Hi there!

I don't post often here but I read a lot.

I'm Mr. Mechano from Italy and owner of HDForums Italia http://HDForums.it

I project exhaust systems for racing cars and baffles or exhaust mods for Harley bikes.

Here my last job on my 2014 Low Rider 103.

The stock headers have been decatalized adding 2 straight pipes that connect into a small chamber.

You know decatalizing an exhaust leaving empty room is bad, exhaust gas loose speed and you have poor performance.

The outlet pipe was 45 mm (1 3/4"), here we have 54 mm (2 1/8") but you can go for 60 mm (2 3/8") for more hi-end performance.

The outlet pipe has been made oval in the first inch for better canalize the flows of both headers.

The rest of the pipe is of this diameter.

Into the muffler there's a wall for backpressure and holes (or it's better to define them windows) before and after the wall have been calculated for good flowing of a 2 1/8" pipe and the 103 ci engine.

We use italian software for this calculations used by Ferrari engineers for their job. And sometimes where software is not sufficient we calculate manually with flowing theory...

For sound we use fiber of stainless steel. It mellows the sound.

Sound is awesame in Italy we care a lot about cosmetic of sound, modulable not obnoxious at low rpms and strong and powerfull at high revs. Lot of down frequencies and poor high pitch.

We have also put the 12mm O2 sensors into 12-18 mm adapters, so it's possible to mount 18 mm wide band sensors for Daytona Twin Scan diagnostics or Daytona TCFI 5 or Thundermax closed loop 18mm wide band LSU 4.2 application.
With this mod the exhaust can be mounted olso on pre-2012 Dynas.

Same job we do with the stock Tommy Gun of Fat Bob, Wide Glide and Low Rider S. And with the 2010-up touring, but maintaining a 2 into 2 configuration.

Here a video, and 2 pictures.


12mm O2 sensors using 12/18 mm adapter:




Trasformation of the catalyzer onto a 2-1 exhaust:



Final result. The muffler is not the stock but an MCJ italian brand of crap. Looks nice rides like ****. That's why it has been modified inside.

 

I "outlawed" my head pipe and didn't notice any performance difference, just louder and cooler.

The biggest difference you can find is ditching that stock "high flow" air cleaner. I went with Arlen Ness Stage 1 and even without adjusting my power commander map, I noticed a huge difference. Maybe it is a combo of slip on, outlaw head pipe and now stage 1 intake.

 

If you could make my FXDL sound like a Ferrari FF, I'd be interested...

 

There's a Screamin Eagle air filter kit under the cover.

I'll tell you about performance after I'll map the ECU with tuning aids.

 

If you are just curious look at http://lamarmitta.it

 

Wrong engine for the job. Suggest targeting a late 60s Chevy L88 or ZL1

 

Like I wrote this is a completely different job, not only outlaw removing catalyzer.

I tuned using Daytona Twin Scan III and Technoresearch Direct Link (similar to Super Tuner and other systems for remapping stock ECU).

Awesome performance!
I've a VE table for rear cylinder plenty of 90-110 numbers in the middle side. It means the flow of this cylinder is perfect. Thanks to the larger diameter of the pipe after 2-1 join.

The front cylinder ha 5-8 point less, it suffers a bit the not centerd inlet into the bigger pipe on the 2-1 of this exhaust.

The engine revs very fast to 4500 rpm and it quickly dies. I think I'll need more aggressive cams.

Plenty of low and mid range torque, thanks to the muffler's baffle design with a wall in the middle and large passages for exhaust gases.
Design is similar to a stock Harley muffler but everythinfg is a lot larger...

 

I am over in Pordenone. Not that far from Verona. I am looking for an exhaust for my 16 Streetbob that sounds good but won't upset my neighbors. I may ride over your way to take a look...

 

We do this job to the stock mufflers. So you can retain the DOT numbers and don't risk big tickets.

http://www.lamarmitta.it/harley-davi...na-street-bob/

The sound is modulable, civil at small throttle open, and thundering for wide open. Pair it with a good air filter.

You can ship your mufflers to Pietro and get reworked.

And if you come to Verona I can remap using Daytona tuning aids.