[canosgmk]

Well,

I am still working on my 2.5" exhaust.

Thanks to someone I will not name, i didn't get the TT 2.5" down pipe (used), so i forked up the brand new one from Germanautoparts.com (cheapest I can find new). Put on the test pipe, down pipe and straight to a magna flow exhaust. I also installed a O2 sensor sim on the back side so i wouldn't get a CEL.

I drove the 5 miles back to my house from the garage I was doing this at and notice 3 things. More top end with more lag on the bottom, VERY FRICKEN Loud with a hard vibration from 2500 to 2900 RPMs under load only, and I got a CEL. Didn't scan the car yet, but I am sure it is for the Cat being taken out.

For the loudness, I am planning on picking up a Resonator ASAP. My wife officially will not drive the car now (yes, it is THAT loud).

The vibration... I have no idea. the exhaust is using all the factory mounting hangers.

Is there something special I should know other then thread in the O2 sensor adapter, then the O2 sensor, tighten, plug in. done.

 

[DerhsLacidar]

Well,

I am still working on my 2.5" exhaust.

Thanks to someone I will not name, i didn't get the TT 2.5" down pipe (used), so i forked up the brand new one from Germanautoparts.com (cheapest I can find new). Put on the test pipe, down pipe and straight to a magna flow exhaust. I also installed a O2 sensor sim on the back side so i wouldn't get a CEL.

I drove the 5 miles back to my house from the garage I was doing this at and notice 3 things. More top end with more lag on the bottom, VERY FRICKEN Loud with a hard vibration from 2500 to 2900 RPMs under load only, and I got a CEL. Didn't scan the car yet, but I am sure it is for the Cat being taken out.

For the loudness, I am planning on picking up a Resonator ASAP. My wife officially will not drive the car now (yes, it is THAT loud).

The vibration... I have no idea. the exhaust is using all the factory mounting hangers.

Is there something special I should know other then thread in the O2 sensor adapter, then the O2 sensor, tighten, plug in. done.

Did you reuse the old rubber exhaust bushings? Could be hitting somewhere on the chassis if the rubber bushings are whooped, added weight from the exhaust and larger diameter can allow that.

 

[canosgmk]

Negative. I bought new bushings. My wife thinks because they are 'harder' then the old, that might be why. I can video the ride today and post. It is sound as... (think something very loud).

 

[nolesfan]

What are you going with for a resonator?

This may be a tad off topic but, I was trying to plan recently what to do when my flex pipe goes, how to replace everything. I have a cat on the car now that is less than 2 years old (warranty replacement), but was contemplating test pipe and other bits, IF it wasn't too loud and IF there were any performance gains. I don't mind sacrificing bottom end for top end a little, but if it's only louder with no really noticeable driving difference to me, then there's no reason to change anything. I'll check this one for updates.

-Mike

 

[SleeperWagon]

IMO, exhausts don't do much unless you're already pushing your motor. If you've got a K04+ with a nice high pressure tune, you're gonna need a bigger exhaust. If you're on stock turbo and software, I swear to you, all the difference you notice will be placebo. Canosgmk, I trust you're chipped +.

I cut my exhaust off and ran with it around town for a bit just for shits and gigs, and wow did it sound horrible. I also noticed no performance differences, only that the exhaust was ridiculous.

Canos, I'd go with a glasspack resonator, as they are cheap and can actually dampen the noise quiet a bit, whilst giving it a nicer tone. I think I'm running a 21" cherrybomb (nice 'n long :thumbup: ) and a Borla Turbo muffler. Exhaust is perfect, not real loud at all until you get in the high revs, and sounds as good as an I-4 turbo can sound. No farts, drones, or rasp, I love it.
(Copied my custom exhaust from the TechTonics design of a big resonator and a Borla muffler, Borla makes the best sounding mufflers for I-4s I've ever heard.)

I wish I had had my exhaust on @ VagFest so you could've heard it, but it was just catless then. Oh yeah, I don't have a cat either.

 

[canosgmk]

Sleeper,

I am APR93 chips with slight mods. My plan is to slowly build for a K04 or franken.

Right now, I have zero resonator. Just a muffler with a TT down pipe and test pipe. I know people said it was 'louder', but holy hell. lol.

I opened it on the highway today and there is a big difference in 4th and 5th gear. Pulls harder. 1-3 is just fun, but i don't think any real gains (on a stock K03 with APR 93 chip).

I also have on hand and NOT installed a TT high flow cat. (plan B)

@nolesfan, no offense, but i didn't read your post yet. I will when I get a little more time tonight.

 

[nolesfan]

Don't worry G, I'm always around. I too am running APR 93 on stock turbo and was just interested in following this a bit. As mentioned above, I too was thinking of replacing my resonator with a Cherry Bomb (thinking it would a) save some weight and b) give very slight exhaust note increase), but keeping the rest stock temporarily. None of my stock exhaust parts seem to be getting close to age, other than the flex pipe showing some wear.

 

[canosgmk]

What i did (history)

OEM resonator deleted and stock muffler and cat on. Louder, deeper tone. A little more throttle response but the tone can become raspy.

resonator deleted, magnaflow muffler with OEM Cat. much better tone and very drivable. didn't notice much in my butt dyno in driving.

2.5" test pipe, TT 2.5" down pipe with flex, 2.5" to larger magna flow. Fricken loud and unbearable inside the cabin for day to day driving (if it was a weekend car, i wouldn't change it). MAJOR torque gain (by butt dyno), lower end seems laggy (might be because it is so loud, I am feathering it), took the car on the highway and WOT in 4th and tried to shift to 5th (i have triptron) and the computer keep pushing back to 4th gear. Would NOT shift in to 5th. So i went back down to 80mph in 4th and half throttle to 4500 RPM and shifted to 5th and went great. The last setup would die right at 4k rpm, now keeps pulling. WARNING, the turbo got A LOT hotter!!!!! much take care not to coke your oil.

hoped that helped.

I am worried about the O2 sensor CEL. Anyone ran in to the issue of the O2 adapter not working correctly and gave the car an CEL still?

 

[SleeperWagon]

As long as you put a bit of steel wool in the spacer(s), in my experience, you'll be fine. A year on a test pipe and never a code for secondary O2.

What the nuts? It wouldn't shift into 5th after 4th? What is that nonsense?

 

[VAGguy]

From what I remember, it's all about throttle position. It will not stay in 5th if you have it floored. Tops speed is only attainable in 4th on a tip trans.

 

[SleeperWagon]

That sucks ass.

Time to hack my TCM lol

 

[canosgmk]

.... took me about 5mins to going through the pages to find my post. All because the owners can't figure out how to put the proper search option back on.

AnyHo....

Loud Exhaust Video

Just to show everyone how loud I am saying this is... When i try to record in the cabin, the tone is so low and loud, the mic can't even capture it all.

K03 Turbo, Test pipe, TT downpipe, 2.5" all the way back to a 2.5" "Thunderbolt" muffler. It turns out it is NOT a magna flow. I called the shopped and they said, "it is the same thing man. Just cheaper"... I keep finding the @ssholes. I tell ya.

 

[highmiles]

IMO, exhausts don't do much unless you're already pushing your motor. If you've got a K04+ with a nice high pressure tune, you're gonna need a bigger exhaust. If you're on stock turbo and software, I swear to you, all the difference you notice will be placebo. Canosgmk, I trust you're chipped +.

I cut my exhaust off and ran with it around town for a bit just for shits and gigs, and wow did it sound horrible. I also noticed no performance differences, only that the exhaust was ridiculous.

Canos, I'd go with a glasspack resonator, as they are cheap and can actually dampen the noise quiet a bit, whilst giving it a nicer tone. I think I'm running a 21" cherrybomb (nice 'n long :thumbup: ) and a Borla Turbo muffler. Exhaust is perfect, not real loud at all until you get in the high revs, and sounds as good as an I-4 turbo can sound. No farts, drones, or rasp, I love it.
(Copied my custom exhaust from the TechTonics design of a big resonator and a Borla muffler, Borla makes the best sounding mufflers for I-4s I've ever heard.)

I wish I had had my exhaust on @ VagFest so you could've heard it, but it was just catless then. Oh yeah, I don't have a cat either.

I was thinking about just such a system, a glasspack in front of a muffler. I want a bit of throaty sound when I get on it, but I want it to go away at steady speeds. No droning, no "fart can". Never messed with a 4 banger exhaust, and have always been a bit scared of doing so because it can easily sound like a disaster. The glasspack thing came from Dad doing it to his old Ford pickup 30 years ago and change. It appears that my thinking was right, and it kills off the higher frequency "farty" noises, letting the muffler deal with the remainder. Can't beat a glasspack for killing high frequencies in exhaust.

 

[V4VanGelder]

That sucks ass.

Time to hack my TCM lol

time for a real transmission oke:

 

[swcrow17]

Geoff...you basically have the same exhaust I do, but yours is WAAAAAAAAAAAY louder than mine. I do have the Magnaflow, as it came from germanautoparts (whole thing) including my HF cat. Weird.

 

[canosgmk]

Ya, i went out today to hopefully get a glass pack put on, but many shops where closing early because some weather guy said 'snow'... I need to get it softer and soon. It gives me a headache driving it more then 20mins at one time. Don't get be wrong, it will be a fun weekend car as it is annoying.

I think some of the issues is the Thunderbolt muffler is not like magnaflow in the design.

I am aiming right now for a 21" or > with a 3" to 4" round with a 2.5" in and output.

After all of this is said and done, I am going to put together a 'Time Line' exhaust video from stock to the end product. That way if someone wants to hear the difference, it is under one video.

 

[zak99B5]

Dude nice video skills. Just use a real mic for any new footage. I bet the glass pack makes it sound good.

 

[Kosmas]

Interesting posts as I've gone and still going thru similar issues trying to sort out an Exhaust that I'm happy with.
(99 1.8T Tip AEB, K04, FMIC, GIAC)
I started with a custom 2.5" with MagnaFlow Cat (MAG59976), Centre Round Muffler (MAG10426 - 4" x 18") and Rear Oval Muffler (MAG12268 - 5"x8"x18")
This was pretty good on idle but a little loud and I was still not happy with the amount of droning inside, I could almost put up with it but not as my daily driver.

I ended up getting a Jetex Exhaust (42-H1) and this has been great in terms of perfromance, sound and lack of droning.
The Jetex has a very effective centre muffler that works ... 22/04/2010 | Flickr - Photo Sharing!
But I still have an issue with WOT sounding annoyingly loud and raspy coming from the rear muffler.

You will definitely need something in the middle to kill the droning (eg glasspack, bigger the better) and it would be interesting to see how much of a difference the TT HiFlow cat will make in terms of cleaning up the sound.

 

[canosgmk]

I got the Magnaflow res put on the car. Major improvement!

The 1st shop I brought the car to refused to work on it because, "the 2nd CAT is not on the car." (they where looking under the car and didn't look in the engine bay) I try to explain to them that my car doesn't come with two cats, only one with a pre and post O2 sensor. They didn't believe me, so i was told to go away. After a google search on my phone, i found another shop with in 20 miles away. When I got to this shop they looked at the issue and listen to my request. $50.00 later, they fixed all the 'bad' welds that gave a really bad leak (down by the 1st shop i went to a month ago) and installed the RES. I was so impressed with this shop, I will be going back and having them redo the WHOLE system for me.

When I get a chance (between sleeping when the baby is sleeping and working 9 hours a day and keeping up with my music career), I'll get another video recording of the updated system.

PS: I don't have ANY cats in my car. only a test pipe and a down pipe.