Hoping to record sound difference with V12VS back box on V8V
Discussion
V8V Pete said:
Never mind (as long as they don't charge you anything).
What's plan B? Decat pipes or 200 cell cats?
Signed-up for the AM de-cat option (it's £1k+ less than the V12VS back box option). Not my first choice as the back box would have provided the bypass option with its valve, but if it's not possible... What's plan B? Decat pipes or 200 cell cats?
AdamV12V said:
I have a V12 Vantage S Manual and there is no oil cooler at the rear either - I cant see the exhaust backbox itself through the grille.
Thanks for confirming Adam! I wonder where they places the oil cooler? Could it be repositioned for the run-of-the-mill V8 models (although this is likely to be more work than I'm probably willing to undertake as the overall effect is still unknown to me).nickv8 said:
AdamV12V said:
I have a V12 Vantage S Manual and there is no oil cooler at the rear either - I cant see the exhaust backbox itself through the grille.
Thanks for confirming Adam! I wonder where they places the oil cooler? Could it be repositioned for the run-of-the-mill V8 models (although this is likely to be more work than I'm probably willing to undertake as the overall effect is still unknown to me).Typo on my original post too - I meant I CAN see the exhaust backbox through the grille (not cant - sorry!
nickv8 said:
V8V Pete said:
Never mind (as long as they don't charge you anything).
What's plan B? Decat pipes or 200 cell cats?
Signed-up for the AM de-cat option (it's £1k+ less than the V12VS back box option). Not my first choice as the back box would have provided the bypass option with its valve, but if it's not possible... What's plan B? Decat pipes or 200 cell cats?
jonby said:
I might be misunderstanding what you are planning, but surely if you de-cat and keep the original back box, you are keeping the valves and therefore the bypass option ? That;s a function of the backbox, not the cats
My description being the problem... 
The AM back boxes are all valved. But my concern was if the de-cats are OTT it's not something you can get around by keeping under 4K rpm.
nickv8 said:
jonby said:
I might be misunderstanding what you are planning, but surely if you de-cat and keep the original back box, you are keeping the valves and therefore the bypass option ? That;s a function of the backbox, not the cats
My description being the problem... The AM back boxes are all valved. But my concern was if the de-cats are OTT it's not something you can get around by keeping under 4K rpm.
Although many of us on here have a 2 way switch (one position being valves permanently open, the other where the valves only open up at higher revs) I've an idea you can get a 3 way switch fitted with one position being valves permanently closed - others on here can confirm.
Personally I wouldn't have thought it would be a problem without, but everyone's idea of what is an acceptable volume level is very different
jonby said:
ah ! :-)
Although many of us on here have a 2 way switch (one position being valves permanently open, the other where the valves only open up at higher revs) I've an idea you can get a 3 way switch fitted with one position being valves permanently closed - others on here can confirm.
Personally I wouldn't have thought it would be a problem without, but everyone's idea of what is an acceptable volume level is very different
Confirm existence of 3 way switch. Quiet, loud and factory variable on revs. On a long run its nice to go into hush mode for a nice quiet cabin, sometimes i even switch the radio on and not listen to the engine at all Although many of us on here have a 2 way switch (one position being valves permanently open, the other where the valves only open up at higher revs) I've an idea you can get a 3 way switch fitted with one position being valves permanently closed - others on here can confirm.
Personally I wouldn't have thought it would be a problem without, but everyone's idea of what is an acceptable volume level is very different
rossyl said:
I have 200 cell sport cats with a standard back box and a remote switch for the valves.
When the valves are open it is LOUD.
De-cat. Does the later V8V have two sets of cats? Mine is a 2006.
Yes, not sure exactly when the change happened but my MY2014 V8VS used to have 2 sets of cats; one in the manifold and one in the usual place. It now has BR manifolds and a single 200 cell cat on each side and I can confirm that with valves open it is LOUD. 3-way switch becomes pretty essential with this set-up but still spends most of the time in only one position When the valves are open it is LOUD.
De-cat. Does the later V8V have two sets of cats? Mine is a 2006.
V8V Pete said:
Yes, not sure exactly when the change happened but my MY2014 V8VS used to have 2 sets of cats; one in the manifold and one in the usual place. It now has BR manifolds and a single 200 cell cat on each side and I can confirm that with valves open it is LOUD. 3-way switch becomes pretty essential with this set-up but still spends most of the time in only one position
It changed around 2010. I have by pass pipes on the secondary cats and a bespoke back box made by a local specialist - epic !!!!
LordBretSinclair said:
It changed around 2010. I have by pass pipes on the secondary cats and a bespoke back box made by a local specialist - epic !!!!
That looks like a great quality box! Congrats 'Fraid I'm going to keep resolutely AM parts/fit whilst under warranty, but it would be the route I'd take a close look at otherwise.
Enjoy
Did anything ever come of the question of the OP? Has anyone ever fitted V12S box to a V8?
I’m hoping someone can shed light on a little issue I have. My 2011V8VS SS ‘Purdey’ has had the full BR exhaust treatment (BR manifolds, 200cell cats with baffle) and has the 3-way switch fitted, as comes standard from BR. She’s also got the switchable Bilstein, light flywheel and V12 clutch - all works fabulously, but for one slight residual issue - the changed noise.
I realise noise is subjective - and I know of other PHers who have done the same exhaust mods to their V8VS and have the exact same set up I currently have and are very satisfied with the acoustic result - but for me the resultant noise quality and volume is not quite what I’d hoped for.
With the valve open, even with the baffle, the car is LOUD, noise quality is fantastic at low rpm or slight throttle opening, with that lovely classic cross plane deep bass burble however at higher rpm and WOT it descends into a rasping scream which is just too much. I only tried it in a tunnel with windows down the once...
Perversely, when the valve is closed the car now goes whisper quiet, much quieter than the OEM set up ever was.. With the BR set up, the ugly ORM manifold and it’s Euro5 driven integrated light off cat or pre-cat is gone, as is the close coupled 600 & 800 cell arrangement in the original catalyst). What remains is BR’s beautiful stainless steel fabrication with a lossless collector that makes the OEM effort look like it was designed and manufactured by a child, the BR 200 cell cat and the BR baffle. The V8VS back box has remained stock
I could not understand why the car could now be both much louder (valves open) and much quieter (valves closed) than OEM at the same time!
Then an automotive NHH engineer friend of mine who works at JLR hypothesised that it was probably interaction between the new baffles and the OEM V8VS silencer fundamentally affecting the tune of the overall system when the valve was closed, despite the fact that the overall attenuation is of course reduced by the removal of all the OEM cats, so evidently the case when the valves are open.
Mike at BR has been very helpful, and of course has long experience of dealing with the highly subjective 1st world whims of his customers. He has offered to install an X-pipe, effectively connecting the two banks together, however I have heard the result before, it seems to make the engine sound like a high revving flat plane crank engine, loses the offbeat bass burble, and more like an F1 car or a Ferrari, which I’m pretty certain I wouldn’t like..
So, short of returning the car to stock, which naturally isn’t going to happen just because I am tone deaf, I think I have only one option - change the back box for a different design, something that attenuates less, and hope that the interaction with the baffle is sufficiently different to produce the right noises with the valve closed. I do still want to be able to switch, which rules out an aftermarket silencer, I still want the option of full on demon open pipe mode.
So - it seems my only option is a V12S box, that’s what the man-maths has concluded, so I have just bought a V12S AMR silencer, which it seems from the above thread will fit straight into my car (no oil cooler) When the lockdown ends I will get a no doubt bemused Mike to fit it. Fingers crossed
In the meantime - if anyone else on here recognises anything in my post, or has done what I plan to do, please let me know - as I haven’t seen the phenomenon described written about anywhere else on PH, I fully understand perception of noise is almost completely subjective, but really have been wondering if all this really is just ‘noises in my head’
I’m hoping someone can shed light on a little issue I have. My 2011V8VS SS ‘Purdey’ has had the full BR exhaust treatment (BR manifolds, 200cell cats with baffle) and has the 3-way switch fitted, as comes standard from BR. She’s also got the switchable Bilstein, light flywheel and V12 clutch - all works fabulously, but for one slight residual issue - the changed noise.
I realise noise is subjective - and I know of other PHers who have done the same exhaust mods to their V8VS and have the exact same set up I currently have and are very satisfied with the acoustic result - but for me the resultant noise quality and volume is not quite what I’d hoped for.
With the valve open, even with the baffle, the car is LOUD, noise quality is fantastic at low rpm or slight throttle opening, with that lovely classic cross plane deep bass burble however at higher rpm and WOT it descends into a rasping scream which is just too much. I only tried it in a tunnel with windows down the once...
Perversely, when the valve is closed the car now goes whisper quiet, much quieter than the OEM set up ever was.. With the BR set up, the ugly ORM manifold and it’s Euro5 driven integrated light off cat or pre-cat is gone, as is the close coupled 600 & 800 cell arrangement in the original catalyst). What remains is BR’s beautiful stainless steel fabrication with a lossless collector that makes the OEM effort look like it was designed and manufactured by a child, the BR 200 cell cat and the BR baffle. The V8VS back box has remained stock
I could not understand why the car could now be both much louder (valves open) and much quieter (valves closed) than OEM at the same time!
Then an automotive NHH engineer friend of mine who works at JLR hypothesised that it was probably interaction between the new baffles and the OEM V8VS silencer fundamentally affecting the tune of the overall system when the valve was closed, despite the fact that the overall attenuation is of course reduced by the removal of all the OEM cats, so evidently the case when the valves are open.
Mike at BR has been very helpful, and of course has long experience of dealing with the highly subjective 1st world whims of his customers. He has offered to install an X-pipe, effectively connecting the two banks together, however I have heard the result before, it seems to make the engine sound like a high revving flat plane crank engine, loses the offbeat bass burble, and more like an F1 car or a Ferrari, which I’m pretty certain I wouldn’t like..
So, short of returning the car to stock, which naturally isn’t going to happen just because I am tone deaf, I think I have only one option - change the back box for a different design, something that attenuates less, and hope that the interaction with the baffle is sufficiently different to produce the right noises with the valve closed. I do still want to be able to switch, which rules out an aftermarket silencer, I still want the option of full on demon open pipe mode.
So - it seems my only option is a V12S box, that’s what the man-maths has concluded, so I have just bought a V12S AMR silencer, which it seems from the above thread will fit straight into my car (no oil cooler) When the lockdown ends I will get a no doubt bemused Mike to fit it. Fingers crossed
In the meantime - if anyone else on here recognises anything in my post, or has done what I plan to do, please let me know - as I haven’t seen the phenomenon described written about anywhere else on PH, I fully understand perception of noise is almost completely subjective, but really have been wondering if all this really is just ‘noises in my head’
Done it ! BR installed the AMR/V12VS back box to my V8VS this week and yes, it is now effectively a straight through (albeit with the mini BR-baffle, so not totally unsilenced) and LOUD. Amazing sound quality though, especially in low-mid rpms under load. Will post some before/after driveaway vids if anyone is interested
Calinours said:
Done it ! BR installed the AMR/V12VS back box to my V8VS this week and yes, it is now effectively a straight through (albeit with the mini BR-baffle, so not totally unsilenced) and LOUD. Amazing sound quality though, especially in low-mid rpms under load. Will post some before/after driveaway vids if anyone is interested
I think we would all love to hear pre-post clips. Congratulations.Oooh! Very interesting. Should sound loud at every mph
Would love to hear the result.
Is it a manual of Sportshift model?
I'm sticking with my V8VS with secondary de-cat. Plenty loud (especially when starting up to creep away before dawn!). I had a great drive the other day and simply recorded 10 mins of driving down a country lane with the revs rising and falling. Astons sound that mesmerising!
Enjoy!
Would love to hear the result.
Is it a manual of Sportshift model?
I'm sticking with my V8VS with secondary de-cat. Plenty loud (especially when starting up to creep away before dawn!). I had a great drive the other day and simply recorded 10 mins of driving down a country lane with the revs rising and falling. Astons sound that mesmerising!
Enjoy!
dalecan said:
I think we would all love to hear pre-post clips. Congratulations.
Happy to oblige ! I did it to make the quiet mode louder - but the result is not only quiet mode louder, it’s loud mode deeper, because the pipe is now essentially straight through when the valve is open. There isn’t enormous difference, however it’s enough for me
Note that to actually hear the difference, decent speakers are needed. You won’t hear it on a mobile, maybe not even with laptop speakers. This was also recorded on a mobile phone’s little mic.
This is the new ‘loud’ mode :
The new ‘quiet’ mode (V12AMR box) :
And old ‘quiet’ mode (V8VS box):
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