Cobb Tuning 3" Downpipe

i dont think so, i was not even able to get a socket by itself on, its so tight i barely got on it with the ratchet side of the open end wrench

[Thestaplegunkid]

Just finished installing my Cobb downpipe.

I have to say I was one of the lucky ones, both O2 sensors came out, threads intact. Total time was around 4 hours, just had the car on a set of ramps. The cobb downpipe fits amazingly well.

Love the sound of the Cobb downpipe with the Cobb CBE....... really nice tone.

Thanks Haltech for the write up, I used it during my install.

[johnsin55]

GGGGRRRR doesnt work with the Vibrant exhaust damnit.....

EDIT: Made it work by cutting off the 2.5" taper right after the weld to keep the angle at the end of the DP and welded a piece of 3" pipe on the end, then hacked my vibrant exhaust to mate up with it and used a butt connector exhaust clamp to hold everything together, works like a champ and sounds like a beast!

[wruss64]

I just finished my Cobb install last weekend, drove it all week, love it. Pulls better, no CEL, just makes me want to keep modding but think I will stop for a bit. As far as the install goes I went in knowing I was going to take my time and take all weekend. It does take patience but can be done. I am fairly wrench savy, but not full time weekend modder. For all of you out there that are like me, just a step above a shade tree mechanic, this mod can be done, but it will take time and patience. And don't go into it thinking you will get it done in 4 hours. I believe the guys on here that do it in that amount of time, but they probably have all the correct tools on hand and really know wrenching inside and out. I soaked everything I could with PB for a few hours and had no real issues with O2 or anything else coming lose. The Cobb fits perfect, very nice piece. I am glad I didn't try to save a few $$ and go with another brand, not that they wouldn't fit nicely either. As far as getting to the bottom bolts with a socket from below, no way I could. I had to use a open end and pulled as hard as I could until I farted and figured I was at the proper torque rating

[]-n3gR0speed3-[]

nice good luck

[papajohn026]

is cobb still actually building stuff for the carS?

[FreeFlyFreak]

Originally Posted by papajohn026 is cobb still actually building stuff for the carS?

Yes...... they killed a few low profit parts when the economy took a dive, but still make intake and downpipe. Who knows they may start back up production/development in the future, as things pick up.

[Ploppity Drown]

The end flange uses the stock donut gasket and factory spring bolts to aid in flex, longevity and proper fitment. This provides an improved seal compared to other methods, as well as reduced noise.

Can anyone here who's seen/heard both the Cobb and CPE downpipes installed with the stock catback back up this claim?

I wonder especially if their downpipe is any quieter due to the use of the donut gasket.

[Boosted333]

Originally Posted by Ploppity Drown Can anyone here who's seen/heard both the Cobb and CPE downpipes installed with the stock catback back up this claim? I wonder especially if their downpipe is any quieter due to the use of the donut gasket.

This is what it'll sound like (before and after vid that I just took yesterday). I installed my Cobb DP with the stock cat-back and so far I am impressed with how the car sounds. Not too loud, but you can tell its not stock. I was also one of the lucky ones with the o2 and the other bolts.... thanks a lot for the write-up here on the forum for some great tips!!!

How did you guys run your wire for the o2? I put a nut/bolt/washer holding a rubber clamp on the firewall (actually on the insulation) and it is securing the o2 wire. Hope that holds up. Now I just hope that smoke was just from the PB Blaster... although I see a puff with the stock video too.

stock-vs-cobb-dp.flv video by TurboSN95 - Photobucket

stock-vs-cobb-dp.flv video by TurboSN95 - Photobucket

[OMGWTFHAX]

For anyone who is running the COBB DP, if you fucked up the secondary 02 Sensor, dont worry. Cobb sells a plug for the port it you are okay with running only 1 02 sensor. The plag is only $5 compared to $180 for an 02 sensor.

[Jujiro_Prodigy_31]

will this oem exhaust donut from streetunit work well enough? its priced at $45 shipped, is that a fair price?

OEM Exhaust Gasket: MS3

haltech (or anyone else that has done a cobb dp install around a year ago),
it has been a little over a year since your cobb dp install. any black smoke, cel's, or anything else we should be aware of?

[OMGWTFHAX]

Here's the Bosch 02 sensor, cheapest price I could find:

Bosch 13770 Oxygen Sensor

Bosch 13770 Oxygen Sensor
Bosch 13770 Oxygen Sensor

[Jujiro_Prodigy_31]

What about the wide band o2 sensor? r the threads just as weak on it? that is more like a $300 replacement

[OMGWTFHAX]

Originally Posted by OMGWTFHAX Here's the Bosch 02 sensor, cheapest price I could find: Bosch 13770 Oxygen Sensor I ordered one just now. It sucks that the Mazda OEM 02 sensor threads are about as strong as a wet paper bag. However for ~$50 you can get a better and stronger rear 02 Sensor.

Just an update, this plug works for our secondary 02 sensor. Ive put about 1200 miles on mine and its great. No CEL.

[OMGWTFHAX]

Theyre the same, however I lucked out when taking out the wide-band. I would have literally shit in my downpipe and lit my local mazda dealership on fire. I dont care if it makes sense.

I got rage problems man.

[Jujiro_Prodigy_31]

rofl

I want to replace my donut gasket when i do the install, is this a fair piece/price?

http://www.streetunit.com/OEM_Exhaus..._p/su40581.htm

[Jujiro_Prodigy_31]

is this a decent replacement for the flange gasket?

JSC Speed: Universal Exhaust Gaskets

[AdriH]

A bit late but I still want to congratulate you on a very fine review. Perhaps one point to the less technically challenged would be to include a picture visualizing the exact position of the downpipe in the MS engine bay. I have been scratching my head quite some time trying to figure it out from the pics provided.
Needless to say I'm no technical buff, if I get one of these things installed, it will be by a -hopefully- skilled technician.

[felt]

Originally Posted by AdriH A bit late but I still want to congratulate you on a very fine review. Perhaps one point to the less technically challenged would be to include a picture visualizing the exact position of the downpipe in the MS engine bay. I have been scratching my head quite some time trying to figure it out from the pics provided. Needless to say I'm no technical buff, if I get one of these things installed, it will be by a -hopefully- skilled technician.

[AdriH]

Thanks .. that looks good..

[Ploppity Drown]

Thanks for posting the video, Boosted333. It does sound like the COBB + stock combo is a touch quieter than the CPE DP + stock combo I'm running currently. But it's not a direct comparison, so I think the jury is still out on this one...

I think either setup would benefit from the Magnaflow 12616 resonator upgrade. It's on my "to do" list. I, too, liked the exhaust sound after installing the CPE downpipe. In fact it got me thinking about installing a 3" catback. But after thousands of miles, I'm back to feeling irritated by the 2-3K RPM "droning" and setting off car alarms. The boost in performance hasn't gotten old yet, though. It's only that my tires and shock absorbers aren't up to the task.

I should also note that I've had no more than 4 "catalyst warmup efficiency" CELs since I installed it last summer, which I consider satisfactory. Initially I was getting some smoke out of the tailpipe, but my ghetto PCV system mod seems to have fixed that (Essentially the same as the PTP "smoking turbo fix"). I've only had 1 CEL in the 6 months since then. Now all I have to worry about is the KR I get under load, yay! I'm going to again try premixing FP Plus, a "lubricious cleaner", to see if that can help smooth things out---now that I've eliminated one source of exhaust smoke.

Oh, and by the way, in case anyone was wondering... the state of California's Air Resources Board tested my car (and paid me to borrow it) purely as an exercise. They classified it as a "gross polluter". I think they were just idling the engine, though, because they said the catalyst never got up to temperature. But monitoring the DashHawk I know it does get up to temperature under normal driving. It could have also been due to the "smoking turbo" problem. I hadn't yet installed my "fix". Nevertheless, the important point was that they said my car would never pass a sniffer test in California. So even if I could find a friendly smog tech to overlook the visual test, I'd still fail. This was disappointing because I had some hope that I wouldn't necessarily have to stock out to pass smog. Maybe the CARB guys were just being a little overzealous. In any case, I'm talking about the CPE Downpipe here, so these concerns may not apply to you COBBlers.

...

I don't remember exactly how I strain-relieved the O2 sensor wire... I think I just snaked it through some other wires to keep it in place.

[FreeFlyFreak]

Originally Posted by Ploppity Drown I think either setup would benefit from the Magnaflow 12616 resonator upgrade. It's on my "to do" list.

I love my Magnaflow, killed the drone.

[Ploppity Drown]

Do you have an aftermarket downpipe, FFF?

[FreeFlyFreak]

Originally Posted by Ploppity Drown Do you have an aftermarket downpipe, FFF?

No.
Sounds nice though.

I am modded with the "easy back to stock" philosophy, so no downpipe for me..... at least not until powertrain warranty runs out, and probably not then, due to install hassle and cali smog hassle.
I got the magnaflow to kill the 2500 off throttle drone of the stock pipes that I hated since new. It did that.
Its a little quiet now I would rather have that though than too loud, but it would prob sound perfect with the downpipe, I just don't want the hassle.

OT: By the way, I took my FSD's off and threw some MS coils on a couple of days ago.

[Ploppity Drown]

Ah, okay. What I'm wondering is if the resonator upgrade is less (or otherwise differently) effective with a downpipe. I'm trying to account for the entire system. Like maybe by changing the volume of the downpipe (3" tubing, only 1 HF cat) I've shifted that resonance peak... I dunno, I'm probably thinking too much... As far as I can tell the downpipe just made everything louder across the board. It seems like that one resonator (it's the first one, counting from the engine back, right?) is directly responsible for the drone...

I saw your thread about MS coils.. and all the attendant drama. haha

How are you liking them, overall vs stock with FSDs?

At some point this summer I'm getting new tires (Ventus V12s, maybe Star specs if I have a windfall...) and new dampers (maybe coilovers, but more than likely just Bilstein Sports)... Now where is that money tree?

There's always more stuff to buy, but lately I've been commuting on my Suzuki Burgman 400 so the urgency to work on my car has cooled. If anything, I'd direct my "extra" money towards new motorcycle gear and/or a new bike (Kawasaki Versys).

But my tires are only a few thousand miles from being unsafe, especially in the wet, so I'll definitely have to get new tires this summer. Hopefully a slick deal will pop up. Still jealous of the deal my brother got on his RE-01Rs last spring.

[FreeFlyFreak]

Originally Posted by Ploppity Drown It seems like that one resonator (it's the first one, counting from the engine back, right?) is directly responsible for the drone... I saw your thread about MS coils.. and all the attendant drama. haha

Actually the resonator that everyone is switching out with the magnaflow is the second one, the one just forward of the rear wheel. I cant remember exactly but I think the magnaflow wont fit where the first one is.

I'll post my impressions of the coils in one of those threads.... I have only a few miles on them so far my initial impressions a) I think I will keep them. b) They are not at all harsh, c) I just sold the MZ3 FSD's d) I wish I had got the KW v3s instead, for less drop in back and more spring up front.

[Boosted333]

No prob with posting the video... I made the video because I could not find one online so I can hear how the stock cat-back sounded with a DP, and I figured it would help others get an idea what it sounded like.

Driving the car, its not loud at all when you are cruising on the highway. No drone. If I get on the gas, it has a very nice aggressive tone... I'm already thinking I want it louder, but the smoking issue is bothering me. If you notice in the video, even with the stock setup, it had a small puff, i never noticed it until I watched the video. Then with the DP installed, the first day it was horrible, smoking all over the place at red-lights!!! Now, it has calmed down, just a little puff when I start driving again when the light turns green. But I have that PTP fitting on the way, and hope that helps.

Borrowing my friend's Dashhawk tonight, to watch the knock before and after that PTP fitting as well. I recall a bunch of random knocks at cruising speed when the car just had the Cobb SRI installed, and the AP Stage 1+SF tune. So I want to see if they are still there with the Stage 2 tune, and if they go away after I install the fitting in the PCV line.