BMW X3
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02-18-2026LAST POST
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02-15-2026
akakrill user avatar
akakrill
New Member
5 REP
12 POSTS
Appreciate the advice, It's exactly what im looking for. I have a heavily modified Xrunner with supercharger and built motor. It just can never be on the level of these things. I dont want to go down another 7 exhausts and try to replace pipes and mufflers to keep sound and rid of rasp and drone.

I'll look into BM3, Paul's tunes, and a valve controller. My roads are shit also in the winter.. KWv3, a trunk sub, and a tune is about all I'm looking to do. I wouldn't mind hearing the turbos whine a little which was the only reason I had considered swapping out the downpipes
Appreciate1
02-15-2026
aldksgo user avatar
aldksgo
Private First Class
Canada
64 REP
131 POSTS
You guys think it’s worth custom without any mods over just OTS stage 1?
Appreciate0
02-17-2026
who is this noob user avatar
who is this noob
who is this noob
381 REP
479 POSTS
aldksgo wrote  
You guys think it’s worth custom without any mods over just OTS stage 1?
Yes. Absolutely.
Appreciate1
02-17-2026
Jnat user avatar
Jnat
DisplacementReplacement
1,837 REP
2K POSTS
Kevin_The_Clean1 wrote
Exactly & I couldn't agree with this more. The factory mid-pipe flows extremely well. FUNNY BUT TRUE FACT, if you get an exhaust valve controller (I REALLY LIKE THE new / quick to sell out 11-Mode unit) you'll get lots more sound & volume from the factory Comp muffler. Trust me when I say this, I've bough the most expensive mid-pipe ever made & modified another one numerous times. And guess what, for $199 you can leave everything in place & can spend that money elsewhere. We've also flow tested the factory mid-pipe on the front lawn with a high CFM leaf blower & guess again, there was no restriction in overall air flow. Don't waste your money on a mid-pipe like many of us did. It's a lot of money for a small amount of additional sound. Learn from our small mistakes & have fun with this vehicle.
I usually agree with you Kevin but on this one i half agree. I have a 2020 Non Comp (because that's what i could find in my color choice loaded at the time and i knew i was gonna tune/mod it so i didn't care) so i have the non comp muffler. I also have the ER mid non resonated with the factory non comp muffler and i have the valves coded open all the time with my tuner, it sounds terrific and i get compliments all the time at car shows/events on how my truck sounds. I think the mid pipe makes a nice difference to either the non comp or the comp muffler, i guess it's subjective and to one's taste... good luck with decision. I digress, the factory downpipes flow fine and i'm flex tuned with the stock pipes with no issues and pass emissions with no smell, incredible set up incredible vehicle.
Appreciate3
02-17-2026
aldksgo user avatar
aldksgo
Private First Class
Canada
64 REP
131 POSTS
who is this noob wrote
Yes. Absolutely.
Will probably look into it eventually. Don't wanna hijack Brock's thread though lol. I wonder if someones compared the OTS stage 1 to a custom one and what the delta was
Appreciate1
02-17-2026
Boogynights822 user avatar
Boogynights822
Private First Class
160 REP
183 POSTS
Racebox did this and the peak gains higher, but the mid-range from a custom tune was where the major gains came from. Screen shot from video shown.

BMW M2
Stock 479whp/451wtq
MHD OTS 93 stage 2 572whp/537wtq
Racebox custom 93 604whp/586wtq
An image attached to this post, provided by the poster
Appreciate2
02-18-2026
who is this noob user avatar
who is this noob
who is this noob
381 REP
479 POSTS
aldksgo wrote  
Don't wanna hijack Brock's thread though lol.
Yeah, feel free to start a separate thread about your build. :cool!:

That way you have everything in one place to guide your path forward. :thumsup:
Appreciate3