Found a video of what your car can sound like with FI HFCs. I'm assuming he did a custom exhaust as well to fit the MD exhaust on his. He might be the only 1 right now as I can't find any other videos.


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You see, I kind of thought that the exhausts would sound very different at first too. Generally speaking, my car should sound like an 35HR Z/G with the HR specific exhaust. The more I think about it though, the difference in sound between the 37 and 35 motors is negligible at best. I don’t really think the VVEL and extra .2 of displacement is enough to warrant an entirely different sound or tone out of the exhaust. If the systems have the same amount of resonators and share he same general piping design, I don’t think the small differences between motors or pipe length between coupes and sedans should be noticeably different.

I’ve seen that video before! I believe the car in that video is a G35S though, which means the exhaust should have bolted up no problem, as the only limiting factors keeping 07-08 AWD Gs from having a bolt-on MD is the transfer case length.

With respect to drone, our 5 speeds spend less time hunting for gears and don’t suffer as badly from the ****ed up gear-ratios that the 7 AT folks have to deal with. I think drone is typically a by-product of being in a bad spot in an rpm range where the engine load is perhaps higher than it should be when consistent. When in 5th gear and cruising between 60-70 mph I’m rarely over 3k, and am generally in part of the rpm band that is kind of tame. I suspect if I do encounter a different world of drone than 7 AT folks, it would probably be in lower rpms and city driving, since the 5 AT doesn’t try to get to final gear with as much haste as the 7, and has 2 less potential rpm bands to deal with there.

As far as I know the TDX is discontinued and has formally been replaced by the Shockwave and would almost identically mimic my E370 that has been sitting around for weeks.

 

Yeah it rips. Berks are coming off the car and getting shipped out Saturday. Yep, happy to get rid of em.

 

Sky is correct, its outrageous. It makes me very happy but Im looking forward to getting rid of the Berks and have the stock cats back on there. That sound with stock cats is sexier and more refined in my opinion.

 

Update: Interestingly, the sound of the exhaust has changed over the course of a couple of weeks. I don't know what about a muffler "breaks in" but there has definitely been a progressive change. The nasal, trumpety tone has reduced quite a bit and become less annoying. In fact, when just revving the engine I sort of like how it sounds. There are pops as the rpms settle back down to idle, and I dig that. It's just under load that I still think it's not a great sound. I'm fully aware that there may be some mental adaptation afoot here, but I also feel like I got my power back and then some. I did reset the ECU right after the installation and I thought it would adjust pretty quickly so I don't know what gives.

I do think it's gotten reasonable enough that I'm not going to tear it off and go back to stock, and I don't really want to waste this money AND spend another $1500 to go a completely different direction. Maybe I'll take a look at that resonated XYZ pipe after all. Can anybody tell me if it will fit AWD?

I'm also going to see about addressing some of the in-cabin noise with dynamat (or equivalent) rather than a different exhaust.

I love the sound I'm hearing from these motordyne exhausts. If only that tone could be had at half the volume level, lol.

 

So what you are experiencing is quite normal with exhausts. Many exhausts have a "break-in" period where some packing/baffling materials/glues burn off as well as the fact that the inside of the mufflers become coated with carbon deposits over time. As a direct result of this, they will usually become more tame or consistent.

I can tell you right now that as of today MD does not make an XYZ pipe for the AWD sedan or coupe.

What in-cabin noise are you trying to get rid of with the dynamat? drone?

 

Yes, drone. It's a little higher pitch than I frequently hear with droning exhaust, but it's just loud enough to be annoying. As usual, it's because I have a 7AT and it's resistant to downshifting when I'm doing anything other than really jamming on the throttle. It's not that terrible as drone goes, but it's annoying enough to seek a solution. It's not like it's pleasant exhaust roar, and it's loud enough that it seems like I have louder exhaust in the car than outside it. It's loud enough that I can no longer hear intake noise even with the windows all rolled up.

I'm pretty certain that the overall volume is louder than typical for the Topspeed because of my RHFC's, and I'm guessing it's amplified the undesirable characteristics as well. I don't have a great place or way to take a video for reference, but if a resonated y-pipe would calm things down a little, that might move me into the just-right range. Bummer about the MD, but theirs is a pretty darn expensive y-pipe anyway. I'll have to look around and see if anything is out there. It's improved a ton, though.

 

I decided last minute not to sell my Berk HFCs. They have mellowed out dramatically since breaking in more and the glaring negatives which I complained about before are greatly diminished to non existent.

 

So no more rasp or drone? You should hook us up with another vid when you get the chance.

 

Well that went total opposite of what I thought you were going to do. Glad you got up keep your initial investment with the Berks instead of having to sell them.

Do you think the tone mellowed out because the Berks broke in or you maybe got used to the sounds in which you didn't like at first and you've grown to tolerate them. Regardless, I feel like your exhaust is now sounding like mine as I seem to get minimal rasp and drone is only there depending on what RPMs your cruising at

 

From my experience the cars equipped with the 5AT tends to have more drone on the freeway than the 7AT and MT cars. Especially when cruising around 75 or 80 mph, which puts me around 3200 RPM's in 5th gear. If I can keep the RPM's below 3K then there's considerably less drone. My car is a 5AT and out of the 5 different exhaust set-ups I've had on the car the only one that I haven't experienced annoying freeway drone with is my current set-up, which still utilizes the OEM resonator assembly.

 

The drone which was present from around 1200-2000 Rpm has gone from a 10 to a 2. It’s so minimal now I barely notice it. Raspiness has also been reduced to to about the same level. I will!

 

The tone has mellowed because the Berks broke in. I got more used to it but that’s mostly because they broke in and it’s so much nicer to drive in all ways now due to the major mellowing of the negative tonal characteristics. My friend thinks it sounds like an old Ferrari when he drives in it and the other friend who owns an E46 acted like I was an idiot for wanting to sell the cats after he heard them. I’m quite pleased with everything about the car now. The cars feels properly sporty and sounds way more exotic and faster than what it actually is. Just waiting on these Admin Tuning intakes to ship then its professional dyno tune time, hoping to put down 300 to the wheels. The thing is the car still feels so much faster to me then what it did before the cat back so I’m still really enjoying that. I have been driving the car so much harder and like a rambunctiousness teen ever since the exhaust was installed. I need to calm down.

 

I’m glad you had a change of heart Jake! Last night I finally picked up the car from the shop. So, two missed days of work, 4 separate 20 mile uber rides of 30+ min each and months of waiting and I finally have my Motordyne catback on. Throughout this process the only thing that’s really remained consistent is RCA’s dedication to making this work. Without them I most likely would have just kept my stock exhaust due to the circus MD decided to put us through. If you’re in the Midwest region, def hit them up.

Now to the exhaust! My my first impressions are...meh.

Build Quality: 5/10 considering they sent me the wrong y-pipe, twice. They also only sent me only 4 out of 6 titanium screws needed to secure the exhaust tips. The laser etched “Motordyne” logo looks very different on my set than other exhausts I’ve seen, I’m not a fan. Other than that, the build quality is fine, pipes are pipes, and the weld quality is consistent with others I’ve seen.

Sound: I honestly can’t tell. It is absolutely louder than my Tanabes and that’s a good thing. It has a really nice burble at idle. From inside the car I can’t really hear the “banshee” screams I was expecting, and was expecting to hear more pops + cracks like I had seen in many YouTube videos. To me it just sounds like a subdued Wookie, and I have yet to hear any of the “screams” you all speak of, even after many tunnel pulls and underpass runs. Maybe I need more seat time with it, and a chance to hear revs from outside the car. I was expecting to have a genuine “holy ****” moment and that just didn’t happen. At this current point in time, I feel like I should have just gone with Ark.

I’ll upload some pictures and some videos here in a bit. Also discovered an exhaust leak after the center resonator.

 

Well s**t... That's a first ..i'm looking forward to the vids and pics.