Exhaust setup for M5x

[dude8383]

Looks really low in the center.

The stock system usually sits a bit low without more modification.

[pandaboo911]

Looks really low in the center.

Yeah, the center cross brace needs to be removed in order for the e36 midsection to fit properly. Possibly the heat shielding as well.

[M3PO]

I ran catless on my e30 and b7 A4 for years. Even in PA where we have yearly "emissions testing" it's based off of visual tests. I am sure happy I don't live in CA and have to worry about passing this test...but in the outlook of life- the BAR is a good thing I guess. Too bad there isn't a cutoff for model years.

Yeah but it means you have to live in PA! :p

(I went to school in PA lol)

[pandaboo911]

Exhaust setup for M5x

Just posting these up for reference if anyone is using e36 stuff on their e30.

Can't recommend Lupe @ redwood city meineke enough. He builds some sweet cars, and always lets me hang out in the shop and fit it just how I want it.

Dont bother using it if your car is super low, if I had 16" wheels this would scrape everywhere. I used all obd2 stuff.

Before:



Mockup, both flanges had to be modified on the midpipe for it to fit.


Subframe clearance, this is with the engine spaced up 1/2"



Showing mods to flange


Cats are the lowest point



How the muffler fits. It's too big imo , dont recommend using it, in hindsight I would've used a turbo core muffler. It's also FUCKIN heavy. At least 50 lbs, probably more.


Rear section mods:




Subframe clearance:





You'll also need to weld/bolt in new hangers. I used a total of 5.

2 on the muffler, 1 at the original subframe mount, and 2 in front of the cats.

Car sounds super nice inside the car, no obnoxious drone. Also has a nice engine rumble at idle due to the stiffer hangers.

[bradmer]

OBD2 BAR exhaust setup

I ran the factory exhaust manifold, catalytic converter and Magnaflow muffler (part#14815 or 6 for $209), they are made just north of me in San Juan Capistrano. Car sits on H&R sports and Bilstein's, cat's are the lowest hanging part of the exhaust and scrape on every speed bump at my kids school when I drop em off.

[TeXJ]

Where'd/how'd you do the o2 sensor bung? I have a obd1 m52b28 and using the stock manifolds, so I have two bungs, front and back. I have the one in the front actually plugged in. However, I'm getting the 1222 code. I need to get the o2 sensor to be able to read both banks of the motor.

So where do you have your o2 sensor?

[pandaboo911]

Exhaust setup for M5x

Where'd/how'd you do the o2 sensor bung? I have a obd1 m52b28 and using the stock manifolds, so I have two bungs, front and back. I have the one in the front actually plugged in. However, I'm getting the 1222 code. I need to get the o2 sensor to be able to read both banks of the motor.

So where do you have your o2 sensor?

I have the 2 post cat bungs plugged. The stock o2 reads only 1 bank. The other has a wideband. Car runs fine for me

If you're using the obd2 midpipe you would have to weld in a small H pipe to mix the two.

I doubt your CEL is related to only reading 1 bank.

[M-technik-3]

OP any reason why you used a obd 1 version of the center section? I'll go on a limb and think it was because it came with the car you parted to do your swap?

[dude8383]

I think OBD2 cars are more of a pain to get through the BAR inspection.

[M-technik-3]

While that maybe true you can use an obd 2 exhaust on an obd 1 car for the advantages it flows better.

[TeXJ]

I have the 2 post cat bungs plugged. The stock o2 reads only 1 bank. The other has a wideband. Car runs fine for me

If you're using the obd2 midpipe you would have to weld in a small H pipe to mix the two.

I doubt your CEL is related to only reading 1 bank.

After doing more research, I may have a vacuum leak. Just wondering how, and if others are reading both banks or just using the one bank for the o2 reading. I do have a "H" pipe the guy gave me. Just have to have it welded in. Though not sure the o2 would reach the plug then.

[SnowB0und]

OP any reason why you used a obd 1 version of the center section? I'll go on a limb and think it was because it came with the car you parted to do your swap?

I swapped in a M50NV so I only have one o2 sensor in the stock location. It's right before the CAT. I'm OBD1 and figured a OBD1 exhaust would make bar easier. I think my exhaust is off of a S50 e36, hopefully it doesn't cause problems.

The reason it hangs low is the cats have the inlet and outlet at the bottom rather than the middle. So the bulk of the cat is above the pipe.

[pandaboo911]

Exhaust setup for M5x

I'm running the obd2 midpipes due to the aforementioned better flow. I thought about welding in an h-pipe but it would be pretty far down stream. Also it would definitely fail BAR inspection that way if that's your intent.

I've had no problems with running the o2 sensor reading 3 cylinders. It should work perfectly fine unless you have a cylinder with low compression or misfire, or other related problems, in which case the car would run crappy anyway.

On my previous exhaust I did weld in an h pipe under the transmission area, I had to extend the o2 plug wiring to reach it. That worked fine as well, but since the o2 sensor is not in direct exhaust flow and much further down the exhaust, it probably gets a less accurate reading than directly on the header. I would recommend leaving it on the header and plugging up additional ports.

[SnowB0und]

The factory o2 location on OBD1 is right around the output shaft on the trans.

[pandaboo911]

The factory o2 location on OBD1 is right around the output shaft on the trans.

True but it's in a proper x pipe that necks down around the o2 sensor