Check this out! It would be rather complicated, but I bet it would sound awesome when awesome sound is desired, and it would be nice and quiet when sneaking home from the strip club at 3 AM.

dmhperformance.com sells electric exhaust "cutouts". They are essentially a Y pipe, and one side of the Y is blocked with a butterfly valve. When the valve is closed the exhaust gases go through the normal mufflers. When the valve is opened the gases go down the other part of the Y, which bypasses the muffler completely and essentially makes the system an open pipe with no muffler. Here's a pic of a dual system from their website. In the picture below, the valves are silvery things on the straight pipes on the outside of the exhaust system



So picture this: behind the X-pipe I could install the electric cutouts. A second pipe would go from the cutout to just in front of the rear muffler, where it would reconnect with the existing exhaust system. When the cutouts are activated, the muffler ahead of the axle would be completely eliminated from the exhaust system, but the rearmost muffler would still be in the system. It wouldn't be as loud as straight pipes, but it would be close.

Using a couple of switches and relays I could rig the system so that the electric cutouts would automatically open when "sport" mode on the transmission is activated and the throttle is wide open. In other words, I wouldn't have to flip any switches, but if I had sport mode activated and the gas pedal floored, the cutouts would automatically open. I could also rig up a manual switch so that I could open the cutouts whenever I wanted.

The two cutouts would only cost $320, and I could probably get my muffler guy to bend the pipes and weld everything up for $200 or so. In the end I could pick my exhaust note based on my mood!

 

Oh Yeahhhhhhhhh!

Like being Clark Kent and Superman.

A friend of mine has this set up on his Mustang and it is Awesome.

Sam, since you a watch guy I can share with you my surprise this Christmas when my wife got me a Breitling Chrono.Took me weeks to wipe the smile off my face.

Put the cutouts in, you can be the next Jaguar bad boy in disguise.

 

PCool! Which model? I have a Breitling Navitimer but I REALLY want their Steelfish Superocean. I actually don't like the Navitimer very much. It used to be my favorite watch, but now I'm more into the bigger, tougher looking watches.

 

What she got me was the Super Avenger but at 48mm it was a little to big for my wrist. So we went and exchanged it for the Chronomat "Evolution" which is 43.7mm.I can see by your videos that the big watches will fit you well.

When are you going to put the cutouts in? Keep us posted!!

 

Reverend, you still disappointed with the modified exhaust? Curious if time spent starting it, and driving it around, has changed from your initial impressions.

 

Way back on Page 2 of this thread, I posted a recording of the irritating sound my car was making with the new X-Pipe installed. XKRacer nailed it when he said to look for leaks. Took the Cat to a very good exhaust shop today to see what they could do, and the first thing they saw was that the idiot who installed my X-Pipe had welded 2.25" stubs to the pipes coming from the cats, slipped the X-Pipe over them and then forgot to weld the X-Pipe to the stub. (Is there a limit to how many head slap icons I can use???)

So, the first thing we did is fix that, then I drove the car. Voila, no buzzing - - - but it was quieter. Phooey.

OK, since these guys do mandrel bending, I had them fabricate new 2.25" stainless pipes from the X-Pipe back, up and over the axle, connecting to the slip fitting on the existing rearmost mufflers or resonators or tomato soup cans or whatever they are. The small mufflers ahead of the axle were NOT reinstalled.

NOW we're talking SWEET SOUND. (My wife, however, has not yet experienced this oh-so-pleasing-to-the-kid-in-me harmonic treat, so the jury is still out on the overall volume.) It is quiet at idle, "respectable" at cruise, and really sweet sounding while accelerating - - - WITH THE TOP AND WINDOWS UP. When I went topless (hey, it's 60F and sunny in Seattle today), it is quiet at idle, "respectable" at cruise, and really, really nasty while accelerating. (Like I said, a harmonic treat.)

The guys at Stan's Headers in Auburn, WA (shameless plug) did a very nice job, and it cost $480 before the State added 10%. That may be a bit high, but they are very proud of those mandrel bends (rightly so). I took some pictures, but I haven't had time to download them yet. I'll post them soon.

Hmm - Just wondering: Is a loud exhaust note a harmonic treat or a hormone-ic treat?

Cheers.

 

Don't know, but a viola is a musical instrument similar to a violin while voila is French for "see that".

So, what is the final configuration?

cats -> x-pipe -> front muffler -> rear muffler ? (deleted resonator)

 

Yeah... still disappointed.

That's what I'm talking about! I might have to try this next. I have a question, however. Are the rearmost mufflers "real" mufflers or are they just glass packs with a perforated pipe through the muffler? I have the same question about the ones just in front of the axle. I'm going to try removing either the front ones or the back ones, but I'd like to remove the ones that will cause the LEAST increase in volume first. If I'm not happy with the sound then, then I'll have my exhaust guy reinstall those mufflers and remove the others.

 

Plumsauce - One of the beauties of this forum is being able to edit a post. Now, instead of saying: "oops" I can say: "voila, all fixed".

The final configuration is: Stock cats, 2.25 inch Magnaflow X-pipe, 2.25 inch mandrel-bent pipes from the X-pipe back over the axle to the stock rear mufflers. The rear muffler is the only one in the stream. Take a look at the pictures below.

Rev - I don't know about the innards of the cans, but XKRacer sez the rearmost are resonators and the ones in front of the axle are mufflers. Since I had the same concern about getting too much increase in volume, my exhaust guy suggested removing the ones in front of the axle, just because they were smaller. Also, if my bride thinks it's not civilized enough, we can stick some small glasspacks in there pretty easily. (She's out of town for the weekend, so I don't know how that's going to go yet.)

Anyway, here are a few shots with very cryptic notes:

BEFORE:








LOOKING UP:


That's all for now. It's late.

 

that's ok, I had to go back and change "see this" to "see that" myself

So, does it sound like a .... mustang?

That's not a criticism. They have one of the sweetest sounding V8 exhaust notes ever heard.

That is the configuration in a mustang according to cutaway drawings. Except that the earlier ones used a H pipe. Apparently, the X pipe tends to be "raspier".

 

Plumsauce - I haven't listened to many Mustangs, but I think mine is probably mellower than they are. My exhaust guy said that the catalytic converters on the Jag are monsters and they are going to quiet it down a bunch before you even get to the pipes. Jason down at Nameless Performance sez his new cats will for sure increase the volume. I do know that this XK8 is MUCH quieter than my '71 LT-1. With solid lifters, tri-y headers, 2.5 inch pipes, one muffler per side and no balance pipe, it draws a lot of attention, especially at about 7000 RPM.

I'm not sure about the X-pipe vs. H-pipe sound, but most of the guys "in the know" on this forum think that the H-pipe is the raspier of the two. When you think about what's happening to the flow, that seems to make sense.

If we ever get another sunny day, I'll try to make a recording with the top down and post it.

Cheers.

 

That looks a proper job....well done


and yes the most rear boxes are just resonators, cut the rear pipe off the box back far enough you can see right through it.

 

XK8+XJ8, I hate to seem critical, but I sure wish your exhaust guy had made both sides of the exhaust symmetrical. It doesn't make an difference as far as performance goes, and it's completely invisible unless the car is up on a lift, but if it was my car it would drive me crazy knowing that the bends didn't match up. On the other hand, I love the bends over the axle. When mine was on the lift the other day I was looking at those factory bends, and the pipes get pinched down to about half of their normal size! I'm going to have either the mufflers in front of the axle or behind the axle removed at some point, and when I do, I'll have new pipes installed over the axles like your's.

One other thing... are you sure he used stainless? The guy who made my X-pipe used aluminized steel and your pipes look a lot like my pipes. the guy who did mine told me that it would have cost two or three times as much in stainless steel.

 

Sam - Regarding the asymmetry, I wasn't out there watching him, so I didn't see it till the job was done. There is a lever mechanism on the left side that the pipe has to miss (you can kind of see it on the 2nd and 3rd pictures), so that's why the bend is so far forward on that side. I guess he could have made the right side look the same, but it doesn't really make any difference to me, so I blew it off. If that was the biggest imperfection in my life, I'd be grateful.

Yes, they are stainless. The difference was just material costs. Aluminized was like $6 per foot and SS was $12, so it added $90 or $100 to the total.

Another point of interest: The existing pipes are actually 2.125 (or whatever the metric equivalent is). Since I wanted it to fit up to the existing slip joint near the rear resonator, he squzz the end of the 2.25 section down to 2.125 at that point.

Later,

 

I just got resonator removed and welded two independent pipes instead. So technically exhaust is now independent on each side.
Should I have placed an X-pipe instead?
So far I can feel that sound is deeper and lower, but the rest is about the same.
Here is quick video.

 

I went with the magna flow X-pipe and mina exhaust. It removed everything except the cat and replaced rear cans. I love the sound... I have a coupe so the top down is not a factor, looks awesome Larry.

 

I originally had the same as you mish, in that each bank had its own independent exhaust...when I listened to it, it sounded...how do I put this...'puffy', you know a puff here and there. When the center resonator is removed, the exhaust no longer mixes, and isn't as smooth...yes, puff puff can be heard. Added a magnaflow x-pipe also on mine and love it personally. There are other small advantages to a crossover pipe, but we do this for the sound right? If you do the crossover, I see you like it louder, just get the H-pipe instead of the X, and it'll sound nice.

 

Thanks, DCRAIN. I'm guessing your system sounds a lot like mine. They're pretty much the same except I have the stock rear resonator where you have whatever Mina puts there. Probably a Magnaflow-like performance muffler. I don't know if that would make it louder or quieter, but I'm pretty happy with what I've got.

Cheers,

 

I started this thread so I thought I would post the results of my exhaust modification. I decided to leave the center muffler as is. I purchased a straight through stainless steel exhaust from Adamesh. So I have pipe from the center muffler all the way back without the two mufflers and two silencers. It took care of the flat over axle sections as well because their system is round. The muffler shop I used welded everything in place for me. There is no knocking, banging or leaks. It is a very tight system. I finished the design with their stainless dual exhaust tips.

By leaving the center muffler in place it allows the gases to merge from each bank. I have no puffy sounds or resonance. Just even flow on both sides. I do notice a very slight gain in power and response especially at higher speeds. This was supplemented by a K & N air filter. However, I only did the modification to get rid of the flat over axle section and for sound. So my expectations for power gain were minimal.

I must say that I still can’t take the smile off my face. Did not know an engine could sound so fine. I had immediate results just by doing this modification. You can image my relief because I have been through other exhaust modifications including a Jaguar XJ-S V12 that just never sounded like this. It is hard to believe that the sound of my uncorked AJ 27 engine is so natural and so lively...just by taking the constricted mufflers off.

 

jagYour, are you referring to these pipees: jaguar xk8 and xkr over axel exhaust section | performance part ?