V12 primary cat delete opinions

[dg73]

I have a 2017 Rapide S, currently stock. Think it produces about 550bhp as standard.
Car is currently at Bamford Rose for some other work.
Mike has suggested a primary cat delete with high flow secondary cat and ECU remap which I think will take it up to about 600bhp.

Have never felt the car lacks power or sound and not sure how much I'd notice an extra 50bhp on a 2 tonne car but I am open minded to anything that would noticeably enhance the drive.

If any V12 owners out there have had this done I'd be very interested to hear how you percieve it changed the power delivery experience or the sound!

Many thanks

[JJbing]

Just do the secondary cat delete. It’s more than enough, as you said 50bhp is probably not too noticeable. The sound gain from the secondaries is epic

[AdamV12V]

I wouldn't bother, another +1 for secondary cat delete as the end result is the same for a fraction of the cost, albeit you wont mitiagate the scarey tales primary cat ingestion, which are in fact very very rare indeed.

The primary delete Mike offers is a bit of a bodge, cutting and welding out the primaries. To do it propely with QS primary manifolds is more like £8-9k, whereas a secondary cat swap proper job job is more like 10% of that.

[dg73]

My car is under extended AM warranty which i plan to renew, so think I would be covered against the rare primary cat ingestion risk, so not inclined to remove primaries just for that reason.

My understanding is that secondary cat delete pipes just make the car louder all the time which I don’t really want. More interested in tone rather than volume.

Also my understanding, which could be wrong, is that secondary cat delete adds nothing in the way of extra performance?

[EVR]

dg73 said:

My car is under extended AM warranty which i plan to renew, so think I would be covered against the rare primary cat ingestion risk, so not inclined to remove primaries just for that reason.

My understanding is that secondary cat delete pipes just make the car louder all the time which I don’t really want. More interested in tone rather than volume.

Also my understanding, which could be wrong, is that secondary cat delete adds nothing in the way of extra performance?

I believe secondary cat delete frees some power, but in the range of 10-20 HP so not very noticeable.

[AdamV12V]

EVR said:

dg73 said:

My car is under extended AM warranty which i plan to renew, so think I would be covered against the rare primary cat ingestion risk, so not inclined to remove primaries just for that reason.

My understanding is that secondary cat delete pipes just make the car louder all the time which I don’t really want. More interested in tone rather than volume.

Also my understanding, which could be wrong, is that secondary cat delete adds nothing in the way of extra performance?

I believe secondary cat delete frees some power, but in the range of 10-20 HP so not very noticeable.

Yes secondaries do add some power, and probably in that range yup...

If you are under AM extended warranty then I most certainly wouldnt change the primaries as you will invalidate that warranty. Its a much bigger change and not one officially sanctioned by AM, unlike the secondaries which they sell an AM part numbered set of bypass pipes (the QS ones), so if anything goes wrong you may find yourself not covered with any primary change. As you say your covered against primary ingestion anyway.

As for tone - neither of the options you have suggested will materially change the tone - both will only add volume and power. To change the tone you really need a new backbox or a whole new manifold with equal length pipes - then it will sound more ferrari like if that's what you are after? Again though most of these will come with potential warranty issues, so secondary deletes is really the only AM approved route forward.

[MMarkM]

Its also quite expensive to do, you could just get a Rapide AMR then you'll have the extra power anyway! Secondary cat delete not a lot of money and great sound improvement aswell

[dbs2000]

Its an amazing transformation and you absolutely will notice. Its more about how much easier the car revs out and how much more responsive it is. It transformed my DBS from lethargic to close to V12VS speeds.

The extended warranty probably would be void though.

[mogg]

dbs2000 said:

Its an amazing transformation and you absolutely will notice. Its more about how much easier the car revs out and how much more responsive it is. It transformed my DBS from lethargic to close to V12VS speeds.

+1. I have the full performance pack, which includes the secondary cat delete and full titanium exhaust. The sound is totally epic as you go up the rev range. Sound level is around 108dBA at 5000rpm static. Lord knows what it is at the red line ! :-)

[dg73]

For those of you that have had the primary cat delete + high flow secondary cat + ECU remap, would you say the power enhancement is more low range torque or more power mid-high rev range?

I am not so bothered about louder or enhanced sound as think it sounds perfect as stock, and the BR 3 way switch will make aggressive sound available more of the time hopefully!

[dbs2000]

dg73 said:

For those of you that have had the primary cat delete + high flow secondary cat + ECU remap, would you say the power enhancement is more low range torque or more power mid-high rev range?

I am not so bothered about louder or enhanced sound as think it sounds perfect as stock, and the BR 3 way switch will make aggressive sound available more of the time hopefully!

Its over the whole range. If you've ever had a car and put a lighter flywheel on it then that's the feeling. Its quite hard to describe but you can tell the car is breathing easier.

I originally had the full BR performance pack which makes the car sound more ferrari like. I missed the burble so when I spoke to Mike, they refitted the original manifold minus the pre-cats. I kept my highflow secondaries and their map. That to me was perfect. Slightly louder than stock but still that glorious AM sound.

[dg73]

I dont think I want the car any louder than it already is with the valves open, so would probably rather give the secondary hi-flow cats a miss.
Not sure how much the secondary hi-flow cats add in terms of extra power, get the impression they are mostly for extra sound?

Tempted to go for just primary cat delete and ecu remap if that makes sense - has anyone out there done just these bits without the secondary cats?

[dbs2000]

The beauty of second cats is they can be added and removed quite easily. So I'd say to just try it, although I think the highflows are circa 1500, maybe BR have a set or a car you can hear and see.

I found my car absolutely lovely with the primaries gone and high flow secondaries. Throw in the exhaust switch and you can quieten down the car nicely for when you want relative silence.

(you've just reminded me I need to get my high flows back off a mate, he has them as he wanted to make an AM flange for his shop)

[AdamV12V]

In simple terms removing either just the primaries or the secondaries will give you pretty much the same result in terms of noise increase and a mild power increase. Very little to choose in the two paths if you keep the other set of cats as original.

However removing the primaries will cost you 4-5x as much as the secondaries for a cheap chop out and reweld job (as I believe you likely being recommended to have), or 10x as much to do it properly with a new manifold such as the QuickSilver one.

Removing the primaries also removes the very miniscule change of a primary cat ingestion. I would suggest you do a bit more research on the chance of such ingestion happening.

There is a lot of hype on the subject and I concluded it is probably cheaper to self insure in the long run as
a) it almost certainly wont happen anyway
b) if it does the cost of a swap out replacement engine is nowhere near as much as you might expect and
c) removing the secondaries is an OEM supported option, whereas removing the Primaries is not.

Also a third party ECU remap may make your car harder to sell in the future, certainly AM main dealers take a dim view on this. OEM mods do not affect their view on part-ex. Given your car is not that old, you may want to consider this point too.

You pays your money and makes your own choice..

Edited by AdamV12V on Tuesday 6th July 08:35

[moveover]

AdamV12V said:

Removing the primaries also removes the very miniscule change of a primary cat ingestion. I would suggest you do a bit more research on the chance of such ingestion happening.

There is a lot of hype on the subject and I concluded it is probably cheaper to self insure in the long run as
a) it almost certainly wont happen anyway
b) if it does the cost of a swap out replacement engine is nowhere near as much as you might expect and
c) removing the secondaries is an OEM supported option, whereas removing the Primaries is not.

Edited by AdamV12V on Tuesday 6th July 08:35

I had the primaries removed by Mike on my Vanquish II, having had a misfire on my previous Virage. Whilst, thankfully, that didn't cause an engine failure, I would disagree that the chance is minuscule. Now I have peace of mind ... and a bit more power, but that wasn't the motivation.

[AdamV12V]

moveover said:

AdamV12V said:

Removing the primaries also removes the very miniscule change of a primary cat ingestion. I would suggest you do a bit more research on the chance of such ingestion happening.

There is a lot of hype on the subject and I concluded it is probably cheaper to self insure in the long run as
a) it almost certainly wont happen anyway
b) if it does the cost of a swap out replacement engine is nowhere near as much as you might expect and
c) removing the secondaries is an OEM supported option, whereas removing the Primaries is not.

Edited by AdamV12V on Tuesday 6th July 08:35

I had the primaries removed by Mike on my Vanquish II, having had a misfire on my previous Virage. Whilst, thankfully, that didn't cause an engine failure, I would disagree that the chance is minuscule. Now I have peace of mind ... and a bit more power, but that wasn't the motivation.

But you didn't actually have a cat ingestion issue because you identified the misfire and dealt with it promptly. Misfires themselves are no so common anyway, so you were unlucky in that respect but when it happened you dealt with it swiftly and correctly, and presumably at minimal cost. It is ignoring a misfire and continuing to drive the car that can then lead to cat damage and ultimately ingestion.

[dg73]

AdamV12V said:

In simple terms removing either just the primaries or the secondaries will give you pretty much the same result in terms of noise increase and a mild power increase. Very little to choose in the two paths if you keep the other set of cats as original.

However removing the primaries will cost you 4-5x as much as the secondaries for a cheap chop out and reweld job (as I believe you likely being recommended to have), or 10x as much to do it properly with a new manifold such as the QuickSilver one.

Removing the primaries also removes the very miniscule change of a primary cat ingestion. I would suggest you do a bit more research on the chance of such ingestion happening.

There is a lot of hype on the subject and I concluded it is probably cheaper to self insure in the long run as
a) it almost certainly wont happen anyway
b) if it does the cost of a swap out replacement engine is nowhere near as much as you might expect and
c) removing the secondaries is an OEM supported option, whereas removing the Primaries is not.

Also a third party ECU remap may make your car harder to sell in the future, certainly AM main dealers take a dim view on this. OEM mods do not affect their view on part-ex. Given your car is not that old, you may want to consider this point too.

You pays your money and makes your own choice..

Edited by AdamV12V on Tuesday 6th July 08:35

My understanding is that primary cat delete is obviously invisible externally to anyone but are you saying the ECU remap would be immediately visible to main dealer when plugged into their diagnostics machine? Concerned about this as want to extend my official warranty at end of year and don’t want to be told I’m precluded from doing this with the ECU remap…

[AdamV12V]

dg73 said:

My understanding is that primary cat delete is obviously invisible externally to anyone but are you saying the ECU remap would be immediately visible to main dealer when plugged into their diagnostics machine? Concerned about this as want to extend my official warranty at end of year and don’t want to be told I’m precluded from doing this with the ECU remap…

Pretty sure the non std ECU remap would be visible to a MD doing a proper inspection yes. Plus would you actually lie to them and try and hide it? I know I wouldnt, I would freely admit I had had it done anyway.

And yes pretty sure an ECU remap would invalidate the extended warrenty, as would a primary cat delete - albeit I accept it may be hard for anyone to spot this as would take quite a lot of labour to take them apart and inspect.

[dbs2000]

ECU remap will probably have a bit of different code or version against it so it will be visible. If the dealer then reflashes the ECU (they have no reason to) you'll get the emission warning lamp on and need someone to program it out again.

[ds666]

Don't think there is any chopping and welding to replace the secondary cats - think they are just bolted in ??

I was considering the primary replacements ( full system ) but I'm told the exhaust sound is significantly different to the standard system ( more Ferrari like ) - one chap I know of says it is the worst thing he's done to his DBS . I like the current sound.

I'd definitely try one before pulling the trigger .

Whilst cat ingestion maybe an issue , not sure it is statistically very likely .