[wassy4]

Hey all,

Finally was able to install the Fabspeed muffler bypass on my 2018 LCI. I've been running a VRSF catless downpipe for a few months now and it sounded great with the stock exhaust, but I found myself wanting a bit more. I was originally looking at valved catbacks such as Dinan, Active Autowerke, etc. but couldn't justify dropping more than $2k on an exhaust. This entire system was a bit over $600 including install (bought the Fabspeed used, retails for ~$1200). I got exactly what I paid for.

Install was very fast and took ~40 minutes, most of which was spent getting the pipe to hang correctly and adjusting the tips. The tips tend to hang low and are slightly offset. Also, for anyone curious, the tip size is 3.5". I'd personally like them to be a bit bigger.

I went into this expecting this setup to be extremely obnoxious. After all, this is basically a full straight pipe except for the stock resonator. The first start up after install proved me wrong and absolved me of my worries of how loud this system would be. Cold starts are very loud, as usual with aftermarket systems, but afterwards the overall volume level is perfect. What's weird is that the car seems to sound louder driving around than at WOT. I must have a high tolerance for loud, as I'm actually a little underwhelmed by it.

The actual sound is much deeper than stock at low RPMs and I feel this contributes to the issues I'm having which I'll talk about later on. At high RPMs the note really comes out and it's amazing. Burbles were increased tenfold with just the downpipe. They are now much more intense, especially in traction mode. I will say the car sounds way better on the outside than on the inside.

Here's where the first, but minor, issue comes in: there's an RPM range around 3000 where the cabin is penetrated by a very trumpet-y, boomy tone that really gets in your ear. I'm aware that this is a common thing with most catless exhausts and this also happened on my last bimmer, so I can't really fault the muffler bypass. Doesn't bother me too much, just something to be noted for anyone interested in this setup.

Still working on solving this one, and I hope there's a fix, but my major issue with this setup is that there is an intense, continuous rattle throughout the interior caused by (what I assume is) the frequency/drone of the exhaust at high gear/low RPMs. It's especially noticeable with the windows up, radio off, and just holding the throttle to maintain speed. However, I just recently took the car for a drive and it was nowhere near as bad this time around. My friend with similar setup but with a catted downpipe said he does not experience this.

All told, for the price I'm pretty happy. I would've preferred a proper turbo-back to save some headache but the car sounds great now bar the aforementioned issues. I'll be posting some videos soon, hopefully by this weekend!

[wassy4]

Video is up, can be found here:

Love the sound and, as always, the video doesn't capture the true sound, especially the overrun. This is a very tolerable setup for a daily volume- and drone-wise, however I'm still experiencing intense rattles coinciding with low RPM resonance/vibration. This has been slowly wearing me down as it makes the interior feel cheap and driving unbearable without windows down or music blasting. Will most likely end up buying a proper catback in the near future to remedy the issue.

[GerardzM]

I wonder if purchsing a catless downpipe with brackets would aid in minimising that resonance you experience?

[wassy4]

Originally Posted by GerardzM

I wonder if purchsing a catless downpipe with brackets would aid in minimising that resonance you experience?

It could be the case but I'm not 100% sure it will fix it. I know for sure that going back to a muffled system will but it's 4-5x the price. I'd rather not dish out for another downpipe just for it not to work

[Perk_1405]

It sounds awesome, I should be installing my DP on Friday.

[mike@x-ph.com]

Congrats OP

[wassy4]

Originally Posted by mike@x-ph.com

Congrats OP

Thanks Mike! Would you be able to chime in on whether swapping out the downpipe for one with brackets would help reduce/eliminate rattles/vibration?

[mike@x-ph.com]

Originally Posted by wassy4

Thanks Mike! Would you be able to chime in on whether swapping out the downpipe for one with brackets would help reduce/eliminate rattles/vibration?

I honestly cant tell without checking the downpipe install and seeing how tight its sealed.

I would also recommend you get a catted downpipe but it does not sound like its a good option for you since you are looking for more sound

[cecaa850]

Originally Posted by wassy4

Thanks Mike! Would you be able to chime in on whether swapping out the downpipe for one with brackets would help reduce/eliminate rattles/vibration?

The downpipe is manufactured without a bracket??? The exhaust is meant to be supported there.

[VisualEcho]

Originally Posted by mike@x-ph.com

I would also recommend you get a catted downpipe but it does not sound like its a good option for you since you are looking for more sound

If the catted down-pipe flows 93% as much as catless, is the sound not 93% as loud?

[wassy4]

Originally Posted by cecaa850

The downpipe is manufactured without a bracket??? The exhaust is meant to be supported there.

Yes, but I've used this brand of downpipe (which is very popular) on two cars now with no issues. Stock exhaust had no problems either but I think the combination of no muffler + no cats causes a ton of resonance/vibration.

[wassy4]

Originally Posted by VisualEcho

If the catted down-pipe flows 93% as much as catless, is the sound not 93% as loud?

It's noticeably quieter in person but still sounds good. I'd rather not spend three times the price for a catted downpipe. The only benefit it has is no CEL on stock tune.

[mike@x-ph.com]

Originally Posted by VisualEcho

If the catted down-pipe flows 93% as much as catless, is the sound not 93% as loud?

Its actually a lot quieter than catless