XK8 / XKR ( X100 ) 1996 - 2006

Engine efficiency

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Old Jun 5, 2018 | 01:06 AM
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Default Engine efficiency

2002 XK8 4.2 convertible.

Engine efficiency versus exhaust pipe deletion
 
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Old Jun 5, 2018 | 07:17 AM
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Are you OK if it throws codes?
And may be horribly noisy?
 
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Old Jun 5, 2018 | 07:32 AM
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Jag V8, TVM for your response.
I don't mind codes as long as I know what they mean and can disregard them.
A modest degree of enjoyable noise is desirable. My car is just too much of the gentleman's grand tourer and not enough rasp and burble like my son's Lotus Elise or my neighbour's Ferrari..
My research so far indicates that replacement of the back end of the system by clear pipes will, for a modest cost, provide various varieties of more "sporty" noise but no one mentions any undesirable side effects such as introducing incorrect pressures in the exhaust system with possible domino effects on the engine, power output (up or down?) and fuel consumption.(up or down?). I need to know the answers to these questions before tinkering.
I'd be grateful for all suggestions.
 
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Old Jun 5, 2018 | 08:03 AM
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You need to do research on this forum. The exhaust is made of several sections that can be replaced with pipes (center resonator, cross pipe and back mufflers). Folks have experimented and found that some replacements cause annoying droning, while some others give a more pleasant sound on throttle. I am personally fine with the way it comes from Jaguar, so I have no direct experience. Best of luck.
 
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Old Jun 5, 2018 | 08:29 AM
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Thank you fmertz; Yes, lots of research needed although it seems surprisingly difficult to obtain quick and clear information on exactly what I want, i.e. reassurance about the effect on the engine when one replaces/removes piping/silencers (mufflers in USA speak). I understand that the drone can be avoided if so desired. I believe that the model after mine (when the shape was changed to look vaguely like an Aston Martin or whatever and it lost that traditional Jaguar identity) was given by Jaguar a more sporty exhaust sound, presumably in response to demand.
 
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Old Jun 6, 2018 | 11:35 PM
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Lots of alternatives out there and you can spend BIG £££/€€€/$$$

I've been running for 8yrs with straight through pipes without baffles/boxes/glasspacks and no issues to report.

I was lucky and found a place that offered a lifetime transferable warranty...plus I paid just £300 and no issues whatsoever:

www.tonybanks.co.uk

Yes there is a drone at 70 which may be more noticeable in a soft-top, but in your case living in a crown dependency just 32x14 miles big you're hardly likely to attain that speed for long?

Interestingly I pulled into a pub for dinner in Essex back in 2015, unbeknown to me there was an Aston regional OC meeting there, half a dozen members wandered over to mine and commented that they wished they're Aston's sounded like that!!

Needless to say that comment still makes me beam

And yes I do 'blip it' in sport mode with windows down through tunnels, if there are supercars in there with me they try to do the same but don't sound as good

Up until 2014 I also ran without catalytic converters and by-pass pipes instead...which was positively biblical
 

Last edited by MarkyUK; Jun 6, 2018 at 11:45 PM.
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Old Jun 7, 2018 | 06:42 AM
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Hello MarkyUK,
Your practical evidence of eight years straight-pipe running unaffected by engine problems is reassuring, unscientific but certainly reassuring. Thanks for the link. I'll go ahead with the conversion.
One reads of manufacturer's carefully calculated exhaust dimensions and correct back pressures and how tinkering will affect the engine, the combustion etc. and one wonders what will happen if the status quo is altered but it seems that nothing of any consequence happens.
I just wonder why anyone buys an Aston Martin when they can have a beautiful Jaguar at three fifth's of the price. . It's all in the movie name I suppose.
Yes, although (outside restricted areas) there is no upper speed limit here on the Isle of Man it is difficult to exceed safely 70mph for long because of the ever present bends, farmers, cyclists and possibility of animals on the road. For a safe driver there is really no need for an upper limit. It is the plentiful supply of idiots that we need to worry about and they will drive how they will anyway.
Thanks Marky.
Best wishes,
 
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Old Jun 10, 2018 | 07:03 AM
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I had the far rear Resonators removed from my 2003.Reused the Chrome tips, to keep the original look. It gave it a very pleasurable rumble up to about 40mph. Seems to turn heads. No irritating levels of noise even with the top down.
 
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Old Jun 10, 2018 | 07:35 AM
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Thanks Sqeeter, Your response is again reassuring and I'll carry on with the conversion.
 
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Old Jun 10, 2018 | 06:10 PM
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Originally Posted by Kumzar
Hello MarkyUK,
Your practical evidence of eight years straight-pipe running unaffected by engine problems is reassuring, unscientific but certainly reassuring.
Nope no issues whatsoever, although at MOT they do comment that it's loud

As to efficiency, I've managed 400 miles on a brimmed tank plus the 350 I can squeeze out of my LPG tank generally means I could travel 750 miles without stopping (natch my bladder couldn't match that). But as you'll know there's nowhere I could drive that distance in the UK without driving into the sea

I do run on fully synth, change my iridium plugs every 20k miles and have just changed the original coil packs for the first time, it made sense as rocker cover gaskets had started to leak (but lasted 6yrs)

But no error codes due to the exhaust
 
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Old Jun 10, 2018 | 06:32 PM
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Marky, That account of your practical experience is invaluable and it would seem that my initial caution was unfounded. Thanks very much indeed for the reassurance.
 
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Old Aug 4, 2018 | 04:59 PM
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I owe a big thank you to all who took the time to respond to my enquiry about changing the exhaust pipes and reassured me as to the result. The rear boxes were removed yesterday and replaced by s/s straight-through Adamesh pipes and I am delighted with the result. Not too noisy but much more satisfactory. Now I have two pipes with boxes, only 3,800 miles and in perfect condition, for sale. Thank you all.
 
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