2015 GTI problem child

[Derushi]

If the Vibrant resonator didn't help much, doubt the OEM resonator would. I tried that before switching the OEM res for something else.

My current setup does the same. At 2800 rpm or so on valve lift, significant noise change. Clubsport S, APR muffler/res, MAP Catted/Res downpipe

 

[Zer0DazE]

If the Vibrant resonator didn't help much, doubt the OEM resonator would. I tried that before switching the OEM res for something else.

My current setup does the same. At 2800 rpm or so on valve lift, significant noise change. Clubsport S, APR muffler/res, MAP Catted/Res downpipe

I would tend to agree. The Vibrant resonator is a good piece, and I don't think the Invidia hotdog resonator is all that bad either. I am going to make the call and say the muffler design Invidia decided on is horrible.

Instead of calling the Invidia catback a total write off, I think I am going to try salvaging the piping and flanges. The 3 piece design makes it easy to work with by myself, and lets me replace sections as needed. Unfortunately the flanges do add a point of failure/leakage.

Taking with Jake over the last week or so he has tried to convince me to give up on the Invidia. There is no doubt he is right. The pipes, flanges, and welds are excellent, but the muffler is a dumpster fire. He did recommend the Borla XS Pro. It would fit in the B-Pipe section, but I am looking to replace that rear suitcase Invidia used.

I have used Vibrant mufflers on a handful of other project cars over the decades, and have been eyeballing the 10632. Since I already have the Vibrant resonator with the pipes cut to fit, and the catback uses the center in/dual out, the 10632 is a simple fit. Based on quick measurements the 10632 is 4" longer, and 2" larger in both height and width. That is a significant difference. I should also be able to salvage the exit pipes and tips to finish it off. When I have some time I will crawl under the car and take some measurements to make sure the Vibrant suitcase will fit, and with some luck I maybe able to also salvage the rear hangers. I hope so... I would hate to waste even more money that could have been spent on bourbon.

All in all I will end up with more into this than I care to let my wife know, and more than I care to admit to myself; however, this combo should have a deep mellow sound. I guess we will see.

As a side note, had I just stayed with the OEM 2.5" this probably would have been really affordable. I think Jake has a resonator/mid-muffler replacement pipe with the Vibrant resonator in it, and the suitcase swap shouldn't be more than an hour or so of labor for a decent exhaust shop.

Cliff notes:
Invidia catback - stay far away from it
Salvaging pipes and going with Vibrant resonator and muffler

edit:
for my own personal notation so I don't forget.
Invidia catted downpipe with oem cat back on the highway at 75mph is 62db between 99 and 125Hz. Going up hill it maxed at 68db.
Invidia turbo back with Vibrant resonator on the highway is a deep base mid 70's db drone closer to 99Hz. Going up hill it climbed to the upper 70's and into the 80's under heavy load.
All Invidia turbo back recorded the frequency at 172Hz with similar db's. I don't totally trust that Hz, but it is possible/probable that the Vibrant resonator killed the resonance at that Hz.

 

[Zer0DazE]

The car threw an EPC light at me on my way to work today. I was hooning on it a bit and as I got near town I began to drive more civilized. After a few miles of "normal" driving the EPC light lit up. I pulled over and listened for any abnormal sounds. With no strange noises I shut it off, sat for a couple min, and then fired it back up. No more light.

I finished my drive in, and drove nicely on the way home until I could get check for stored codes.

3 Faults Found:
15074 - ROD - Unknown Error Code
- 00 [096]
Intermittent - Not Confirmed - Tested Since Memory Clear
Freeze Frame:
Fault Status: 00000001
Fault Priority: 2
Fault Frequency: 1
Mileage: 76258 km
Date: 2018.09.23
Time: 09:20:33

15125 - ROD - Unknown Error Code
- 00 [096]
Intermittent - Not Confirmed - Tested Since Memory Clear
Freeze Frame:
Fault Status: 00000001
Fault Priority: 2
Fault Frequency: 1
Mileage: 76258 km
Date: 2018.09.23
Time: 09:20:33

It looks like there are 2 codes from when I wasn't getting on it. I believe it's a misfire code and the other is "Cylinder disabling"... I'm not real sure what causes that.

I have plans to pull the intake manifold in the next couple of weeks to clean the intake valves. It's possible those being are heavily coated with crud and could be causing an issue. I should probably pull and check the plugs when I do that as well. I will have to keep an eye on it I guess.

 

[Zer0DazE]

The new Vibrant suitcase showed up today. I didn't toss it on the scale, but it easily weighs 2-3x what the Invidia piece weighs. Here is a video of the uber scientific finger flick test.
https://www.youtube.com/watch?v=wEM-4EmeMWM

Jake was right, the Invidia piece is a beer can. The Vibrant is a straight through design like their other mufflers. I will post pics of that later. If things goes as planned I will have it installed with the Vibrant resonator tomorrow and can post in car recordings with db and Hz numbers. Hopefully the results are good. It would make for an affordable catback if you used Jake's mid-pipe and had a local muffler shop swap the OEM suitcase for this... or it could be a giant flop. I guess we will find out tomorrow.

 

[Zer0DazE]

A lot of work got done today. I got up this morning and decided I would going to fix whatever was rattling in front suspension on the driver's side. When I popped the little black cover off the strut tower I saw glitter... not a good sign. I checked and the 3 bolts and nut on the strut were still torqued properly.

After pulling the strut mount and bearing I found the issue. The upper mount was all chewed up where the strut passes through. The strut was obviously moving around, and you can see where the threads on the strut were eating the mounts. It had gotten to the point where the noise wasn't just on bad roads, I would hear things rattle when I was letting the clutch out.

As luck would have it, I had the original upper mounts and a set of strut bearings in the shop. Parts replaced on both sides with OEM, checked multiple times to ensure everything was seated properly, and then confirmed torque. On the test drive the car was silent. Win!

I did find that the shop that installed the clutch did a number on the threads on the driver's side axle. I guess the next time I pull the front suspension apart I will need to replace that.

During that time USPS delivered the last exhaust reducer I needed. Dirty, and powered only by a pot of coffee and a beer for lunch I made my way to the exhaust shop. $140 and 2 hours later I had this.

Yeah it's dirty, today is the first day it hasn't rained in like a week.
There is plenty of room in that b-pipe for a second small muffler if need be.

Home and clean

The catback has 2 lap clamps, 1 at the downpipe, and 1 where the b-pipe meets the muffler, everything else is welded. I had him weld the 3" resonator section to the 2.75" b-pipe. The b-pipe didn't need much work to be a slip fit to the 3" pipe. This should minimize leaks, and make removal easy. The tips ended up like a half inch or so lower than they were, but now I can actually clean them. With the original Invidia setup they were tucked up nicely, but I couldn't get around them to clean them properly.

It looks good, but how does it sound? Way better!
I didn't drive it very far, had the seats down, and all the leftovers in the hatch, so things were rattling around. At idle it is just a tad louder than OEM, under 2500 it seems about as loud as OEM but much deeper in tone, and then at 2800 and up it comes alive.

I have to make a 4 hour drive back home for a memorial this weekend and will get some in cabin video and db with Hz readings.

The 40+ year old me thinks he would like it a little quieter between 2800 and 3000 (after 3k I say let loose the lion), the 30 something year old me would have been very happy with this setup, and the 20 something year old me probably would have wanted it a little louder.

 

[Zer0DazE]

edit:
for my own personal notation so I don't forget.
Invidia catted downpipe with oem cat back on the highway at 75mph is 62db between 99 and 125Hz. Going up hill it maxed at 68db.
Invidia turbo back with Vibrant resonator on the highway is a deep base mid 70's db drone closer to 99Hz. Going up hill it climbed to the upper 70's and into the 80's under heavy load.
All Invidia turbo back recorded the frequency at 172Hz with similar db's. I don't totally trust that Hz, but it is possible/probable that the Vibrant resonator killed the resonance at that Hz.

So with the Invidia catted downpipe, 3" Vibrant 17950 resonator, 2.75" piping (reused from Invidia catback) and Vibrant 10632 suitcase muffler.
This is a video of this setup at it's loudest on the highway under load.

https://www.youtube.com/watch?v=ClxbOOJYxWI

Cruising with rpm between 2200 and 2500 kept kept the db level around 67 climbing to 70 going uphill. At 65 mph the db level was right around 65. In all situations as with frequency was around 100Hz (as expected).

I had a 4 hour drive on the highway yesterday with speeds between 65 and 70 mph, and I am happy with the results. The exhaust note is deep and not over bearing, and I arrived without a headache. The Vibrant 10632 gives a little more sound than the OEM suitcase, and provided a serious reduction in sound from the Invidia suitcase.

 

[Jose_Gti]

So with the Invidia catted downpipe, 3" Vibrant 17950 resonator, 2.75" piping (reused from Invidia catback) and Vibrant 10632 suitcase muffler.
This is a video of this setup at it's loudest on the highway under load.

https://www.youtube.com/watch?v=ClxbOOJYxWI

Cruising with rpm between 2200 and 2500 kept kept the db level around 67 climbing to 70 going uphill. At 65 mph the db level was right around 65. In all situations as with frequency was around 100Hz (as expected).

I had a 4 hour drive on the highway yesterday with speeds between 65 and 70 mph, and I am happy with the results. The exhaust note is deep and not over bearing, and I arrived without a headache. The Vibrant 10632 gives a little more sound than the OEM suitcase, and provided a serious reduction in sound from the Invidia suitcase.

It sounds much better now, glad you figure it all out. I remember after installing my DP I could hear the car from inside my house and it was great until I made a trip with my wife and two friends and for 3 hours the droning was so bad at 75mph that I started researching in the forum under “how to get rid of f. unbearable noise”....

 

[Zer0DazE]

Drove the car back home another 4 hours. The only time I think it's a little too loud is between 75 and 80 (closer to 80) under load going uphill.

I did also pop a P00AF while getting into it in 3rd. I had my laptop with me and my cable. Out of curiosity I checked the voltage at idle and not running with just the key at "On" 3.614v. It's the first time the car has tossed that code at me. In the morning I am going to loosen the arm and adjust it again. I am going to try to get it between 3.58 and 3.6.

Stratified also sent me a new tune to test out, so after I fill the tank I will get to try that out.

 

[Zer0DazE]

I have been driving this new exhaust setup for 2 weeks now. It is very livable for daily driving. The sound/tone has mellowed a bit and has developed more of a Subaru sound than a buzzy Honda sound, though it is still not as nice as that Subaru burble.

No issues with long highway drives (I have done a few 4 hour drives), and it sounds great at WOT.

I my opinion (and it's not worth much) is that Jake's downpipe and mid pipe with resonator with the Vibrant suitcase replacing the OEM muffler is probably the way to go.
You will make power and sound good, and won't break the bank. If this Invidia downpipe ever gives me an issue (cracks near the turbo flange are a worry) I will grab a catted downpipe from Jake.

Other happenings.
My Stratified v1.40 tune arrived, and it is making positive pressure and not throwing codes. That's a win.
https://datazap.me/u/zer0daze/strat-v140?log=2&data=4-8

I have developed an issue though. From a stop the shaking is letting the exhaust tap the rear cross brace. I get the feeling that my engine mounts and dogbone should be my next upgrade.

 

[Zer0DazE]

The recent increase in vibration while letting the clutch out has been a bit of a concern. I have also noticed that the clutch engagement seems to be lower than it was. Engagement is very close to the floor. Bleeding and re-bleeding didn't seem to change anything. Hopefully this is normal for this clutch and not an issue with the throw out bearing. The clutch is more like an old truck than at this point with the weight and long travel.

Earlier this month I received news that I will be relocated to the North Virginia area, so I will be without my tools and shop starting next month until we can find a new house. So I made the decision to clean this intake valves today. The car is just under 50,000 miles so I am sure they are filthy. I picked up the tool from Bimmer help to blast them and with a little luck it will make the job a little easier.

Results to come.

 

[Zer0DazE]

Ok, that job sucked. It ended up taking me 6 hours from rolling into the garage to test drive.

Notes:
-The triple square for the manifold support is a real pain to get to.
-The lower nut for the fuel line is very difficult to get a tool on. I used an old 17mm that I had cut in half for something else, and then used a 15mm on the end of it so I could pull on it. I had a leak there after reassembly.
-Before tightening the fuel line nuts, tighten the screw that secures it to the manifold. Doing this will keep the line from twisting when you tighten the nuts.
-The next time I do this I will also flush the coolant. If the coolant lines were out of the way (and maybe the charge pipes) this would have been an easier job.

Long story:
Pulled the car in the garage around 10am, opened ESC's pdf for installing a throttle body boost tap, and got after it. Most of the disassembly went without issue. I did have some trouble with the manifold support bracket bolt. It required a couple of extensions with a wobbly in the middle and some bloody knuckles. The fuel line is tough to get at under the manifold and behind a few connectors. I am glad I had the same flexible grabby thingy ESC had for pulling the manifold bolts out.

With the manifold out here is what I found... not as bad as I expected, but not good. My phone did not want to focus on the dirty valve stems for some reason.

I started with picks to scrape off the heavy stuff, and then blew it out. Then I used the Bimmer Help adapter to blast everything with walnut. I got after it with the picks and a brass gun cleaning brush, blew it out, and hit it with waltnut again. The using a nylon gun cleaning brush that I would soak with carb cleaning I gave it a scrub, wiped it out, and then blew it out. I spent maybe 15-20 min per port.

Results, much better

The manifold was sort of a pain to get back into position, and as mentioned in the notes, next time I will pull the coolant lines and flush the system at the same time. Getting the coolant lines out of the way would leave a lot more room to work.

Replacing and tightening the lower fuel line nut is difficult because of the lack of space. I used a 17mm I had cut in half for a prior project and then slipped a 15mm box end over the end and pulled on it to tighten it. Initially I did not do that and when I fired up the engine I found that I had a slight leak.

Anyways, after fighting with that, and having to jack the car up so I could remove the splash guard to find the wrench I dropped, I was ready for a test drive. Uneventful is the only way to describe it, and another inspection of the fuel line showed no leaks.

It's not a difficult job, easier than a turbo swap, but there are some points that will make you swear, and it is not an enjoyable job.

 

[Zer0DazE]

Stratified tune complete... for now
https://datazap.me/u/zer0daze/v170?log=1&data=4-8

Alex at Stratified has been awesome to work with. The early goings were a little slow, but a lot of that came from the car not wanting to make boost. With a little time Alex was able to work it out, and at v1.70 it is all squared away. The car runs and drives great, and the only way I could be happier is if Alex could make Blanton's bourbon flow from the water dispenser on my refrigerator.

 

[Zer0DazE]

It's been a while. Updates... the move to VA is done, and the garage is set up. We had to hang all sorts of shelves to fit a 2 car garage and 4 car shop into this new 2 car garage, but its all in there with room to park. Now I am working on making room for a lathe and mill... I may need to get rid of some other shit.

The car is running great on the Stratified tune, and the IS38 I picked up from Notorq is running strong. My commute went from 17 miles a day to 80. In those 80 I have to drive over a mountain, and because of this I have removed the catback and gone back to the OEM one with the downpipe. Driving up the mountain requires a downshift and keeps the revs right were the car is loud and obnoxious, and I just couldn't deal with it.

I also pulled the Boomba short shift adapter out of the car. Even after adjusting the cables it was notchy, and would fight me going into first. Without it the trans does what it is supposed to when I tell it too. I guess I am just going to have to move my hand 28% more when I shift.

No issues with the ED springs, and I believe they are the early models that I have read about others having issues with, and the 034 front upper mounts I replaced with OEM units continue to be quiet. So from this I am going to say the ED springs are great for the price (don't expect race car from a $300 part), and as has been noted from prior generations of VW's on other forums, the 034 front upper mounts should be avoided.

The replacement DKM clutch has 6000 miles on it now, and has been great. It feels exactly like everyone who is happy with theirs describes. A little heavier than OEM and grabs hard up high. My wife moved my car the other day (she never drives my car) and commented on how nice the clutch felt. As noted in the million page thread here, they had issues early one, but the new units seem to be squared away. I believe some of the issues with bolts backing out and awkward wear patterns may be due to shade tree mechanics. It happens.

With almost 60k on the clock my brakes are about ready for service. This has me looking at possible upgrades for all 4 corners. I will probably need to decide between going big brakes and the lathe and mill I want. I wish they would have had a car with the performance pack on the lot when I purchased this car.

 

[Zer0DazE]

Guess I should make a last update. Sold the car and picked up a 2017 A3 Premium Plus with 13000 on it. It's funny, in some ways the Audi is nicer, and in others the GTI was way better. A couple of things I especially miss are the adaptive headlights that moved with the steering wheel, and the color drive information screen. I was a little surprised to see those weren't just standard on a car with a 45k original sticker price. What was interesting was that in my area the Audi was a better bang for the buck buy. I had looked at 2017 and 2018 GTI's but they were either priced the same with more miles or a couple grand more with similar miles.

The new A3 is nice, and the premium plus puts the S-Line exterior package on it making it look nice, but the original owner/lease I'm assuming was an not a car person since they ordered it with the standard suspension (straight Stomper style) and without the S-line interior upgrades. Both issues are easily rectified, and I would have done (and most certainly bitched about) suspension work anyways, so it's not a big deal. I have already replace some interior bits and will be adding the ambient lighting over the winter. That leaves me with the winter to decide on the suspension and wheel set up.

As for go fast mods, I will probably just stick with a JB1 or 4 and ride out the warranty. It's going to take me a year to pay what I borrowed, and I am sure that after that I will be full of bad decisions... so I that 3 year warranty may or may not last.