MMP M62B44 Build Project "Jack-N-Coke"

[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.

[MonkeyMadness]

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

[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...

[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.

[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]

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

[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.

[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.

[The Dark Side of Will]

OK, well like I said, I put an x-pipe on my m6x e30, which is what the OP is also considering, and it made no noticeable difference in sound or performance. I think that's the topic at hand...

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.

[LJ851]

[JGood]

I disagree. The X-pipe has a big impact on sound. I went from duals to X-pipe on my Northstar Fiero and the change in sound was significant. Even my girlfriend can tell the difference between my car and a loud Mustang just by sound when both cars are out of sight.

Can you tell the difference in sound between an LS1, and LS2 and an LS3?
There's more difference among those engines than there is between the LS7 and LS9. The 7 & 9 even use the same exhaust manifolds.

That being said, there are a LOT of different formulations of both X-pipe and H-pipe and each one's going to sound slightly different... however, overall X-pipes have a certain character and H-pipes have a certain character and I think MM would like an X-pipe more. As I mentioned earlier, the big improvements from an X-pipe in terms of keeping power while reducing noise come from having the X as close to the manifolds as possible, which is difficult in a BMW. I can do it in the Northstar because the front bank manifold goes straight under the oil pan.

AFAIK, the BMW manifolds are unique in the cross-plane V8 world.

OK, well like I said, I put an x-pipe on my m6x e30, which is what the OP is also considering, and it made no noticeable difference in sound or performance. I think that's the topic at hand...

[The Dark Side of Will]

I disagree. The X-pipe has a big impact on sound. I went from duals to X-pipe on my Northstar Fiero and the change in sound was significant. Even my girlfriend can tell the difference between my car and a loud Mustang just by sound when both cars are out of sight.

Can you tell the difference in sound between an LS1, and LS2 and an LS3?
There's more difference among those engines than there is between the LS7 and LS9. The 7 & 9 even use the same exhaust manifolds.

That being said, there are a LOT of different formulations of both X-pipe and H-pipe and each one's going to sound slightly different... however, overall X-pipes have a certain character and H-pipes have a certain character and I think MM would like an X-pipe more. As I mentioned earlier, the big improvements from an X-pipe in terms of keeping power while reducing noise come from having the X as close to the manifolds as possible, which is difficult in a BMW. I can do it in the Northstar because the front bank manifold goes straight under the oil pan.

AFAIK, the BMW manifolds are unique in the cross-plane V8 world.

[JGood]

I think both LS9 and LS7 are CNC ported, but I believe the LS7 uses larger intake valves, which are enabled by its larger bore.

Right, and differences like that (along with the 6.2 vs 7.0, the supercharger, etc....) will probably have more of an impact then x-pipe vs h-pipe... that's all I was getting at.

[The Dark Side of Will]

The LSA from the CTS-V is more like a supercharged LS3. The LS9 has piston oil squirters, titanium rods, etc, and is a lot more than a supercharged LS3.

Pretty sure they use the same castings. The LS7 heads have small chambers, while the L92 heads have (don't know the casting #'s right off) have the same ports but larger chambers. I'm not sure which the ZR1 uses.

I think both LS9 and LS7 are CNC ported, but I believe the LS7 uses larger intake valves, which are enabled by its larger bore.

[JGood]

They use the same head castings... hard to get much more apples to apples than that.

The LS9 is based on the LS3. I've never held either heads in my hands to know if they're the same casting, but the LS7 has different port dimensions, among other differences.