Discussion
High flow Cats with a baffle to keep a lid on noise is the answer, but I’ve known folk who have the non baffle version and say the upgrade nowhere close meets their expectation of noise increase.
With a baffle returns deeper bass / baritone note which sounds like a smooth symphony, without the baffle is more like a single shouty trumpet and a few dB louder
3- way switch for a permanent quiet mode also helps, a totally silent cold start is helpful to keep the neighbours friendly
With a baffle returns deeper bass / baritone note which sounds like a smooth symphony, without the baffle is more like a single shouty trumpet and a few dB louder
3- way switch for a permanent quiet mode also helps, a totally silent cold start is helpful to keep the neighbours friendly
mhurley said:
The reason I ask is I've seen a few second hand and I wondered if the owners found them too loud and wanted to go back to stock
imo absolute loudness isn’t the issue, it’s the sound characteristic of the cat without a baffle being single trumpet shouty, especially on a 4.3L / 4.3L silencer.One reason there’s a few secondhand around could be because folk have sold the car and they have put back to standard to sell the kit separately. Linked to that, if the brand of cat triggered emissions faults continually, owners might not want to sell a car which would do that to a new owner.
Not quite what you are asking but I removed the secondary cats on my 4.7. It is noticeably louder and angrier sounding now than my old 4.3 with valves open now and if I’m honest I preferred the sound of the original 4.3 fuse out but with a fuse switch fitted you get the best of both worlds. Fuse in relatively quiet mode. Fuse out angry rasping V8. I mostly drive in loud mode 😀
I had 200 cell cats on my 2007 V8V. It was one of the first things I did with the car and the effect was awesome. Definitely nowhere near being too loud. I changed them back for the originals when I traded the car and sold the sports cats for around 80% of the original cost within a few days, and could have sold them a few times over. Just do it.
Best money I ever spent was putting decent 200 cell cats on my 4.7
The sound went from nice to awesome, but in no way would I consider it too loud.
Car may well be being sold in the next month or two (after 5 years of ownership), and I will probably put the originals back on and sell the 200 cell ones.
The sound went from nice to awesome, but in no way would I consider it too loud.
Car may well be being sold in the next month or two (after 5 years of ownership), and I will probably put the originals back on and sell the 200 cell ones.
So does doing this sort of thing void your insurance? I live in Australia and I was under the impression that if you deleted your cats or modified your exhaust then your insurance company would not pay out in the event of an accident. I thought that the assessor would inspect the vehicle for modifications and any modification would give them the ability to not pay out.
With this in mind I've simply taken fuse 22 out. or fuse 15... it was one or the other.
With this in mind I've simply taken fuse 22 out. or fuse 15... it was one or the other.
In the UK high flow cats wont void your insurance. A total cat removal would make your car fail the yearly MOT emissions test which would be illegal to drive and your insurer may invalidate your insurance. High flow cats are just that e.g. cats that flow better, lighter, sound louder and your car should still pass the MOT emissions test.
Insurers want you to tell them of any mods then they decide if there is a premium hike or not. Many older cars will run non OEM exhaust. You just let your insurer know and they make a note of the modification and sometimes adjust your premium, particularly if the modification is considered "performance enhancing".
Thankfully if you are a petrolhead, the UK is one of the best Euro countries to live in
In some other EU countries they are a lot more draconian, where you will hear stories of confiscated vehicles because the owner fit a louder exhaust silencer etc 
Insurers want you to tell them of any mods then they decide if there is a premium hike or not. Many older cars will run non OEM exhaust. You just let your insurer know and they make a note of the modification and sometimes adjust your premium, particularly if the modification is considered "performance enhancing".
Thankfully if you are a petrolhead, the UK is one of the best Euro countries to live in
In some other EU countries they are a lot more draconian, where you will hear stories of confiscated vehicles because the owner fit a louder exhaust silencer etc LPH said:
What's the current CAT of choice for the 4.3 V8V? Looking to get a set soon as I've just picked up a pair of equal length stainless exhaust manifolds 
Well, you've got a few choices, either Bamford Rose or David Appleby would be more than happy to help. If you've already got the manifolds, then it would be advisable to get an ECU re-tune as well to maximise the upgrade.You can get other 200 cell cats off the internet, but I couldn't comment on the quality/fit. Although, you do usually get what you pay for............
I got mine from AHM. I could have got cheaper elsewhere, but am glad I didn't.
I was doing it as the first stage of improving the sound, and fully intended to change the back box / manifold as necessary, however, after fitting the cats the sound was so good I left everything else as was. Car can still be driven without standing out when you want, but sounds amazing and turns heads when you get heavy with the right foot.
I was doing it as the first stage of improving the sound, and fully intended to change the back box / manifold as necessary, however, after fitting the cats the sound was so good I left everything else as was. Car can still be driven without standing out when you want, but sounds amazing and turns heads when you get heavy with the right foot.
Dingle Dell said:
I got mine from AHM. I could have got cheaper elsewhere, but am glad I didn't.
I was doing it as the first stage of improving the sound, and fully intended to change the back box / manifold as necessary, however, after fitting the cats the sound was so good I left everything else as was. Car can still be driven without standing out when you want, but sounds amazing and turns heads when you get heavy with the right foot.
I bought some second hand prodrive 200 cell cats first, then had an aftermarket Tubi backbox (loud version) fitted. Its sounded epic and for most maybe a bit too loud, but as I only drive it weekends etc then its perfectly fine for me. I ended up taking off the prodrive cells and getting the upgraded, Manfolds/ cats and ECU tune done at the same time by David Appleby engineering. I was doing it as the first stage of improving the sound, and fully intended to change the back box / manifold as necessary, however, after fitting the cats the sound was so good I left everything else as was. Car can still be driven without standing out when you want, but sounds amazing and turns heads when you get heavy with the right foot.
I also made some custom air filter brackets, fitted aftermarket air filters and removed the air boxes, which probably provides a bit more airflow too.
LPH said:
What's the current CAT of choice for the 4.3 V8V? Looking to get a set soon as I've just picked up a pair of equal length stainless exhaust manifolds
RS Fabrications 200 cell sports cats vs the originalhttp://www.rsfabrications.com/?s=sports+cats
leerandle said:
Well, you've got a few choices, either Bamford Rose or David Appleby would be more than happy to help. If you've already got the manifolds, then it would be advisable to get an ECU re-tune as well to maximise the upgrade.
You can get other 200 cell cats off the internet, but I couldn't comment on the quality/fit. Although, you do usually get what you pay for............
The plan is to get an ECU tune when it's all fitted. Master plan is AMR twin plate clutch and get the manifolds / cats fitted when having that fitted as most of the bits have to come off to do the clutch anyway. Just the drivers side exhaust manifold that needs to come off on top of the normal clutch stuff.You can get other 200 cell cats off the internet, but I couldn't comment on the quality/fit. Although, you do usually get what you pay for............
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