New 3” X pipe exhaust by Dr. Jekyll

By diyauto
( 1 )

8 minute(s) of a 18 minute read

9-11-2013

I've got a big update coming :-) 


For inquiring minds: The exhaust is simply amazing. Chris has managed to completely eliminate the drone but keep the straight through 3" design and the aggressive sound. In other words, it is perfect.




9-14-2013


As I discussed in my original post, I loved the sound, design and look of the exhaust that I originally bought from Chris at Unobtainum Welding. But I was a bit taken back by how badly these cars could drone with a free flowing exhaust. I had watched a ton of videos of X-piped cars but the low frequency drone just can't be captured by video cameras. I was bummed about the drone because it was an otherwise perfect exhaust. 


So after I decided I just couldn't live with the exhaust being that droney, I gave Chris a call. Chris, being an audiophile as well as an amazingly talented welder, had some tricks up his sleeve. Using math and science he figured he could create a helmholtz resonator that basically canceled out the specific "drone" frequency. After some testing we isolated the specific frequency the car droned at and I sent the exhaust back to him for some tweaks. 


Even though I loved the super aggressive sound, I felt it was bit much for normal, around the town driving. The noise outside the car didn't really bother me but I knew it would attract unwanted police attention. So I also asked Chris to V-band in some larger resonators as well. That way I could have the best of both worlds. And, to be completely honest, I wasn't sold that Chris could fix the drone with some math and science wizardry  I mean, if it was that simple why hadn't all the other tuners done it already? 


So, if you couldn't tell, I had some pretty high expectations. I wanted a loud, aggressive, free flowing, lightweight exhaust that didn't drone and could sneak by cops when I wanted. Quite the challenge for Chris. 


After a few months of fab work and testing this is what I got back:






Pretty crazy looking huh?  


I knew Chris had already installed it and tested it on another 996 but I was still a bit skeptical that it would actually fit in the limited space we have. I was wrong, again:






It fit perfectly. I didn't have hammer, bend or modify anything to get it to fit. 


Even with all the modifications and Chris not actually mocking this thing up on my car, the sweet slant cuts tips fit perfectly in the bumper.




I installed the resonators for the initial install since that will be my every day setup. The resonators are not the typical packed/louvered design. They are a very free flowing chamber design. So no packing material to break down or burn up. Honestly, they didn't look like they would do much of anything (I think this is the 3rd time my initial thoughts were wrong). 


Cold start is still loud, but I could tell the resonators helped to bring the volume down just enough that the neighbors wouldn't complain (perfect). When the car settles down, it's actually very close to stock-like. It's still clearly modified and has a much deeper, aggressive tone, but it's not loud. A quick jab of the throttle and it sounds really pissed off with the turbos clearly audible. I'm pretty sure I was giggling like a school girl for a solid 5 minutes as I just kept tapping the throttle 


Now for the drive. 


Immediately I could tell the drone was gone. Before, between 2k and 3k rpm the drone rattled everything in the car, including my brain. After 15 minutes of driving it gave me a headache. Now, there's nothing. That low frequency vibration is completely gone. Even at highway speeds, where the drone was the worst, it's completely gone. I was amazed. I could not (and still can't) believe Chris was able to completely rid the cabin of that noise without adding a muffler. Incredible. 


Outside, the car sounds very similar to the video I posed before. It crackles and pops at low speed, the turbos whistling on spool up and spool down. It's friggin awesome. 


The resonators tamed the exhaust just enough that at low speeds and stop lights it's not obnoxious. I've driven past multiple cops without any issues (and I'm in the south with Connecticut plates). As long as I keep it around 2k rpm, I can sneak by without being overly obvious. 


WOT is a different story. Just like in the video, it's glorious  I just want to keep flooring it because it sounds so friggin good! The resonators definitely didn't tame this part of the exhaust  It sounds very GT3 like, except with turbo whistle. It has to be heard in person to really appreciate the intoxicating sounds it makes.


Needless to say, Chris has managed to hit each of my requirements. The drone is gone, the around-the-town volume is tamed without effecting WOT and the exhaust remains free flowing and aggressive. But... my wife's standards are even higher. 


The wife test: My wife is very sensitive to loud and low frequency noise. If an exhaust is too loud or droney in the cabin, she'll get a headache/migraine (which isn't pleseant of either of us). So I didn't even bother taking her out with the original iteration of the exhaust on the car. But I knew she would be ok with the new version. So, the day after I installed it, we went for an hour long cruise. Not only did she not get a headache, but she loved the way the car sounded now. We've since gone on a few more cruises (both back roads and highway) and she has yet to complain about the noise or drone. 


She did have one issue she wanted me to pass on to Chris though. I scare her with the short 1/2 throttle pulls now because the exhaust sounds so pissed above 3k rpm that she feels like we're going faster than we actually are  


So, if you couldn't tell from the above write-up, I'm extremely happy with the exhaust now. I honestly have no idea how Chris managed to hit all my expectations. I did not think I would be able to find "the perfect" exhaust. But I did. 


Chris was great to work with throughout this whole process. He made it his goal to make me happy and I can't thank him enough for his hard work. And, all said and done, even with all the shipping back and forth to Canada, the price was still lower than most exhausts on the market. 


I'll do another update in a few weeks once I get some new dB readings and can put together another video (although the lack of drone is hard to capture since you can't really hear it on the first video). Plus I'm sure some of you skeptics will be saying "the drone disappeared because of the resonators after the turbo, not the helmholtz resonator." Chris tested the exhaust with the straight pipe section on and said the drone was gone. I'm sure he's being truthful, but when I get a chance to slap the straight pipes on, I'll report back.



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