LOUD and proud!
Discussion
quote:
Just had the soundproofing stuff removed from the exhaust of my Griff 500. Exhaust note now much harder-edged and LOUD, even with all three cats still in place. I am well chuffed, but does anyone know of any downsides to this?
Except for frightened pets and grannies that it!!
You can't go and play on a track cos you are too loud...
Steve
Done exactly the same on my Griff, and the sound checks normally read around 103dB, which is fine for most sprints and track days.
Figures vary depending on the individual method employed at the circuits (because there's no packing whatsoever, the noise won't increase due to deterioration of the silencing), but I've rarely experienced problems, and it does sound really good. - Apparently, the commentator at Loton Park voted it one of the best sounding cars at the hillclimb in May.
Figures vary depending on the individual method employed at the circuits (because there's no packing whatsoever, the noise won't increase due to deterioration of the silencing), but I've rarely experienced problems, and it does sound really good. - Apparently, the commentator at Loton Park voted it one of the best sounding cars at the hillclimb in May.
quote:
Done exactly the same on my Griff, and the sound checks normally read around 103dB, which is fine for most sprints and track days.
Try coming down sarf...
Commonly around 98-100 dB and getting tougher all the time. The MSA dropped the rallying limit to 100 dB this year and rumours are it may happen to sprints as well.
Steve
'The MSA dropped the rallying limit to 100 dB this year'
And when they've forced every car to run at 0db, they'll start to add some extra emissions regulations too, or some lifestyle regulations, or some EU regulations, so that nobody is allowed any enjoyment whatsoever and we all slog along in a robotised 100% tax Euro environment. But drinking and gambling will be compulsory because the spinners say it makes us happy.
And when they've forced every car to run at 0db, they'll start to add some extra emissions regulations too, or some lifestyle regulations, or some EU regulations, so that nobody is allowed any enjoyment whatsoever and we all slog along in a robotised 100% tax Euro environment. But drinking and gambling will be compulsory because the spinners say it makes us happy.
How does one remove the silencing ?
In the past I've usually gone for the custom S/S route and usually gone for a full system with only one box. I'm not doing this on the Griffith as i) its too expensive and ii) i'm not sure I'd get any performance benefit.
Removing the silencing sounds like a good way of increasing noise without too much cost or risking gas flow problems etc.
What is involved ?
Dave
In the past I've usually gone for the custom S/S route and usually gone for a full system with only one box. I'm not doing this on the Griffith as i) its too expensive and ii) i'm not sure I'd get any performance benefit.
Removing the silencing sounds like a good way of increasing noise without too much cost or risking gas flow problems etc.
What is involved ?
Dave
Cut open back box, remove packaging, change perforated pipes with straight ones, refit packaging, weld up back box. Total cost £150. Fernies a superb job on mine.
Ian A.
Ian A.
quote:
How does one remove the silencing ?
In the past I've usually gone for the custom S/S route and usually gone for a full system with only one box. I'm not doing this on the Griffith as i) its too expensive and ii) i'm not sure I'd get any performance benefit.
Removing the silencing sounds like a good way of increasing noise without too much cost or risking gas flow problems etc.
What is involved ?
Dave
By removing the packing and the perforated tubes, surely aren't you removing back pressure and hence losing power? Don't know either way but have heard that this mod is not recommended by certain circles as you lose power? But how do i know, would be good to get some cars together for a rolling road session....
Back pressure never helps an engine's ultimate power, though can improve low end torque. The important thing is the resonance characteristics of the whole exhaust system, which could well have been changed by altering the packing. However, I don't think a relatively untuned Rover v8 is massively worried by this.
PS Getting some cars together on a rolling road session won't prove anything - I bet the difference between individual engines will swamp the difference that an exhaust makes - the only fair test is to do it immediately before and after the mod on the same road.
PPS Another downside - depending on the year of manufacture of your car, it's illegal with a potential fine of £5000.
PPS Another downside - depending on the year of manufacture of your car, it's illegal with a potential fine of £5000.
Intrigued Now
How can de-furring the back box be illegal with a 5k fine? Can anyone explain this one?
De-catting yes as legal requirement post 92 but I've never had problems with any of my exhaust and for the last 5 years they've all been one off custom jobbies with only a single very small straight through box and the rest just 2-3" pipe work.
Believe me the Mazda was very loud. (Especially when de-catted).
Hence considering removing the silencing from the Griffith as it seems too quiet.
Dave
How can de-furring the back box be illegal with a 5k fine? Can anyone explain this one?
De-catting yes as legal requirement post 92 but I've never had problems with any of my exhaust and for the last 5 years they've all been one off custom jobbies with only a single very small straight through box and the rest just 2-3" pipe work.
Believe me the Mazda was very loud. (Especially when de-catted).
Hence considering removing the silencing from the Griffith as it seems too quiet.
Dave
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