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      07-21-2012, 02:05 AM   #1
Vybz's Avatar

Drives: Adidas and Puma
Join Date: Sep 2010
Location: Kitsap County, WA

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2012 BMW M3  [4.12]
Post RPI GTC Exhaust Review

So as some of you might have known, I've been in the market for a new exhaust for a while. I ordered the RPI GTC last week and as of about 6pm today I finished installing it. I had been bouncing back and forth in my mind between the GTC and the GTM. I decided against the GTM because of the drone people kept complaining about in the low rpms. The GTC seemed like it would be all the pros with none of the cons.

Initial impression:

I can feel an increase in power, but I wasn't able to TRULY test it out so I'll get back to that topic down the road. The GTC & GTM claim +28 rwhp and +35 ft/lbs tq and if you remember I recently got my car dyno'ed while it was bone stock. It was for this exact reason, so we will see if RPI is true to their claim.

Installation was cake, everything bolted right where OEM was, and fitment was perfect. The only thing that you have to keep in mind is that you do need to utilize the OEM exhaust clamps to connect the x pipe to the connecting pipes.

Now for sound. So I started the car windows up, and I immediately was like ... damn should have gone with the GTM lol. ( I think my opinion though at that time was a little biased though, because for the last week, I've been rolling with only the stock x-pipe on the car and no muffler... needless to say that was very loud ). As soon as I started to pull away though I could immediately hear the change. 3k rpm and below and the exhaust is as docile as can be, head towards WOT and the exhaust screams.
I never really understood the description of "deep french horn overtone" until today. It is definitely loud when you want it to be. Ironically after I installed the exhaust I went out to eat and when I was leaving the restaurant, I set off the alarm of the truck parked next to me upon start up .
On the topic of drone ... there is none. The GTC truly fixes that aspect of the GTM. If I wanted to, I could drive around conservatively and make the car sound stock. There are times I wish it was a tad more aggressive (really only when I'm rev-matching) , but I'm sure the car is MUCH louder from outside then from within the cabin.

I plan on doing a full and proper review, and I know everything above doesn't mean anything without sound clips. I'll get them to the community asap and It'll be in a variety of situations and environments so you can get the best idea of what the exhaust sounds like.

I'll be heading back to the shop to get the car dyno'ed so I'll also post the exhausts TRUE gains when I have the new numbers.

Here's a link to my stock dyno pull if you missed it, the numbers are in the description. The workhorse had some impressive numbers for stock so if the GTC truly adds it's figures on to that, I'll be impressed and I'll be that much closer to my goal of 400+ rwhp while still NA.

I'll continue to update this post as information rolls in.

BMWCCA Member # 459350
Audi B6 A4 - S O L D