kezwaldo

Will a 3 inch decat downpipe fit to a 2.5 inch centre section. I'm being told it will by a member on here , I'm not sure if my centre section is 3 inch or 2.5 just want to know it will fit either way before buying the item thanks.

RS_Matt

Depends on the downpipe make, some 3" DP's mate to smaller centre pipes via flange design and others taper down to 2.5 near the end.

My 3" Cobra sports downpipe fits to my 2.5 centre section via a conical ring gasket..

kezwaldo

We'll the member on here is saying it def came off his newage 3 inch decat all way threw and joined to his 2.5 with no other gaskets or reducers etc!????? This is a minefield lol don't want to waste money on the wrong pipe I think mines 2.5 exhaust but can't be 100%

powerwrx

iTrader: (11)

you need to find out what you have on your car first then go from there. you cant go from a 3" opening to a 2.5" without any sort of gasket to compensate.. look what you have then find one that will fit if your exhaust is 2.5" then get a downpipe with a 2.5" bore where it meets.

your asking the same questions over and over and you still have no idea what is on your car. have a look and buy what you need!

kezwaldo

I don't know what system is on my car and I DONT know how to get a accurate measurement to find out what size the centre is '!!!!!!!!! Secondly I only need the first pipe, most are 1 piece to delete both cats I have half of that already!!!! Honest mate you can't find NOTHIng on the net to help me!!! Just want a bloody part that fits lol

kezwaldo

Power wrx how would u measure the exhaust to see what size it is"??????? I don't want to buy the wrong part on day of my remap and then have to cancel so i need to be 100%

powerwrx

iTrader: (11)

undo it and measure the bore its pretty simple.. are you fully decatting or looking to keep the second cat in place

RS_Matt

You should be able to tell with the naked eye but tape measure the top to bottom if not. Find out the make of DP and check its specs online to see if it can mate to both 2.5" and 3" 3rd cat pipes

kezwaldo

Full decat! I have 4 sections to my exhaust first cat,second decat pipe,centre section,rear box. All I need is the first cat de-catted . I understand most decat downpipes are 1 piece but I think when who ever had car before me had it first cat back not second cat back. So I need just half the one piece which I can't find anywhere!!!!! I'm happy to buy the one piece but how do I know what I'm buying is right!!!! Last thing I want is to buy a 2.5 inch on day it's meant to be mapped and it don't fit,!!!!!!!! I've measured it just the whole pipe and it seems little over 2.5 not quite 3 . But that's a amateur reading!!!

kezwaldo

When I say second cat back I'm coming from the back box toward engine!!! It's first coming from engine side

powerwrx

iTrader: (11)

If its just over 2.5 then ide say a 2.5 system is what you have..just buy the one piece downpipe and sell the other bit you have already

kezwaldo

Cheers mate I'm just short on funds with baby on the way and need make sure my money's spent wisely , I'll try try get a accurate measurement by my mechanic before I buy one! I think other members trying to sell me 3 inch decats saying they will fit just want a sale!?? If u say I need 2.5 I need 2.5

fez the plodder

Hi... I'm selling the Hayward and Scott short down pipe which goes from 3inch bore down to 2.5 then I have the 2nd decat pipe! Also Hayward and Scott!
Some one please explain this to him....
Unless I'm wrong?

kezwaldo

I want the pipe fez the pipe was measured today I need 2.5 check your pms