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After owning my G37S Sedan for almost a year now, I am ready to make some performance upgrades. I know that i want to get the Admin Intakes and tune.
But first I need to figure out what to do about the exhaust. I have decided on doing the berks rhfc but I'm stuck on the catback. I originally planned on getting the Stillen, and after watching many Youtube videos and also PM some members on here, I was pretty much sold.
Well a few days ago, I finally heard a sedan in person with stock cats and Stillen cbe. It was definitely louder than I wanted.
So that brings me to the Invidia Q300. I can only find one dyno of this exhaust and I am totally confused by it. The diameter is much bigger than stock, but yet doesnt really gain much hp at all. Are the Q300 mufflers that restrictive?
The dyno showed a loss of power from 0-3500rpm. From 3500-5800 it was even with oem. 6000-7500 it finally showed gains, but little. Since this is a daily, I will never be up in the 6000 range.
So would i be better off doing a ypipe and mid pipe and keeping the oem mufflers?
Does our stock mufflers seems to flow better than the invidia?
Is it completely unreasonable to use the q300 ypipe and midpipe to mate up with the oem mufflers?
I know that once I get tuned, it should help out some, but i dont really know.
Basically what i am trying to do, is add power and not sound, I know hard to do. I am sensitive and impatient to drone and loud exhaust in general. What are your thoughts?
What about just doing a hfc and leaving the rest of it stock?
I was at this very same dilemma a year or two ago. I was in the same boat, didn't want to add too much sound but gain performance since I daily drive it ~70 miles a day. I ended up with the Stillen exhaust and still on the OEM cats. I go back and forth between getting some resonated test pipes or the resonated HFC from fast intentions since I like the sound level it is at now. Scientifically, you can't get what you're asking. More performance means more flow, which means bigger pipes or less restrictive mufflers. The Q300 exhaust from what I heard is just a tad louder if not the same as stock (as well as heavier) which lead me to believe it does not do much in the performance department. Granted I've never heard it in person so I can't fully guarantee that. I went with Stillen because of the proven dyno numbers and it checked off all the things I was looking for; lighter weight, slightly amplified sound, more performance. Not sure if you heard the exhaust at start up only, but it was a lot quieter cruising around once the engine had warmed up.
Since it sounds like you are getting intakes as well, I would recommend that first. It will change the sound of the exhaust so you might as well start with that piece and go from there.
Thank you for replying. I only heard a cold start up, with some revving. He stated that at 60-70 mph he could hold a conversation without a lot of sound.
do you think that adding hfc to the stillen would increase the noise alot or just slightly?
I think it depends on the HFC you choose. The higher flow the cat (i.e. Z1) the louder they will be. I'm not sure how to quantify how much louder it would be since I do not have any first hand experience. I would recommend intake then exhaust first to see how you like it. If that doesn't satisfy, replace the OEM cats.
03-06-2019, 12:22 AM
