Fix your Magnaflow Exhaust!

[rusty]

If you own a 2nd gen and have a Magnaflow exhuast you need to fix it. I know it's an awesome exhaust but it's restrictive as hell. The flange that connects to the test pipe is very narrow 2.25-2.4". I compared to the flange to stock exhaust and it's actually a bit smaller. Don't know why Magnaflow thought this would be a good idea on a 3" exhaust.

If you take this pipe to your local exhaust shop they can cut and weld a 3" flange like this one in it's place for very cheap. I paid $30 for the cut and weld and $40 for the flange.

Finished product:

Here's a before and after looking down the pipe.
Before:

After:

You probably thinking there would be a performance bump and you're right there was! Without any modification to my tune whatsoever I picked up an extra pound of boost. It's pretty clearly that original flange was restrictive AF.

(circa 2013 when i had a shitty setup)

Here are the flanges I could find that are 3" throughout:
1. http://www.ebay.com/itm/3-00-HEADER...ash=item236b484715:g:8aoAAOSwmrlUtZ~Q&vxp=mtr
2. http://www.ebay.com/itm/3-00-HEADER...ash=item25bea3baa5:g:FOsAAOSwm8VUvvF4&vxp=mtr
3. http://www.ultrarev.com/Kooks-7106S...oCg4uTFyl8LiyVfGuAGuX54jZMxPl7hsUsaAmD58P8HAQ
4. https://www.summitracing.com/parts/...aKkyhkSqRiLAR5uX7QCxk16eMe0P_3ViwMaAm-a8P8HAQ

Enjoy!

 

[Redline]

Good catch/fix. That's definitely a design head-scratcher. Why, but why, Magnaflow?
The restriction isn't very long, so it doesn't make a HUGE difference, but why get a new exhaust that's not all upgraded in size, right? LOL

 

[Maisonvi]

I did the same thing with my GReddy exhaust (now @HawkeyeGeoff 's) But that was 80mm to 2.5". What a pain to find an adapter that was. Have to imagine it helped a flow a lot.

 

[Raider]

@rusty, did you ever contact Magnaflow about that? Seems like a quick fix on their end.

 

[Gizmo]

I would love to see this fixed on magnaflow's end, I like the sounds it makes. its tied right up there with corksports sound for me.

 

[rusty]

@rusty, did you ever contact Magnaflow about that? Seems like a quick fix on their end.

No I didn't, I probably should have but I guess it didn't cross my mind at the time. Asking them now might be pointless since the car is no longer being made. I could be wrong.

Good catch/fix. That's definitely a design head-scratcher. Why, but why, Magnaflow?
The restriction isn't very long, so it doesn't make a HUGE difference, but why get a new exhaust that's not all upgraded in size, right? LOL

I think I know why they did it, it was probably the best flange that connected to the stock testpipe. The 3" flange fit the stock testpipe also but not as well as the flange that was included. The restriction was enough to for 1 psi of boost on this none aggressive tune, I would think if you were running 100 WGD on a K04 or running a BNR S3 it would be a lot worse. I think what it creates most is exhaust turbulence.