Considering removing the back boxes ,not expensive the pipe is about £30 ( $ 36 ) bend it myself and tig weld. BUT having listened to recordings I know under full power you get a nice growl but is it loud when cruising at about 70MPH...dont want a headache ...( ie the wife moaning). did think of just changing one.

 

I have them all removed apart from the center x box. At 70mph it's just a slight rumble/drone. It's not a problem. With just the back boxes removed you will be fine.

 

Thanks for that ..I could buy at about £200 but why have the TIG and not use it .
The bends are at 170mm from end 117 degrees and 210mm from centre of first bend 15 deg.
Its all in the same plane so you can lay it out on the floor. Cut at 30deg rotate gives 60 deg.
I got some stainless end trims for £6.99 pulled out the innards and they are perfect.

 

My ‘96 XK8 came with a Paramount system which only has a custom centre silencer and straight piped from there. Thought it was overly resonant for the first 9 months or so and tried all sorts of extra insulation and lagging until I discovered it had been fitted hard against the floor pan in one place and the whole structure of the car was resonating in sympathy - d’oh. Ten minutes work with a crowbar gently ‘persuading’ it to take a slight detour made all the difference. Most tolerable now!
On my ‘02 XJ8 I’ve pretty much done what you’re proposing except I don’t have the welding gear so bought prefabricated stainless elbows and straight sections to straight pipe it from the back axle. Still very refined but just a bit more v8 burble at the back. My conclusion from all that? ‘Go for it’ 👍

 

I might need to look at mine then because mine resonated hard at around 3000rpm. Could be touching something. I can't see it touching anywhere, it has gotten better since it being isntalled last year but it's never gone away. Not a big deal, just mean you have to rev it either above or under 3000rpm.

 

Worth a look. Definitely more noise than the standard item and perhaps not for everyone. The noise changed from a constant and almost intolerable drone between 70 and 80 to a much more m pleasant background growl once I’d shifted the pipe.

 

Couldn't find anything. My car is fine at any speed just not at around 3000rpm. I think it's just how my exhaust is really.

 

I'm looking at changing just the over-axle section - Adamesh Stage 2. I think the full stage 1 and 2 is a bit overwhelming and I'll get grief from wifey, so my thoughts are to do the stage 2 only, get a nice borp and hopefully release another 20 or so horses at the same time

Thoughts?

 

It is probably the best option. As for the power increase I think it's best to go in wanting the sound not the power increase, I didn't notice any difference and although in theory the cruches section in the OEM part should be worse that isn't always the case. If you gained 20hp from that alone I would have thought Jaguar would have done it correct from the factory because that is a pretty big increase in power.

 

That will resonate well in the Valleys ...unless its Pontarddulasis Ohio.
Changing the rears is easiest and cheapest. Still with you limited to 20 MPH who cares.

 

I'm hoping for a nice Welsh Barritone note - pleasant to the ear .. Even though Drakeford is trying to stop us driving, there are still some nice national speed limit roads around, if you know where to look.

Cheers guys, I'll get my local exhaust place to fit the stage 2 and if I fancy it later I can do the rears myself

 

Interesting. My boom was at about 2,300rpm but wildly exacerbated by the contact with the shell of the car. Just returned from a quick blast in the old girl now and can confirm that there's generally more sound than in the cabin than with a standard exhaust but also that there's no boom and that, for my tastes, it's perfectly acceptable overall.

 

Hi Piston.
I fiddled about with the exhaust for a while when I first got my 99 R coupe. That terrible 5 box system on the early XK's was just awful and the first replacement needed...so much squashed piping and back pressure. I got the end pipe system to take out the mid and back boxes, but it sounded like a tractor so ditched that and ended up getting a full Cat back stainless system from Poweflow for £600 all in and fitted. It has the first muffler from the engine and 2 back boxes. It sounds great and a good compromise to reduce the back pressure and growels without being stupid loud. 2.5 inch pipes throughout... I think 👍 That was 12 years ago and still doing great.

 

Dont forget that backpressure is what keeps the charge in the cylinder during valve overlap.
If you let fresh charge out into the exhaust the fuel injection compensates and you get nowhere.
I agree those bends over the axle are a bit squashed. Was that the same on later models?

 

The Adamesh has smooth bends without diameter changes. If you 'cut and weld', then it may change the sound compared to the recordings you heard. Bends are best if you have the mandrel bender...
If you 'cut and weld' then it's certainly a nice little project. I don't have proof but it seems reasonable that smaller angle changes will yield better gas flow and sound.

 

That looks like second box replacement

 

Yes, the section from rear axle to tail pipe. I thought that was what you meant by saying 'back boxes'.in your thread starter.

 

I am planning on going in the complete other direction...

I think the pipes from the mid silencers back are 2 inch pipes. Under axle. No rear silencers. I drove about 350 miles highway for the first time early summer.

By the time I did my thing up and down the hills in Western Massachusetts,,, highway there and back home again, I was ready to SHOOT the car. Top down or up,,,, the DRONE was/became unbearable... Hard to talk with my lady in the car.

NOTE - I am an old fogey and an old soul. Slow-ish casual driver. I don't like noise, generally... That's just me.

Sometimes the sound coming out of the car is/can be just SWEET without the rears,,, but sometimes - even local driving - it can be toooooo much.

It has to be a preference thing, for each his/her own.

I'm looking for a non full OE silencer weld in muffler solution as we speak. Any suggestions will be taken.

 

The best solution is to delete the overaxle silencers but keep the rear silencers. You won't get any drone that way. Replacing the rear silencers with aftermarket ones is also a good idea, lighter and open the sound up a tad more.

 

Jay jay jay ...you said under axle but the pipe is over axle ....so what exactly is missing from standard on your car?
What I really want is a quiet cruise at say 70 and a roar when you floor it to pi$$ off some idiot.