Yea there is no proof of gaining much from a test pipe, but if your turbo the most free airflow you can get is probably better. Now if your running N/A theres no point and an exhaust would probably be just noise.

 

this car dynoed 115whp all it had was high flow cat, header and 2.25 catback. so im assuming the high flow cat helped somewhere.

this mirage had 95 hp at the crank.

 

Yeah and see i said the cat does help somewhere, but tell them to just try the header with just the catback and see how much they will gain.

 

Check your battery too, an overcharging battery can smell like fried eggs when it starts to really heat up.

 

i think i saw a thread in the evo sections about stock evos going catless gain about 15-20whp. and there was another one that proved a high flow cat vs stock, not that big of a gain.

so for turbo lancer, maybe gain half of that. and for some reason lancers are REALLY quiet without cats, resonators, and just a muffler. you dont need to worry about cops

 

That's stock cat (super restrictive) to no cat (no restrictions). Don't forget that evos also run more boost than 99% of lancers and that will certainly have an effect. I believe it was SCC that had an entire article dedicated to the high flow cat vs. test pipe debate and the difference was minimal, like 1 HP minimal. It's personal preference really, I didn't want to go catless for a variety of reasons but a lot of people do.

 

that car had a high flow cat, that dynoed.

 

Well a major problem with that dyno is no baseline, as far as we know, it's abnormally high reading thus the gains could be minimal. However, I do think that going from the stock cat to a high flow cat is worth it.