V8 Quicksilver Cat Replacements
Discussion
Yes I've fitted the Quicksilver 200 cell cats only. It makes quite a difference! I've got a switch which activates fuse 22 without which it would annoy the neighbours and the neighbours neighbours neighbours! As well as extra sound they also make the engine rev more freely, I'd read about this but thought, would you really be able to tell? You certainly can!
The sound is great, a real rasp and crackle on the overrun.
I may have had my fun with them now though so could be tempted to move them on.
The sound is great, a real rasp and crackle on the overrun.
I may have had my fun with them now though so could be tempted to move them on.
My understanding is that you will get an emission service error, if you just change the cats and don't perform an ECU flash. I am thinking of getting some 200 cell cats too, but was going to use Bamford Rose, for the cats, air box and ECU flash at my next service.
However, I would be happy to be corrected regarding emission warning if fitting only cats.
However, I would be happy to be corrected regarding emission warning if fitting only cats.
Are your sport cats, primary or secondary cat replacements. I understand that later Vantages have 4 cats instead of 2. I have a N420 with 4 cats and a rear sports box which gives a deeper note than standard which I love but was hoping to benefit from the driveability/performance improvement which comes from sports cats or decat pipes without necessarily making the sound level ridiculous. I prefer the deeper burble type of noise like a Corvette. Some vids on You Tube are insanely loud.
acollin5 said:
Are your sport cats, primary or secondary cat replacements. I understand that later Vantages have 4 cats instead of 2. I have a N420 with 4 cats and a rear sports box which gives a deeper note than standard which I love but was hoping to benefit from the driveability/performance improvement which comes from sports cats or decat pipes without necessarily making the sound level ridiculous. I prefer the deeper burble type of noise like a Corvette. Some vids on You Tube are insanely loud.
N430 / 4.7L after around 2010 had the newer design exhaust system which is a primary catalyst in the exhaust manifold and a secondary catalyst further downstream in the downpipe, 2 cats per side / 4 in total, whereas all earlier 4.3L's and some 4.7L cars just had the catalyst in the downpipe. The older system is still technically 4 cats in total because each can has 2 cat bricks within, its just you have no real idea there are two separate cats inside the one big can.Just concerning the newer level exhaust post approx 2010, the secondary cat is not monitored for emissions performance so it can be deleted without the need to reflash the ECU. But because the primary cat / the main restriction is left in place, deleting secondary cat will only nudge the sound up a very small subtle amount and have no real tangible performance gain. The ECU cant really be upgraded because the primary catalyst will not tolerate running hotter, means that if you went secondary cat delete you have reached the limit of how far you will be able to upgrade the car without throwing what you have away and starting again.
The best bang for buck IMO would be to remove your existing exhaust manifold and delete the primary cat (so no cat in manifold at all) and fit a 200 cell secondary cat. This spec returns the best performance gain for the spend (because instead of limited use decat you instead buy a 200 cell cat) this spec allows for an ECU reflash which would return better on throttle driveability and responsiveness and would give the most devilish exhaust note possible without going OTT
BamfordMike said:
N430 / 4.7L after around 2010 had the newer design exhaust system which is a primary catalyst in the exhaust manifold and a secondary catalyst further downstream in the downpipe, 2 cats per side / 4 in total, whereas all earlier 4.3L's and some 4.7L cars just had the catalyst in the downpipe. The older system is still technically 4 cats in total because each can has 2 cat bricks within, its just you have no real idea there are two separate cats inside the one big can.
Just concerning the newer level exhaust post approx 2010, the secondary cat is not monitored for emissions performance so it can be deleted without the need to reflash the ECU. But because the primary cat / the main restriction is left in place, deleting secondary cat will only nudge the sound up a very small subtle amount and have no real tangible performance gain. The ECU cant really be upgraded because the primary catalyst will not tolerate running hotter, means that if you went secondary cat delete you have reached the limit of how far you will be able to upgrade the car without throwing what you have away and starting again.
The best bang for buck IMO would be to remove your existing exhaust manifold and delete the primary cat (so no cat in manifold at all) and fit a 200 cell secondary cat. This spec returns the best performance gain for the spend (because instead of limited use decat you instead buy a 200 cell cat) this spec allows for an ECU reflash which would return better on throttle driveability and responsiveness and would give the most devilish exhaust note possible without going OTT
And the cost for all of that (on a 2009 4.7) and will it pop and f4rt on the over run!?Just concerning the newer level exhaust post approx 2010, the secondary cat is not monitored for emissions performance so it can be deleted without the need to reflash the ECU. But because the primary cat / the main restriction is left in place, deleting secondary cat will only nudge the sound up a very small subtle amount and have no real tangible performance gain. The ECU cant really be upgraded because the primary catalyst will not tolerate running hotter, means that if you went secondary cat delete you have reached the limit of how far you will be able to upgrade the car without throwing what you have away and starting again.
The best bang for buck IMO would be to remove your existing exhaust manifold and delete the primary cat (so no cat in manifold at all) and fit a 200 cell secondary cat. This spec returns the best performance gain for the spend (because instead of limited use decat you instead buy a 200 cell cat) this spec allows for an ECU reflash which would return better on throttle driveability and responsiveness and would give the most devilish exhaust note possible without going OTT
As mentioned I have the Quicksilver 200 cell secondry cats, they were on my late 2009 4.7. So no primary cats off the manifold. In answer to an earlier question, Yes the lambda sensors triggered, however a simple flash sorted that. The cats were purchased because they were an itch that had to be scratched. You know how it is. They really do give a quicker throttle response, with the engine revving much more freely, I can imagine that with Mike's BR clutch and lightened flywheel it would be perfect.
The sound from the standard exhaust with the Quicksilver cats fitted is something else. You have two sound levels though.
1. With the baffles active (fuse 22 in) you get a sharper tone throughout, at low rpm under load there's a deep mellow rumble, as the revs increase slightly, the sound level almost feels as if it's been left behind. Then, as the baffles start to open you're engulfed in a louder and crisper sound than the standard exhaust and cats ever made. There's less base, more midrange and just more loudness, not uncomfortable, just louder. As you get up to max rpm it's wonderful.
2. Then you deactivate fuse 22. Baffles open all the time. Now it's loud. Anything above 2300 rpm and under load is simply mad. It's sharp, angry, and reminds me of Le Mans. People turn to see what's approaching, and it's an extremely addictive sound, like Crack or M&S cheese puffs, you just want more. If you drive carefully though and change at lower rpm than you may be used to, you could drive around without drawing to much attention to yourself, but as soon as you floor it... Bam! In your face!
In both situations you get plenty of pops crackles and farts on the overrun, lovely.
So, why did I take them off? Simple, As I said, that full on sound was really addictive and I found myself driving round in loud mode more and more, however it ultimately came down to my personal preference, I prefer the gradual build and more mellow and deeper sound from the standard 4.7 setup with fuse 22 deactive. As soon as I took the 200 cell cats off though I noticed the instant response was gone, this was a great shame. But when the time comes I'll get a BR clutch and flywheel.
Now having covered a little over a thousand miles or so they simply sit in my garage wondering what to do with themselves. Ping me an email if anyone is interested.
The sound from the standard exhaust with the Quicksilver cats fitted is something else. You have two sound levels though.
1. With the baffles active (fuse 22 in) you get a sharper tone throughout, at low rpm under load there's a deep mellow rumble, as the revs increase slightly, the sound level almost feels as if it's been left behind. Then, as the baffles start to open you're engulfed in a louder and crisper sound than the standard exhaust and cats ever made. There's less base, more midrange and just more loudness, not uncomfortable, just louder. As you get up to max rpm it's wonderful.
2. Then you deactivate fuse 22. Baffles open all the time. Now it's loud. Anything above 2300 rpm and under load is simply mad. It's sharp, angry, and reminds me of Le Mans. People turn to see what's approaching, and it's an extremely addictive sound, like Crack or M&S cheese puffs, you just want more. If you drive carefully though and change at lower rpm than you may be used to, you could drive around without drawing to much attention to yourself, but as soon as you floor it... Bam! In your face!
In both situations you get plenty of pops crackles and farts on the overrun, lovely.
So, why did I take them off? Simple, As I said, that full on sound was really addictive and I found myself driving round in loud mode more and more, however it ultimately came down to my personal preference, I prefer the gradual build and more mellow and deeper sound from the standard 4.7 setup with fuse 22 deactive. As soon as I took the 200 cell cats off though I noticed the instant response was gone, this was a great shame. But when the time comes I'll get a BR clutch and flywheel.
Now having covered a little over a thousand miles or so they simply sit in my garage wondering what to do with themselves. Ping me an email if anyone is interested.
Gassing Station | Aston Martin | Top of Page | What's New | My Stuff