Arcteryx Posted July 21, 2017 Share Posted July 21, 2017 Hmm. So currently my (electronic) boost gauge is T'd off the BPV. From what I'm reading, the ideal setup is to swap the FPR and boost gauge lines so that the FPR is now T'd off the BPV and the boost gauge is now reading from the cylinder 4 vacuum where the FPR used to be? I'm also currently running an etune from Cryotune - do I need to update the tune after doing this mod (assuming I also install the STI FPR)? Link to comment Share on other sites More sharing options...
covertrussian Posted July 21, 2017 Share Posted July 21, 2017 Hmm. So currently my (electronic) boost gauge is T'd off the BPV. From what I'm reading, the ideal setup is to swap the FPR and boost gauge lines so that the FPR is now T'd off the BPV and the boost gauge is now reading from the cylinder 4 vacuum where the FPR used to be? Definitely just swap them, your boost gauge is for your eyes only (and maybe logging) so accuracy is not a must, while the FPR is a vital part to keeping your engine alive. I'm also currently running an etune from Cryotune - do I need to update the tune after doing this mod (assuming I also install the STI FPR)? You should be fine, I didn't see any changes in my air to fuel ratios to require a retune. 05 LGT 16G 14psi 290whp/30mpg (SOLD) 12 OBP Stock 130whp/27mpg@87 Oct 00 G20t GT28r 10psi 250whp/36mpg 22 Ascent STOCK Link to comment Share on other sites More sharing options...
ashwinearl Posted July 21, 2017 Share Posted July 21, 2017 Definitely just swap them, your boost gauge is for your eyes only (and maybe logging) so accuracy is not a must, while the FPR is a vital part to keeping your engine alive. You should be fine, I didn't see any changes in my air to fuel ratios to require a retune. just FYI I read in this thread or related thread that someone had issues the first time they tried to tap off Cylinder 4 to a boost gauge using stock hose line. They upgraded to a heavier duty hose and seems to work better.. Link to comment Share on other sites More sharing options...
ashwinearl Posted July 21, 2017 Share Posted July 21, 2017 For my 05, your #1 and #2 each corrected a separate issue. #2 helped with a tip-in bog I had. Example: if I was cruising or decelerating, and I pressed the throttle, there would be an annoying momentary hesitation, then it would go. Changing to the later regulator fixed that transitional bog. I have this too when decelerating coming out of a corner in 3rd or 4th and then getting back on the gas. Link to comment Share on other sites More sharing options...
covertrussian Posted July 21, 2017 Share Posted July 21, 2017 just FYI I read in this thread or related thread that someone had issues the first time they tried to tap off Cylinder 4 to a boost gauge using stock hose line. They upgraded to a heavier duty hose and seems to work better.. I had an issue with just capping it, the cap disinter-graded in no time and was causing an air leak. Since then I connected my boost gauge hose to it and a zip tie, holding great 2+ years so far. 05 LGT 16G 14psi 290whp/30mpg (SOLD) 12 OBP Stock 130whp/27mpg@87 Oct 00 G20t GT28r 10psi 250whp/36mpg 22 Ascent STOCK Link to comment Share on other sites More sharing options...
heiche Posted July 21, 2017 Share Posted July 21, 2017 I know the caps you speak of. They're sold as vacuum caps, but seem to not be made of a material that can withstand automotive underhood conditions for even half a year. BtSsm - Android app/Bluetooth adapter. LV, logging, gauges and more. For 05-14 Legacy (GT, 2.5, 3.0, 3.6), 02-14 WRX, 04-14 STi, 04-14 FXT, 05-09 OBXT Link to comment Share on other sites More sharing options...
covertrussian Posted July 21, 2017 Share Posted July 21, 2017 Yeah they suck. My new method of making a vacuum port block is to take a regular hose and stick a bolt into it, then clamp it. Definitely want to clamp it with higher boosts, otherwise it might become a projectile. 05 LGT 16G 14psi 290whp/30mpg (SOLD) 12 OBP Stock 130whp/27mpg@87 Oct 00 G20t GT28r 10psi 250whp/36mpg 22 Ascent STOCK Link to comment Share on other sites More sharing options...
ashwinearl Posted July 21, 2017 Share Posted July 21, 2017 2) replace stock FPR with 04-07 STI AND 1) Does anyone have a part# for an OEM STI fuel pressure regulator that works well in our 2005 LGTs? I have seen several aftermarket ones like Cobb, Perrin but am assuming that for this application (daily driver just trying to overcome these annoying stumbles) that an OEM one is adequate. Link to comment Share on other sites More sharing options...
heiche Posted July 21, 2017 Share Posted July 21, 2017 does anyone have a part# for an oem sti fuel pressure regulator that works well in our 2005 lgts? I have seen several aftermarket ones like cobb, perrin but am assuming that for this application (daily driver just trying to overcome these annoying stumbles) that an oem one is adequate. 22670aa351 BtSsm - Android app/Bluetooth adapter. LV, logging, gauges and more. For 05-14 Legacy (GT, 2.5, 3.0, 3.6), 02-14 WRX, 04-14 STi, 04-14 FXT, 05-09 OBXT Link to comment Share on other sites More sharing options...
covertrussian Posted July 21, 2017 Share Posted July 21, 2017 Unless you absolutely want to spend $100 on a new one, post up a Wanted to Buy thread here and on Nasioc. I got mine for about $25 used. 05 LGT 16G 14psi 290whp/30mpg (SOLD) 12 OBP Stock 130whp/27mpg@87 Oct 00 G20t GT28r 10psi 250whp/36mpg 22 Ascent STOCK Link to comment Share on other sites More sharing options...
Flinkly Posted July 21, 2017 Share Posted July 21, 2017 mcmaster sells silicone rubber nipples in a size to fit the runner nipple. stick some sort of clamp over that and consider it sealed for life. * Build Thread * 26.53 MPG - 12 month Average * Link to comment Share on other sites More sharing options...
FJuan Posted July 21, 2017 Share Posted July 21, 2017 Nipples and clamps, I'm getting all hot and bothered over here. My wife's balls are delicious. Link to comment Share on other sites More sharing options...
Underdog Posted July 22, 2017 Share Posted July 22, 2017 EPDM or silicone are the caps you want. The Crimson Dynamo Link to comment Share on other sites More sharing options...
FJuan Posted July 22, 2017 Share Posted July 22, 2017 This is a follow up after several months of rerouting the FPR. The car is still running good with little to no stumble. Plus the car has not gone into "limp" mode since! This is by far the cheapest and easiest fix I've done on this damn car. My wife's balls are delicious. Link to comment Share on other sites More sharing options...
Slammed05 Posted July 22, 2017 Share Posted July 22, 2017 How do you know weather or not the car enters "limp" mode? Link to comment Share on other sites More sharing options...
FJuan Posted July 22, 2017 Share Posted July 22, 2017 How do you know weather or not the car enters "limp" mode? When the car only boost 50%. My peak boost is 16psi, when it goes in limp mode it's 8psi. It's a safety mode when the ECU senses something wrong with the A/F mixture. My wife's balls are delicious. Link to comment Share on other sites More sharing options...
Flinkly Posted July 22, 2017 Share Posted July 22, 2017 When the car only boost 50%. My peak boost is 16psi, when it goes in limp mode it's 8psi. It's a safety mode when the ECU senses something wrong with the A/F mixture.and cruise isn't available, right? been a while since i've limped. * Build Thread * 26.53 MPG - 12 month Average * Link to comment Share on other sites More sharing options...
goob_os101 Posted July 27, 2017 Share Posted July 27, 2017 I am about do put in a new (04-07 STP FPR) and do the FPR manifold reference relocation...I want to make sure I have all the right parts: Gates Barricade Fuel Line Hose 5/16 (2x packs of 2ft hose) Dorman 800-080 Fuel Line Quick Connector for 5/16 (4x) Subaru 22670AA351 Fuel Pressure Regulator 5/32 t-connector Do I need a new vacuum hose from the BPV to the FPR or can I re-use the existing one? Link to comment Share on other sites More sharing options...
covertrussian Posted July 27, 2017 Share Posted July 27, 2017 Resuse existing one, trim it to fit though, since the longer the line the more resonance it can have. 05 LGT 16G 14psi 290whp/30mpg (SOLD) 12 OBP Stock 130whp/27mpg@87 Oct 00 G20t GT28r 10psi 250whp/36mpg 22 Ascent STOCK Link to comment Share on other sites More sharing options...
goob_os101 Posted July 28, 2017 Share Posted July 28, 2017 Resuse existing one, trim it to fit though, since the longer the line the more resonance it can have. Thanks...I can't wait to get this car sorted Link to comment Share on other sites More sharing options...
goob_os101 Posted July 28, 2017 Share Posted July 28, 2017 noob question...what psi max does the fuel hoses need to be for the FPR? Link to comment Share on other sites More sharing options...
covertrussian Posted July 28, 2017 Share Posted July 28, 2017 noob question...what psi max does the fuel hoses need to be for the FPR? Absolutely make sure you buy a Fuel INJECTION hose, and not a Fuel Hose (meant for lower pressure carburetors). Fuel Injection hose will be rated for above even 4 bar base PSI's. But to do the math, stock is 3 bar = 43psi at 0psi of boost. Add your boost levels to that base to get your total, so at stock 13.5psi = 56.5psi. If you run 4 bar (58psi), your gonna start going up there in total PSI's. 05 LGT 16G 14psi 290whp/30mpg (SOLD) 12 OBP Stock 130whp/27mpg@87 Oct 00 G20t GT28r 10psi 250whp/36mpg 22 Ascent STOCK Link to comment Share on other sites More sharing options...
goob_os101 Posted July 28, 2017 Share Posted July 28, 2017 I was looking at these two hoses: Dayco Fuel Injection Hoses 80079 "special braided reinforcement delivers a recommended working pressure of 100 psi, with a burst strength of 900 psi" or Gates 27335 Barricade MPI Fuel Injection Hose "Working Pressure: 225 psi" Link to comment Share on other sites More sharing options...
covertrussian Posted July 28, 2017 Share Posted July 28, 2017 Gates one if you have the time, higher working pressure = extra headroom. I personally just used what ever my local parts store had, it's usually around $6 a foot. 05 LGT 16G 14psi 290whp/30mpg (SOLD) 12 OBP Stock 130whp/27mpg@87 Oct 00 G20t GT28r 10psi 250whp/36mpg 22 Ascent STOCK Link to comment Share on other sites More sharing options...
ashwinearl Posted July 28, 2017 Share Posted July 28, 2017 I am about do put in a new (04-07 STP FPR) and do the FPR manifold reference relocation Please do me and I'm sure others here a favor and document this install with some picture and final parts list/sources. Every time I look at the FPR I just see spaghetti. What do you plan to do with Cylinder 4. Will you cap it or use it to feed a boost gauge? Link to comment Share on other sites More sharing options...
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