Graves just set a whole new benchmark for R3 engine performance
I’ve recently had the opportunity to buy an as yet officially unreleased R3 engine performance package from Graves Racing / Motorsports. The package is impressive enough that it just set a whole new benchmark for R3 engine performance. I am unaware of any available production package that comes anywhere close to what this package does.
In this posting, I will describe:
- The background
- What’s in the Package
- Dyno chart analysis
- Why it’s so special
- Key features
- DIY Installation
- Early impressions and how it performs
- The cost and availability questions you are sure to ask and that I can’t answer
Most of you on the forum know about Graves Racing Services / Graves Motorsports. This is a “dual markets” business run By Chuck Graves, that operates in two different market / services segments.
Graves Racing Services supports racers with both turnkey Yamaha R3 racebikes and ongoing support services.
Graves Motorsports serves street enthusiasts and track day riders with a very broad range of Graves branded products and non-Graves-specific products, for a wide variety of sportbike models from many manufacturers.
Some of the products developed originally for the R3 racebikes and their support at Graves Racing Services eventually trickle down in one form or another into Graves Motorsports products. Because those products are conceived, built, and supported in the demanding environment of racing, they tend to reflect a very deep level of expertise and experience that goes well beyond what a typical aftermarket sportbike products manufacturer or dealer can offer.
I’m a degreed mechanical engineer and engineering physicist who managed manufacturing plants and design departments for a big chunk of my work career, and consulted to many more. I recognize engineering and manufacturing competence when I see it, and in my opinion, Graves has them both. Chuck Graves and his team know what they are doing.
Many of you on the forum know that I purchased a Graves Cat Elimination exhaust shortly after buying my brand new R3 early this year. That system (which is a predecessor to this new one) was, and still is, a marvel of high quality practical engineering. Basically, what it does is combine a Graves carbon fiber muffler, and a Graves midpipe, with the OEM Yamaha header you already have on the R3 to make a freer flowing, high power exhaust, when coupled with a proper ECU tune. Because it takes the header cost out, it is a bargain to buy.
When combined with a Graves Cat Elim ECU tune, it increases the R3’s rear wheel horsepower by about 14%. Graves publishes a dyno chart on its website that you can examine. The Graves dyno is very conservative, so shows a stock R3 as producing about 35 rwhp. The Cat Elim kit takes that to about 40 rwhp. It is impressive not only for the 14% increase, but equally important, for the fact that the 14% occurs basically EVRYWHERE along the power curve. It is NOT bunched up at high rpm, nor does it have any “dips” anywhere. It’s an obviously very well engineered and developed solution.
There is also a more costly Graves package that includes a Graves header, which produces slightly more power because of the header’s more ideal sizing and shaping.
But, this new package takes things a LOT further.
What’s in the package
This new package combines the following elements:
- The Graves carbon fiber exhaust muffler
- A new more ideally dimensioned and shaped midpipe
- 2 separate, very slightly different headers of varying diameter and meticulous 3D configuration – one each for the left and right cylinders
- A significantly modified airbox that apparently flows a lot more air
- A new ECU tune that takes advantage of all of the above plus Graves’ extensive actual racing experience
The result is pretty spectacular.
Dyno chart analysis, Why it’s so special, and Key Features beyond the power
I said above that the result is pretty spectacular, and I really mean it.
Take a look at the Graves dynoi chart I’ve included below, which compares the new package to a stock R3 engine.
The conservatively, properly calibrated Graves Dynojet dyno shows a 47 rwhp peak, and this is with the raw readings being corrected to the most conservative dyno ambient conditions standard: The SAE standard (versus the more liberal STD standard), with factor 5 smoothing applied so that weird impressive but non-representative mini peaks get smoothed down to an actually reproducible curve.
47 rear wheel horsepower means at least 52 to 54 crank horsepower, depending on what the actual driveline losses are, which varies with the sprockets, chain, rear wheel bearings, wheels, and brake rotors used, and their quality and condition, as all of these components affect both driveline frictional losses and diversions of power to overcoming rotational moments of inertia (“MOI”). MOI is a big deal on any inertia drum type of dynamometer, and the industry standard dynamometer, the Dynojet, is that type of dynamometer.
47 rwhp is 34% more power than the stock engine, measured on the same dyno, corrected to the same conservative standard, as the 35 was measured for the stock engine.
Bottom line: This is very impressive power from a 320cc twin cylinder motorcycle engine.
This is 147 rwhp per liter, or 163 to 169 crank horsepower per liter.
From the least expensive, “entry level” sportbike in the Yamaha lineup of motorcycles.
Sure, there are “superbikes” out there that make more power per liter, BUT those bikes’ engines are 4-cylinder, were designed from the outset to make maximum power, and cost really big bucks.
But the R3 was designed as an inexpensive “entry level” bike, for learners and commuters, with a very strict manufacturing budget. To get its engine to 163 to 169 crank horsepower per liter, WITHOUT DOING ANYTHING TO THE INSIDE OF THE ENGINE, is a heck of achievement.
The QUALITY of that power though is a story that is, to really informed observers, even bigger, for these reasons:
- The power peaks at “only” about 1000 rpm beyond where the stock Yamaha R3 engine peaks
- The power is increased by about 1.3 over stock VIRTUALLY EVERYWHERE IN THE RPM BAND right up to the rpm at which the stock engine makes its peak power
- Then, the Graves engine keeps making LARGER gains over the stock power curve as the rpm climbs and the stock engine’s power fades rapidly. At 12,000 rpm, the Graves engine is making over 50% more power than the stock engine. By 12,200, when the stock engine is already taking a very deep dive, the Graves engine is making 59% more power.
- There is NO point at which the Graves engine makes less power than the stock engine. Period. So much for traditional theories about how souping up an engine narrows its powerband.
THIS is incredibly good, detailed, well considered engineering and pretty much perfect execution.
At Chuck Graves’ request, I cannot provide a lot of the details of how Graves did this. I understand that, as Graves has undoubtedly spent lots of time, effort, and money to develop this package, and so it can’t afford to simply give its secrets away. However, some of the key features include:
- The exhaust system is physically long enough to support optimized power tuning. Note how the muffler ends almost at the end of the tail section of the motorcycle. (see photo below).
- The carbon fiber muffler, complete with carbon fiber mounting ring, has a specific “hexagonal” versus round shape.
- The carbon fiber muffler is cool to the touch moments after a ride. You can throw a motorcycle cover on pretty much immediately.
- The headers change diameter along their length, hit 35mm maximum diameter, and are notably larger overall average diameter than those on the stock R3.
- The mid pipe too is very large diameter, and is remarkably straight for great air flow.
- The new graves rear exhaust hanger is much shorter (about 3”) than the OEM rear footpeg hanger used to support the Cat Elim exhaust and some other aftermarket exhausts, so it lifts the muffler higher and faster than the Cat Elim exhaust (for better ground clearance), and tucks it in nicely, and by the way, that Graves hanger weighs only 0.22 lb, versus the 0.89 lb that the stock hanger weighs.
- The Graves airbox, which started as an OEM Yamaha R3 airbox, has no snorkel, has a big piece also cut out of its left side, and the not-to-yet-be-discussed interior of that box, which has different velocity stacks than OEM, has to be dramatically different overall, as the stock airbox weighs 3.48 lb but the Graves airbox weighs just 2.84 lb, (That 0.64 lb reduction actually was what got my personal, already much-lightened R3 down below the magical 300 lb, before gas target I had established!)
- The OEM R3 exhaust system weighs a total of 18.2 lb.
The Graves Cat Elim exhaust system weighs 8.5 lb plus it also uses the 0.89 lb OEM rear footpeg hanger.
The Graves “full” exhaust system weighs 8.6 lb with larger header piping than OEM plus it also uses the 0.89 lb OEM rear hanger
This new Graves full exhaust system weighs 8.15 lb with larger/better headers & mid pipe, and includes the weight of the new lighter rear bracket. So, this is a 10.05 lb weight reduction on the surface, but a 10.94 lb REAL overall weight reduction versus OEM.
- The rev limit is raised in the new ECU tune to 13,500, but NOT for power reasons. Chuck explained that the rev limit increase instead is to avoid confusing the speedshifter that the racing rules body requires the racers to use, as that speedshifter gets confused around the rev limiter, so the rev limit has to be set high enough that it will not normally be encountered.
- My performqance modeling software supports Chuck’s assertion that the 13,500 is NOT needed for power purposes. My software tells me that in a run seeking best acceleration, the shift from 1st to 2nd should occur at 13,000, and then each shift after that at a progressively lower rpm, until the shift from 5th to 6th is made at just 12,200.
- The routing of the exhaust system is superb. It never gets closer than about ½” to ANYTHING along its route, except the “stirrup” in the brake linkage system, where with my specific aftermarket rearsets (Attack), the mid pipe clears the stirrup by about 1/8” or 5/32”. Plenty of clearance from the swingarm, the rear brake caliper, the bodywork, the crankcase, the oil pan,, the oil drain plug, and the oil filter. A mechanic’s dream.
- The header material appears to be stainless steel (I haven’t asked Chuck). Perfect bends, and no dents needed to clear ANYTHING on the bike.
- The airbox, being based on an OEM airbox, simply bolts in in place of the OEM airbox. All the magic is inside it, except for the extra hole and the absence of the snorkel.
- The ECU is a simple out and back in, with a reflash occurring in between. No new connectors to be inserted into the bike’s wiring. None of that awful “tapping into” OEM wires that degrades weatherproofing and long-term durability. Once you have the passenger seat, mid-panel, and rider seat off the bike, the ECU is an easy out and in. A few minutes total.
This is a solution that a reasonably experienced R3 owner could install him/herself, either entirely or at least partially, depending upon degree of experience and the completeness of a personal tool kit.
- If you are already running an aftermarket exhaust without oxygen sensor, then the entire exhaust system can be installed without even removing ANY fairing panels. If you still have an oxygen sensor, you’ll need to take off some bodywork.
- I made a dumb mistake on my first exhaust installation attempt (which I will explain later), and had to undo the whole thing. Even so, taking off the improperly partially mounted new exhaust system AND then installing the system again except properly this time, took exactly one hour. This is easily the easiest exhaust system I have ever had the pleasure of installing, and I’ve done quite a few of them over 50 years of motorcycling.
- Tools needed for the exhaust installation: 12 mm socket, 12mm open end wrench, ratchet, 6” ratchet extension, 3” ratchet extension, spring hook, needlenose pliers, torque wrench. That’s all.
- About my error: I had visually examined the 2 header pipes, which is hard to do with parts that are 3D in a complex and non-linear shape. To me they looked identical. However, even though the 2 header pipes look identical on visual comparison, they are not. This is because the R3 cylinder head exhaust ports are further apart than the 2 forward ends of the mid pipe are, so the geometry to run the headers down to and along the right side of the engine crankcase is NOT a Parallelogram. The left header pipe MUST be longer than the right one, and indeed it is by about 1/4” when you actually measure it carefully. Since many (most?) buyers won’t read instructions even if they are provided, and since Graves did not provide me with instructions for this not-yet-released kit, I figured it might be a good idea to put a small “R” and ”L” masking tape sticker on the right and left header pipes before you start an install. ☺
- The airbox installation is about the same time duration as the exhaust (one hour total) IF you know your way around the process of removing the necessary body parts, the fuel tank with its venting, fuel, and electrical conenctions, and the airbox, and IF the Yamaha assembly line worker who installed your airbox mounted the 2 specially-featured glorified “hose clamps” that connect the airbox to the 2 throttle bodies PROPERLY (i..e with both of the hose clamp screwheads facing UP. The assembly line worker who assembled mine somehow got one of the clamps installed upside down (probably by pre-assembling the airbox to the throttle bodies). This would have required me to disassemble much of the throttle body area just to get the airbox out! I didn’t want to attempt that in an unheated work area (we have had very cold winter weather here recently), and with my limited skills, so my friend, Tony, who runs the service department at my local Yamaha dealership had one of his aces do the job for a very friendly price (maintenance departments are pretty quiet in winter), and he managed to get it all done in UNDER one hour while I waited and teased the sales staff!
- The ECU reflash with the new Graves tune was done by Chuck himself. I simply sent the ECU to him from Canada, he did the reflash, added the exhaust kit and the airbox, and sent the entire package to me back across the border. He turned the ECU around in one day. I simply re-installed the ECU.
Early impressions and how it performs
The first “startup” with the new kit was impressive. My R3 had sat 39 days since the last time the engine was run, due to a combination of bad weather, my recent focus on completing some important mods and testing on my Kawasaki Z125 Pro (competitor to the Honda Grom), before the weather gets even worse, and of course the downtime while I shipped my ECU from Canada to Graves and back. Also, the Lithium Ion battery had gone unmaintained, as I don’t have a charger that can properly handle a Lithium battery, since I don’t normally ever NEED one. Nevertheless, when I finished installing the exhaust and ECU, and pressed the starter button, the engine, with the new tune, fired up INSTANTLY and settled into a smooth idle right away. No “hopped up engine” negative symptoms.
The new exhaust LOOKS great! What an upgrade, especially from the OEM header. And it follows the lines of the seat and tail section PERFECTLY (See photo below).
I love the way the muffler is now even higher than before, and without creating any servicing issues.
I am experiencing no exhaust leaks or vibrations of any sort.
My first test run was very short and extremely cautious, as the city’s brine dispensing trucks had had to do the streets just hours before my test ride, due to frost having formed on the roads overnight.
The exhaust sound, at least when idling and in low throttle / low rpm use, is sufficiently close to what the Cat Elim system sounded like that I can’t see anyone complaining that it is too loud. Not like what some other companies are putting out there. And the sound on closed throttle decal is wonderful.
The decal is gentler than OEM, but still there for those of us who like to use it.
Same for the intake sound, under the same tame conditions.
CLEAN and eager throttle response! No “development race bike” feel. It feels “factory”.
My performance modeling software says that this new system cuts quarter mile time by 0.57 second versus the Cat Elim system I had. That’s HUGE.
I won’t even try to do a comparison to a stock R3 here, as my R3 has been lightened by 44.5 lb as of this latest mod, and that’s AFTER ADDING a full pound of Shogun frame sliders. But you can probably imagine what a 34% power increase over stock EVERYWHERE across the rpm range does for you.
The performance modeling software says that the top speed increases by about 7 or 8 mph, solidly into the 120s with a moderate size/weight rider.
This tiny 320cc under 300lb motorcycle is now notably quicker than my first superbike, a 1970 Norton 750 Roadster that was one of the quickest bikes on the road in that era. We HAVE progressed. A lot.
I cannot do a local dyno run to verify the graves dyno chart because the nearest motorcycle Dynojet is an overnight trip across the border, and even if I wanted to undertake the time and expense, the winter weather around here prohibits doing that anyway, But a company with Graves’ reputation can’t afford to fudge or exaggerate dyno results, and it has demonstrated its conservative standards simply by reporting its dyno results the way it has.
I got a chance to do my second ride today. It was still very cold out (2 degrees C = 36 degrees F) , and there were still wet places because we have a LOT of TALL (up to 300 foot) trees here right alongside the roads (Timber is one of our biggest exports from Vancouver Island).
The exhaust is surprisingly quiet at cruising speeds. The wind noise easily overrides it. The less restrictive intake manifests at highway cruise speeds simply because it actually sounds louder than the quiet exhaust. No kidding. It’s a sort of intake “moan”. Nothing unpleasant, and very smooth versus staccato. Give the bike just a bit more speed and it too gets overwhelmed by the wind noise.
I mention this intake noise because on some bikes and some kits, intake noise becomes so obnoxious that it detracts too much from the ride. I had this happen on my Kawasaki Z125 Pro project, where putting on an aftermarket intake created such a loud and unpleasantly “sharp” sound that I ended up taking it off after just a couple of rides.
The breadth of the new usable powerband is breathtaking. I deliberately got the bike down to an indicated 57 kph = 35 mph in FIFTH gear at a steady cruise, and there was NO stuttering. By 55 kph, I got a bit of stutter at steady cruise. That’s about 4100 rpm. That’s pretty impressive on a 13,000 rpm engine in 5th gear.
I found a handful of spots where I could use full throttle. What a ride! The big deal when you apply full throttle is not sound or vibration or anything else like that. Yes, the exhaust is louder, but still not unpleasantly so. The big deal is that the front suspension unloads, and the rpm heads for the end of the tach, VERY quickly. Then you do it again in the next gear, and here’s the big difference over stock and over my previous Cat Elim exhaust: the rate of climb does not seem to slow with the higher gears. You have to really watch either the tach or the shift light, because things happen very quickly even in 3rd and 4th gears.
I got a feeling that fuel mileage might now be different than it has been . . .
The biggest impression: This entire package reflects a lot of experience and design and tuning skill. This does not fell like a hot-rodded motorcycle with the usual negatives that come with one. It feels more like an expertly crafted fun machine that now is very, very quick.
The cost and availability questions you are sure to ask and that I can’t answer
You’re probably wondering what this package would cost you. Sorry, but I don’t know. It’s still pre-release.
But in case you are wondering if I got mine “free”, the answer is no. I had alerted Chuck some time ago, after BB on this forum leaked news of the package’s early existence, that I would really like to buy the package when it becomes possible to do so. He contacted me very recently (after he and I exchanged a series of Kawasaki Z125 emails), and offered me the package, pre-release, at what I viewed as a very fair price given the performance and quality. I have no idea what Graves will be selling this package for once it is released.
Regardless of how fair a price Graves puts on it, I’m sure there will be some R3 owners who will say ‘Hey, that’s “X” percent of the value of the entire bike! Why would I spend so much on an entry level, inexpensive bike?”
Here are some GREAT reasons:
- This package requires ZERO work internal to the engine, and yet delivers 34% more power across the rpm range. That automatically makes it an incredible bargain if the price is ANYWHERE NEAR reasonable for what you get. There are supercharger kits for other bikes and cars that don’t achieve as much!
- Sure, its cost will undoubtedly be a significant percent of the price or current value of an R3, BUT that’s ONLY because the R3 is so inexpensive compared to almost any other sportbike (That’s why it is so popular for racing!). Traditionally, to get 34% more power, you needed to go DEEP inside an engine, and the cost of doing THAT is MUCH higher than anything Graves is likely to charge for this package.
- DIY is a realistic possibility for this package, as I noted earlier. Think of the dealership labour costs that saves right away. (My total dealership cost for the airbox work was $116 CDN and that includes 12% sales tax)
- Unlike internal engine upgrades, this package has NOTHING that can realistically “break”. Mufflers, mid pipes, and headers don’t normally break. Airboxes don’t normally break. And ECU tunes remain constant and reliable, unlike carb adjustments. You cannot say that for packages that include cams, pistons, stroker kits, and other mechanical changes. Those kinds of internal kits require careful, experienced assembly and tuning, and mechanical reliability is often less than great, and the costs of fixing broken parts is high.
- This package, via its dependence on very experienced ECU tuning, versus mechanical parts, makes changing things easy: just reflash.
- If you reflash using only Graves tunes, you’ll also be getting the benefits, and reputational reliability and experience, of the Graves team making those tune changes for you. What’s THAT worth?
Another question I’m sure you have is “When will this package be generally available to buy?”
I cannot answer that. You need to ask Graves. If you’re seriously interested, send an email to Graves and ask ([email protected]
Overall, I am very impressed. Graves has developed a package that jumps the power of an R3, across the entire rpm range, by a third. Its installation is easy. It can’t break. Unless graves goes really stupid with pricing, it’s going to realistically be a bargain compared to any sensible alternatives. WHY would anyone NOT want one?