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Perscitus- is that the Vibrant ultra quietly resonator you have welded in there? Just curious.
Yup. Its been part of my catback setup from the day I put the catback on, loong before the headers and custom-y.

 

Vibrant Ultra Quiet Resonator (3" ID, 14" long flavor for clearance, 18" might fit but would be tight).

 

I'm also adding two Vibrant Bottle-style 2.5" ID resonators in-place of the cats/cat-less cats this week. I'll keep everyone updated on how that goes and sounds.

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Maybe I need to stop having dreams because while they are awesome I end up disappointed, the one I had last night is below, and makes me sad because it doesn't exist...at least not yet.

 

Anyway in 2017 Subaru will refresh the Legacy and would most likely be updating the engines. (The 6 hasn't changed since the 08 Tribeca and they are falling behind their competitors)

 

1) A smaller displacement 6 cylinder pushing out 300 hp (We know what ours can do with some mods already)

 

2) Subaru bringing the 2.0 DIT from the WRX/Forester, putting it into the legacy and giving us a 6 speed manual? (Legacy GT reborn anyone?)

 

Personally, I would prefer a mix as I LOVE the 6 cylinder sound and want a manual. AKA what I want is something that would never be done.

 

What do you guys think is more likely to happen?

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Y-pipe R&D continues... attempt 2, welding and design by Al AutoMaster, racecar genius.

 

Maybe I missed it but whats the difference in the Y pipe your working on now vs the one currently on your car?

 

I apparently am not getting pictures on my computer at work right now.

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Minor changes, the y remains the same but we are replacing the catless cats from frozenboost with some Vibrant bottle style SS resonators. Reason for this is the catless cats were not welded correctly internally resulting in fuel getting into the baffles and burning with raspy pops under WOT. Drove me crazy. No such issues with straight pipes and hopefully this new setup. ;) Added benefit, moarh quiet.

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Edited by Perscitus
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Y-pipe R&D continues... attempt 2, welding and design by Al AutoMaster, racecar genius.

 

I dont want to jinx it (likely just did, lol) but if all goes well 2nd time will be the charm. ;)

 

That is great, Perscitus!

 

I was thinking glasspacks, but this works well too.

 

Glasspacks would get too hot and the fill inside would melt as it is too close to the motor, but it would still quiten the exhaust.

"It's within spec" - SOA :rolleyes:

"Depth is only shallowness viewed from the side." - Fredism

"So, how much did it cost for your car to be undriveable :lol:." - Stephen (very close friend)

"You have done so much it would be stupid to go back." - Sunny of Guru Electronics

 

2018Q50RS | 2015WrxThread | Shrek

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Re: pipe sizing - its all in my build thread, and a few and a few dozen pages back in this thread.

 

Re: high temp coating - No, we left the headers as-is to make spotting any issues (overheating, leaks) easier.

 

I just drove back home and she sounds great again! Quiet under cruise, very nice rumble under WOT or engine breaking. Longer runners seemed to have added some low-end torque too and the different lambda bong locations seem to have helped clear up some phantom/noise FKCs.

 

While we had her on the lift, Al also helped me install front and back Perrin end-links. Fronts were factory installed and helped up well after 60K, rear were adjustable Whitelines - one of them beat, the other always loosened itself after a few K and needed to be re-adjusted. What a difference with the Perrins!

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Edited by Perscitus
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I just drove back home and she sounds great again! Quiet under cruise, very nice rumble under WOT or engine breaking. Longer runners seemed to have added some low-end torque too and the different lambda bong locations seem to have helped clear up some phantom/noise FKCs.

 

I guess 360 ft lbs wasn't enough was it :lol:

 

 

Those Perrins sound like a good idea too, next time I talk to rob I'll suggest it and see what numbers he can come up with.

 

Getting anxious, the cars stock power is starting to feel..sluggish, I could use a bit more kick from her.

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he he he - she's still close to 360ft-lbf... maybe 355-370 ft-lbf (depending of which pull we did). Pump AKI93 E10 gas tune.

 

The engine would make more power and safely if we could get control of the 2nd bank of cylinders. Until then, timing gets pulled due to cylinder 2 and 6... 4 running a bit hot as a result (evident in visual inspection of the header runners). Luckily she's NA and doesn't mind the slight lean condition across the Bank 2 cylinders... but once we can control that (Rob is close!) then the car should pickup some power throughout.

 

The main reason for the y-pipe changes had to do with DD, sound, cop radar, etc.

We finally have a PERFECT solution that will work for any/all 3.6Rs and keep the exhaust tone almost the same as pre-headers. You still get all the benefit of installing them and the sound is more exotic but even less drone, and nicer deeper tone.

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he he he - she's still close to 360ft-lbf... maybe 355-370 ft-lbf (depending of which pull we did). Pump AKI93 E10 gas tune.

 

The engine would make more power and safely if we could get control of the 2nd bank of cylinders. Until then, timing gets pulled due to cylinder 2 and 6... 4 running a bit hot as a result (evident in visual inspection of the header runners). Luckily she's NA and doesn't mind the slight lean condition across the Bank 2 cylinders... but once we can control that (Rob is close!) then the car should pickup some power throughout.

 

The main reason for the y-pipe changes had to do with DD, sound, cop radar, etc.

We finally have a PERFECT solution that will work for any/all 3.6Rs and keep the exhaust tone almost the same as pre-headers. You still get all the benefit of installing them and the sound is more exotic but even less drone, and nicer deeper tone.

 

 

Running lean still isn't the best thing for her. So I fully understood why he had you dialed back a bit before. I am curious to see what kind of power gets picked up once Rob fully gets the 2nd bank controlled.

 

I love that its staying quiet. I love the note but the Mrs. is why I have to be cautious about what I do to her. Speed and handling is great but if I don't keep her happy it won't be fun for very long.

 

Glad to see Perscitus is on the cutting edge of 3.6R engine modification. Keep trailblazing for us :-)

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It's official, I think my cats are getting chewed up like Perscitus's. I have an appointment next weekend to take measurements and discuss options for sourcing some magnaflow high flow cats that should take Tim's abuse better.

 

Word to the wise: If you get the raptor headers, plan on getting high flow cats done at the same time....

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It's official, I think my cats are getting chewed up like Perscitus's. I have an appointment next weekend to take measurements and discuss options for sourcing some magnaflow high flow cats that should take Tim's abuse better.

 

Word to the wise: If you get the raptor headers, plan on getting high flow cats done at the same time....

 

Or just go catless if you want. Apparently Al can program it in such a way to not trip the emissions tests when getting it inspected.

 

Its interesting because Perscitus will have spirited driving but not play race-car that often. I can imagine someone with my miles (75k) pushing it hard and forcing all that heat into the cats.

 

Speaking of heat and what: Anyone know if Gio either removed his cats or placed high-flows? He should be producing more heat then any of us.

 

Good thing I am having rob add the high flows into the quote now, kind of stinks you guys are the "test dummies" as it were but since this isn't a typically modified car I guess that was to be expected.

Edited by Golferdude1087
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I'm not interested in catless... But I'm sure there are cats on the market that can take the abuse because there are other cars out there that are putting out way more exhaust pressure than our cars could ever that have cats.

 

I don't know if Gio has the headers on. I think the issue may be due to exhaust pressure more so than heat, the stock headers are comically bad, I pried the heat shield off them after we removed them and they're basically 1" pipe that merges as quickly as possible with no thought given to turbulence. I would bet that we're producing a good bit more exhaust pressure than it's possible to push through the stock headers.

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I'm not interested in catless... But I'm sure there are cats on the market that can take the abuse because there are other cars out there that are putting out way more exhaust pressure than our cars could ever that have cats.

 

I don't know if Gio has the headers on. I think the issue may be due to exhaust pressure more so than heat, the stock headers are comically bad, I pried the heat shield off them after we removed them and they're basically 1" pipe that merges as quickly as possible with no thought given to turbulence. I would bet that we're producing a good bit more exhaust pressure than it's possible to push through the stock headers.

 

Considering how comically small the stock headers are, that doesn't seem to surprise me about the stock cats. Way to go Subaru for severely detuning a car just because it can easily make more power then their flagship off the lot.

 

Rob has already quoted me about $400 for 2 high flows, I suggest giving AMR a call and seeing what cats they are installing on the 3.6R's now.

 

Edit:

Sorry didn't see the "sourcing magnaflows" my bad.

Edited by Golferdude1087
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Its actually an issue of flow and EGTs. With the Raptor headers (regardless of intake - stock, Takeda or custom) the CFMs out the headers and the EGTs the frontal area of the stock cats are seeing are BOTH way too much for them. Even if you open them up to say 2.25 or 2.5" ID.

 

Initially they are fine, but with time they can't take the heat (I logged 1400F with normal highway driving, some spirited, most just cruising at 55-65mph).

 

The substrate begins to separate from the casing, chips, cracks at the edges creating hot spots as the exhaust gases follow the path of least resistance, accelerating the process. The substrate itself starts to overheat and collapse on itself (each cell becoming smaller) which is most apparent in the dead center of the substrate material.

 

When we pulled the OEM cats off my car, they were NOT very bad yet, but created enough restriction to raise back-pressure (especially spikes @ tip-in, CL->OL, etc.) enough to cause random misfires. They are all gone now without them.

 

High-flow cats will be OK but should be installed a bit further back than the OEM location (see my latest setup). This does two things: 1. helps them 'live' longer 2. effectively extends the header runners (typical mod on racecars to increase low and mid-range torque).

 

I'd recommend going with either Vibrant metal or Magnaflow spun-metal cats. Vibrant cats are a bit hard to come by since they no longer manufacture them.

 

Doesn't really matter if OBDI or OBDII (bungs can always be welded before and after the cats) since high-flow cats without tuning and turning off the secondary (narrow-band) lambda sensor will likely fail emissions anyway.

 

Do not get ceramic substrate cats (even if high-flow). The CFMs/EGTs we saw will eventually cause them to fail just like the OEM units... and ironically enough, potentially faster.

 

Al and Rob both have a very well developed opinion and mod path for our exhaust systems by now. They have 2 OEM 3.6R headers and y-pipes sitting in the shop just to remind them how ridiculous they are - in fact the headers and runners are SMALLER and flow worse than the OEM part on a FB2.0i and FB2.5i!

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