I ran my vortech setup on a Q300, switched to an N1, and then back to the Q300. Did not notice a difference, but my butt dyno has not been calibrated in some time.

so what do you guys think I should do? I don't want back pressure coming from my catback. This may sound stupid but how am I supposed to know how it feels like? Does it happen when I shift?

Also, if I ran say a 2.5" catback would I need a 2.5" frontpipe and matched overpipe as well? Does everything need to match?

If cost isnt too much, just find another catback. But you're talking roughly 3mm difference in piping. Also, I don't know if you got the Q300 for a quieter noise, but I'd get them to figure out a way to make it work.

As for everything needing to match, look at it this way: you can have just the catback. But if you're going to do the rest of your exhaust, just get headers and leave the catback. The midpipe/ overpipe don't make much difference.

Yeah I got the q300 due to noise, I had the n1 but the droning drove me insane. What do you guys think of the blitz single pipe with a delete? and some tomei el headers

I'd get a good el header and 2.5" overpipe if you haven't already .

As said above a good header makes it come alive as I found out :burnrubber:

I was told to skip on chevron and use 76 gas for a month and come back for a checkup re-tune so I guess I should change out my headers for now.

Will headers decrease performance without a tune? I am using bill's flash and go does it take those into account I wonder?

Also, what do you guys think of the blitz nur spec r single pipe? Since this is a 4 cyl boxer wouldn't that be "better" breathing? Even for FI

You'd need to get your tune to account for the headers. Otherwise it will run poorly. Also why not just run 91 or 93 octane? I don't get that. Another exhaust to consider may be the Perrin resonated.

Doesn't bill's flash and go tune account for the headers? According to bob the one who stated above us is using a tomei el header. I'm assuming he's just on a flash and go without having it accounted for? correct me if I'm wrong

It's possible, but there are so many different headers you'd want to at least want to contact them and find out. I'd say retune it just for the reassurance.

You will have to have Bill generate the proper flash and go for whatever exhaust hardware you have on the car. If you put an aftermarket header in the car that doesn't have a cat then the secondary O2 sensor will have to be disabled to prevent a CEL. Honestly IMO you are going to gain WAY more by putting a EL header and aftermarket overpipe on the car than switching your catback.

So the tomei EL is what you'd recommend? what about the overpipe / front pipe? While I'm at it should I just do the front pipe as well?

My goal is the EL / OP / FP / E85 tune hoping to keep my catback so I don't have to spend that extra money for a catback.

Yes I think the Tomei EL is very good for the cost.

The order I did the mods was N1, FP w high flow cat, OP, and Header. The N1 gave me the sound I wanted, the rest increased performance IMO.

Hey quick question for you. You drive an A/T for autox right? Do you know why the a/t jerks after installing the supercharger is that due to the "back pressure" or is that due to too crappy of a torque converter and or a need of fluid change?

Who's your tuner? Is it jerkiness when you try to accelerate at low rpms?