So after removing the first 3 exhaust boxes from the system the sound has improved tick over has a slightly deeper tone and when giving it some beans it has a much sportier sound with a little exhaust rasp but not quite what I wanted so further work is needed. I have now started to play with the rear tailpipe boxes. They are big and heavy and the plan was to remove them and maybe cut them in half, and make them half the size.
Inside the box I found half is a normal exhaust box with perforated tube and fiberglass lagging, the other half has a port tube in an empty chamber? Was not expecting this? I think I with replicate the setup but shorten it all so it’s half the length. I tried it with one rear box missing and it sounded too loud and just like a car with the exhaust blowing from the manifold so it needs some exhaust silencing for sure.

 

So V8esprit, were you just sitting around bored one day and said... "eh, I feel like cutting my Borla exhaust up to see what's stopping it from making the noise I want..."? Just kidding, but I do have to say, that's an adventurous endeavor. Perhaps you could get us some sound clips?
Magnaflow has a listing of replacements with in/out diameters and lengths for custom order. Member greverrr has a list of what he has on his car in his sig and has a few videos of the sound, just look him up in a search.

 

I am in full support of destruction for knowledge.

 

I'm glad you posted this, it's interesting to see that. I'll be following with interest! I will want to have a stainless system made for my XJ, and I was wondering what my best options would be.
The aim for me is to release some of the V8 sound without it being anti social or uncomfortable for myself or passengers.

 

What do you mean you don't want to be anti social ....Isn't that the reason to have a loud exhaust? I have a Corvette I won't start up until after 9AM, it has straight pipes all the way back.

 

I finished one side of the rear boxes and its louder and getting close to how I want it, will be a couple of days until I can attack the other side. Will post a video clip up when its finished.
when I removed the front box I replaced it with a fast flowing H pipe, looks like a crossover pipe put its not.

 

Since you are into destruction ... what's inside the other three boxes?

The port arrangement is somewhat like a helmholtz chamber. It's meant
to dampen/resonate at a specific frequency.

 

the middle boxes are just perforated tube and fibre glass lagging, the first box is half perforated tube and what looks like just straight tube with no baffling for the other half? will cut it open in a few days when I get some spare time. The rear boxes are jaguar branded I wonder if cheap replacements have the port tube? I bet they don't.

 

Look forward to it. The most interesting bit will be whether the two banks
are joined at the first box.

The rear replacements from say Magnaflow will not have that tube/closed chamber.

 

Will sound like this:



My 3.2l X308. Rear silencers are new for an X300 4.0l/3.2l. The front center Box was replaced with an X Pipe and the middle boxes replaced with pipes.

Doesn't drone when warm and sounds nice outside. Inside it is still nice and quiet.

 

Best option IMHO.
Vector

 

Ohh man you put me in a difficult position here, I am trying hard not to start playing with the exhaust of my car. LOVED your video.... Probably my next project this Fall.

 

I intend on using this car for long drives to France, Belgium, Germany etc so I don't want the car to become an unbearable environment for myself or my passengers. The video that's been posted is close to what I'm aiming for.

My little Triumph has a 2 litre Straight 6 engine with a semi sports stainless steel exhaust system, she makes more than enough noise if I want to be anti social!

 

Lol....what don't want to fall asleep with that drone slowly seeping into your conscious?

I want to do what Vector did....as a matter of fact, if he parks to close to me one day he may find it swapped out...

 

That is what I love about the cut outs, you can open them a little or all the way and anything in between: Luxury car quiet to race car loud or just a little rumble.

On the highway, she is a stock XJR, quiet and regal.

Cost is moderate too, about $400 or so, DIY.
Vector

 

Sounds mean

 

I got the last rear box finished today and fitted.
This pic is of the driver side rear with outer skins removed, you can see the port tube and the poor packing of the lagging in the other chamber. The other box was well packed and had fiberglass lagging like in loft insulation.
This box had long strand lagging almost looked like hair! Still had plastic wrapping left on and did not cover the perforated tube 100% poor construction/quality control.

This pic is of my shortened version, It’s a similar setup as the original but about half the length. I will try and get a sound clip/video of it running soon.

 

It's going to be interesting to see how the reduced size of the port chamber
moves the frequencies ... or not.

 

Albeit you have a premuffler (to say) in front to soften the tone, I think it will sound like this Flowmaster... SUPER 10 Series Flowmaster Delta Flow Mufflers ....this is the one I want to put on my Vette when I repipe it.
Its at about the 5:00 mark...

 

Looks like a week of rain in good old Blighty! Which is going to stop play with the exhaust….
After driving the car now for a couple of days I need to do further work to the exhaust. It drones on lower revs the usual driving around in traffic at 20 -30 mph under 2000rpm but give it some beans and it sounds really nice once the jaguar is unleashed! So I am looking into getting some more rear boxes to play with. I really need some vacuum solenoid valves to play with as this is the only way I believe you can achieve the best of both worlds.
Quiet nice driving at low revs and aural pleasure when she`s at full chat.
Just having very little silencing is not the sound I want. Have you heard an F Type? Look at the exhaust picture below its tuned to sound good.


I bet the solenoids start to open after 2500rpm