3" v twin 2.5"

[canedkydd]

ok here goes, ba xr6 turbo has cat delete. just picked up a middle muffler delete twin system and a single 3' with single 3' rear muffler. question is should I keep stock rear twin muffler and piping ?  really interested to find out which would sound better but also which will perform best. second question before I crawl under to change exhaust will rear section fit without having to drop rear cradle ?  before the attacks start I live in NZ so cat delete is legal. 

[k31th]

single 3 is smaller than the stock twin 2.25.  Go 2x2.5 or 1x3.5 or 1x4

 

Yes, you can do it with the car jacked up without dropping the cradle but it'll get scratched at the rear.

[canedkydd]

ok fitted it a couple of days ago. cat delete (was already done) middle muffler delete (twin straight pipes 2.5) this then goes twin 2.5 merge into a single 3" resonator. sounds awesome but is a little too loud. now wondering do I get a decent 3" muffler to replace the resonator ? refit middle muffler ? refit rear muffler/ resonator ? have tested it and seems to go much better with this set up 

[k31th]

try a muffler instead of the middle muffler delete... should solve the "loud" issues and if you get a decent high-flow straight-through sort of muffler it will still hold plenty of power.

[Puffwagon]

Yeah man I would buy a decent high flow muffler and put it into the 3 inch section somewhere.

[bossmang]

why NZ allows no cats baffles me

[Puffwagon]

38 minutes ago, Admin (as if) said:

baffles

 

 

I have a venom cat in my current 4 inch system and it seems to be fairly free flowing

 

It'd be worth checking the hydrocarbons when it's back on 98 just for the sake of some more data.

[canedkydd]

thanks for all the advise guys and yes baffles me why here in NZ we can delete the cat. kind of slaps in the face the clean green NZ image. Ok so it goes full twin 2.5 over the diff then merges after the diff into a single 3" muffler/ resonator. I assume by removing both middle and rear mufflers I will need a retune and yes I have been driving like ya Nana until done. question is I can get a baffle that slips into that 3" muffler to quieten it down for purpose of annual warrant of fitness check and to keep the cops off my back when needed but if I get it tuned with this removed to give best possible flow does that mean I cannot refit baffle or my engine will go bang bang snap when I boost it ? yes this turbsky thing is all new to me. have had a ton of old school v8s that I could tune in my sleep but elecrikosity stuff gives me the heebee geebees not being able to do it myself.