N54 135i with Electric Cutouts?

[Dmacc]

Just wondering has anyone done this or thought of doing this to their 1? I assume the less back pressure the better, but what about putting this in place after the downpipes before the midpipes?

[BSM 135i]

+1!

[onefastman]

Wanting to do this for a while but just have not got it done.

If I did do it I would go with manual cut-outs because I hear that the electric ones fail/leak after a while.

[Dmacc]

Originally Posted by onefastman

Wanting to do this for a while but just have not got it done.

If I did do it I would go with manual cut-outs because I hear that the electric ones fail/leak after a while.

Yeah i was reading your posts on e90post and saw the same thing, manual sound like the way to go because they're also not as expensive.

[onefastman]

Just run it into the cabin and your ready to go.

[Dmacc]

To me this seems like you could get a good amount of gains from this mod.

[Top Gon]

I'd be interested in seeing someone run a cutout. I assume it would sound something like this?

[Dmacc]

This seems like you could see some substantial gains off of this.

[spun]

Some guys on the other forum I go (Cobalt SS) ran into the same problem when attempting this (electric failing) so the ran a cable with 2 notches similar to the ones you would find on the release cable for your garage door (if it has an opener) Pull it all the up its closed push it down its open.

The big problem they ran into was where to disperse the exhaust without A) the fumes coming back up into the car and B) without melting any moldings along side of the car.
The last I checked no one had found a solution yet. This however is on a Supercharged car with a single 3" pipe. (Plus its a GM so...) Those two issues might not be so serious on something a lot better built like a BMW.

[bavarianx]

It would probably sound just like the RSD exhaust:

http://www.e90post.com/forums/showthread.php?t=397953

I hear they may be making on for 135 as well.

[Mad Maxx]

If / when I get my 1, I'm doing Boost Activated Cutouts.

No Switches or Cables to have to worry about or Run, and Fully Adjustable.

[135forthewin]

Shouldn't be a problem heat-wise. I know a guy who un-bolted his rear muffler section and drove it around for a couple months.
It sounded badass and didn't cause any visible damage under the car.

[onefastman]

It could be an issue. I melted my meth vaccum line and had the meth line not been ss it would have gone too.

I ran around with just the dp's and mid (no muffler) and it happened in a matter of a min. Be careful!

[ScarecrowBoat]

Originally Posted by Dmacc

Just wondering has anyone done this or thought of doing this to their 1? I assume the less back pressure the better, but what about putting this in place after the downpipes before the midpipes?

I'm going to be doing this soon, but am not sure where to run everything. Did you by chance find anybody who has yet? It would be nice to lot learn everything from scratch.

[Dmacc]

I've only seen someone on e90post attempt to do it, I talked to a guy at a muffler shop, and he agreed that it would be really hard to do it right after the downpipe on our 1's because of the lack of room.

the only place that it could work, would be at the beginning of the axleback, right after the midpipes, but that doesn't make sense because it won't really give you any power gains. But if you're looking for better sound, then you could do that.

[TheDeathDealer]

Originally Posted by bavarianx

It would probably sound just like the RSD exhaust:

http://www.e90post.com/forums/showthread.php?t=397953

I hear they may be making on for 135 as well.

A cutout will sound like a cutout.... Straight headers almost. Much louder than any catback even if it's just straight piping.

[The1]

I considered this on my old 1er, but after looking underneith, there wasn't much reasn in my opinion, because any cut outs would have to aim downwards, leaving more metal sticking lower on an already low car, now this wouldn't normally bug me, but i planned on lowering the car and i didn't want to run any risks.

and as mentioned above, it would have to basically be immediately after the downpipes, and there just isn't that much room. and you don't really want to run wide open untill about 18" after a turbo anyhow, so that would be pushing that limit and possibly ruin some efficiency.

the e90 post link looks like your best bet, however, we already have a bunch of mufflerless units out there, so it really would be unnecessary.

[TheDeathDealer]

If you really wanted a electric cutout there would be lots of places you could mount it. You can also put a turndown on the cutout and not lose any ground clearance. Your best bet is to put the car up on a lift and search around for a good spot to put it and then search for the right cutout.

[ScarecrowBoat]

I just had another thought for possibly the perfect exhaust...catless downpipes, straight pipes to replace the two cats on the midpipe, and then a cutout before the rear muffler. It would let you be a little louder than stock, or open the cutouts and effectively have straight pipes. There is just the one big muffler in the rear, right?

[TheDeathDealer]

Besides sound putting the cutout that far back would be useless. Best case senario is having the cutout at the end of the down pipe(s).

[ScarecrowBoat]

Originally Posted by TheDeathDealer

Besides sound putting the cutout that far back would be useless. Best case senario is having the cutout at the end of the down pipe(s).

How so? It would be straight pipes. Plus you would only need one instead of two cutouts. The point is that the exhaust exits out the back so I don't get fumigated in the cabin...

[The1]

Originally Posted by niceworkbavaria

How so? It would be straight pipes. Plus you would only need one instead of two cutouts. The point is that the exhaust exits out the back so I don't get fumigated in the cabin...

that's the point of cut outs though, the exhaust system at a whole is too long for the proper efficiency of a turbo. the optimum would be about 18" which is right around the start of the secondary cats.

even a straight through exhaust is going to have kinks and bends and such that will take away from power

and as you pointed out, the two exhausts go into one of a not very large diameter defeating the purpose of having a clean clowing exhaust.

the cut outs placed properly would be the best thing next to doing a drag racing setup, which would basically be a trumpet shaped exhaust coming out the fender.