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Discussion Starter #1
Can someone help me understand the physics of how JLR produces such a huge range of exhaust sounds from the same engine?

I apologize in advance to those who quite understandably feel that these vehicles should remain serene and wafty; I personally feel that the environment in which it is driven (and actually also the colour of the car) permits a range of experiences. In my case (big city, black car) I find a deep ominous rumble to be amusingly incongruous. (to be clear I'm not talking muscle car loud, more restrained but obvious indications of capability)

Some things that have brought me to this question:
RR Sport Series 1 4.0L S/C – removed the 2 central resonators for an awesome deep rumble (for $150!).
RR Sport Series 2 5.0l S/C - removed the 2 central resonators as above but it resulted in gunshot backfires on every downshift, which had passers-by ducking for cover – I had to add back a small Magnaflow resonator to kill the crossfire but the end result was a similarly awesome ominous rumble.
FFRR Autobiography 5.0l S/C – gave up after $3000(!) spent with a custom exhaust shop. Any additional volume just boomed inside the car. Of note, at one point the shop removed the entire exhaust from the cats back and while a little rough it was still remarkably quiet.

Considering the fabulously obnoxious noise that comes out the back of an F-Type R/SVR etc. which has the same engine as the last 2 above (not to mention the fabulous RR Sport S3), what is being done to produce such a huge range of tone and volume? As noted above with the FFRR it's not just the exhaust downstream of the cats.

I suppose one way to think of it is how would we make a whisper quiet FFRR AB sound like an F-Type SVR? (That is hypothetical, btw…)

Thanks.
 

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I don't have any answers for you, but for me personally, the more quiet the better on the ffrr.

That being said, I do like how Jaguar implements an exhaust sound switch on the f-type. I think that's a great idea for a sportier car.
 

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Discussion Starter #3
Indeed, I added such an exhaust switch to a Maserati Convertible, which to my mind has one of the most spine tingling exhaust notes there are (better IMO than the Ferrari 430 with which it shares an engine). Sadly my neighbours don't agree, hence the addition.

Best mod ever actually, it's a $150 switch that sits on the existing valves that stock are annoyingly automatic and preset to the driving mode - you can't drive gently with volume or aggressively and quietly. Now all I do is hit a button and I choose the volume irrespective of how I'm driving.

Additional pertinent factoid here is that I once fitted sport cats to the Maz and had to take them off as they were just too loud. i.e. the cats can make a significant difference.

Wondering if we have anyone here who has knowledge of some of the range of exhaust systems on the JLR cars. Does the F-Type have different cats to the FFRR? Does the RR SVR have different cats to the Autobiography or just a different rear muffler? (it's not the latter considering the $3000 of experimentation I did....)
 

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My understanding is that the exhaust noise of all these modern vehicles is artificially manipulated including feeding signals into the vehicle's sound system to produce whatever sounds the manufacturer wants. Personally I like the quietness of the Range Rover and do not want to attract speeding tickets,

Cheers

John
 

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Discussion Starter #6
My understanding is that the exhaust noise of all these modern vehicles is artificially manipulated including feeding signals into the vehicle's sound system to produce whatever sounds the manufacturer wants.

This is indeed partially true in some instances, BMW are known to pump sound into the cockpit, however I'm referring here to the true sound outside the vehicle.
 

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Discussion Starter #7
Interesting, yes. Basically, as the guys says, there are bunch of factors.

We always tend to think that it's all in the exhaust, but it isn't. If were to reverse my earlier question about how to make a Rover sound like an F-Type and instead ask how we would make an F-Type as quiet as a Rover we would probably say to simply strap on a very efficient quietening exhaust, but that's only a part of it.

I couldn't believe how quiet the Rover still was with the exhaust entirely removed, a lot of the work is in the cats and possibly even upstream from there.

His point about "fueling calibration" affecting the pops and bangs on the over-run (meaning spitting a little unburnt fuel into the exhaust so it detonates there) certainly makes sense. My Maz does a very good job of that already but the cats themselves still filter out a lot of it, as demonstrated when i temporarily replaced mine with "sport cats". The rest of the exhaust was stock but the sport cats practically doubled the volume, which was way too much on that car.

Worked very well on a previous DB9 though...
 

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Have you looked at the quicksilver exhaust, sounds pretty good, I'm torn on how it tips look but I'm considering getting it for my FFRR. I had a SVR and I do miss the sound, but I think the quicksilver exhaust might help because it sounds deep and aggressive.
 
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