Question about x pipe design and muffler

[65 drop top]

I’ve seen x pipes where the exhaust pipes basically run parallel to each other and then the pipes just bump into each other forming the x. Then I’ve seen x pipes that are a true x shape in design. Apparently both work just fine.

Due to my chassis constraints an x pipe is not possible, and actually the possible muffler locations are somewhat limited. So I’ve been thinking about a creative way to run the exhaust. I think I could possibly fit a transverse muffler, something similar in design to the attached picture. I would install it as I have marked it up, even though most manufacturers show the inlets being on the same end of the muffler. At first I thought this could cause excessive turbulence, but the more I look at it, I don’t see why this would be much different than running the inlets on the same end. Either way, the exhaust will cross paths in the x. Any thoughts on this? Thanks.

[dontlifttoshift]

Have you ever seen a figure eight race?

[CSG]

I’m not smart enough to know but my thoughts:
An x pipe works because the exhaust pulses in each pipe basically help scavenge the other side. I feel like what you posted is more of an open chamber than intersecting pipes and then add in that it will be far from the exhaust ports. I think the figure 8 race comment has merit.

[Mr Nick]

Have you ever seen a figure eight race?

LOL thanks for a laugh Donny!

OP - I would not suggest what you're thinking. Instead, try to find a dual in/dual out muffler that does NOT have an internal X pipe, or just use two bullet style mufflers next to each other like this:

[Mr Nick]

Here is another idea... if you don't need dual pipes the whole way back, merge your headers/exhaust manifolds to a single main pipe, then use a transverse muffler to split the exhaust to dual tail pipes. Many manufactures have mufflers like this:

https://www.borla.com/products/universal-muffler-40477

[65 drop top]

Thanks for the replies, I appreciate it. Like I mentioned, just trying to come up with something creative. I really like the dual bullets though, that would package very nicely.

[65 drop top]

Here is another idea... if you don't need dual pipes the whole way back, merge your headers/exhaust manifolds to a single main pipe, then use a transverse muffler to split the exhaust to dual tail pipes. Many manufactures have mufflers like this:

https://www.borla.com/products/universal-muffler-40477

Thanks, but I have to run dual exhaust, you can see in picture the chassis has passages for the exhaust to go through. Most guys with this chassis, AME tri five, put the mufflers before the rear crossmember which puts the mufflers under the rear seat foot wells, but I just don’t want them there. I’ve also seen them mounted right after the cross member but they just look too cramped in that area. I haven’t actually measured yet but I think a transverse, or dual bullets would fit between the rear end and the gas tank.

[showdog75]

K.i.s.s.

[BrianP]

Many cars had transverse dual exhaust. You just need to find a muffler that you like. Here’s a Magnaflow first gen Camaro transverse muffler that would probably flow a lot better than the X-pipe shown in your example. The muffler will not provide the same benefit as an X-pipe up front. Do you have room up front for a H-pipe?

[65 drop top]

Interesting, MF is definitely using the muffler they exact way I was asking about. No, there is no room for an x or h pipe especially when using a t56, the center crossmember really makes things snug at the rear if the trans. Thanks for the picture.

[dontlifttoshift]

Aside from the aforementioned figure eight issue and adding four more 90* bends to the system, I think getting up and over the axle and then turning 90* into the muffler is going to be a chore.

I assume the "standard" location bothers you as you are worried about drone or noise. Get the longest case in that spot that you can and then use bullets at the rear between the frame and quarter panels.......that should keep it pretty damn quiet.

[67King]

I actually think that will be effective, with one caveat. Can you keep the pipes leading into it equidistant? If so, your primary pulses should still always be 90 degrees apart. Granted, things look funny once they merge, especially with the wonky firing order of about every V8 not made by Ferrari (or the Ford Voodoo). But if you can make sure the pipes ahead of that muffler are the same length, that should help alleviate issues of pulses arriving to the intersection at the same time, and you may end up with them working like braids, rather than a Figure 8 race!

All that said, I'm not sure that having it that far back will be as effective. You ideally will have changes at lengths similar to your primaries. You'll get a reversion wave when you have changes to the airflow (I picked up about 2% on a road race car, Porsche 968, by changing gradual flares to abrupt steps - counterintuitive as it hurts flow, but beneficial due to the tuning impact). Not as big here, but something. Also, since the exhaust gasses are going to be cooler by the time they reach the rear of the car, the length of the pipe where the tuning will be seen gets shorter (due to the speed of sound, which determines the resonance, slowing down as the exhaust gasses cool).

I think you may actually benefit from running a smaller diameter H-pipe that will package. Say, maybe right at the very back of the transmission. This is complete speculation mind you. But the whole scavenging this is not just the venturi effect, it is also resonances. Anecdote, look at a Ferrari F430 dual plenum intake, and look at how much smaller the comm valve is than each plenum.

[67-LS1]

Just curious, why don’t you want them under the rear seat area?