California BAR smog referee woes

[JoeMadoo]

Yea, I might need to borrow back that recirculating one i gave you... I feel like it's a waste of time to mock up an afm in there, their gonna figure out i have megasquirt anyway. I'm hoping to catch them at the end of the day and some new guy will slap on a sticker.

[lifeiskaos]

Hey guys. What air filter setup did you use to get BAR inspected?

[Justin B]

I have a question, since now theyre supposedly pushing off the visual to the smog techs (still?) to get the sticker, what happens if I want to run a single 2.5" exhaust after the down pipes? The dual 2" in single 2.5" out is not the stock replacement for the M5x motors. Aside from having to go through some loops to get that cat, would they fail it just for something trivial like that? They specify a dual in/out 2" cat, but I dont want to run dual pipes.

Also, about the engine designation; I'm running an M52 converted with M50 parts with the welded obd2 manifolds, am I going to try to tell them it's actually an M50B25 from a 1994 or so 325i? Do they check the casting on the block? It'll say 2.8...

These are some things I've kind of wondered about my swap and how I need to get it legal and not red flagged by the ref.

[golde30]

you gonna be fubar with those parts Jb, mite as well run the stock m50 manifolds and try to pass it like that.

[surebimmer]

I passed visual with obd 2 manifolds. You can tell them it's what ever motor you like. They will give you a sticker for what motor is say it is. Then it's up to the smog shop you take it too to make sure you have the correct parts for said motor.

[Jean]

You will most likely fail visual if you don't retain stock exhaust config up to (and including cat) cat. They only don't care what's after the cat.

[Justin B]

well thats fuckin stupid. The VIN on the engine is the 528i. How am i going to pass the obd1 m52 to begin with?

[MR 325]

well thats fuckin stupid. The VIN on the engine is the 528i. How am i going to pass the obd1 m52 to begin with?

They won't check that. I'd recommend running it as an M50 or S50.

[619E30]

Thanks for the heads up. My friend lives in Jamul. So I think I'm just going to register my car under his address since they don't have to smog cars there

[Justin B]

I think I may have found a solution, I have obd1 and 2 manifolds so at least that is a non issue if it comes up I can change it, but I doubt they would care about the manifolds, right? I found a 1996 m3 midpipe for sale, but that's not the s50 obd1 pipe. Is there really any difference between the two besides extra o2 ports I'd have to plug up, or do I really need to find a 95 midpipe? I could say it's an S50 with obd2 converted to 1 exhaust, but idk if that will fly. Im just trying not to buy anything more than I have to for the first time ever. Is there any difference between the m50 and s50 cat sections anyway?
If there is a difference that they give a shit about, is there any reason I'd want to specifically say it's an S50 rather than M50? Different displacement, any idea on if the emissions standard for the s50 may be less?

[eandrade]

There is no S50 OBDII.
There is only S50 OBDI or S52 OBDII.

S50 (OBDI) has only one O2 sensor. If you look at the midpipe, the dual pipes blend into one pipe before splitting again into the dual cats. This is how the one O2 sensor will work properly.

http://www.realoem.com/bmw/showparts.do?model=BF93&mospid=47486&btnr=18_0177&hg=18&fg=10

S52 (OBDII) has 4 O2 sensors. If you look at the midpipe, it's dual pipes all the way from the manifolds to the cats. 2 O2 sensors on the manifolds, 2 O2 sensors post cats.

http://www.realoem.com/bmw/showparts.do?model=BG93&mospid=47488&btnr=18_0253&hg=18&fg=10

My plan:
I don't want OBDII because I wanted the M/S50 intake manifold (technically it is illegal to modify anything pre-cat).
I don't want the S50 because I wanted a newer motor (S52) with the extra .2L of displacement.
So I will convert the S52 over to a full OBDI setup. Externally, the motor will look just like an S50USB30 (except for a few minor details that I doubt the smog shop will notice). I'll take the S52 midpipe (it's what I had), have the muffler shop fab up a y-pipe/crossover pre-cat and install an O2 sensor bung so that the single O2 sensor will work. Plug up the 4 O2 sensor holes with a Toyota oil drain plug (cheap, and it fits!)

Technically, this is illegal, but functionally, it should work. I won't be able to replicate the exact cross section diameter or length of the single S50 midpipe, but I don't see that having too big of an impact on O2 sensor functionality.


Don't you just love this state?

:)


Oh and sorry Justin, honestly I don't know if there is a difference between the S50/M50 regarding smog restrictions.

-Ernie

[Justin B]

Ok, I was being redundant than in saying "but that's not the s50 obd1 pipe", I know there is no OBDII S50. Didn't even think about the usability of only one 02 not breathing all 6 cylinders. Bother. May have a lead on a 1994 325i cat section though if its still around, so if I get that I'll just declare my engine an s50b30 too.

[eandrade]

Yup, that should work!
Sorry Justin, I didn't read your other posts to know if you're going with an S5x motor...if so, is there an efficiency/diameter difference between the 325i and M3 midpipes? (I think the part numbers are different?).

Reason I ask is that if you're running an S5x motor you might be choking it with a 325i midpipe.

-Ernie

[Justin B]

I dont know, but the reason why I came to that conclusion is that bavauto sells the same part number for 1995 e36's whether it's an m3 or 325i. I figure it will be fine at least to be legal, then I can take it off if I feel like it. I have an M52 that I'm converting to obd1.

[eandrade]

Cool deal.
Interesting...real OEM shows different part #s for the E36 325i midpipe vs the M3 midpipe.

No big deal, you're running an M52 so I'm guessing you should be OK with respect to cat efficiency.

Definitely let us know how it goes! (I'll be doing mine in a few weeks)