Butterfly valve on exhaust?

[The Bogan]

1 hour ago, Dose Pipe Sutututu said:

Euro 4 or 5 or 6 spec?

I'm heading down the same path (soon), however might do a 3" AES valve to bypass the cat/mid muffler and join back to the rear muffler if post turbine pressure creeps up.

Similar to this:

https://www.facebook.com/project7dere/posts/pfbid02TRQxyu9g19CJc1wit6yddh9WyDhjo3uabivNzsG5r5DhjWkg2ZPfgtUuLG4rGMhVl 

i.e. no Western Sydney GT-R mode

Euro 4, IIRC 2 of the 4" body ones for my 3" Y pipe

Only a couple of hundred each, the Euro 5 high flow were more expensive but had a 5" body, I needed 2 so cheaped out on the Euro 4

The car (2002) only needs to meet Euro 3 but it ain't stock, so 1 extra Euro was acquired, which going of todays conversion rate is $1.67AUD, so I'm making money not fumes!!!!!!!

 

[Dose Pipe Sutututu]

11 minutes ago, Murray_Calavera said:

If you get a chance to do before/after dyno runs when you throw the real cats in I would be super keen to see the results

Car will just go back on with the same timing map, fuel map & boost, same type of dyno, however not the same one and my old run won't be there either.

However being a Mainline Pro Hub, they seem to be quite consistent in terms of reading.

[joshuaho96]

2 hours ago, R3N3 said:

We have pretty loose emission laws here in NZ and I did not need a cat to keep my car legal…. However I may look to install one in the future as I’m hoping it will also remove a db or two from the volume of the exhaust.

It will reduce noise substantially. When I got my car CA emissions compliant they added a bunch of cats and despite the Apexi catback and HKS front pipe it's quieter than a 100% stock exhaust. It also causes a hilarious amount of exhaust restriction because of how many they added but at least for now that means my turbos on wastegate boost no longer hit the R&R corner of the map.

Edited August 4, 2023 by joshuaho96