MMP M62B44 Build Project "Jack-N-Coke"

[The Dark Side of Will]

180 degree headers sound much more refined and euro in my opinion. It eliminates two power pulses hitting the collector at roughly the same time which gives the uneven, rumbly sound.

Would probably be a big pain in the ass to do on a V8 e30.

They are pretty awesome, but also really tough to fit in anything but a GT40 replica...

However, as shown in your video and elsewhere, there are Corvettes that have them.

[ForcedFirebird]

For best effect, the X-pipe needs to be as closer to the manifolds as possible... getting it closer than 5 feet in a BMW is difficult.

For sound, maybe, for performance you want to pick up on a harmonic.

[ForcedFirebird]

They are pretty awesome, but also really tough to fit in anything but a GT40 replica...

This guy fit them in a FWD GM 660 platform, but a Monte Carlo with a 6cyl would have more room than an e30 with a v8, I imagine. (post #119, click on pic to hear/see his video).

http://60degreev6.com/forum/showthread.php/48375-3400-N-A-Monte-Build-Thread?p=449943&viewfull=1#post449943

[The Dark Side of Will]

For sound, maybe, for performance you want to pick up on a harmonic.

Without long tube headers - pointless... There's no point in the pipe that is "in tune" for all cylinders. It's not a harmonic, as there's no standing wave... it's a reflection. The difference between time domain analysis and frequency domain analysis is a subtle but significant one that's lost on a lot of people.

WITH long tube headers, put the X right at the end of the collector to properly terminate...

This guy fit them in a FWD GM 660 platform, but a Monte Carlo with a 6cyl would have more room than an e30 with a v8, I imagine. (post #119, click on pic to hear/see his video).

http://60degreev6.com/forum/showthre...l=1#post449943

With a 120 degree firing interval, a V6 can't have 180 degree headers by definition ;)

Also, the V6/60 has even fire banks, so conventional long tubes operate on it the way 180 degree headers operate on a cross plane V8.

[ForcedFirebird]

Without long tube headers - pointless... There's no point in the pipe that is "in tune" for all cylinders. It's not a harmonic, as there's no standing wave... it's a reflection. The difference between time domain analysis and frequency domain analysis is a subtle but significant one that's lost on a lot of people.

WITH long tube headers, put the X right at the end of the collector to properly terminate...



With a 120 degree firing interval, a V6 can't have 180 degree headers by definition ;)

Also, the V6/60 has even fire banks, so conventional long tubes operate on it the way 180 degree headers operate on a cross plane V8.

Not the place for this, but will say that BMW stock manifolds are better designed than you think, and still can take advantage of putting the x-pipe in the best location. timing the reflected pules helps evacuate the chamber. The m60/2 are try-y inherently, in fact ;)

On a 6cyl by definition, no, they aren't firing 180 degree apart, but you are pairing the cylinders on opposing strokes (phased headers), and this is what gives that exotic flat plane crank sound. You have been around the 60v6's long enough, and you know good and well, they don't sound anything like the two examples in that linked post.

[JGood]

For best effect, the X-pipe needs to be as closer to the manifolds as possible... getting it closer than 5 feet in a BMW is difficult.

I'm sorry, I thought the point of the conversation was about the value of an x-pipe installed in an m60 e30 with the magnificent stock m62 manifolds (there's a reason BMW used the m60 manifolds on the M5...), in a realistic location. I thought that's why he asked for input... Real world experience from people who have this engine, in this car, both with and without an x-pipe.

Carry on with your theory, if that's what he's looking for...

[MonkeyMadness]

Lol.... this is why I think I may go in a different direction altogether.

[The Dark Side of Will]

Not the place for this, but will say that BMW stock manifolds are better designed than you think, and still can take advantage of putting the x-pipe in the best location. timing the reflected pules helps evacuate the chamber. The m60/2 are try-y inherently, in fact ;)

On a 6cyl by definition, no, they aren't firing 180 degree apart, but you are pairing the cylinders on opposing strokes (phased headers), and this is what gives that exotic flat plane crank sound. You have been around the 60v6's long enough, and you know good and well, they don't sound anything like the two examples in that linked post.

The M20 manifolds are just logs, but S52 manifolds are decent for shorties.

Only 1 of the M60's is try-y ;) which is something I found interesting.

[The Dark Side of Will]

Carry on with your theory, if that's what he's looking for...

Well... I don't think he's interested in following the crowd...

[The Dark Side of Will]

Lol.... this is why I think I may go in a different direction altogether.

You weld... build some long tubes to get the most out of that blower.

[JGood]

Well... I don't think he's interested in following the crowd...

I was just looking for some R3v input on it.

OK, sorry. I'll keep my mouth shut from now on.

[MonkeyMadness]

Lol.... no no please I have enjoyed this read. Very interesting and educational.

[ForcedFirebird]

The M20 manifolds are just logs, but S52 manifolds are decent for shorties.

We aren't quite discussing the m20, but will tell you, shorties, do nothing over stock "logs" as you call them (more like tubular headers). I have dyno tested various headers on m20's, and the stock cast units are actually decent. Only until you get over 24" or so, will you see gains, and that's only in torque (best of 5wtq, 0whp to date).

BMW OEM exhaust was very well designed for being what it was, specially when we are talking about decades old, at that.

[LJ851]

We aren't quite discussing the m20, but will tell you, shorties, do nothing over stock "logs" as you call them (more like tubular headers). I have dyno tested various headers on m20's, and the stock cast units are actually decent. Only until you get over 24" or so, will you see gains, and that's only in torque (best of 5wtq, 0whp to date).

BMW OEM exhaust was very well designed for being what it was, specially when we are talking about decades old, at that.

Have you found gains in other areas of the exhaust on a stockish M20? Are the down pipes big enough? 2 into 1 exhaust superior? Or is the whole stock exhaust hard to beat?

[ForcedFirebird]

Have you found gains in other areas of the exhaust on a stockish M20? Are the down pipes big enough? 2 into 1 exhaust superior? Or is the whole stock exhaust hard to beat?

RD headers>true merge y>2.5" Vibrant resonator>true merge y>Billy Boat e30 triple chamber made 157whp on a 200k mile m20 with a chip (no baseline on that one though :() That's .020" over well built Spec e30 engine territory, most high mileage m20's make 140-148 (even chipped).

Done derailing this thread, sorry, carry on Jeremy...

[/HIJACK]