dahoseman Posted January 31, 2016 Share Posted January 31, 2016 My 2005 OBXT has larger aftermarket turbo/injectors/Walboro pump/tune/etc. For quite some time, I have noticed a very annoying RPM pulse at light throttle which makes it accel/decel repeatedly at lower RPM (quite unpleasant in parking lots). I had the fuel line extension on for quite a while before taking it off when I put the master cylinder brace on. It didn't seem to change anything, in any case. For various reasons, I also have a Perrin Adjustable Fuel Regulator sitting around from another project, which is now sitting idle. I am not certain if fuel pressure is the issue or not, but since I have this unit sitting in a box of parts untouched and without a future, I am thinking of replacing my OEM dampers/regulator with the Perrin unit. I haven't seen many reviews of it in general, even on NASIOC and IWSTI (I suppose because they're new-ish?) Perrin also states that it is explicitly for 08+ STi's, but I dont' see any reason why it would not function on the LGT's or OBXT's. 1) Has anyone installed one of these or have first-hand experience? Any thoughts? 2) Is there any reason why it cannot (or should not) be installed on a 2005 OBXT? Other than the semi-outrageous list price, is there any reason why no one seems to use them? 3) Should the pressure screw be adjusted out of the box? Link to comment Share on other sites More sharing options...
dahoseman Posted February 3, 2016 Author Share Posted February 3, 2016 nothing? Link to comment Share on other sites More sharing options...
sjxbrd Posted February 3, 2016 Share Posted February 3, 2016 Please see the post below. With bigger pump and injectors, OEM fuel pressure regulator will cause issues. I have fuel lab FPR and 07 STI style in-line fuel damper on my car, I wish I have dyno data but the graphs I saw show that fuel pressure is significantly more stable compared to OEM FPR. As a result, the lean spot around 5000-5500 rpm is gone, and tip in throttle feels better. http://legacygt.com/forums/showthread.php/fueling-issues-5000-rpm-222707.html Link to comment Share on other sites More sharing options...
dahoseman Posted February 3, 2016 Author Share Posted February 3, 2016 Please see the post below. With bigger pump and injectors, OEM fuel pressure regulator will cause issues. I have fuel lab FPR and 07 STI style in-line fuel damper on my car, I wish I have dyno data but the graphs I saw show that fuel pressure is significantly more stable compared to OEM FPR. As a result, the lean spot around 5000-5500 rpm is gone, and tip in throttle feels better. http://legacygt.com/forums/showthread.php/fueling-issues-5000-rpm-222707.html what pressure are you running at? Link to comment Share on other sites More sharing options...
gtonstilts Posted February 3, 2016 Share Posted February 3, 2016 i have 05 obxt with DW 850cc & DW65c i used 04 sti regulator and completely remover the whole stock assembly, its much simpler now and runs smoother. here is a pic of part number for regulator and connector ends so you can plumb it all up. if you search i did an install how to a while back Link to comment Share on other sites More sharing options...
sjxbrd Posted February 4, 2016 Share Posted February 4, 2016 what pressure are you running at? I think it should be 45 psi with the reference line removed. Link to comment Share on other sites More sharing options...
Grothe08LGT Posted February 4, 2016 Share Posted February 4, 2016 Install is fairly simple. Helped a friend install on his STI. Comes with different orrifices (spelling??) to change fuel pressure. But he left his with the one that came on it. One thing you need to check is make sure all ports are tight. They were loose when we started doing the install. One thing that didn't work out so well was we had to flip the lines that came with it. He has a Perrin master cylinder brace so we had to make a one off bracket and find a way to essentially make it work. Another, the fuel lines are crossed. Feeds on the bottom and returns on top. Silly design and looks weird.. But overall wasn't bad to install. As for working on outback or LGT.. No clue. To be safe, I would install an FP gauge and make sure it's running at the correct fuel pressure. Link to comment Share on other sites More sharing options...
dahoseman Posted February 13, 2016 Author Share Posted February 13, 2016 hmm, that's odd that they would design a product specifically for the turbo subarus and then produce it with fuel lines opposite of the factory orientation. Link to comment Share on other sites More sharing options...
Grothe08LGT Posted February 13, 2016 Share Posted February 13, 2016 RIGHT!!! That is exactly what we thought while installing it. It works perfect. Install was just odd lol Link to comment Share on other sites More sharing options...
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