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Discussion Starter #1
as I am a fresh owner of my beast, I am very naive to all the things I hear about needing to modify on it.

the latest thing I hear was that I should upgrade my cats to race cats. can anyone offer some feedback? the recommended race cats are from a German company called HJS which makes race cats for the DTM series. www.hjs.com is it worth doing the work? it isn't cheap, apr 2000 USD (parts and labour)

and, has anyone any feedback on the Alpha N management software? another expensive upgrade that is supposed to give me extra HP and eliminate the MAF's

thanks
 

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Alpha N works, and very well. Dont waste your money on race cats.
If I were to do it again.. I would just go cat-less... :byebye:
 
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as I am a fresh owner of my beast, I am very naive to all the things I hear about needing to modify on it.

the latest thing I hear was that I should upgrade my cats to race cats. can anyone offer some feedback? the recommended race cats are from a German company called HJS which makes race cats for the DTM series. www.hjs.com is it worth doing the work? it isn't cheap, apr 2000 USD (parts and labour)

and, has anyone any feedback on the Alpha N management software? another expensive upgrade that is supposed to give me extra HP and eliminate the MAF's

thanks
Always search...

here you go...

http://www.m5board.com/vbulletin/e39-m5-e52-z8-discussion/169057-ecu-performane-software.html
 

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Another one here for DECATS !
 

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What about the MOT tho ?
The car will always fail with no cats.

I suggest you put your old cats back in for the MOT.

Hassle yes, power liberation from a decat, especially when you are racing at top RPMs is astounding, though.

Good Luck
 

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The car will always fail with no cats.

I suggest you put your old cats back in for the MOT.

Hassle yes, power liberation from a decat, especially when you are racing at top RPMs is astounding, though.

Good Luck
There is only power over and above worn/damaged cats. Over a good set of stock cats don't expect much gains.
 

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at what mileage would you consider the cats worn/damaged in regards to performance
 
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