CAT question for Brian Moore (and others)

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k10
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Mon May 19, 2008 1:41 pm

I'm interested in this process also.
I like Brian's idea of removing the cat the old fashion way, (smashing with a pipe).
Brian, I have a 2 piece system, does the front section have to be removed from the car to remove the bits of smashed cat, Just seems a hassle removing the front exhaust section on a 2 piece. Is it possible to lift the front to get most of the cat out? I have a new rear section ready to go on and was going to cut the cat out, but leaving the pipe there and smashing the cat out seems a simpler and quicker approach!
I would have thought there must be a few BHP to be had on a 325 by removing the cat. My only evidence for this is that my 2 pre 87 non cat 325i's went better than my 2 post 87 cat 325i's ? But then I read somewhere that the compression was slightly adjusted on the M20 after 87 so perhaps it has more to do with that?
Also if the cat has been removed in a 1989 325 do they still test the emissions to cat standard? Or if you inform the tester that it's been removed do they test to a lower standard?
Thanks
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k10
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Mon May 19, 2008 10:32 pm

Any opinions on this??
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k10
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Tue May 20, 2008 5:27 pm

No-one has decatted an E3o then?
jmc330i
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Tue May 20, 2008 7:27 pm

k10 wrote:I'm interested in this process also.
I like Brian's idea of removing the cat the old fashion way, (smashing with a pipe).
Brian, I have a 2 piece system, does the front section have to be removed from the car to remove the bits of smashed cat
I would think its easier to do with the exhaust off the car.
I would have thought there must be a few BHP to be had on a 325 by removing the cat. My only evidence for this is that my 2 pre 87 non cat 325i's went better than my 2 post 87 cat 325i's ? But then I read somewhere that the compression was slightly adjusted on the M20 after 87 so perhaps it has more to do with that?
Pre 87 cars do have a higher comp ratio and they will make much closer to the claimed 171bhp because of this, and they will be quicker than the low comp 'facelift' cars.
Also if the cat has been removed in a 1989 325 do they still test the emissions to cat standard? Or if you inform the tester that it's been removed do they test to a lower standard?
Not many 1989 UK E30s will have had Cats fitted from new anyway, only those after 1992. A 1989 325i would be subject to the pre August '92 emissions test and as long as the engine is in good order will have no problem passing, even if it was a de-catted 325i.
James
'91 325i Sport
'93 318i touring 16v
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k10
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Fri May 23, 2008 7:48 pm

Many thanks for reply...

K
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