote Link to comment Share on other sites More sharing options...
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