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MG MGF Technical - North Weald Activity Day - CAT replacement pipe?

Do any of you chaps that are going to the North Weald Activity Day on Friday 30th January 2004 have a CAT replacement pipe fitted with an otherwise standard exhaust? (Even better if fitted to a 1.8i)

I know from Rob's site that the noice level went from

61.7 dB @ idle to 62.7dB
81.4 dB @ 400rpm to 84.7 dB
89.6 dB @ 90%max revs to 90.2 dB when the bypass tube was used. In % terns this does not look like a big increas BUT what does this mean in real life?

If possible I want to listen both inside the car and out. So any volunteers?

Thanks in advance

Steve

As i understand it, a difference of +8db is the equivallent of a doubling in volume. Not sure if this helps much but here's an extrapolation based on the figures given:

61.7 dB @ idle to 62.7dB = +1db = 1/8th louder
81.4 dB @ 4000rpm to 84.7 dB = +3.3db = 3/8ths louder
89.6 dB @ 90%max revs to 90.2 dB = +0.6db = 1/8th louder

So, on a standard car there is a difference, but not a big one and it's most noticable during normal driving (as opposed to idling or giving it some welly).

Not sure if this will help you, a cat bypass on a standard set up is fairly rare, they tend to be used to maximise the noise output of an aftermarket system. But you might be lucky, there are after all a lot of cars turning up.

SF
Scarlet Fever

Jee what are the figures for the Trev Taylor pipes I have complete with bypass pipe?

I was lucky last time I did a trackday the bloke took a reading from the wrong tailpipe!!!
Neil

Goodwood is fairly strict on noise limits and some of us only just made it under their 98db static test (three quarter revs/50cm away from the tailpipe at 45degrees) - that's with after-market exhausts and with a cat!
Dave Livingstone

Hmm, i feel Dave that i would have failed that one then!
Kingsley

Me too!

oeer!

anyway I cant make it for the 30th BUT it looks like snow may piss on everyone's bonfire!
Neil

> 30th BUT it looks like snow may piss on everyone's bonfire!
Is what way - sounds much more fun ;-)
Will Munns

Yep, considering the opbject of the day is to find out how the car and driver reacts beyond the limit - i think a snowstorm should make it more instructive!

LOL :-)

SF
Scarlet Fever

Oh Dear!

Neil

Just so long as we can get there in the first place. 70 miles around the M25 through the roadworks in the snow .... hmmmm
Steve Ratledge

i know i left it a bit late, but does anyone know any good b&bs fairly close to activity day on the 30th....
cj lawton

This thread was discussed between 22/01/2004 and 26/01/2004

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