V12 Vantage exhaust manifolds

[Number Eight]

I need to replace the primary cats in my V12V, it seems Aston don't have any on the shelf and I need them in a bit of a hurry. Having spoken to Quicksilver they can get some to me in the timescale. Does anyone have any first hand experience of the quicksilver manifolds and cats? How's the quality? Do you need and ECU re-map to stop the emissions light from coming on? Do they get through an MoT test ok? Are they offensively loud (I currently have secondary de-cats)? Any information is greatfully received.

Many thanks.

[anonymous-user]

Number Eight said:

I need to replace the primary cats in my V12V, it seems Aston don't have any on the shelf and I need them in a bit of a hurry. Having spoken to Quicksilver they can get some to me in the timescale. Does anyone have any first hand experience of the quicksilver manifolds and cats? How's the quality? Do you need and ECU re-map to stop the emissions light from coming on? Do they get through an MoT test ok? Are they offensively loud (I currently have secondary de-cats)? Any information is greatfully received.

Many thanks.

I am pretty sure the QS manifolds, like the Bamford Rose and APVelocity ones, don’t have cats. They are equal length tubing manifolds that increase gas flow and bump power a bit.

This means you’ll need to reinstate your secondary cats to get through an MOT, which presumably come as part of the QS package.

The APV ones are supposed to give a higher exhaust note (more Ferrari like); the BR are supposed to preserve the deeper AM exhaust note. I’ve only heard them on YT where it’s hard to be sure. Don’t know about the QS ones.

Yes, you need an ECU remap to prevent the car thinking the primary cats are there but have failed and throwing an error message.

You will get through an MOT but it will help if your tester knows what you’ve done. The cats need to be hot to operate. Primaries get hot fast but secondaries take a bit longer. Plus factory primaries and secondaries give 1000 cells per side (600+400) so dropping to 200 just underlines that the high flow 200 cell secondaries need to operating optimally to clean the exhaust gas.

eBay sometimes has used AM V12 manifolds. The manifold is supposedly common across all NA V12 Gaydon cars. Bit of a high risk purchase maybe…

[AdamV12V]

Astonmartinbits are showing that they have them in stock, both new and used at a substantial saving.

[Astontony]

Just a thought.
While you are replacing the primary cats I would do some research beforehand to check what the best solution would be to prevent catastrophic failure of the engine due to the primary cats breaking down and being sucked into the engine. This is caused by simple missfires and there are many discussions re this and warnings. BR will know a solution so you can get through MOT
I would look at removing them as many have done.

[leman600]

The removal of the primary cats on the V12 is very good for piece of mind re the cat ingestion.
Bamford and may be others offer cat removal from original manifolds which I've read does not dramatically change loudness or tone.
The engine will need to be mapped to suit but I've also read that it can be programed to reduce the fuel (needed to cool the cats) therefore getting noticeably better mpg.

[AstonV]

I bought mufflers for my Jaguar from Quicksilver. I would bet the quality of their manifolds are better than factory possibly. Made in the UK, not made in China! They would be able to answer any questions. No doubt they sound epic as well. Great customer service.

[Felonious]

Worth a call to BR. They may have some originals that have been removed and not wanted by the customer. Call them early in the day for best chance of response.

[AdamV12V]

Astontony said:

Just a thought.
While you are replacing the primary cats I would do some research beforehand to check what the best solution would be to prevent catastrophic failure of the engine due to the primary cats breaking down and being sucked into the engine. This is caused by simple missfires and there are many discussions re this and warnings. BR will know a solution so you can get through MOT
I would look at removing them as many have done.

You may wish to check the OP's previous post at the end of October.

https://www.pistonheads.com/gassing/topic.asp?h=0&...

[Finding Neutral]

If it was me, I’d look to the aftermarket as the stock AM manifolds look like they were put together by a three year old. They’re horrible things.

Reinstate secondary cats and remove the manifold cats. Better arrangement all round and a better flowing engine to boot (around the 600bhp mark with that set up from memory. Oh, and safer as car ingestion IS a thing.

Win win.

Edited by Finding Neutral on Tuesday 10th May 09:26

[Number Eight]

Thanks for all that. Seen the ones on Aston Bits now, that might be an option. I am concerned about the possibility of cat ingestion, the technician said he's going to borescope the cylinders when he does the work to check for any evidence. That's what made me think about the QS manifolds originally but I don't want to get the thing re-mapped or have it struggle to get through an MoT test. Also AM Nottingham, who have the car have offered me a good discount on the originally quoted price using OE manifolds, which they're now struggling to get. The car is supposed to be taking me and my new wife to Italy on honeymoon at the begining of June so I need it fairly quickly and to be reliable. With the QS manifolds it looks like the sensors are still positioned pre and post-cat so does it still need re-mapping?

[AdamV12V]

The QS manifold doesn't require a remap as it comes with extension cables to reach the new O2 sensors around the secondary cats. (I know because I called QS and asked myself when I was looking into it, but eventually decided it wasn't for me, and instead I went the OEM powerkit and titanium secondary bypass route instead).

That said any V12 with a decat is prone to emissions warnings far more than one with both sets of cats in place, and the removal of the primaries causes more issues than the removal of the secondaries seems to, and a primary delete is indeed more challenging to pass an MOT with as the secondaries take far longer to warm up, hence a cold startup and test will likely result in a mot fail.

[Number Eight]

So, spoken to AM Nottingham today. They've heard back from Aston Martin Parts and they're making a new batch of manifolds as we speak. They'll be at the dealer's in a couple of days and be fitted and good to go next week. Fingers crossed. So, I'm just going to stick with the OE manifolds and cats. The one's that have come off have been there for 50 odd thousand miles, it's only just had new plugs and coils so hopefully that'll sort out misfires, knackered cats and all the unpleasantness that goes along with it for a good while yet. Fingers crossed. Also Mrs M is now happy because she can go on honeymoon in comfort and with space to bring back wine. As long as nothing else has gone wrong in the seven months it's been stationary.

Thanks to everyone for taking the time to reply, much appreciated.