High Flow Cat Vs Stock

[Deza3000]

Hey guys,

Apologies if this question is stupid, but i have a awkward scenario where google wont be much help.

So today i remembered im still running the stock cat on my evo. I had a full 3inch exhaust system which i installed 2 years ago however it came with a test pipe as oppose to a high flow, so i left the factory cat on to keep the car legal. As time progressed i focused on other mods and i totally forgot about the exhaust till today.

Recently I got my car tuned on e85 - stock turbo @1.6 bar & stock motor and made 242awkw/460nm.

I was wondering whether it will still be worth getting a high flow cat post tune, or whether the results will be negligible...

Cheers

[GTSBoy]

You could see at least another 20kW with a better cat. Probably more. Checking the tune would be wise.

[Deza3000]

Yea i thought so. 20kW is a good bit of power given the cost of a cat. Ill visit an exhaust shop and get them to weld one on. I also just realised my stock cat is 2.5inch, might be causing some turbulence as well, kind of wish i remembered sooner.

Cheers mate.

[Missileman]

It shouldn't cost that much for a touch-up on the tune, ask your tuner what he / she thinks.

[Deza3000]

Yep will definitely have a chat to him about it. Kinda exciting though, more untapped power

[Dose Pipe Sutututu]

If your tuner has been wise enough to interpolate the cells around the loaded parts of the map then you'll be fine.. especially on a car that runs an AFM

A quick squirt on the dyno would be a great way to check.

[Deza3000]

Hey guys,

Just an update. I got the cat swapped out with a 100 Cell high flow and its a good thing i did!

My old cat absolutely crapped itself, there was debris blocking 50-70% of the cat. Even a brand new stock replacement would of seen some gains! Unfortunately i didnt get to take a picture of it in time as it made its way to the bin.

I drove the car and i definitely need a retune. The car is hitting 1.6 bar of boost in 2nd under 75% throttle (i thought full boost is usually seen in 3rd gear?), where as before it tapers off @0.9 ~1.1 bar in 2nd. I was scared to full throttle as i dont have a Wideband.

Its not as loud as i thought it would be, just a bit raspier.