02 sensors galore + secondary air pump (?) W12

[Chin]

When I got the car it needed a sensor 1 bank 1 02 sensor replacing so I replaced it and cleared the fault, I also ran a whole bottle of cataclean and all was well, until today I had the car scanned and now sensor 1 bank 2 has gone **** up I don't know how hot the engine should feel after a spirited drive because Ive never had a car with such a big and powerful engine but there is quiet a bit of heat coming out of it, also ive noticed that theres a slight "noise" coming from the front drivers side arch , is that where the secondary air pump is ? its not a rattle or squeak but sounds more like tapping , not overly loud you can just hear it if you bend over to listen to it. Is this normal ?

Now the car is still under warranty but a) id have to take a day off work and loose out on £££ and b) it would cost me at least £100 in fuel to drive to warrington and back so I would rather pay someone £250 max to replace the sensor for me as AFAIK id need to get the manifold off to get to it and I don't really fancy doing that , not on a W12 anyway

Is taking the engine out REALLY necessary to get rid of the b@stard cats ?

I know im a pain in the back but im all new to this big petrol engine malarkey

[darrenjoe90]

I used to have a D2 S8 and when one of my cats went faulty i had the car de-cated. I have always said if one of my cats go faulty in my W12 it will also be de-cated

[Chin]

Hi Darren , are all your 02 sensors ok ? Where did you get the D2 de-cated and how much did it cost ? Id love to get mine de-cated but if it does cost £1000+ then it'll have to wait

PS, what colour is your car ? Looks same colour as mine , is Silver Violet the proper name for it ?

[darrenjoe90]

Hi Chin

I got my de-cat done at a place called Zorstec near bradford and from what i remember it was about £200. I am pretty sure it will be more for the W12(A lot more)
I think my car colour is called Dirty silver

[Architex_mA8tey]

Originally Posted by darrenjoe90

I think my car colour is called Dirty silver

lol thats a very close colour to your D2 S8 which was dirty blue

[David's8]

Originally Posted by Architex_mA8tey

lol thats a very close colour to your D2 S8 which was dirty blue

Is that Ming-ing Blue?

[Chin]

Well I got it booked in at a local custom exhaust place so they can get it up on the ramp and see whats what, im not getting my hopes up but you never know

Catalytic converters are a devils work indeed !

[daviesbike]

Depending on how much you want to spend the W12 engine is easy to take out infact easyer than the rs6 engines. The front end comes off you move all relivent piping ect out the way disconect ac ect .. and it comes out compleat as a power plant with gear box and all. I would speak to martin adams aka grizz on the forum. I have asked him in the past and had a verbal quick quote as I was looking to do the same and it was about 1k to take the engine out and put it back in. Im sure he could de cat it for you and then remap it while your there and see yourself about 500 ponies the cats are the most restrictive part of a w12 that and the exhaust of course. Not many people tune the W12 but I am quite an ocd freak so I tend to reserch to the max.. ive done the math and figures. I wont go into too much detail. But standard bhp is 450 we all know that.
A remap will see you easy 480 some companys claim as much as 505bhp but a real figure I would say close to 485-490bhp on a nice fresh healthy engine running on 99 ron
I calculated the restriction in the 1 cat based on a 1.5L engine witch is essentially what the w12 is x 4
Just a decat on a 1.5L engine would free up as much as 18-23 bhp dose not sound much but remember ... the w12 has 4 of thease one for each bank of 3 so thats a potential extra 80 or so bhp couple that with a free flow exhaust maybe 15-20bhp ... you see where im going with this ...

450 can soon turn into 480...or coupled with the other mods 580 bhp ish .. with a remap and running 99 ron fuel. Yes you will be restricted by injectors .. but the w12 shares the same injectors as other audi moddles and there easy as pie to change .. because I have changed mine myself.. so when the duty cycle becomes less of an issue on the injectors the only thing that remains is a fuel pump...ahh but wait ...
The w12 comes standard as dose the s8 with not one but two fuel pumps that are both 255 lph
Simmillarly speced to that of a walbro 255 pump with a claimed upper limit of arround 450-500bhp
But you guessed it ... theres two of them one for each bank. Its like two sepirate engines that work in unisen..2 ecu's 2 fuel pumps 4 cats ... hmmm close to 600bhp naturally Spirated if any engine can do that its an audi engine indeed...

Feel free to correct me if im wrong any where there but this is something I have been reserching for a long time .. I also had a quote oc martin of about 15k for a full twin turbo set up on the w12 ... and yes the bhp was estimated to be arround 1000bhp gear box dependant ect ... but tcu could be mapped to not give max torque untill a higher gear. Oh and about 1200ftlbs of it
People that say the w12 is not tunable or is hard to work on have clearly not reserched it themselves and have not taken the engine to bits. When you start stripping it down you start to realise its not as complicated as many people think it is.. just my 45pence worth ...I would say two pence worth .but seem things are getting more expencive thease days .. I went to spend a penny the other day in new town public toilets and it was not a penny at all but 50 pence !!

[ainarssems]

Just a decat on a 1.5L engine would free up as much as 18-23 bhp

What 1.5 engine are you talking about? Maybe on a highly tuned turbo engine with 200BHP +. On the average 90-100BHP 1.5 you will be lucky to get extra 10BHP.

[sarg]

have to agree with ainarss, de-catting will not give you another 80bhp on a W12, no chance