Are these going to fit my car ?

[simonbuk]

With my head soon to be replaced things are obviously coming off so i want to do as much as possible whilst i'm there.

Are these two items correct for my car ? Will they all fit together nicely ?!

http://www.piperexhausts.co.uk/pipersto ... pgafqbit76

http://www.piperexhausts.co.uk/pipersto ... ts_id=4829

Bit confused as the pre cat elinmiator says suitable for 2 1/4 inch systems.

The down pipe says its made from 2 1/2 bore ?

Which comes first the pre cat elinmiator or downpipe ?!

I have the Piper 2 1/4 system with sports cat fitted.

Cheers

[dapinky]

Simon,

You don't need both of these - it's one or the other!

It becomes a bit clearer if you consider the time-line history (which is easy for me to say, 'cos I was involved in it from the start, but not necessarily so clear to anyone who hasn't been here for 10 years or so, so it is no disrespect intended to yourself).

Originally, the exhaust was a 2" pipe all the way from the front pipe to the back of the car - then a couple of aftermarket suppliers replicated the OE in stainless steel.....

... then along came Peco with a 2 1/4" stainless system - this released extra power, but had a 'noise' which some found annoying....

.... then Piper wanted to make a 'modular' system so people could have what they wanted/needed - initially it was a choice between 2 1/4" & 2 1/2" pipework...

.... as a result of a request from someone on here, the PCE was developed to replace the cast iron 'dustbin' above the front pipe - the OE part is both heavy and restrictive - not noticed with the OE exhaust, but once a freer flowing system was introduced, the other parts became restrictive to the overall result...

... then the downpipe was introduced to replace the whole cast-iron stuff from the turbo backwards - more weight saving and efficiency - but basically also replaces the PCE...

... then Peco was taken over by Cybox, and their system was modified to reduce the 'drone'...

...and then they offered an extra silencer...

...and so it goes on.

What I would say is that if you currently have a 2 1/4" piper system, a PCE will give you an improvement (as would the whole downpipe), but they would both give a very similar improvement - but if you have a 2 1/2" system, the downpipe will give more improvement to a PCE.

Whichever way you decide to go, make sure that you have plenty of spare change for the swearbox - getting all the bolts which hold the PCE to the topbox out can be "fun".

[bbjon]

I literally fitted the downpipe yesterday - I can heartily recommend it! It's a little louder but the car spools more quickly. It's also massively lighter and easier to fit. Piper claim it will only work with their exhaust but it happily bolts up to the cybox/peco. You do lose all the heat shields but with the current temperatures what does it matter!

[simonbuk]

Thanks Dave - thought i was getting unnecessarily confused! !

So, (hopefully) what you are saying is you either buy the PCE which bolts onto the existing downpipe, or buy the new improved downpipe which replaces both ?

[roy666]

Sounds great. Is this on the SE? I've got a S2 and I've been told if the pre-cat is removed then the car will not pass the MOT emissions test. I've got a PNM exhaust... so no main cat (box) on the system. Can an S2 pass the MOT without any cat on it then?

[simonbuk]

It is on an S2 yes. I thought being over 20 years old the pre cat would be pretty much useless anyway ? I've got a sports cat in the main part of the exhaust.

[Simon_P]

The pre cat is to comply with the law rather than the MoT test.

When the engine is cold the main cat hasn't warmed up to its "light off " temperature and isn't effective.

The pre cat being close to the manifold heats up faster and compensates.

With the engine hot and the main cat working you should pass the MoT test.

Tested to the correct standard with a strict tester. The sports cat is marginal. You may need a warm up drive if the car has been idling.

If you remove the pre cat you may pass the MoT but may not comply to laws regarding construction and use.

[dapinky]

Thanks Dave - thought i was getting unnecessarily confused! !

So, (hopefully) what you are saying is you either buy the PCE which bolts onto the existing downpipe, or buy the new improved downpipe which replaces both ?

Simon, basically, yes - but a picture will save me writing the rest of the thousand words.....

manifold.jpg

The PCE replaces item number 53.

The complete downpipe replaces number 53 and number 36

[simonbuk]

ok great, understand now thanks.

And Piper got back to me confirming i could purchase just the PCE without the cat, its just their website that doesn't allow it !!

[HJ2]

I just came acros this:

https://www.jaguarforums.com/forum/xf-xfr-x250-44/xf-3-0-sport-magnaflow-exhaust-helmholtz-resonator-191691/

Did anyone ever tried to add a helmholz resonaor to a PECO exhaust in order to get rid of the drone noise?
Sounds doable, but need to check if there is space at all for this...

[GeoffSmith]

I've often wondered what the acoustic equivalent of the Zobel network/Boucherot cell looked like…