Enhance Performance & Sound: Yamaha R1 & R1M Exhaust Upgrade

Enhance Performance & Sound: Yamaha R1 & R1M Exhaust Upgrade

Yamaha completely reinvented the superbike category upon unveiling their revolutionary YZF-R1 in 1998, then repeated themselves again with the even more advanced R1M variant in 2015. Central to the performance and emotional draw of these machines is the unique exhaust note pumping from their crossplane crankshaft engines. An aftermarket exhaust allows you to customize this soundtrack while releasing meaningful power gains.

In this comprehensive R1/R1M exhaust guide, we’ll investigate OEM and aftermarket offerings ranging from slip-ons to full race systems. You’ll learn what each component does, view hard performance data, weigh cost considerations, and gain professional advice on optimization. Let‘s dig in!

Stock Exhaust System Explained

Before modifying your bike’s emissions pathway, you should first understand what you’re working with from the factory. Here we’ll compare details between the standard R1 and up-spec R1M:

Assembly Layout
As mentioned, Yamaha employs a somewhat unique 3-piece exhaust system:

1. Header Pipes
   Include catalytic converter internals on road-going models to reduce harmful emissions. Bolts to cylinder head.

2. Pre-Chamber / Mid Pipe
   Routes converged exhaust gases rearwards from header collector towards muffler inlet. Often contains servo motor that actuates a control valve for low RPM sound reduction. Key restriction point.

3. Muffler / Slip-On Silencer
   Shapes exhaust pulses into preferred frequencies while limiting overall volume through absorbing materials. Styled to reflect brand image.

Doing away with a traditional 4-1 collector layout, Yamaha instead pairs two header pipes from each bank of cylinders into a separate pre-chamber, effectively making a 2-1-2 system. Why does this matter?

On the one hand, this divided design better handles the engine’s uneven 270-degree crankshaft firing, promoting pulse scavenging. But it also necessitates ultra-precise valve timing for optimal low-midrange output. Aftermarket options with merged 4-1 geometry gain top end power yet disrupt lower RPM torque.

Stock Header & Mid Pipe Materials

R1

• Stainless Steel Headers
• Stainless Steel Mid Pipe
• Carbon Fiber Muffler

R1M

• Titanium Headers
• Titanium Mid Pipe
• Identical Carbon Muffler

So while sharing a common silhouette and internals, the R1M benefits from lightweight titanium used throughout the system’s first two stages. Reduced mass equals quicker revving, especially important when direction changing on track. Exact weight difference:

• Stock R1 System: 38 lbs
• Stock R1M System: 31 lbs

That’s over 7 lbs of excess bulk removed off the higher R1M trim, amounting to significant heft when considering the bike’s total mass. While titanium also allows thinner pipe walls for slightly improved flow, the restrictive midpoint remains. Read on.

Why Upgrade?
If Yamaha’s engineers expend such effort perfecting the R1 family’s exhaust, why change anything? Two words – restrictions and sound. First let‘s quantify stock performance:

2015-2021 Yamaha R1 Horsepower Ratings

• Stock Peak HP: 177 bhp @ 11,500 RPM
• Stock Torque Rating: 82.6 ft-lbs of torque @ 9,000 RPM

2015-2021 Yamaha R1M Horsepower Ratings

• Stock Peak HP: 200 bhp @ 13,500 RPM
• Stock Torque Rating: 83 ft-lbs of torque @ 11,500 RPM

Factor in real world losses from muffler packing materials and catalytic converters, both engines leave plenty of unrealized potential. And even if maximum output exceeded your needs, altering the exhaust system‘s resonance dramatically impacts the rider experience via enriched soundtrack. Let‘s weigh some aftermarket offerings.

Mid Pipe Considerations
As previously outlined, the R1 exhaust system’s mid pipe section plays a major role in airflow restriction thanks to its convoluted passages. Effectively a bottleneck between upstream and downstream stages, mid pipe upgrades provide substantial gains. Here we revisit leading options:

Arrow Street Legal Slip-On Compatible Midpipe

• Horsepower Gain: +12 RWHP / +15 BHP
• Weight Reduction: -2.6 lbs
• Sound (1-10): +2 over stock

SC Project CRT-R1-X Midpipe

• Horsepower Gain: +7 RWHP / +10 BHP
• Weight Reduction: – 2.1 lbs
• Sound (1-10): +3 over stock

AC Covich GP Mid Pipe (Street Oriented)

• Horsepower Gain:+10 RWHP / +13 BHP
• Weight Reduction: -1.9 lbs
• Sound (1-10): +2 over stock

AC Covich Track Day Mid Pipe (Race Oriented)

• Horsepower Gain: +10 RWHP / +13 BHP
• Weight Reduction: -2.5 lbs
• Sound (1-10): +1 over stock

With street legality concerns, Arrow‘s Midpipe strikes an ideal balance of added horsepower and moderate sound increase for daily riding. The SC Project and AC Covich pieces trade a bit of extra noise for circuit use in exchange for comparable power bumps around 10 bhp. Weight drops up to 2.6 lbs. As you‘ll notice, the modifications making the most power focus on mid pipe de-restriction.

Moving rearward, let‘s examine slip-on considerations.

Slip-On Mufflers
While mid pipe swaps require more labor, slip-on mufflers allow easy customization of styling and sound. They bolt to the stock mid pipe using a sleeve adapter. Here are top options:

Arrow Slip-On Silencer

• Peak Horsepower Gain: +1/+2 BHP
• Weight Reduction: -1.8 lbs
• Sound (1-10): +3 over stock

Akrapovic Slip-On Muffler

• Peak Horsepower Gain: +0/+1 BHP
• Weight Reduction: -3.1 lbs
• Sound (1-10): +4 over stock

SC Project S1-R Slip-On

• Peak Horsepower Gain: +0 BHP
• Weight Reduction: -2.3 lbs
• Sound (1-10): +6 over stock

While power increases are negligible, most riders upgrade slip-ons for aesthetic and acoustic reasons. Among brands, Akrapovic stands out providing aggressive styling and an intoxicating soundtrack in one tail-end package. See this R1 with a Titanium Akra slip bolted on:

[PICTURE OF YAMAHA R1 WITH AKRAPOVIC SLIP-ON MUFFLER]

Notice the high-swept silhouette amplifying visual mass over the rear wheel. Expect envious glances when rolling up at bike meets! If drawing such attention (and law enforcement scrutiny) seems undesirable, consider AC Covich‘s low-key alternatives again:

AC Covich GP Slip-On
[PICTURE] Retains a stock appearance while adding feisty wail at higher RPMs. Perfect for the sleeper street machine.

AC Covich Track Slip-On
[PICTURE] Built for closed circuit racing where sound check compliance gets mandatory. Retains gains of uncorked midpipe upstream without excessive external noise. Skip post-session disqualifications!

So whether you ride the street, track, or both, AC Covich cater specifically to R1 riders with purpose-built slip-ons.

Full Exhaust Systems

Thus far we’ve demonstrated that mid pipe and slip-on muffler swaps achieve worthwhile gains respectively through reduced restriction and emotional auditory impact. What about maximizing overall performance with a complete full exhaust replacement?

Full systems come pre-integrated from header rearward. Major benefits over mixing/matching include:

• No fitment issues between mismatched components
• Smoother internal geometry for unimpeded exhaust pulse transitions
• Further weight reduction from additional titanium/carbon pieces
• Tuned products deliver optimized crossover balance
• Complete aesthetic overhaul

Leading turnkey full exhaust options include:

Akrapovic Yamaha R1 Titanium Full System

• Peak Horsepower Gain: +18 BHP
• Weight Reduction: -18.7 lbs
• Sound (1-10): +5 over stock

Arrow R1 Stainless Steel 4-2-1 Full System

• Peak Horsepower Gain: +15 BHP
• Weight Reduction: -13.4 lbs
• Sound (1-10): +4 over stock

Omega Racer R1 Titanium Full System

• Peak Horspeower Gain: +16 BHP
• Weight Reduction: -15.2 lbs
• Sound (1-10): +3 over stock

As expected, completely removing OEM exhaust hardware reaps further benefits. However, there are downsides:

• Extremely expensive
• Permanent alteration with no revert capability
• Potential street legality issues
• Requisite fuel tuning needs

Like our mid pipe discussion revealed, most power lies upstream. So those considering a full system should ensure restrictions get addressed using proper fuel mapping adjustments. Now let‘s peek under the hood…

Fuel Tuning & Complementary Mods

We‘ve focused primarily on exhaust layouts and rearward components. But remember intake manifold design playing a key role as well. Yamaha already utilizes trick offset cylinder positioning for straight shot airflow into the R1 combustion chambers. What else aids performance?

Data clearly shows that when adding an aftermarket full exhaust system or midpipe sans catalyst, fuel mixtures require adjustment to avoid running dangerously lean. Why? The OEM oxygen sensor expects elevated backpressure from stock hardware and delivers correspondingly rich fueling. Remove said hardware and engine parameters get altered.

While some slip-ons mildly impact air/fuel ratios, midpipes and especially full systems necessitate mapping corrections. Solutions include:

• Power Commander Piggyback Module + Tuning
• Bazzaz Inline Fuel Tuner + Map Flashing
• ECU Reflashing by Qualified Tuner

Plan between $400-600 for plug and play modules with pre-loaded calibration maps. Or budget $800+ for dyno tuning if chasing every last ounce from your R1. Avoid cope aesthetic exhaust upgrades with poor running performance!

Further complementary intake upgrades include:

• High-Flow Air Filters (BMC Race Filters)
• Velocity Stacks
• Air Funnels
• Ram Air Ducting

And don‘t forget about ancillary pieces supporting modified exhaust flow:

• AIS Block Off Plates
• O2 Sensor Eliminators
• ECU Flash De-Restriction

As you can see, optimal R1/R1M performance requires carefully syncing various intake and exhaust modifications to engine conditions. Apply the same meticulous approach to weighting all exhaust hardware options as well. Now let‘s shift gears towards sound…

Comparing Tones From Aftermarket Exhausts

If amplifying performance ranked as the sole reason for exhaust upgrades, we‘d end our discussion here. However the soul-stirring sound produced by free-flowing R1 engines deserves equal attention! Yamaha‘s unique "crossplane" crankshaft utilizing unevenly spaced firing intervals provides a signature raspy scream at full song.

While power peaks around 13,500 RPM, the engine‘s differentiated combustion sequences generate maximum acoustic energy between 9,000-11,500 RPM for an intoxicating mid-range voice. Aftermarket exhausts amplify varying elements of this soundtrack:

• Midrange Bark
• High RPM Wail
• Throaty Growl

So which options deliver the most stirring crescendo? Listen to these clips comparing stock vs aftermarket note:

Akrapovic Slip-On vs Stock
SC Project Slip-On vs Stock
Arrow Full System vs Stock

Notice one common theme – added mid-range vocalization gravitates towards a sharper metallic timbre. This aligns with our technical understanding of less restriction allowing pulses to traverse the system quicker. Different internal tube lengths and diameters also tune the resulting frequencies.

While power outcomes rely strictly on hard data, choosing your ideal exhaust song remains deeply subjective. Compare samples from leading manufacturers and decide which one connects best with your auditory emotions. Let‘s now shift from pleasure towards practicality…

Installing Exhaust Components Yourself

From mid pipes to slip-ons, full systems to extra ancillaries, what skills and tools should R1 riders have for DIY projects? Or would you rather leave it to the pros? Here are considerations around self-performed exhaust upgrades:

Recommended Skill Level: Intermediate home mechanic comfortable with power tools, basic welding, electrical troubleshooting
Estimated Installation Time: 1-3 hours depending mid pipe vs full exhaust

Required Tools:

• 3/8" ratchet and extension
• 14, 12, 10 mm sockets
• Torx T20 and T30 bits
• Spring hose clamp pliers
• Scribe marker
• Wire cutters
• Electric drill
• Butterfly impact gun

Optional Tools:

• Ergo stand
• Wiring crimpers
• Small tack welder
• Angle grinder with cut disk

Clearly slip-on mufflers rate easiest given single mounting point disconnect and bolt-on replacement. Expect more labor intensive tasks when fitting full systems:

• Header fastener access challenges
• Midpipe custom bracket fabrication
• Collector gasket creation from template
• Exhaust wrap application
• Dealing with stuck hardware seizures

If lacking tools, skill, or patience don‘t worry – every city has qualified shops who specialize in performance motorcycle work. Expect around $250+ for mid pipe swaps and $400+ for full system installs including custom fuel tuning. Use the following checklist when evaluating potential exhaust upgrade candidates for your R1 or R1M:

[EXHAUST UPGRADE CONSIDERATION MATRIX]

With so many mid pipe, slip-on, and full exhaust options on the market, use this grid to narrow down ideal upgrades based on key factors. Plot both quantitative data like horsepower and weight along with qualitative variables including sound rating and aesthetic judgement. Then determine the short list of exhaust components that align closest to your R1 build goals and budget limitations.

Finally, let‘s equip you with some key takeaway points:

Summary & Key Takeaways

• The R1 & R1M use a unique 3-piece exhaust format including header, midpipe with servo, and slip-on muffler
• Aftermarket mid pipes and full systems make the most power through de-restriction
• Slip-on mufflers allow easy customization of style and sound character
• Always properly tune your ECU when upgrading beyond a basic slip-on
• Peak power arrives around 13.5K RPM but max sound energy comes 1K-2K lower
• Carefully weigh quantitative data vs qualitative preferences when choosing parts
• Either DIY or use qualified shops for bolt-on simplicity or full installs

So whether you‘re chasing lap times or seeking auditory stimulation on weekend rides, this complete guide to R1/R1M exhaust upgrade paths equips you to achieve your mission. Now get out there and uncork that crossplane four to sing proudly!

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