135i exhaust - true "dual" like 335?

[fishbulb]

I know it exits on the one side (which I do prefer, looks-wise) but does anyone know yet if the 135 has a separated exhaust like the 335?

my guess is no, but with the same power spec, who knows? I'll even take educated guesses!

thanks!

[Wiggum]

I was thinking about this as well...

For best clues, we need to see the underside of the new 535, it will tell all...

I can't imagine BMW joining the downpipes together, but anything is possible...

[335i=:)]

Ideally it would be one pipe to save weight. Also, one 3.5 inch pipe flows as much as two 2.5 inch pipes. Due to less friction from less surface area. Only one 3.5 inch pipe weighs 40% less, around 20-30lbs'. If it is separate, when I buy my aftermarket tbe, I'll get a single anyway for these reasons.

[imported_MPower]

Clearly for the parallel turbos to work, it at least needs to be a true dual right at the beginning. The question becomes whether it converges into one pipe or continues as two separate pipes. Im thinking that one pipe would be a cheaper, more compact way of getting the job done.

[chemhalo]

My guess is that the car will have dual cats and then merge to 1 pipe.

[dna550]

Originally Posted by chemhalo

My guess is that the car will have dual cats and then merge to 1 pipe.

Well, yes! For some time now, all six cylinder BMW engines made for North America have had catalytic converters in the exhaust manifolds and there are two three-port exhaust manifolds.

This was done to meet stringent California and now 50 state requirements for emissions. This also means that these cats take a lot of punishment and also reduce performance. Ask me about this, I had to replace one, at considerable expense, since the engine had to be pulled!

Example, Euro spec E46 M3s had the cats down stream in the exhaust pipe, giving the Euro spec E46 M3 a little more performance versus the NA spec E46 M3, which had cats in the exhaust manifolds.

[fishbulb]

good call on the weight issue.....had not thought about that! (and i am almost always thinking about that!) of course, it may be easier to route two smaller pipes side by side (thinking of the 3.5" pipe dia...)

Not sure how the 535i exhaust will give us clues... that is even bigger (more room for pipes) than the 335. Please explain - thanks!

-jac

Originally Posted by 335ito135i

Ideally it would be one pipe to save weight. Also, one 3.5 inch pipe flows as much as two 2.5 inch pipes. Due to less friction from less surface area. Only one 3.5 inch pipe weighs 40% less, around 20-30lbs'. If it is separate, when I buy my aftermarket tbe, I'll get a single anyway for these reasons.

[Wiggum]

The reasoning on my comparison to the 535, was because it has a single sided exhaust just like the 1 series...

[fishbulb]

hmmm...well, that makes a LOT of sense....D'oh!

thanks!

Originally Posted by Wiggum

The reasoning on my comparison to the 535, was because it has a single sided exhaust just like the 1 series...

[strtfghtr]

Originally Posted by Wiggum

The reasoning on my comparison to the 535, was because it has a single sided exhaust just like the 1 series...

Makes sense to me

Hey Wiggum I see you are over here from the MS6 forum as well

[Wiggum]

Yes sir, lighter=better

[TheoIam]

Well both the E36 M3 and the E46 330's had two pipes all the way back to single muffler and one sided exit. So maybe the 135i does also? :iono:

[fishbulb]

no kidding? So are they set up like the 335? three cylinders into a collector and then each pipe?

thanks!

Originally Posted by TheoIam

Well both the E36 M3 and the E46 330's had two pipes all the way back to single muffler and one sided exit. So maybe the 135i does also? :iono:

[vintage42]

Originally Posted by dna550

.. all six cylinder BMW engines made for North America have had catalytic converters in the exhaust manifolds and there are two three-port exhaust manifolds... I had to replace one, at considerable expense, since the engine had to be pulled...

So that is what those swellings are in the headers. Would the engine also have to be pulled to work on the turbos in the same area?

[240M3SRT]

Originally Posted by vintage42

So that is what those swellings are in the headers. Would the engine also have to be pulled to work on the turbos in the same area?

Id be quite suprised to hear you had to pull the engine to remove the turbos.

In response to the 3.5" pipe comment, thats overkill for most of us. Assuming your turbos can even flow that much CFM your gonna have clearance issues with the exhaust tunnel and the reduced ground clearance. A 3" pipe can handle 500+hp.