Actually, VitViper from Vituned was able to demonstrate that there was 3-4Hp to be gained form going form the 2.5 to 3 inch resonated perrin catbacks even in NA.

As far as whether it would help with turbo versus supercharger, someone who's more knowledgable than me would need to answer that. For sure it would help with turbo and the noise levels come down noticeably.
Not sure about super charging however.

Nope. Mine was a resonated 3 inch. I was running a catted nameless FP/OP combo before running the catless but resonated FP/OP from Ultimate racing.

The nameless was noticeably louder as well. The resonator in the UR FP/OP really does work. Plus losing the cat, I picked up 2-3 more HP almost across the board compared to the nameless.

Well worth looking into the HKS resonated FP as an alternative to the Ultimate Racing too.

Does he have dyno sheets for that? I'd love to see them! I get a lot of people that don't believe us when we say it does make more power on an NA car.

That's crazy! Mine didn't drone at all with the PERRIN 2.5 front pipe. I could have even had it a little louder!

i have no drone on my perrin 3inch FP/CBE but there is a touch of rasp around 3-4k rpm with a tomei UEL and perrin OP.

tbh, i miss my old setup of tomei UEL, perrin OP, 2.5 inch Ark resonated catless fp and 2.5 inch perrin resonated cbe.

i'd be tempted to trade my FP/CBE for a full 2.5 inch perrin or some mixture of perrin cbe and HKS or JDL front pipes.

Never heard of "turning off the cold start" could you explain what you did exactly?

Not crazy. just reporting what I experienced. I had it on my car for almost a month before I couldn't take it anymore.

Maybe we just hear differently, which isn't entirely out of the realm of possibility.

I'm like 80% sure it's something you can do with a tune.

cold start is to heat up the cats...if you have no cats this can be tuned out and essentially makes the car not have the obsurdly loud cold start that comes with the car from the factory

It is something that you have to do with a tune, there's a huge thread about it here: http://www.ft86club.com/forums/showthread.php?t=55676

I used the EcuTEK to do this, it was actually really easy to do. Unfortunately it's not something that we normally include in our PERRIN maps.

It basically takes out the timing retard when it's cold, which will make the cats take a little longer to warm up, but won't cause any issues. I ran it like this on my car for a couple years without problems, and there's a lot of other guys that have ran it for longer.