3" Exhaust, is it necessary? Why not 2.5"?

[Sparkie]

So looking to do the exhaust.
Possible I'll go for a turbo back custom built jobby.
Slightly cheaper than Cobra etc and from someone I have complete faith in.
Question is,
Is a 3" the way to go or will 2.5" do the same with hardly any difference.
I get that breathing is key and better air flow equals power gains.
My LCR will have a Badger TIP along with Jr cone filter and heat shield.
Along with a map from AMD most likely.
So it breathes in well and it wants to breath out well.
People say different things re size
What are my advantages and downsides of both sizes?
In addition what is the difference in sports cats being 100 or 200 cell?
I haven't the foggiest.
Hoping to be enlightened.
Cheers.

 

[andycupra]

3" downpipe and 2.5" exhaust seems common..
Is there a clearance issue over the rear beam with 3" exhaust?

as for the CAT. 100 cells has 100 cells, and the 200 cells for a given area. therefore the 200 cell CAT will have more restriction, but offers more Catalysing capacity.
many go with the 100cell and report they can go through MOTs ok, but its near the mark, personally I'd say go 200 cell, the difference is not great performance wise but gives you a more robust product in theory.

 

[Sparkie]

3" downpipe and 2.5" exhaust seems common..

Is there a clearance issue over the rear beam with 3" exhaust?

.

Good question.

As to the cat, a 200 cell sounds the way to go.
Thanks


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[icestorm81]

There isn't a clearance issue as I have a TSR custom made 3.5'' downpipe on my car.

 

[Sparkie]

There isn't a clearance issue as I have a TSR custom made 3.5'' downpipe on my car.

Cheers. Good to know.


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[Sparkie]

Ok to revive this thread.
I've been quoted two prices for a custom turbo back with sports cat for my LCR.
£650 for a 2.5" pipe
And £800 best price on 3" pipe.
The guy making it used to work in the mapping industry and seems to think the 2.5 is more than adequate unless taking the power beyond 280.
Is there a noticeable gain or loss for having either or?
Once my car is mapped which will work in harmony with the induction kit etc better?
Large or small?
My guess would be bigger bore. Better breathing or does pressure come into play too?


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[LCR33]

Mine for sale.

http://www.ebay.co.uk/itm/112421702173

 

[Sparkie]

Mine for sale.

http://www.ebay.co.uk/itm/112421702173

Thanks but doesn't answer the burning question.


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[LCR33]

Ok to revive this thread.
I've been quoted two prices for a custom turbo back with sports cat for my LCR.
£650 for a 2.5" pipe
And £800 best price on 3" pipe.
The guy making it used to work in the mapping industry and seems to think the 2.5 is more than adequate unless taking the power beyond 280. TRUE, UNDER 300-320 BHP 2.5 IS FINE
Is there a noticeable gain or loss for having either or? AS ABOVE
Once my car is mapped which will work in harmony with the induction kit etc better?
Large or small? AS ABOVE AGAIN
My guess would be bigger bore. Better breathing or does pressure come into play too?

3” also works better when performance head work has been done.



HTH

 

[ibizacupra]

3" at turbo, or even larger is a benefit on k04 however... backpressure on k04 cars is high...

 

[Sparkie]

3" at turbo, or even larger is a benefit on k04 however... backpressure on k04 cars is high...

Could you explain further. I'm challenged when it comes to these cars


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[ASQ1983]

No much difference between 2.5" vs 3" as longg as its straight through

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[ibizacupra]

Could you explain further. I'm challenged when it comes to these cars


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google is your friend fella

 

[LCR33]

Mines still for sale

 

[Andrewwright]

Mines still for sale

Is nice, Like how you can change quickly to de-cat, surprised it didn't sell.

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[LCR33]

Is nice, Like how you can change quickly to de-cat, surprised it didn't sell.

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i knooooooooooooow lol its an absolute bargain, tried to help fellow nuts and just get stupid enquiry's and people turning there nose up !!!!!!!!!!!!!!

might increase the price lol.

 

[Andrewwright]

i knooooooooooooow lol its an absolute bargain, tried to help fellow nuts and just get stupid enquiry's and people turning there nose up !!!!!!!!!!!!!!

might increase the price lol.

I search all the time for parts everywhere, this didn't come up once, add more names like GTi a3 cupra 1.8t ect ect as much as you can and it will link to general search I think. Will open up more buyer's I should think.

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[LCR33]

Cool cheers dude

 

[Sparkie]

i knooooooooooooow lol its an absolute bargain, tried to help fellow nuts and just get stupid enquiry's and people turning there nose up !!!!!!!!!!!!!!

might increase the price lol.

Thanks for the offer.
Thing with me is it's a one time affair with this car. Doing everything new to last me.
Where I'm having mine done I have complete faith in his work as I have an exhaust from him at present. 8 years and 80 odd thousand miles and still in really good nick.
He's doing me a top deal too. Sorry.

 

[LCR33]

Sweet np. So hard to find a good honest garage. I went trough a few myself.