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2 Posts
Hi everyone! I made a DIY video on how to replace the downpipes on an M5/M6 S63TU in case someone wants to tackle the project themselves. Feel free to share.

4 Posts
Hey all,

I just finished producing my newest video of my F10 M5.

F10 M5 RPi GTM Exhaust with Custom Fully Catless Downpipes. LOUDEST F10 M5 in the world! - YouTube

The catless downpipes combined with the RPi GTM (Muffler Deleted) exhaust system has now made my F10 M5 the first in the world to be 100% Fully Straightpiped. We're talkin NO cats, NO resonators, and NO mufflers whatsoever. What you will hear in this video is pure unadulterated engine and turbo sound from the S63tu platform. The catless downpipes have utterly changed the entire character of the F10 M5 and it's incredible. I would like to reiterate for a moment that I used to own a Full RPi Stage 2 E60 M5 (also straightpiped) and the straightpiped F10 M5 is as good and better than the note of the straightpiped V10 in the E60. The performance gains from the straightpiped F10 M5 don't even compare to the straightpiped E60 M5, the F10 M5 completely blows the E60 away in the performance gain department. As you will see I have made huge power and torque gains. I have about 1000 miles on the M5 with the new downpipes already and I can honestly honestly say that I don't think I will EVER go back to get another V10 just for the F1 exhaust note that I miss.

Also just for some comparisons, I did an exhaust off 2 weekends ago with my friends fully straightpiped Lamborghini Gallardo Superleggera (still to this day the absolute loudest car I have ever heard) and my F10 M5 was only slightly quieter than his Superleggera. If his Lambo was on a scale of 1-10, an resounding 10, then mine was easily a 9.5. It's that LOUD! My F10 M5 was even louder than the IND F10 M5, which also has fully catless downpipes from AMS, and a full Eisenmann Race Exhaust on it. The IND F10 M5 was also very loud, but the note was a lot cleaner and a lot more refined but had no burble in it like my exhaust does or a V10 does.

A while ago I made an exhaust loudness comparison thread. It now needs to be updated. Here's the new list:

1: F10 M5 Stock Exhaust (Although the crack from the stock exhaust is louder than most other aftermarket exhausts, I think it may be because the stock mufflers are actually smaller than a lot aftermarket ones)
2: RPi GTS Exhaust / Akropovic Exhaust
3: F10 M5 Eisenmann Sport (Mufflers Only)
4: F10 M5 RPi GT Exhaust / F10 M5 Supersprint Exhaust (Mufflers Only)
5: F10 M5 Eisenmann Race Exhaust (Mufflers Only)
6: F10 M5 Meisterschaft GT Exhaust
7: F10 M5 RPi GTM Exhaust (The Cracks from the exhaust will actually hurt your eardrums though) / E60 M5 RPi GTS Exhaust
8: E60 M5 RPi GT Exhaust / E60 M5 Eisenmann Race Exhaust / E92 M3 RPi GTM Exhaust.
9: E60 M5 RPi Stage 2 with Full GT Headers and GT Exhaust / Almost any E60 with Headers and Exhaust / Straightpiped Merc C63 / Straightpiped Aston DBS / Straightpiped Lexus ISF / F10 M5 with AMS Catless Downpipes and Full Eisenmann Race Exhaust
F10 M5 with Catless Downpipes and RPi GTM Exhaust
Straightpiped Lamborghini Gallardo Superleggera / Straightpiped Porsche Carrera GT / Straightpiped Lambo Aventador

Now you might be wondering where did I get my catless downpipes from. I basically wanted to try some catless downpipes that a custom shop in LA makes called Motiv Concepts since the RPi GT Catless Downpipes are still in development, I figured I'd give these a try. Notice the pipes have no kinks in them, instead they are a smooth flowing design. I had my downpipes ceramic coated with black coating as well. In case you are wondering, Motiv Concepts does not have these downpipes in production. They are a special order set, so you will have to call them yourself if you want them made also. I don't know how much they will charge you either, so you will just have to call them and find out.

Also notice the stock downpipes and how clunky and sloppy they look.

Installation was pretty easy, only took about 2 1/2 hours, but this was only because they did another F10 M5 before mine once, and they had experience on what to do.

The 1st dyno chart pictured below shows the BLUE line and the RED line. The BLUE line is my baseline that I did with ONLY my GTM exhaust and Charcoal Filter Delete. The RED line is with the Catless Downpipes. Notice the gains pretty much all over the rev band and the huge gains in the mid-range. Looks like about 50hp and 50tq to the wheel in the mid-range! On run 16 I actually made 554whp though, which was my highest peak hp of the day. You can feel it too.

The 2nd dyno chart pictured below is my (RED) Catless Downpipe dyno compared to another customer's (who was at EAS that day) C63 AMG with a COBB tune (BLUE). You can see how my power and torque band just murders the C63 AMG's all day and all night, even with his tune.
are you in San Diego? I see the Mr. Ticket sticker haha he saved my *** a few times!

5 Posts
I doubt it's a case of people not trusting your experience, and more so of people just not sharing the same taste. The power is great, the noise is ridiculous. I'm all for having great sounding cars, but this thing is unbelievably loud, to the point of being overly obnoxious. It works for you and some others, but not for everyone.

Greatly admire your continual modding of your car though :) gotta love the passion behind trying to get more and more out of it. Keep it up Dave, I'd love to hear this thing in person since we're both in San Diego. Shoot me a PM if you plan on attending any local car events soon.
Hey I was wondering when you installed down pipes did your engine malfunction and misfire . And what can I do to get my baby back lol.
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