Posts : 3232 Join date : 2010-05-30 Age : 40 Location : Easington Lane
Subject: Exhaust gains query Wed 13 Nov - 12:30
How much of a difference should I expect going to 3" from 2.5" on a full decat exhaust?
Is it worth it?
Hutchy1979
Posts : 700 Join date : 2012-07-05 Age : 44 Location : Sunny aycliffe
Subject: Re: Exhaust gains query Wed 13 Nov - 14:19
I'm wondering the same thing mate have been told I need a 3" for that 400 mark but I like the look and sound of the 2.5 I have on
byers
Posts : 3378 Join date : 2011-02-19 Age : 45 Location : Hpool
Subject: Re: Exhaust gains query Wed 13 Nov - 15:22
Hardy was 397 on a 2.5"
Hutchy1979
Posts : 700 Join date : 2012-07-05 Age : 44 Location : Sunny aycliffe
Subject: Re: Exhaust gains query Wed 13 Nov - 17:07
I think Mario's is a 2.5" to
Jonny Gav Admin
Posts : 6837 Join date : 2010-03-12 Age : 53 Location : Durham
Subject: Re: Exhaust gains query Wed 13 Nov - 17:50
byers wrote:
Hardy was 397 on a 2.5"
Are you sure about the power output?
A true 3" exhaust will cause less of a restriction at high rpm and high gas flow, this will result in better cylinder filling at the engine as the engine can get rid of more waste exhaust gas leaving more room in the cylinder for more air and petrol, this will result in more power.
Last edited by Jonny Gav on Wed 13 Nov - 21:12; edited 1 time in total
byers
Posts : 3378 Join date : 2011-02-19 Age : 45 Location : Hpool
Subject: Re: Exhaust gains query Wed 13 Nov - 17:52
Yes he said it made 397 and I took the exhaust of the car...
Tizer
Posts : 565 Join date : 2012-05-27 Age : 37 Location : Northumberland
Subject: Re: Exhaust gains query Wed 13 Nov - 18:26
Seems we have all been thinking about this as it was playing on my mind too. I have a 2.5 and was wondering if it would be worth going to 3inch. There does seem to be mixed views on the subject.
byers
Posts : 3378 Join date : 2011-02-19 Age : 45 Location : Hpool
Subject: Re: Exhaust gains query Wed 13 Nov - 18:42
Jonny is right mate in what he is saying
maca
Posts : 3232 Join date : 2010-05-30 Age : 40 Location : Easington Lane
Subject: Re: Exhaust gains query Wed 13 Nov - 19:21
Cheers Jonny, do you know what the difference in bhp would be though? ( I know ya haven't got a crystal ball but just wondering as you know so much )
Say 30bhp?????
Ha im pleased I put this up now seeing as a few people were wondering, I bet we all end up going 3"!
Hutchy I love the sound of mine but if its going to restrict my engine and I (we) have spent a canny bit on performance enhancing mods we might as well go that little bit further lol
maca
Posts : 3232 Join date : 2010-05-30 Age : 40 Location : Easington Lane
Subject: Re: Exhaust gains query Wed 13 Nov - 19:23
byers wrote:
Yes he said it made 397 and I took the exhaust of the car...
Id be buzzing with that but im thinking mine will be around the 360 mark due to being restricted on what boost I can run with the intercooler ive got on, that could even be a bit optimistic tbh!
maca
Posts : 3232 Join date : 2010-05-30 Age : 40 Location : Easington Lane
Subject: Re: Exhaust gains query Wed 13 Nov - 19:25
Jonny Gav wrote:
A true 3" exhaust will cause less of a restriction at high rpm and high gas flow, this will result in better cylinder filling at the engine as the engine can get rid of more waste exhaust gas leaving more room in the cylinder for more air and petrol, this will result in more power.
Would it not cause less of a restriction at high rpm and high gas flow?
Just thinking with it being of greater diameter (you going to show me up now aint ya )
oggy
Posts : 1096 Join date : 2012-05-25 Age : 59 Location : middlesbrough
Subject: Re: Exhaust gains query Wed 13 Nov - 19:31
iv got a full 3inch ststem on mine and it sounds great
Hutchy1979
Posts : 700 Join date : 2012-07-05 Age : 44 Location : Sunny aycliffe
Subject: Re: Exhaust gains query Wed 13 Nov - 19:33
Hutchy I love the sound of mine but if its going to restrict my engine and I (we) have spent a canny bit on performance enhancing mods we might as well go that little bit further lol[/quote]I know mate I got a couple of days left to decide what to do
Guest Guest
Subject: Re: Exhaust gains query Wed 13 Nov - 19:33
My exhaust is 2.5 inch straight through - however Andy Kindon said when he was inspecting it that it looks more like a 2.75 as most of the 2.5s he has seen look narrower than mine. But whether it is or not, it was bought as a 2.5 inch (separate sections) and it doesn't seem to have any negative impact on my power, which is in the very high 400's
I have the following:
Afterburner 2.5 Cat Pipe Afterburner 2.5 De-cat Downpipe Hayward & Scott 2.5 De-resonated Centre Section Tornado 2 Rear Silencer
....and if it makes any difference I have RCM GT Spec 2 Headers & Harvey Smith 3 bolt up-pipe
maca
Posts : 3232 Join date : 2010-05-30 Age : 40 Location : Easington Lane
Subject: Re: Exhaust gains query Wed 13 Nov - 19:42
Hutchy1979 wrote:
Hutchy I love the sound of mine but if its going to restrict my engine and I (we) have spent a canny bit on performance enhancing mods we might as well go that little bit further lol
I know mate I got a couple of days left to decide what to do [/quote] Not much time then mate lol
Get ya hand in your pocket......................AGAIN:lol:
maca
Posts : 3232 Join date : 2010-05-30 Age : 40 Location : Easington Lane
Subject: Re: Exhaust gains query Wed 13 Nov - 19:42
oggy wrote:
iv got a full 3inch ststem on mine and it sounds great
Im swaying towards a new exhaust
natski
Posts : 3898 Join date : 2012-02-22 Age : 44 Location : Smog city
Subject: Re: Exhaust gains query Wed 13 Nov - 19:45
My exhaust is a 2.5 and I wouldn't change it not even for an extra 50 BHP cos it sounds very good.
maca
Posts : 3232 Join date : 2010-05-30 Age : 40 Location : Easington Lane
Subject: Re: Exhaust gains query Wed 13 Nov - 19:46
Marietto wrote:
My exhaust is 2.5 inch straight through - however Andy Kindon said when he was inspecting it that it looks more like a 2.75 as most of the 2.5s he has seen look narrower than mine. But whether it is or not, it was bought as a 2.5 inch (separate sections) and it doesn't seem to have any negative impact on my power, which is in the very high 400's
I have the following:
Afterburner 2.5 Cat Pipe Afterburner 2.5 De-cat Downpipe Hayward & Scott 2.5 De-resonated Centre Section Tornado 2 Rear Silencer
....and if it makes any difference I have RCM GT Spec 2 Headers & Harvey Smith 3 bolt up-pipe
Them figures would be a little bit higher with a 3" system though I would imagine from what im reading (not that you need it! )
Bet them RCM headers weren't cheap
maca
Posts : 3232 Join date : 2010-05-30 Age : 40 Location : Easington Lane
Subject: Re: Exhaust gains query Wed 13 Nov - 19:47
natski wrote:
My exhaust is a 2.5 and I wouldn't change it not even for an extra 50 BHP cos it sounds very good.
Valid point, if your happy then there's no need to change at all
Guest Guest
Subject: Re: Exhaust gains query Wed 13 Nov - 19:53
maca wrote:
Bet them RCM headers weren't cheap
I paid £450 for them mate brand spanking new and fully DEI Heat Wrapped by the late Harvey Smith himself - They are about £594 from Roger Clark without the DEI heatwrapping so a bargain really. This is them:
The Harvey Smith up-pipe was £155 (Alyn at AS Performance sells them now)
garyblake
Posts : 3603 Join date : 2011-11-27 Age : 41
Subject: Re: Exhaust gains query Wed 13 Nov - 20:00
Interesting read up on that exhaust! Little bit more than I would pay for one tho
Guest Guest
Subject: Re: Exhaust gains query Wed 13 Nov - 20:17
maca wrote:
Interesting read up on that exhaust! Little bit more than I would pay for one tho
A 3 inch full Milltek decat exhaust system (Newage) is around £700 - if I was going to go 3 inch that's what I would go for. Along with TGV delete mod I'd probs be touching 500....ooooh tempting!...but I won't do it as I am happy with the horses I have
Mikeblobsti
Posts : 967 Join date : 2012-05-01 Age : 41 Location : Spenny
Subject: Re: Exhaust gains query Wed 13 Nov - 20:30
When I went from 2.5 to 3" the turbo seemed to spool quicker and definitely a increase in power, get a nice deep rumble from a full 3" too if you like that sort of thing
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