Neal Cassady Posted February 28, 2020 Share Posted February 28, 2020 Looking for feedback/opinions/ideas for reducing the exhaust resonance/bass/vibrations on my wagon, heard/felt outside the vehicle. It occurs around 1000-1500 rpm, especially on start-up/cold idle. The reverberation will shake the house and seems excessive. Overall the car is not much louder that stock, if at all, in terms of volume, but the resonance outside the vehicle is substantial. There is some exhaust boom/drone in the interior, but it is livable and goes away to essentially nothing while driving. I have gone over the various sound deadening threads, but they seem to focus on interior resonance. I will try likely try some of the solutions anyway. I have checked for exhaust leaks and have not found any obvious ones, but I will try a smoke test on the exhaust side to confirm. Vehicle is a 2006 LGT Wagon: - Stage 2 tune - OEM exhaust manifold - OEM STi non-catted up-pipe - Grimmspeed catted downpipe - OEM midpipe and y-pipe - JDM Legacy STi wagon twin tip axleback mufflers I've read an ELH could help since it eliminate the unbalanced exhaust pulses, as well as adding resonators/mufflers to the midpipe (with the COBB and other CBE). Open to hearing any and all suggestions! First image courtesy of Gex. 2006 Legacy GT Wagon - Regamasters, Evo X Recaros, STI 6MT, Brembo 6-Pots (in progress) @regashiii Link to comment Share on other sites More sharing options...
Max Capacity Posted February 28, 2020 Share Posted February 28, 2020 Have you tried to lengthen the tips. They need to be past the bumper. 305,600miles 5/2012 ej257 short block, 8/2011 installed VF52 turbo, @20.8psi, 280whp, 300ftlbs. (SOLD). CHECK your oil, these cars use it. Engine Build - Click Here Link to comment Share on other sites More sharing options...
Neal Cassady Posted February 28, 2020 Author Share Posted February 28, 2020 Thanks for the input. I have a JDM wagon bumper and they protrude past the lower part of the bumper (see profile photo), but do not extend completely past the bumper when viewed from above. It's definitely better than being sunk in the USDM bumper, however I didn't notice a change in the resonance when the JDM rear bumper was installed. I could try putting some extra piping over the tips to temporarily extend them and see if it has any impact. cheers 2006 Legacy GT Wagon - Regamasters, Evo X Recaros, STI 6MT, Brembo 6-Pots (in progress) @regashiii Link to comment Share on other sites More sharing options...
Keyan Posted February 28, 2020 Share Posted February 28, 2020 you may have to swap out those JDM sti mufflers. I am running muffler deletes and a oem midpipe and albeit loud, I don't get resonance. Link to comment Share on other sites More sharing options...
Neal Cassady Posted February 28, 2020 Author Share Posted February 28, 2020 I was worried about that possibility, I've found a few places that people mention the deeper bass from STi mufflers. 2006 Legacy GT Wagon - Regamasters, Evo X Recaros, STI 6MT, Brembo 6-Pots (in progress) @regashiii Link to comment Share on other sites More sharing options...
Keyan Posted February 28, 2020 Share Posted February 28, 2020 I have a coworker with the OEM upgrade "sti" catback on his 17 WRX, and it is bass-y and LOUD. That is why I think the mufflers are at fault. Link to comment Share on other sites More sharing options...
Max Capacity Posted February 28, 2020 Share Posted February 28, 2020 After I posted that earlier today, I thought may be I should have suggested you go pick up some flashing for a roof and hose clamps and make some extensions. 305,600miles 5/2012 ej257 short block, 8/2011 installed VF52 turbo, @20.8psi, 280whp, 300ftlbs. (SOLD). CHECK your oil, these cars use it. Engine Build - Click Here Link to comment Share on other sites More sharing options...
Enlight Posted February 29, 2020 Share Posted February 29, 2020 I have a wagon that I recently installed the STi quad tips on. The resonance that can be experienced from inside the house is something I noticed as well. If I'm planning any road trips I may swap the stock mufflers back on. Also sound deadening is in the hopper. Sent from my Pixel 3 XL using Tapatalk muFreight.co A JDM Container Sharing Service from Japan to NYC Website | Instagram | Email Bessie II's Thread Link to comment Share on other sites More sharing options...
Pleides Posted March 3, 2020 Share Posted March 3, 2020 Well, at the risk of sounding like an a-hole, you're complaining about resonance and a resonator would probably help with that Another thing to look for would be that your exhaust hangers are still looking OK. When they get old they allow for a little more play. Link to comment Share on other sites More sharing options...
Neal Cassady Posted March 3, 2020 Author Share Posted March 3, 2020 Haha I wish it were that simple. As far as I know that only helps with higher pitched tones/"raspiness". Sounds good, I've been meaning to do those anyway to tuck up the tips a bit more. I'm thinking I will pick up a pair of stock mufflers to confirm that fixes it, then see about grafting the twin tips on the stock mufflers. Thanks all. 2006 Legacy GT Wagon - Regamasters, Evo X Recaros, STI 6MT, Brembo 6-Pots (in progress) @regashiii Link to comment Share on other sites More sharing options...
Pleides Posted March 3, 2020 Share Posted March 3, 2020 (edited) Haha I wish it were that simple. As far as I know that only helps with higher pitched tones/"raspiness". Sounds good, I've been meaning to do those anyway to tuck up the tips a bit more. I'm thinking I will pick up a pair of stock mufflers to confirm that fixes it, then see about grafting the twin tips on the stock mufflers. Thanks all. A resonator helps with pretty much any drone created by an exhaust. I would still say it's worth trying out a universal resonator from Borla and seeing if that helps. I noticed at cold start right away that my car was quieter with my new, nice Borla catback (resonated) than my old Ebay special that had mufflers, but no resonator. Edited March 3, 2020 by Pleides Link to comment Share on other sites More sharing options...
Neal Cassady Posted March 3, 2020 Author Share Posted March 3, 2020 Fair enough! I'll see what swapping axlebacks does, then look into adding a resonator to the OEM midpipe. cheers 2006 Legacy GT Wagon - Regamasters, Evo X Recaros, STI 6MT, Brembo 6-Pots (in progress) @regashiii Link to comment Share on other sites More sharing options...
Neal Cassady Posted March 23, 2020 Author Share Posted March 23, 2020 Swapped mufflers to OEM JDM LGT wagon axle backs, all resonance gone. Looking at the STi twin tip axlebacks, the spot welds along the seam of the muffler have some corrosion, so I'll smoke test and see if it's leaking. Thanks everyone for their input. cheers 2006 Legacy GT Wagon - Regamasters, Evo X Recaros, STI 6MT, Brembo 6-Pots (in progress) @regashiii Link to comment Share on other sites More sharing options...
Max Capacity Posted March 23, 2020 Share Posted March 23, 2020 (edited) You can buy exhaust tips in many styles and length's and have a exhaust shop make a custom system. https://www.google.com/search?ei=lSV5Xu6mF6eoytMP-piW4A0&q=dynamax+exhaust+tips&oq=dynamax+exhaust+tips&gs_l=psy-ab.12..0i13j0i13i30l4j0i8i13i30j0i333.4080.7093..10813...0.2..0.141.958.0j8......0....1..gws-wiz.......0i71j0j0i7i30j0i7i10i30j0i5i30j0i7i5i30j0i8i30.NmJPB8OL1nQ&ved=0ahUKEwiuxertwLHoAhUnlHIEHXqMBdwQ4dUDCAs Here's mine from back in 2012, Edited March 23, 2020 by Max Capacity 305,600miles 5/2012 ej257 short block, 8/2011 installed VF52 turbo, @20.8psi, 280whp, 300ftlbs. (SOLD). CHECK your oil, these cars use it. Engine Build - Click Here Link to comment Share on other sites More sharing options...
Max Capacity Posted March 23, 2020 Share Posted March 23, 2020 Here's the same tips and mufflers today with a different inlet pipe. 305,600miles 5/2012 ej257 short block, 8/2011 installed VF52 turbo, @20.8psi, 280whp, 300ftlbs. (SOLD). CHECK your oil, these cars use it. Engine Build - Click Here Link to comment Share on other sites More sharing options...
Neal Cassady Posted March 23, 2020 Author Share Posted March 23, 2020 Yeah, I was thinking of transferring over the STi tips since I like their proportions and I already have them. 2006 Legacy GT Wagon - Regamasters, Evo X Recaros, STI 6MT, Brembo 6-Pots (in progress) @regashiii Link to comment Share on other sites More sharing options...
ashwinearl Posted March 25, 2020 Share Posted March 25, 2020 Slip on extender tips I recall a post that discussed using these slip on tips with Q300 to extend past the end of the bumper on a wagon. Link to comment Share on other sites More sharing options...
Mortal2None Posted March 28, 2020 Share Posted March 28, 2020 I used this resonator on one of my wagons (single scroll) and it made a huge difference. I can talk in the car on speakerphone without any issues now and can still enjoy 'tunnel resonance' with my right foot when desired: https://www.summitracing.com/parts/vpe-1142 You can also get it for far cheaper than summit and on amazon there is someone with a 4th gen GT wagon with a comparison vid. Link to comment Share on other sites More sharing options...
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