Megan Racing exhaust issues - 2g AWD

[turbosax2]

I'm trying to bolt on my 2g AWD Megan Racing exhaust, downpipe, and o2 housing. When I tried bolting them all up, the o2 housing and downpipe didn't want to go together nicely, and when I forced them too the downpipe was pressed firmly against the transfer case. Also, the little heat shield near the carrier bearing was smashed in from the flange between the downpipe and the catback adapter. This is with the most current revision of the downpipe.

I thought maybe the MR o2 housing was the issue, so I removed that and put the stock one back on. The situation improved some, and the downpipe now slightly sits against the oil pan instead of smashed into the transfer case. However, the little heat shield near the carrier bearing is still tweaked.

Has anyone else ran into these problems or have any advice for me? With as many people that have this setup I figured I would have read about these problems by now, unless other people have these issues and just don't care. I could remove the heat shield but I believe it's there to protect the carrier bearing in case you have an exhaust leak at the downpipe to catback connection.

Here are pictures to show the issues.

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[JFZERO ECLIPSE]

You might have got an older version of the MR downpipe or catback...I know they did change the flange angle a while back due to clearance issues...just not sure which piece

 

[rlacasse1]

you can probably trim the little heat shield

 

[Atuca]

I removed that shield, and for over a year had no issues. I couldn't honestly tell what it was for when installing my turbo back, I removed the one around where the cat would be as well, so really I considered it a weight reduction

my .02

 

[turbosax2]

You might have got an older version of the MR downpipe or catback...I know they did change the flange angle a while back due to clearance issues...just not sure which piece

They revised the downpipe, and I have the most current revision.

I removed that shield, and for over a year had no issues. I couldn't honestly tell what it was for when installing my turbo back, I removed the one around where the cat would be as well, so really I considered it a weight reduction

my .02

Removing it is one option, although I would like to keep it if I could. Do you happen to remember if your catback would have hit that shield if you would have kept it? I just want to make sure I'm not missing something stupid that's making this a problem.

 

[Atuca]

Unfortunetly, I was at a friend's during the install and I dropped the whole stock turbo back when I installed the Megan. I noticed it was hitting after I spent an hour or two trying to line up the exhaust as I thought I was the one in error (as I usually am).

In the end I removed a long flat piece of exhaust heat shield where the cat was as well as the smaller shields it appears you have pictured. Looking at it, it looks like it is there to prevent excess heat from interfering with the driveshaft seal that appears to be there. My car is down for a build as you know and there are no ill effects to my knowledge. I DDed the car about 5 miles round trip and WOTed maybe once or twice a month.

Racing the car may prove side effects, but ^^above is all I know for sure.

 

[KevinBoosted]

Ive got the megan downpipe and catback. Im pretty sure i got the bad batch because when i was installing the downpipe i had the hardest time trying to connect it to the o2 housing. I even dropped the turbo and manifold to help with the angle. I wound up just using a drill and going around the inside of the bolt holes and widening them. After all this just like you it was rubbing against that heatshield so i just said f* it and removed the heat shield If i had another exhaust i would have sent it back to megan on the spot but i couldnt afford driving the car around with an open o2 Well its now been over a year since ive had the turboback on and from drag racing to the road course i cant say i really noticed a difference but then again the only other exhaust ive had on my car was stock so i wouldnt know what to look for in difference i guess. I will however have a custom downpipe made this year and ditch the megan one since i have a feeling the weird angle it is at is causing some kind of power loss, however i will keep the megan catback since that does fit nice

 

[turbosax2]

I fixed the issue. I decided to port and polish my stock o2 housing to use since it fit better.

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Then I hacked the flange off a spare 2g o2 housing to use as a spacer between the o2 housing and downpipe (thanks to Oldsid for the suggestion ). I also ported and polished this to match the o2 housing. This fixed the issue of the downpipe hitting the oil pan/transfer case and it now sits evenly between the two and has about a fingers width of space between the downpipe and the bottom of the oil pan. The spacer was shaved so that it is not level so it helps the issue of the downpipe and o2 housing flanges being not parallel, but not too much that it affects how the downpipe nuts sit. Since the spacer is there the stock o2 studs are no longer long enough, so I talked to Jeff at ssstuds.com and he's sending me custom studs that are 1/2" longer than stock. I haven't received them yet so in the meantime I'm using bolts in place of the studs. I am using 2 gaskets at the o2 housing now - one on each side of the spacer.

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The spacer also helped the heat shield issue some. I still had to some minor trimming to the shield and a lot of bending, but now it fits ok.

I'll take some pictures of the heat shield and how the downpipe sits next time I'm under the car.

 

[turbosax2]

Pictures as promised.

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[LiquidX]

I know this is a little old, but I just purchased my Megan Racing AWD down pipe as well. Packing was good and it came with 2 gaskets (3" and 2.5") and 4 bolts+nuts. I think I may have found out about the fitment issues while I was taking some pictures of the pipe. I'm not sure if anyone else has noticed. These shots were taken with the the DP laying flat on the side and the hanger pointing in the air. These also start at the flex section.

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This one is just to show how straight through it is.

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[bmoha2]

3". I think I kinda know what you were going thru here with the Megan even tho I have a ss 3" punishment racing dp. I was very impressed with how it looked straight out of the box. Unfortunately when I bolted it up I realized it was in direct contact with the underside of the oil pan. I'm impatient so I drove out to my friends shop and welded in a 3/8" long section of 3" ss tubing and voilà no more problem. It was ss and I welded it with ss stick. I had bought a 3" flange and was considering having a double stacked flange similar to what you have done but decided to just weld in an extention

 

[turbosax2]

Since you bumped this thread, I might as well give a quick update. I removed the carrier bearing heat shield awhile ago thinking it was contributing to a knock issue I was having. It was flexible enough that it was (I believe) vibrating on the exhaust. It didn't eliminate the knock I'm seeing, but I'm sure it wasn't helping.

 

[HaveBlue83]

BUMP for more info. mods don't kill me.

yeah, you got what i got.....the old version that was made for the EVO3 o2 housing the test car they used had the EVO3 16g and they didn't know it had a different 02 angle. my dad took an orange-shaped slice out of the DP and bent the flange down to fit. i wasn't too happy about the fitment, but it now works perfectly. my GS-T didnt have this issue. its only the old AWD DP's. I got mine from extremepsi.com and they said it was the new one....but how can they know unless you open it and look.....

FWD vs AWD w/evo 02 angle. MUCH more angled on the AWD EVO one.

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(AWD one has a larger pipe diameter though than the FWD. its about 2.75 for only that little part, then 3" back. FWD is 2.75 until the Flex.

What slice we cut out and bent down.

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this worked GREAT.....then we had to weld the two DP sections together after assembling because they kept coming apart.

all in all the DP = not fun. The Cat-back = EASY.