elgin.owens Posted April 30, 2015 Share Posted April 30, 2015 I'm interested if or how people are integrating fuel pulse dampers into their setups that use the Injector Dynamics Top Feed Conversion with an aftermarket FPR. First a little background information on why I'm asking... I'm experiencing some surging in light throttle / low load situations. Last summer I installed the Injector Dynamics Fuel Injectors 1000cc w/ Top Feed Fuel Rails, using the I.D. Side Feed Conversion Feed Line Kit. Then I had a shop install my Fuelab FPR just before they did the tune and they added two fuel pulse dampers right at the transitions between the hard lines and the AN fitting hoses. That means they are no where near the rails and the second one is actually after the FPR, which I believe makes the dampers less effective. Wondering if maybe the location of these dampers is causing that surging to occur. What I'm thinking of doing is getting two of the Radium Engineering Fuel Pulse Damper Kit's and installing them as close after each rail as I can. http://www.radiumauto.com/GetImage.ashx?maintainAspectRatio=true&maxHeight=400&maxWidth=600&Path=~%2FAssets%2FProductImages%2Fproduct-5341.jpg Anyone care to share their opinion on this idea vs just buying fuel rails that have provisions to mount dampers on them (such as the IAG Performance fuel rails). Does anyone have a better solution for integrating dampers with my current fueling setup? Link to comment Share on other sites More sharing options...
elgin.owens Posted April 30, 2015 Author Share Posted April 30, 2015 Here's a picture of the dampers the shop installed.http://i216.photobucket.com/albums/cc228/elginowens_photos/Legacy%20GT%20Project/20150430_144108.jpg The top one is after the FPR, bottom is before the first fuel rail. Link to comment Share on other sites More sharing options...
Th3Franz Posted May 1, 2015 Share Posted May 1, 2015 Are you sure you need dampers? I was experiencing some light surging when the fueling was scaled very closely where it was alternating between +2-3% and -2-3% correction causing some slight surging. -Franz The end of a Legacy http://www.youtube.com/th3franz Link to comment Share on other sites More sharing options...
elgin.owens Posted May 1, 2015 Author Share Posted May 1, 2015 Thanks for the tip Th3Franz. Is that something I could check with a datalog? Not sure I can actually access the tune or fuel scaling tables, because it is a locked Accessport pro-tune by Cobb. I'm not really even sure if I even need dampers. I just figured since the guys at Cobb thought they were required, that I actually did need them. Plus the factory rails had dampers right at the injectors, so I thought that with the larger ID1000's it would be equally, or even more important. Although I know some people with ID1000's don't run them at all... Link to comment Share on other sites More sharing options...
Th3Franz Posted May 4, 2015 Share Posted May 4, 2015 By design an aftermarket fpr located close enough to the rails acts as a damper. You can log af correction to see if that is alternating between positive and negative. -Franz The end of a Legacy http://www.youtube.com/th3franz Link to comment Share on other sites More sharing options...
elgin.owens Posted May 4, 2015 Author Share Posted May 4, 2015 I already keep a pretty close eye on AF corrections and can tell you right now that they swing between -/+ all the time, peaking at -25/+25 pretty regularly. I suppose you're suggesting to log the AF corrections during the surging events to see if it's swinging around then? I'll have to do that tonight and report back... The surging is incredibly predictable/repeatable I can make it happen easily given the right load/throttle/rpm. Heck the tuner was even able to do it on the dyno using cruise control, I could see it bucking away while he feverishly tried everything he could think of to correct the issue. Ultimately he gave up and said it was because my heads are ported, but I'm not buying that excuse. Link to comment Share on other sites More sharing options...
Nightmaresmk Posted May 4, 2015 Share Posted May 4, 2015 U say you have a fuel lab fpr butin the picture you still have the oem fpr's. three fpr would cause an issue. A fpd after the fuel preasure regulator is useless. you want them close to the fuel rails. Link to comment Share on other sites More sharing options...
Th3Franz Posted May 5, 2015 Share Posted May 5, 2015 I did add an inline fuel filter which has pretty good volume. It may help reduce pulses. -Franz The end of a Legacy http://www.youtube.com/th3franz Link to comment Share on other sites More sharing options...
elgin.owens Posted May 5, 2015 Author Share Posted May 5, 2015 What you're seeing in the picture is not the stock FPR, it's two OEM dampers. I believe the one on top is the original from my car and on bottom is a damper from an STI. I think you're correct that the FPD won't do anything if it's placed in the fuel system after the FPR. Th3Franz - In another thread I saw a picture of your fuel filter and wondered if you had bypassed the in-tank filter or if you were simply running two filters? Covertrussian did a really nice write-up How to: Convert Intank Fuel Filter (05+ LGT/OBX 08+ WRX/STI) to Engine Bay Filter. I was planning on doing this conversion at the same time I install the fuel dampers, since both will require some reconfiguration of the fuel lines under the hood. Link to comment Share on other sites More sharing options...
Nightmaresmk Posted May 5, 2015 Share Posted May 5, 2015 the position of those two is the stock fpr position. that far from the rails and after the fpr are useless. Link to comment Share on other sites More sharing options...
Th3Franz Posted May 6, 2015 Share Posted May 6, 2015 The stock in-tank filter is very coarse. I wanted something finer, so I added my 10 micron filter in the engine bay in addition. -Franz The end of a Legacy http://www.youtube.com/th3franz Link to comment Share on other sites More sharing options...
cynner Posted January 19, 2016 Share Posted January 19, 2016 I know this is quite an old thread... but did you end up getting anywhere with your fuel pulse dampers? Th4Franz - when you say you had surging when the "fueling was scaled very closely"... what do you mean? The Primary Open Loop fueling table? Or the injector scaling? Link to comment Share on other sites More sharing options...
elgin.owens Posted January 20, 2016 Author Share Posted January 20, 2016 I didn't actually put the FPD in yet, however I did buy the new in-line version Radium Engineering FPD w/ boost reference. I'm waiting to install it when I replumb my system for E85 and relocate the filter to the trunk. I was able to greatly reduce the surging I was experiencing by simply replacing the spark plugs. It turns out when I built the engine I accidently installed the wrong plugs. So even during my tuning session I was running the plugs for a SOHC N/A motor, which are way bigger gap and about 1/2" shorter overall! It's really pretty amazing that my tuner never even bothered to take a look at the plugs, although I'm surprised he was able to tune the thing at all considering how far off the plugs were from spec. It's running much better now that I have the appropriate NGK SILFR6A plugs installed. I do think it could benefit from a re-tune though now that the plugs are correct, we would probably find all sorts of extra power and smoother performance all around. It's still a little rough on the tip-in and tip-out, so it would be nice to see that smoothed out. I'm plan to upgrade the turbo in the next couple months so I don't think it's worth the $ for a re-tune before I get the turbo because I'll definitely do one afterwards. Anyways I'll try to remember to post an update when I install the FPD. It should be done soon because I want that fuel system re-plumbed before the turbo swap & re-tune. Link to comment Share on other sites More sharing options...
cynner Posted January 20, 2016 Share Posted January 20, 2016 Ah, interesting. I have the correct SILFR6A plugs... my mechanic thought maybe the coils are ageing. Thinking of getting some of these to see if they help: http://www.ebay.com.au/itm/SUBARU-FK0186-IMPREZA-EJ20-EJ25-WRX-STi-LEGACY-FORESTER-PERFORMANCE-COIL-PACKS-/121850920879?hash=item1c5ee17faf:g:GtYAAOSwv0tU4kUP Link to comment Share on other sites More sharing options...
Th3Franz Posted January 26, 2016 Share Posted January 26, 2016 What I meant was that it was going from +2% to -2% correction and it could be felt. Was pretty subtle but I could tell it was going on. -Franz The end of a Legacy http://www.youtube.com/th3franz Link to comment Share on other sites More sharing options...
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