John M Posted June 24, 2010 Share Posted June 24, 2010 If anything, parallel makes sure each injector is spraying the same amount of fuel. In theory, the last injector in a series will have lower pressure and thus spray less fuel. I don't know how much we actually suffer from that, both stock and especially with the upgraded lines. Series can only make things safer. Link to comment Share on other sites More sharing options...
NSFW Posted June 24, 2010 Author Share Posted June 24, 2010 In practice, I don't think anyone has done a proper test, so all we can do is speculate. I speculate that it doesn't really matter, so I'm going with series for now. Maybe I'll switch to parallel after my car has been running properly for a while and I get curious enough to blow a few hundred bucks on EGT sensors just to see what happens. Link to comment Share on other sites More sharing options...
NSFW Posted June 24, 2010 Author Share Posted June 24, 2010 4 really any better? Dunno which is better, but 4 would be cooler. Link to comment Share on other sites More sharing options...
ClimberDHexMods Posted June 24, 2010 Share Posted June 24, 2010 If anything, parallel makes sure each injector is spraying the same amount of fuel. In theory, the last injector in a series will have lower pressure and thus spray less fuel. I don't know how much we actually suffer from that, both stock and especially with the upgraded lines. Series can only make things safer. I've actually been wondering what is the Fuel pressure difference with series from bank to bank. Don't know anything about it. Is this theory in fact true (at least as far as theory goes)? [CENTER][B][I] Front Limited Slip Racing Differentials for the 5EAT now available for $1895 shipped, please inquire for details! [/I][/B][/CENTER] Link to comment Share on other sites More sharing options...
NSFW Posted June 24, 2010 Author Share Posted June 24, 2010 In theory, theory and practice are the same. But in practice, they're different. I'm not sure who said that but it seems appropriate right now. Link to comment Share on other sites More sharing options...
John M Posted June 24, 2010 Share Posted June 24, 2010 And I must point out after all that I typed, I meant to say parallel can only make things safer! Link to comment Share on other sites More sharing options...
lil_z_33 Posted June 24, 2010 Share Posted June 24, 2010 i got the part numbers...curious to know what fittings you get with the fpr tho... Link to comment Share on other sites More sharing options...
LittleBlueGT Posted June 24, 2010 Share Posted June 24, 2010 Are you using the advertised latencies? What flow scaling are you using? Full tune of 68HTA, KSTech 73 MAF, Racer X FMIC and ID1000s................by the DataLog Mafia!!! Link to comment Share on other sites More sharing options...
ClimberDHexMods Posted June 25, 2010 Share Posted June 25, 2010 And I must point out after all that I typed, I meant to say parallel can only make things safer! One side would argue that this is the opposite. People have some idea of how to tune out lean cylinders on the left bank in series configuration. If the first injectors to get fuel indeed see the highest pressure, then this adds weight to the idea that the left bank runs lean and Subaru engineers gave it more pressure on purpose. With parallel you are a) shooting in the dark with tuning, and b) eliminating the configuration that may or may not be a safety buffer. I am just the messenger, none of this is original thought. I simply want to provoke someone knowledgeable to find or tell us what is the safest and optimal way to do this. First, does anyone know what injectors would see the highest/lowest pressure (if any) in a series configuration? Would love to know... [CENTER][B][I] Front Limited Slip Racing Differentials for the 5EAT now available for $1895 shipped, please inquire for details! [/I][/B][/CENTER] Link to comment Share on other sites More sharing options...
mwiener2 Posted June 25, 2010 Share Posted June 25, 2010 You would need to be injecting fuel near the limit of the fuel pump's capacity for there to be any significant drop in fuel pressure from the first injector to the fourth. This is because the FPR is after the injectors. The fuel pump is trying to push as much fuel as it can and the FPR is letting all the extra fuel by as it can to keep the fuel pressure at 43.5psi. There is alot of fuel being bypassed, so as long as you are within the capacity of the pump, the pressure should remain static. Plumbing 101 shows that a parallel system would hold steady pressure better than a series system. In the case of our fuel system, I imagine you could run a little more on the edge with a parallel system, but that's not somewhere you want to be anyways. The one big advantage of a parallel system is that the injectors and rails will stay cooler. Each side gets it's own fresh supply of fuel where in a series setup, #4 always gets the hot stuff. My Mods List (Updated 8/22/17) 2005 Outback FMT Running on Electrons Link to comment Share on other sites More sharing options...
LittleBlueGT Posted June 25, 2010 Share Posted June 25, 2010 You would need to be injecting fuel near the limit of the fuel pump's capacity for there to be any significant drop in fuel pressure from the first injector to the fourth. This is because the FPR is after the injectors. The fuel pump is trying to push as much fuel as it can and the FPR is letting all the extra fuel by as it can to keep the fuel pressure at 43.5psi. There is alot of fuel being bypassed, so as long as you are within the capacity of the pump, the pressure should remain static. Plumbing 101 shows that a parallel system would hold steady pressure better than a series system. In the case of our fuel system, I imagine you could run a little more on the edge with a parallel system, but that's not somewhere you want to be anyways. The one big advantage of a parallel system is that the injectors and rails will stay cooler. Each side gets it's own fresh supply of fuel where in a series setup, #4 always gets the hot stuff. ^^^ He is right............ Full tune of 68HTA, KSTech 73 MAF, Racer X FMIC and ID1000s................by the DataLog Mafia!!! Link to comment Share on other sites More sharing options...
NSFW Posted June 25, 2010 Author Share Posted June 25, 2010 Are you using the advertised latencies? What flow scaling are you using? Advertised latencies + 10%. Advertised scaling. Added 10% to my MAF scaling across the board, and the fuel trim are within a few percent. However I don't think I've been above 40 g/s since installing the injectors. Things got much better when I added those 10% changes, but in retrospect I think it's likely that I had a lot of air bubbles in my fuel lines and those were causing most of the trouble I had at first. Other than the long cranking before starting, they work really well for idle and cruise. I don't notice any difference in cruise, but idle no longer has occasional misfires. AFR is much more stable than with the old injectors. I used to think that it was bouncing around a lot due to the ECU playing games with target AFR for emissions and possibly due to moving the O2 sensor behind the turbo. It was never noticeable when driving but it looked noisy in the logs. Driving still feels the same, and AFR does still move around due to the rich/lean thing the ECU does, but now it doesn't look random, I can see it moving in concert with the CL fueling target. I have a box from Summit, I'll describe the contents in a bit. Link to comment Share on other sites More sharing options...
NSFW Posted June 25, 2010 Author Share Posted June 25, 2010 In case anyone else wants part numbers, etc. one fuel pressure regulator - http://www.summitracing.com/parts/AEI-13109/ two hose ends - http://www.summitracing.com/parts/EAR-600136ERL/ ORB fitting for each port on the regulator - http://www.summitracing.com/parts/EAR-AT985006ERL/ Plug for one fitting on the regulator - http://www.summitracing.com/parts/AEI-15626/ (until I go parallel) fuel pressure gauge - http://www.summitracing.com/parts/AEI-15633?part=AEI-15633 o-rings - http://www.summitracing.com/parts/EAR-176006ERL/ Adaptors for the factory hard lines - http://www.summitracing.com/parts/RUS-640863/ Not going to use those soon, but eventually... 5/16 to -6AN fittings - http://www.summitracing.com/parts/AEI-15635/ Those were not this order, but mentioned previously. Last but not least... 90-degree stainless fitting - http://www.summitracing.com/parts/EAR-609296ERL/ Not included in this shipment. Due by 7/1... No FPR upgrade until it arrives. This is for the rear port on the passenger-side fuel rail. If anything goes wrong here it will leak fuel onto the up-pipe. Went with stainless out of fear more than anything else. Link to comment Share on other sites More sharing options...
LittleBlueGT Posted June 25, 2010 Share Posted June 25, 2010 Advertised latencies + 10%. Did you try my trick (I may not have invented it, but I did think of it) for checking latencies? -pick a MAF voltage (or 3), say 2.5 volts. -log OL fueling target -enable OL only mode (14.65......................................) -log 2.5 MAFv at 2500 rpm for as long as you can, then log 2.5 volts at 5500 rpm for as long as you can. Filter data, and see percentage AFR error. From there you can adjust latencies. Maybe there is a flaw in my logic, but I think that is more accurate then just using fuel trims over time. Full tune of 68HTA, KSTech 73 MAF, Racer X FMIC and ID1000s................by the DataLog Mafia!!! Link to comment Share on other sites More sharing options...
NSFW Posted June 26, 2010 Author Share Posted June 26, 2010 Haven't tried it, but it sounds reasonable. I'll try it after I get my FPR installed, which will hopefully be the weekend after this one. Link to comment Share on other sites More sharing options...
NSFW Posted July 13, 2010 Author Share Posted July 13, 2010 New FPR went in the weekend before last, I've just been lazy about taking pictures. http://i193.photobucket.com/albums/z151/Legacy_NSFW/Injectors/FPR1.jpg Astute observers will note that there's fuel in the pressure gauge. The front of the gauge is now totally hazy, like frosted glass. Can't even see the numbers on the dial. Will have a word with Summit about that. And here's a glimpse of the fitting for the 2nd braided line... http://i193.photobucket.com/albums/z151/Legacy_NSFW/Injectors/PassenerRear2.jpg Braided lines are kind of a pain in the ass, so I'm not sure it was worth the trouble. And it makes me a little nervous, there doesn't seem to be much of a margin between 'tight enough to seal' and 'tight enough to strip.' I haven't actually stripped fittings any but it takes quite a bit of torque to get them to seal up. Link to comment Share on other sites More sharing options...
ClimberDHexMods Posted July 13, 2010 Share Posted July 13, 2010 Off topic, is that a MBC? [CENTER][B][I] Front Limited Slip Racing Differentials for the 5EAT now available for $1895 shipped, please inquire for details! [/I][/B][/CENTER] Link to comment Share on other sites More sharing options...
mwiener2 Posted July 13, 2010 Share Posted July 13, 2010 Lube the AN fittings. They'll snug up easier and won't strip. They even make actual AN fitting lube. My Mods List (Updated 8/22/17) 2005 Outback FMT Running on Electrons Link to comment Share on other sites More sharing options...
NSFW Posted July 14, 2010 Author Share Posted July 14, 2010 Yes, it's a Hallman Pro Rx. I'll add a BCS later, but for now I really like being able to set my boost level without reflashing. I'm rescaling the MAF, since I was never really satisfied with my old MAF scaling. I am up to 15psi and 300 g/s so far. Thanks for the lube idea, that sounds useful. I oiled the o-rings but didn't think of the threads. I'll try that if/when I have to futz with them again. Link to comment Share on other sites More sharing options...
lil_z_33 Posted July 24, 2010 Share Posted July 24, 2010 which connector types did you order for the injectors? were they 100% plug n play? I am going to order on Monday...thanks for your help... Link to comment Share on other sites More sharing options...
NSFW Posted July 24, 2010 Author Share Posted July 24, 2010 I got the PnP adaptors, and they work fine. Link to comment Share on other sites More sharing options...
lil_z_33 Posted August 5, 2010 Share Posted August 5, 2010 is it possible for you to post a diagram or take pics of step by step from the factory hard lines of how you routed the lines to the rails, and then the fpr and back. more importantly, what fittings were you used at each step and what not. I am doing this on friday and am thinking of using the oem hard line adapters which you posted from closest to the firewall and then to each rail and then back to the return. due to the return being a rubberized, what adapter did you use on the return port to connect it to the oem rubber? Link to comment Share on other sites More sharing options...
NSFW Posted August 7, 2010 Author Share Posted August 7, 2010 Sorry for the delay... I don't have time to make pictures, but here's what the fuel passes through, from the supply line at the bulkhead to the return line at the bulkhead. If you want a pic of anything in particular just let me know and I'll take some on Sunday. You can also have a look in my photobucket, I think it's got a couple that haven't been posted in this thread. http://s193.photobucket.com/albums/z151/Legacy_NSFW/Injectors/ If you were fuel, and you escaped the injectors, this is what you'd see on your journey out from my firewall and back: OEM hard line with quick-disconnect fitting OEM hose with quick-disconnect connector (the hose that used to go to the FPR assembly) OEM fuel pulse damper (which I extracted from the FPR assembly) 5/16 fuel line 5/16 to AN-6 adapter, with buna-N o-ring added ID fuel rails and injectors -6 ORB to AN-6 adapter Earl's Speed-Seal straight AN-6 hose end Earl's Speed-Flex hose runs from driver's side to passenger's side, over the alternator. Earl's Speed-Seal straight AN-6 hose end -6 ORB to AN-6 adapter ID fuel rails and injectors Originally I had a 5/16 to AN-6 adapter in the rear fitting of the fuel rail, and then rubber hose to the stock FPR. The FPR was mounted on my strut brace. The first post in this thread still has pics of that arrangement. But now the rear fitting of the passenger side fuel rail goes to: -6 ORB to AN-6 adapter Earl's Speed-Seal 90 degree AN-6 hose end Earl's Speed-Flex hose Earl's Speed-Seal straight hose end Aeromotive A-1000 fuel pressure regulator (it has two input ports - the other has a -6 ORB plug) 5/16 to AN-6 adapter on the FPR's output port. Rubber 5/16 fuel hose 5/16-to-5/16 "hose mender" - basically a short 5/16 brass tube with barbs on each end Factory fuel hose with quick-disconnect fitting Factory hard line with quick-disconnect fitting Pic of the new FPR, and the defective gauge that came with it: http://i193.photobucket.com/albums/z151/Legacy_NSFW/Injectors/FPR1.jpg EDIT: I just realized that I've already posted that pic a couple weeks ago... oh well. That's the OEM pulse damper hanging in space to the right of the FPR. It's actually pretty secure there, with zip ties on its hoses, but that is something I intend to clean up. There's a bolt extending from the bottom, I'm just not sure what to screw it into yet. For most of the fittings, brand doesn't matter, but Earl's Speed-Flex hose requires Earl's Speed-Seal hose ends. Speed-Flex is Teflon-lined so there is no fuel smell. There may be other line that works, but this is the only stuff I've ever used (this is the only project I've ever done with braided-steel fuel line). It's a bit stiff, but it bent well enough for the way I routed it. All hose ends are aluminum, except the 90-degree fitting, which is stainless. For rubber 5/16 fuel hose, make sure you get fuel-injection hose. The hose made for carburetors is only expected to run 8-12 psi or something like that, whereas we run 43.5 psi static and 60+ under boost. The factory stuff is actually 8mm, but that's almost exactly 5/16. Link to comment Share on other sites More sharing options...
lil_z_33 Posted August 9, 2010 Share Posted August 9, 2010 thanks for the write up, that helps alot...can you please elaborate a little more on the pulse dampener install...I do not think I know where the stock fpr is, and which one the pulse dampener is either. also, where does the vacuum line come from that connects to the fpr? Link to comment Share on other sites More sharing options...
lil_z_33 Posted August 9, 2010 Share Posted August 9, 2010 also, how did you mount your new fpr? Link to comment Share on other sites More sharing options...
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