Which exhaust for 103 with Stage 4 RACE kit?
 

I have a 2014 Breakout with the Stage 4 Race (not street legal) kit. That kit uses the 259 cam set with Harley's own dyno charts showing that peak torque is intended to be at 4000 rpm with those cams, and peak power basically at the 6200 rev limit. The duration on these cams is something like 240 / 250, with LOTS of overlap. The kit also includes CNC Factory heads, 10.5 pistons and 58mm throttle body. I've opened the exhaust via the Harley Extreme Billet air cleaner setup.

I had the dealer install a D&D Low Cat (same as Fat Cat except tilted up at rear for better ground clearance), but that exhaust seems to be fighting the cams instead of working with them. That Low Cat system appears to work really well on the STOCK 103 (which operates at lower rpm), but really badly on my Stage 4 kitted 103 (higher rpm).

Clearly, the "best" exhaust for this setup is one that will work with the cams, 58 mm intake, and CNC heads to emphasize high rpm power.

I don't want to run true duals because then I really take a hit on low rpm torque, unless I can find a duals system that has an interconnection between the two pipes ("Power Chamber" in V&H speak).

On my last bike, a Honda VTX 1800R, I had a set of V&H staggered duals which did have the power chamber, and they worked GREATm giving me really good top end and also much stronger low rpm torque than the true dual system they replaced. But, V&H literally has NO system I could find on their website, that either has a power chamber or is a 2 into 1 system instead, that will fit the Breakout. Only true duals for the Breakout.

I did see that Bassani offers long megaphone and short megaphone versions of their "Road Rage" systems, but have seen no technical evaluation of those anywhere, nor any actual dyno charts at all, let alone dyno charts for a Stage 4 kitted 103.

I need some help, from 2 kinds of forum members:

1. Breakout 103 (not 110 CVO ) owners, with a Stage 4 kit, who have gotten good results with an exhaust system: what system worked for you, and what kind of hp and torque did you get, and oat what rpm?

2. Engine builders and exhaust gurus: what exhaust dimensions/features I should be looking for for my setup?

I've already made a $750 error on a system that works well for stock 103s but not well for the kitted 103, and I really don't want to make another error.

Despite the local Harley dealer being overall a great job, with good technicians, those technicians are of no help on this. They just don't know other than by trial and error what will work.

Jim G

Surprised that the low cat wont do the job, Sell it and call rb racing and ask them about their lsr-1 for a breakout with your mods. Ive got a bobcat by d and d on my breakout but no internal mods yet. I am using the powervision 2 , and its running great.Pm me if the lowcat goes on the market

What makes you think the d&d is hurting the performance? Has the bike been dyno tuned or just running a canned map? Just curious mostly, I did notice the lowcat doesn't have the baffle options that the fatcat does. I know they recommend the perforated baffle for most built motors, could be the louvered baffle is holding you back. Super trap 2-1 systems offer a lot of versatility for tuning the pipe to your bike, not sure if they have one for breakouts though.

D&D is one of, if not the best exhaust systems on the market. It may be the 58mm TB that's giving you fits on the numbers and performance you're expecting. It can be a bitch to tune correctly.

I am preparing a detailed set of charts and data to post. I didn't want to post details until I first got some feedback because I don't want to "jump to the conclusion" that the exhaust is the problem, even though the dealership head dyno tech has asserted that. For reasons you'll see later, I don't necessarily accept his assertion, but he COULD be right. There is some VE table evidence that could lend credibility to his assertion. So, I don't feel I should malign him, at least not yet.

Jim G

The interesting thing is that the tune feels remarkably sharp. The low rpm seat of the pants feel for example is very much better than the dyno data would suggest, and the engine response when blipping the throttle to synchronize on downshifts is razor sharp. The tune was in fact done by the man acknowledged to be the sharpest technician in the dealership with really detailed and patient work practices, but not at all an engine power curve analyst by any means.

Jim G

Which exhaust
 

this maybe a dead thread but i got a 103 breakout with stage 4 race kit and V&h 2-1 big rad with modified baffle ( 1/2" hole drilled thru baffle end cap)
is there a better exhaust ?

111.24HP@6000
112.76TQ@4000


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