Scubaboo Posted February 4, 2019 Share Posted February 4, 2019 I've read the power mods sticky and modeling my power upgrade around it. Stage 2 stock turbo with DP and TMIC upgrade and change out the BPV for reliability. It's already noted there that stock exhaust is good to above stage 2. Also mentioned all over the net for Subarus in general. It wouldnt be cost-effective or really neccessary to do it at this stage. That said a lot of users here are at that level with exhausts anyway just because we can. I have a few options I am considering after the DP: Keep current set up: mating the 3" D/P with the stock midpipe with a Grimspeed adapter, and keeping my custom 2-1/2" Borla axlebacks. Stock midpipe with custom 2-1/2" Y-section and 2-1/2" branches all the way to the Borla axlebacks. To get rid of the crappy tiny stock Y. Custom midpipe with new resonator 2-1/2" to 3" (stock looks to be 2-1/4") to the 2-1/2" axlebacks. Interested in everyone's thoughts. Link to comment Share on other sites More sharing options...
cww516 Posted February 4, 2019 Share Posted February 4, 2019 Well, the stock mid and the crappy tiny stock Y-pipe may or may not end up being the only thing that can keep boost in check, so that'd definitely be a good reason to consider keeping those parts. Definitely port the wastegate if you do plan on opening things up downstream of the downpipe, and it'd probably be a good idea even if you do end up staying with the stock mid/Y. Link to comment Share on other sites More sharing options...
Scubaboo Posted February 5, 2019 Author Share Posted February 5, 2019 Oh yeah, that is one thing to consider. Did you happen to experience this yourself? Did porting alone work for you? Link to comment Share on other sites More sharing options...
cww516 Posted February 5, 2019 Share Posted February 5, 2019 Nope, my exhaust flow is still restricted by the cardboard box my downpipe is in I'm still deciding how far down the rabbit hole I actually want to go, but I do plan on porting the wastegate somewhere along the way. Link to comment Share on other sites More sharing options...
FLlegacy Posted February 5, 2019 Share Posted February 5, 2019 I have swapped out my downpipe with the nameless part and left the stock catback and have had no boost creep issues. My boost is very well controlled in the tune, I have room to tune out any creep if the need arose. I would be interested to see if your mufflers make any difference. Link to comment Share on other sites More sharing options...
stewdogg Posted February 5, 2019 Share Posted February 5, 2019 I have swapped out my downpipe with the nameless part and left the stock catback and have had no boost creep issues. My boost is very well controlled in the tune, I have room to tune out any creep if the need arose. I would be interested to see if your mufflers make any difference. I wonder if your humidity and warm temps help to keep your boost in check? I really did notice a jump in boost with 40F and dry air this fall. I have hot and humid in the summer here as well and a drop in boost. So, maybe Scubaboo would be fine with the warm and humid temps of the Philippines and opening the exhaust...? Link to comment Share on other sites More sharing options...
Scubaboo Posted February 5, 2019 Author Share Posted February 5, 2019 Nope, my exhaust flow is still restricted by the cardboard box my downpipe is in I'm still deciding how far down the rabbit hole I actually want to go, but I do plan on porting the wastegate somewhere along the way. Lol me too! Hence this thread. I have swapped out my downpipe with the nameless part and left the stock catback and have had no boost creep issues. My boost is very well controlled in the tune, I have room to tune out any creep if the need arose. I would be interested to see if your mufflers make any difference. I wonder if your humidity and warm temps help to keep your boost in check? I really did notice a jump in boost with 40F and dry air this fall. I have hot and humid in the summer here as well and a drop in boost. So, maybe Scubaboo would be fine with the warm and humid temps of the Philippines and opening the exhaust...? I have read its a cold weather thing. I just got my boost gauge on a few months ago and havent really checked for creep, but I dont feel anything untoward with my 2-1/2" axlebacks. They are very far downstream after the stock Y though. What boost range are you guys seeing btw as normal? Link to comment Share on other sites More sharing options...
cww516 Posted February 5, 2019 Share Posted February 5, 2019 I noticed a difference when I switched from the stock cans to the Nameless 5", but nothing outside the range of what the OTS tune was able to handle. I believe FLlegacy was in about the same boat when he was running the Nameless 5" cans, which would make sense, considering I bought my mufflers from him. I think I'm usually closer to 14 psi during the summer, and right at the 15 psi target in the winter. Up until the ECU goes into buzzkill mode at about 15-20 degrees and starts trying to keep the transmission intact, at least. Link to comment Share on other sites More sharing options...
FLlegacy Posted February 5, 2019 Share Posted February 5, 2019 I see 20.9 psi pretty regularly 21.0x when its chilly out. My WGDC is around 67% IIRC and boost error is pretty low. It has been a while since I logged a run I might do that this week just to see if anything stands out. Link to comment Share on other sites More sharing options...
Scubaboo Posted February 6, 2019 Author Share Posted February 6, 2019 Just looked back at some Torque App screenshots i have. Pre-axleback: peak boost right at 14psi, air temp 37c. Post axleback: peak boost a bit above 14psi, air temp 30c. Not enough of a sample to conclude anything really but I dont think the axlebacks are a factor at this point. Link to comment Share on other sites More sharing options...
BBPeik Posted February 12, 2019 Share Posted February 12, 2019 Fwiw I have stock mid and y pipe with invidoa catted dp. I hold steady at 23psi at 52% wgdc. The smaller mid prob helps hold boost down and keeps it nice and quiet. What can I say, I'm getting too old for loud exhaust. My someday I will be done with it thread. Link to comment Share on other sites More sharing options...
Scubaboo Posted February 12, 2019 Author Share Posted February 12, 2019 Well, a very experienced tuner put it this way: It would be better to see if he can reach his boost target on the stock exhaust and work up from there, rather than try to reign in boost creep from a larger exhaust. Link to comment Share on other sites More sharing options...
ripstik Posted February 13, 2019 Share Posted February 13, 2019 Just looked back at some Torque App screenshots i have. Pre-axleback: peak boost right at 14psi, air temp 37c. Post axleback: peak boost a bit above 14psi, air temp 30c. Not enough of a sample to conclude anything really but I dont think the axlebacks are a factor at this point. biggest downside of the stock axle back is the weight, those sucker are heavy! Link to comment Share on other sites More sharing options...
Scubaboo Posted February 13, 2019 Author Share Posted February 13, 2019 ^good point, thats one reason to upgrade. I came across a guy in a different forum who out an aluminum pipe exhaust on his DSM because of that. Pretty cool! Link to comment Share on other sites More sharing options...
Humble Rumble Posted February 13, 2019 Share Posted February 13, 2019 biggest downside of the stock axle back is the weight, those sucker are heavy! This is a very good point. When I installed my Nameless axlebacks, I did a stand test on my bathroom scale of me and then me+nameless, and then after install, me+stock axleback, and the stock axlebacks weighed 14 lbs a piece while the Nameless weighed only 7 lbs each, for a total of 14 pounds of weight saving from install. Weight dropped is weight dropped. 2012 Legacy 3.6R Build Thread 5th Gen Legacy BM/BR Body Kit Compendium Thread Link to comment Share on other sites More sharing options...
ripstik Posted February 13, 2019 Share Posted February 13, 2019 This is a very good point. When I installed my Nameless axlebacks, I did a stand test on my bathroom scale of me and then me+nameless, and then after install, me+stock axleback, and the stock axlebacks weighed 14 lbs a piece while the Nameless weighed only 7 lbs each, for a total of 14 pounds of weight saving from install. Weight dropped is weight dropped. are you saying the stock cans only weighed 14 lbs a piece? i would have pegged them closer to 30 lbs? Link to comment Share on other sites More sharing options...
Humble Rumble Posted February 13, 2019 Share Posted February 13, 2019 That's what my scale said. I have mine at home, I can toss one on a scale again to confirm. 2012 Legacy 3.6R Build Thread 5th Gen Legacy BM/BR Body Kit Compendium Thread Link to comment Share on other sites More sharing options...
RWebb Posted February 14, 2019 Share Posted February 14, 2019 I see 20.9 psi pretty regularly 21.0x when its chilly out. My WGDC is around 67% IIRC and boost error is pretty low. It has been a while since I logged a run I might do that this week just to see if anything stands out. The high here today was 12deg F. Whats "chilly" in your hood? 65f? **** thats short weather for me Link to comment Share on other sites More sharing options...
Scubaboo Posted February 14, 2019 Author Share Posted February 14, 2019 Yeah our OE axlebacks arent that heavy. 14lbs sounds about right. Link to comment Share on other sites More sharing options...
ripstik Posted February 14, 2019 Share Posted February 14, 2019 That's what my scale said. I have mine at home, I can toss one on a scale again to confirm. granted i haven't handled mine in 4 years and i never actually weighed them. Link to comment Share on other sites More sharing options...
FLlegacy Posted February 14, 2019 Share Posted February 14, 2019 The high here today was 12deg F. Whats "chilly" in your hood? 65f? **** thats short weather for me [emoji38]40 to 50 degrees anything over that doesnt affect the boost in my experience. Sent from my SM-G965U using Tapatalk Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.