just installed a 20g last week and my numbers are lower than expected, but sean ivey assures me its due to the high flow cat that i run. he claims 20whp if i were to ditch it.ilet me just point out i am not disapointed with my numbers because the car feels awesome. sean did a great job, and is a great guy to work with too.
anyway i am am keeping the cat for now and looking into a cutout so i can pass emissions in mass still, and keep the car quiet when im just tooling around town and dont need the extra hp.

but i was wondering how many people are running high flow cats with any turbo larger than the stocker?

 

what were your numbers?

is your cat ceramic or metal substrate?

 

Why not just gut your old stock cat and compare with the S.O.P. dyno.

 

ive got a high flow cat on my car right now for emissions testing which is a week overdue already. i've got a 35r with meth injection running 28 psi. it definitely feels slower then it should ( i could notice a SOTP difference on the stock turbo too with the HFC in when i was doing emissions). from my experience i would agree with sean.

 

Yeah,
What were the numbers?

 

if they are below 330 (aiming real low) im gonna be dissapointed and say drop your cat. people are putting out 350 on the stock turbo... I dont know how much you know about emissions, but here in IL I used to work for the emissions team (envirotest) and they only do obd checks now. OBD1 sniffer tests are long gone for almost a year now. As long as you dont have a CEL youll be okay. The mechanical fix takes care of that for $5 and it works wonderfully.

now if your in cali, they do the obd2 scan and they do a sniffer.

On a sidenote if your looking for a cut out I have a brand new Qtp electric cutout. It comes with everything looking for $140 shipped (killer deal i paid near $200 new). GL

 

im running a hfc on a t3/t4 setup right now and is a little sluggish compared to test pipe which i also have but the hfc is on for inspection purposes. i say ditch the cat and get a test pipe and if it throws a cel then get the mechanical o2 fix as mentioned above

 

i think i was around 350/360 whp/tq. i dont have the logs or even a dyno sheet to be honest. worst part is my cat just started throwing a code (po420 i think)

 

roflmao if your cat is throwing the cat code then....rip that bish out.

 

definately pull that thing out.