[Info@mad-us.com]

Presenting the all-new MAD F90 M5 FATBOY Primary Downpipes – our most expansive offering to date! Crafted for unrivaled performance, these cutting-edge downpipes are meticulously engineered with a singular objective: to accommodate the most substantial piping diameter achievable between the flanges. Objective successfully achieved!

Crafted from premium-quality T304 stainless steel, these downpipes are built to last. They are mandrel-bent for maximum flow and feature smooth, non-restrictive transitions that minimize turbulence and improve exhaust gas flow. The result is a noticeable increase in power and torque, along with a more aggressive exhaust note that will turn heads on the street and at the track.

Installation is easy and straightforward, with no cutting or welding required. The MAD F90 M5 Primary Downpipes are designed to bolt directly onto your BMW F90 M5's factory exhaust system, and they come complete with all necessary hardware and gaskets for a hassle-free installation.

So if you're looking to take your BMW F90 M5 to the next level, the MAD F90 M5 Primary Downpipes are the perfect upgrade. Don't settle for a stock exhaust system – unleash the full potential of your engine with these high-performance downpipes.

Coming Soon!

[EM5C]

Difference between these and the ones you offer already? Cost? Looks pretty great!

[Info@mad-us.com]

Originally Posted by EM5C

Difference between these and the ones you offer already? Cost? Looks pretty great!

The major difference is the piping diameter from flange to flange. Our fatboy does not taper.

[EM5C]

If you need a test subject I am more than happy to volunteer! 😆

[Info@mad-us.com]

Originally Posted by EM5C

If you need a test subject I am more than happy to volunteer! 😆

Appreciate it! These have been in testing for the last 3 months

[pbonsalb]

I like it. Used to be that Keller was the only option for a 3.5” primary. Have not seen any 3.5” secondaries, but maybe the downpipe does not need to stay that big for a tiny GT22 turbo. I have a full 3.5” exhaust on my turbo E36 M3 that runs an EFR9180.

[Info@mad-us.com]

Originally Posted by pbonsalb

I like it. Used to be that Keller was the only option for a 3.5” primary. Have not seen any 3.5” secondaries, but maybe the downpipe does not need to stay that big for a tiny GT22 turbo. I have a full 3.5” exhaust on my turbo E36 M3 that runs an EFR9180.

Appreciate it! Our non fatboy version works great but for big power guys who want as large as possible this will be a great option and our pricing will be Well... MAD .

[Info@mad-us.com]

Fat Boy's start shipping next week

[Info@mad-us.com]

Now live on the site

[mike@x-ph.com]

[warpeacelove]

How much additional power gain are these from your standard downpipe?

[Info@mad-us.com]

Originally Posted by warpeacelove

How much additional power gain are these from your standard downpipe?

That would totally depend power you are making. If stock it would be marginal maybe a little better throttle response.

[warpeacelove]

Originally Posted by Info@mad-us.com

That would totally depend power you are making. If stock it would be marginal maybe a little better throttle response.

Indeed, I am tuned. Therefore, I'm asking what is the difference between the two primary downpipes in your catalog?

[Info@mad-us.com]

Originally Posted by warpeacelove

Indeed, I am tuned. Therefore, I'm asking what is the difference between the two primary downpipes in your catalog?

Unfortunately, we do not have any data to backup any claims between our regular catless and fatboy version however in theory larger piping should reduce back pressure resulting in faster spool times and more horsepower when enough exhaust pressure is applied.

At this point we are pushing the boundaries within the constraints of the stock turbo flange sizes we have available. If you're an enthusiast who values pushing those limits, the Fat boy is the right choice for you. However, if you're looking for a more budget-friendly option, our alternative might be the better fit.

[CrashCade]

Anyone interested in a great deal on the original style to help me justify upgrading to these?

Any MAD holiday sales coming up?

[Info@mad-us.com]

Originally Posted by CrashCade

Anyone interested in a great deal on the original style to help me justify upgrading to these?

Any MAD holiday sales coming up?

Black friday but that is still a little ways out.

[E92TTKING]

How much bigger are these than the original? 3.5"? Original 3"?

[pbonsalb]

The taper from 3.5 to 3.0 is much more gradual.

[Info@mad-us.com]

Originally Posted by E92TTKING

How much bigger are these than the original? 3.5"? Original 3"?

Yes, correct!