How to [NOT] Tune FZ Engines (2 blown ones...)

[jb.junior 95]

What a season.  After crazy supply-chain delays, and various bullsh*t, I finally get two top-notch, reputably built, superbike engines, which ran amazingly in club races on race fuel, only to blow them both almost immediately when trying to run and tune them for VP MGP fuel.  Both went out the same way: overheated, then blew out shortly after.  Sputtering out, blowing smoke, and oil and water mix in the air filter box.

Sadly, both engines ran super without even being tuned specifically; just running the old map that was on the ECU from last year; set for VP U4.4 (high oxygen, 105 octane, race fuel).  Someone experienced in tuning, though relatively inexperienced in Flashtune and with FZ engines, then tuned them both for MGP, to prep for MotoAmerica (it's the spec fuel there...), and seemingly really got it wrong, as both blew within a day of riding.  We were using Flashtune.

I've heard all kinds of advice and input about how this happened.  Some have said that cylinder 1 runs more lean than 2, and you have to tune each cylinder individually, with bungs welded on to each header, to get it right.  I'm about to bring my ECU somewhere for some forensics, but it looks like the "standard" setting in Flashtune had way to much ignition for this sht*t, 92 octane "race" fuel.  I don't know much about this stuff but am [unfortunately] learning a lot right now and trying to figure out exactly what happened and how to do it better going forward.

Engine 1 has been pulled apart, and it's probably totally toast (see first three pics).  Engine 2 (last two pics), we removed yesterday, and will bring to engine builder for diagnosis tomorrow.  But the pieces of valves that came out of the exhaust and in the air filter are obviously very a bad sign; and we suspect it too is totally trashed (head, block, pistons, etc.).  Input from engine builder so far is "very likely" pre-detonation from too advanced ignition. 

I think I have another newbuild superbike engine lined up, while we build some more (if either of these can even contribute anything...), so at least there's that.  If that works out, I should hopefully get that sorted soon and be back racing in July.

Thinking a lot about what to do about engine management / electronics once I do get the next engine.  I've had nothing but problems dealing with Flash tune, if not just that their licensing is a pain in the ass, and their support sucks, so I think I'm done with them.   I may go with an A-racer ECU, which has wonderful support (the owner / guru actually goes to all of the MotoAmerica races; and the A-Racer is tunable remotely, so he can "look in" and see what's up from a distance).  And I have a Power Commander on the "back-up"  bike, so maybe that too. 

Such a shame.  I was the third owner of the last engine, and ran something like 84 races on it last year, before sending it off to be rebuild over the winter.  It was super worn out, but still ran pretty good, though likely down on power.  I get some decent firepower for MotoAmerica, and totally bamboozle them.  I guess they can't all be good seasons.  Anyway, I'll re-group, rebuild, and come out screaming in July...

If anyone is new to racing the FZ engine and is building a superbike, be really careful in knowing how it's build and how to tune it. I'm happy to share my learnings if anyone is interested.  It seems that these things are really hard to get right, as a lot of people that I know are having similar issues -- even ones built and tuned by big names...  The arms race to keep up with the Aprilia RS660 has made everyone building these things on the razors edge.  I saw a big-name front runner swapping their blown engine out at VIR after 1/2 a practice session...

Edited June 15, 2022 by jb.junior

[cosp600rr 106]

I went through this a couple years ago with the FTecu. My solution was to have Matt Spicer at Robem Engineering build the motor and change all electronics to Aracer and have him tune it. Im on my second season with the motor and tuning with no issues at all.

[M. Hausknecht 361]

I have the aRacer Super2 ecu with a WBO sensor and autotune capability. I have mixed feelings about the ecu. It is reasonably capable but could do a better job adhering to the target AFRs you set, whether operated on autotune or as a closed loop system. It tends to run too lean and too rich at times, even after making manual changes to the fuel maps.

As for support, Kae seems nice (he is just the aRacer USA guy) but I've been disappointed with his inability to answer fairly basic questions about how the ecu and software work. Moreover, he is the only english-language support provided by aRacer world-wide beyond some very basic videos. He seems to pay attention to the MA guys but has little bandwidth for the rest of us. I've found Spicer to be very much too busy or otherwise unwilling to assist me (but then I'm not running MA and I'm not a current customer). For example with Kae, I asked him 4 questions about how the acceleration enrichment options work, and he said he never changes them from the base aRacer-provided map and couldn't answer my questions. There are a number of other adjustable functions within the ecu that are not adequately explained or documented by aRacer. When I pointed this out to Kae, he basically said aRacer is relatively inexpensive so don't expect it to provide the kind of support or documentation you get from MoTeC, for example.

Yes, the cylinders don't have the same fuel needs and, in my experience, the stock spark plugs are too hot to provide useful info on either mixture or spark advance. I've also found that the aRacer-provided map for the CP2 carries excessive spark advance for 93 octane fuel, even with stock compression. It might be ok on the street with a motor with stock volumetric efficiency and no sustained high rpms. I'm currently using a few degrees less advance throughout than the aRacer spark map provides, and that is with 100 octane fuel and stock compression. I've also found engine heat to be a excessive. At least with air temps in the mid-80s or higher, the engine runs warmer than I'd like. Of course, horsepower is heat, so adding fuel to cool the motor helps a bit without hurting power too much, as does a larger or more efficient radiator (still trying to source). 

JB, I hope your fortunes improve.

[jb.junior 95]

Just now, cosp600rr said:

I went through this a couple years ago with the FTecu. My solution was to have Matt Spicer at Robem Engineering build the motor and change all electronics to Aracer and have him tune it. Im on my second season with the motor and tuning with no issues at all.

I appreciate that, and I'm glad that you have a good solution.  I think part of why Robem is so "pro" A-Racer is because they had a lot of problems with engine failure with Flashtune (so I've heard...).  I'm going to see what this new tuner wants to do today, but I'm leaning towards A-racer.  Like I mentioned above, what's also great about it, being in MotoAmerica, is that the owner / tech guy is always there and involved in it.  Plus you can remote tune, so they can "get in to it" remotely and troubleshoot.  

Just weird, because I bought that bike with whatever file / flash was on on the ECU, and I ran either VP U4.4 or Sunoco 110, and it ran smooth and fast all year.

[fzar 624]

Just now, M. Hausknecht said:

As for support, Kae seems nice (he is just the aRacer USA guy)

 

Just now, jb.junior said:

I think part of why Robem is so "pro" A-Racer is because they had a lot of problems with engine failure with Flashtune

As far as I know he now has a helping hand now, and I know Robem is working with Chloe at A-racer for MA rounds.

[jb.junior 95]

Just now, M. Hausknecht said:

I have the aRacer Super2 ecu with a WBO sensor and autotune capability. I have mixed feelings about the ecu. It is reasonably capable but could do a better job adhering to the target AFRs you set, whether operated on autotune or as a closed loop system. It tends to run too lean and too rich at times, even after making manual changes to the fuel maps.

As for support, Kae seems nice (he is just the aRacer USA guy) but I've been disappointed with his inability to answer fairly basic questions about how the ecu and software work. Moreover, he is the only english-language support provided by aRacer world-wide beyond some very basic videos. He seems to pay attention to the MA guys but has little bandwidth for the rest of us. I've found Spicer to be very much too busy or otherwise unwilling to assist me (but then I'm not running MA and I'm not a current customer). For example with Kae, I asked him 4 questions about how the acceleration enrichment options work, and he said he never changes them from the base aRacer-provided map and couldn't answer my questions. There are a number of other adjustable functions within the ecu that are not adequately explained or documented by aRacer. When I pointed this out to Kae, he basically said aRacer is relatively inexpensive so don't expect it to provide the kind of support or documentation you get from MoTeC, for example.

Yes, the cylinders don't have the same fuel needs and, in my experience, the stock spark plugs are too hot to provide useful info on either mixture or spark advance. I've also found that the aRacer-provided map for the CP2 carries excessive spark advance for 93 octane fuel, even with stock compression. It might be ok on the street with a motor with stock volumetric efficiency and no sustained high rpms. I'm currently using a few degrees less advance throughout than the aRacer spark map provides, and that is with 100 octane fuel and stock compression. I've also found engine heat to be a excessive. At least with air temps in the mid-80s or higher, the engine runs warmer than I'd like. Of course, horsepower is heat, so adding fuel to cool the motor helps a bit without hurting power too much, as does a larger or more efficient radiator (still trying to source). 

JB, I hope your fortunes improve.

Very insightful and helpful, thank you.  Yeah, as much as I'm hearing back things about FTecu, I'm hearing other complaints about A-Racer.  Interesting to hear you put some color on those issues from your perspective.  Yeah, I guess I'm seeing it as "rosey" as I met him at MotoAmerica, and that has been my focus.  But good points.

Wow, even more stuff to consider.  What a pain in the ass.  Again, my engine last year I think had 89 hp on U4.4 (high octane, with lots of oxygen).  It was really beat up, after three dog seasons on it, and likely down on horsepower, but damn, it ran great and cool.  Combination of running this sh*t MGP and have a more aggressive build has just messed up my entire racing "chi."  What a drag.  I'm obviously not a mechanic or tuner, and really don't like getting too much in the weeds on this.  I relied on people's expertise, and they didn't get it right, so here I am.  Sorry to whine, I'm just totally bummed, as all I want to do is ride.  People may like the "tinkering" -- I hate it, and don't have time.

A couple of things on your heating:  One, try a Suzuki thermostat; it's about 10 degrees Celsius lower activation temperature.  I can get the part number, if you want.  We put one in my bike.  Also, you've probably done this, but get a higher pressure radiator cap.  Lastly, try this R6 "secondary" radiator.  Guys on R7s are using them (saw it on Hayden Schultz's bike at VIR), because it seems the R7 has worse airflow than the FZ because of the body work (or so it is theorized...).  Here's a link of one on ebay, and I'll attach a pic.  It will of course require some engineering to get it to fit on the FZ.  A friend & fellow racer of mine is putting one on now.  I can keep you posted.  Lastly, try putting the fan back on.  I'm going to put mine back on.  I'm not an expert, but it seems logical that it would help -- slow corners, cool down laps, sitting on hot pit, etc.  Again, I suck at all of this, and you probably know more than me, but that's my tentative plan for cooling.

My bike was running hot before they blew, but this was of course was because of the detonation.

[shinyribs 1,669]

Open with my disclaimer that I'm not a CP2 engine guru. Spent some decades tuning N/A, turbo, blown and nitrous domestic V8 engines and I recognize that doesn't necessarily translate to these engines. However, detonation is universal. Detonation severe enough to blow pistons crowns apart should be easily audible. I've never seen detonation pop valve heads off, but floating bits of piston can do that for sure. 

 

Do you have melted or cracked piston crowns to point towards a fuel mixture issue? 

Is the valve train stock?  Too stiff spring pressure, especially with an aggressive cam lobe ramp could pop valve heads off pretty easy, even at lower rpms. 

Spark plugs stayed together? Suzuki had a two stroke bike years ago that would run fine on just about any plug you put in it, so nobody wanted to run the $30 plug Suzuki asked for. But that expensive plug had specific materials in the electrode construction that could handle the harmonics of that engine. The cheaper plugs ran great, right up until the centers fell out and wiped out the top end. 

What I'm saying is, inspect the physical damage you have in front of you for clues vs " well, I've heard this "tune" can do such and such, etc" or blaming fuels. The fuel could be the issue, or the parts were already hanging by a thread and just happened to let loose when you swapped fuels, giving the impression something had changed.  I'd hate to see you chasing ECU programming or whatnot and pop off another set of valve heads due to valve train geometry/stability issues. 

 

 

Edited June 16, 2022 by shinyribs

[M. Hausknecht 361]

Thanks JB for the cooling suggestions. Reinstalling the fan offends my sensibilities but it is a good idea. I once installed a Suzuki GXSR 750 radiator on a Yamaha FZR 400 putting out 50% more horsepower than Yamaha intended. It nearly bolted right on and only needed one special hose that I was able to put together. I found it by going to motorcycle dealerships and measuring radiators, and examining mounts and hose locations until I found something close.  It fit nicely within the bodywork and I never had a heat issue again.

Over the years I've found maybe a handful of people who were able to help me with my various racing programs, and many more who were better at marketing than utilizing their actual abilities. In part for that reason and, in part, because I think I'm smarter than most (I do not mean to say that I am, just that I've tended to think I am), I've done the work of learning by reading, watching, listening, and doing. I still screw up and try to learn from it, but I always know where to look when there is a problem. I can't even begin to imagine the difficulties if I'd had to rely on others for what is involved in running a highly modified machine. I know it won't help you now, but perhaps in the future run a supersport class machine?  The Twins Cup class is very much a "builder's class" these days and the only true superbike class in MA.

[cosp600rr 106]

Ill just say, Im not a tuner or an engine builder but after mine blew up in 2020 I learned a few things. The original motor that I got with the bike and the FTecu already installed and tuned always ran hot. I made it 4 club race rounds before it blew up and was running the Sunoco 260GT 100 octane fuel. After it blew up I started doing a ton of research trying to figure out what caused it and how to prevent it in the future. The most valuable recourses I found where Matt Spicer and JD Hord. Both with experience with the FTecu and built motors. If I understood and remember correctly the FTecu comes from FT with the ignition tables already installed that are way too advanced. To finish out that season the solution was to install a stock motor I found, then to load the stock ignition maps into the FTecu and completely remove theirs, then we mapped the bike for pump gas and I finished the last couple rounds with it like this and it worked fine and ran much cooler.

That winter I sent the entire bike to Matt Spicer and had him build the motor like the ones that they were running in Moto America the season before. He also said to get rid of the FTecu and install the Aracer ecu, quick shifter and Af1 wide band module. He tuned the bike before I picked it up and have been running it for last season and so far this season. I dont have a fan on the radiator, no special radiator and just a better radiator cap. The bike now never runs hot. My last race weekend a couple weeks ago was in the mid 90's and the bike ran at 185-190  the entire weekend. No issues with it getting hot like it did previously. I have no idea about what thermostat or if it even has one or not as I didnt build the motor and have had no reason to even check it since the bike runs cool all the time. Matt has a lot of experience with this motor and in my opinion did a great job with everything I asked him to do. My request was for the motor to be pretty strong power wise and the be as reliable as it could be for being a built motor. I believe he accomplished that. I suppose that may be best said at the end of this season if the motor is still going!! LOL  The bike made 92Hp on his dyno when he tuned it and have not a single issue with the motor or the electronics since I got it back from him.

[jb.junior 95]

1 hour ago, shinyribs said:

Open with my disclaimer that I'm not a CP2 engine guru. Spent some decades tuning N/A, turbo, blown and nitrous domestic V8 engines and I recognize that doesn't necessarily translate to these engines. However, detonation is universal. Detonation severe enough to blow pistons crowns apart should be easily audible. I've never seen detonation pop valve heads off, but floating bits of piston can do that for sure. 

 

Do you have melted or cracked piston crowns to point towards a fuel mixture issue? 

Is the valve train stock?  Too stiff spring pressure, especially with an aggressive cam lobe ramp could pop valve heads off pretty easy, even at lower rpms. 

Spark plugs stayed together? Suzuki had a two stroke bike years ago that would run fine on just about any plug you put in it, so nobody wanted to run the $30 plug Suzuki asked for. But that expensive plug had specific materials in the electrode construction that could handle the harmonics of that engine. The cheaper plugs ran great, right up until the centers fell out and wiped out the top end. 

What I'm saying is, inspect the physical damage you have in front of you for clues vs " well, I've heard this "tune" can do such and such, etc" or blaming fuels. The fuel could be the issue, or the parts were already hanging by a thread and just happened to let loose when you swapped fuels, giving the impression something had changed.  I'd hate to see you chasing ECU programming or whatnot and pop off another set of valve heads due to valve train geometry/stability issues. 

 

 

Man, all great input, and honestly, maybe a bit above my mechanical "paygrade" for me to really digest or respond with any intellect.  I did very little investigation on my own with either engine.  The pics you see of the cylinder are from the engine builder.  He did the breakdown on the first, and will now do the second.  I'll see what he says, what I can comprehend, and relay it back here.  Not sure about the spark plugs.  But they were brand new in both engines.  As was pretty much everything.  (Not sure if I mentioned this before or was clear enough about it, but both engines were totally fresh, newbuild engines.   With new pistons, etc.  Well, the first one had a few weekends on it at that point, actually.  But the second was new.)  I basically am going to have to just trust what the engine builder says. And he's saying it's looking like detonation based on too advanced timing.  Again, I don't know enough about it to be of any use or value in the breakdown forensics.

Data points I do understand: one, neither of these engines was "worn out" or at the end of their lives. 

Next, neither has been gradually building or losing power or such.  Something really, really bad happened, happened right after the tune.

Also, these two engines were built by two different people.  The first, came on a basically brand new "barn find: FZ07r that I found with a few hundred miles on it.  The second was a fresh build engine, with donor head and block from something very low mileage.  The first ran great on U4.4 and 110; just on the old map on the ECU from last year.  Just amazing.  Then it was retuned for MGP and then on MGP, and immediately ran like shet, overheated, lost power, never felt rights, and within a few sessions destroyed.  Regarding the second: it was built by a really reputable guy; "super," but carefully not overbuilt or too much compression.  He built the last one that lasted three years of racing. 

Just seems to "serendipitous" that two engines, both pretty much new, both from good builders, both, well, one, ran great on the previous tune and on U4.4, to both feel and act the exact same way and then fail in the exact same way.  Again, I don't know enough about how to look inside a failed engine and diagnose, but logic is just telling me the independent variable here is the tune and low octane fuel...

But, again, I do appreciate your comments and will find out what I can.

Edited June 16, 2022 by jb.junior

[jb.junior 95]

Just now, cosp600rr said:

Ill just say, Im not a tuner or an engine builder but after mine blew up in 2020 I learned a few things. The original motor that I got with the bike and the FTecu already installed and tuned always ran hot. I made it 4 club race rounds before it blew up and was running the Sunoco 260GT 100 octane fuel. After it blew up I started doing a ton of research trying to figure out what caused it and how to prevent it in the future. The most valuable recourses I found where Matt Spicer and JD Hord. Both with experience with the FTecu and built motors. If I understood and remember correctly the FTecu comes from FT with the ignition tables already installed that are way too advanced. To finish out that season the solution was to install a stock motor I found, then to load the stock ignition maps into the FTecu and completely remove theirs, then we mapped the bike for pump gas and I finished the last couple rounds with it like this and it worked fine and ran much cooler.

That winter I sent the entire bike to Matt Spicer and had him build the motor like the ones that they were running in Moto America the season before. He also said to get rid of the FTecu and install the Aracer ecu, quick shifter and Af1 wide band module. He tuned the bike before I picked it up and have been running it for last season and so far this season. I dont have a fan on the radiator, no special radiator and just a better radiator cap. The bike now never runs hot. My last race weekend a couple weeks ago was in the mid 90's and the bike ran at 185-190  the entire weekend. No issues with it getting hot like it did previously. I have no idea about what thermostat or if it even has one or not as I didnt build the motor and have had no reason to even check it since the bike runs cool all the time. Matt has a lot of experience with this motor and in my opinion did a great job with everything I asked him to do. My request was for the motor to be pretty strong power wise and the be as reliable as it could be for being a built motor. I believe he accomplished that. I suppose that may be best said at the end of this season if the motor is still going!! LOL  The bike made 92Hp on his dyno when he tuned it and have not a single issue with the motor or the electronics since I got it back from him.

Thanks for this.  I'm glad that your engine has worked out.  Yes, that's what the tuner who tuned it has also found in retrospect: the FTecu comes loaded with ignition maps that are way too advanced (32, I think; I've been told nothing over 25 on these CP2s...).  Now, should he have known that, or at least anticipated that?  Perhaps.  But it seems that he's in good company, because I know of a lot of other instances (I guess 5 now, including yours here), that have had the same problem, based on FCecu and tuning.  I think that you've had the fortunate position of having been on the "back end" of Robem's development and learning curve of FZ tuning.  Because from what I've understood, they went through a lot of similar "pains" tuning these things and failures with FTecu.  I definitely know of a few...  Is A-racer the panacea?  Maybe, maybe not.  But I think it's just all about the builder and tuner knowing what they have, how to make it all work together, understanding the nuances of these particular engines, and, perhaps most importantly, knowing the nuances of the tuning software and hardware they are using.  I think I missed on a few of those with these bike builds.  In his defense, the tuner was not a fan of FTecu, preferred another method, but went with it for my bikes because it was already on there, another customer of his was using it on their FZ.  I wasn't aware of how easy (?) it is to f*c k this process up, so I'm definitely going to manage the process organizing these professionals and services better, going forward.  I'd say I kind of failed as "general contractor." 

Yeah, I think with the right maps and such, the bike should run cool enough.  I thought at first that maybe the overheating I had with both of these engines was a cooling issue.  But I think the conclusion now is almost for sure that the heat was a symptom of this tuning / timing issue, and not the cause.  Even when I did all of the cooling system upgrades after the first one blew, the second engine still blew.

Yeah, 92hp is about the right mix of power and durability -- exactly what I was shooting for.  Both of mine were dynod about that as well.  So they weren't "crazy" (98hp, etc.)

Edited June 16, 2022 by jb.junior

[jb.junior 95]

1 hour ago, M. Hausknecht said:

Thanks JB for the cooling suggestions. Reinstalling the fan offends my sensibilities but it is a good idea. I once installed a Suzuki GXSR 750 radiator on a Yamaha FZR 400 putting out 50% more horsepower than Yamaha intended. It nearly bolted right on and only needed one special hose that I was able to put together. I found it by going to motorcycle dealerships and measuring radiators, and examining mounts and hose locations until I found something close.  It fit nicely within the bodywork and I never had a heat issue again.

Over the years I've found maybe a handful of people who were able to help me with my various racing programs, and many more who were better at marketing than utilizing their actual abilities. In part for that reason and, in part, because I think I'm smarter than most (I do not mean to say that I am, just that I've tended to think I am), I've done the work of learning by reading, watching, listening, and doing. I still screw up and try to learn from it, but I always know where to look when there is a problem. I can't even begin to imagine the difficulties if I'd had to rely on others for what is involved in running a highly modified machine. I know it won't help you now, but perhaps in the future run a supersport class machine?  The Twins Cup class is very much a "builder's class" these days and the only true superbike class in MA.

It's funny how everyone who races hates fans.  What's the downside?  1.4lbs (that's what they weight on the FZ)?  

Yeah, you're a "doer," and I respect that.  I honestly just suck at it, don't like doing it, have limited interest in being a "mechanical" expert, and would rather focus on my job (which is busy as shet and allows me to pay for this "outsourced" model), and focus on training and riding -- which I'm actually pretty good at and enjoy.  For me, anyway, I've viewed this like picking up and giving a go at a larger organization; moving up from a "sole proprietorship."  At some point, you have to involve other people, and the focus becomes managing them, as opposed to knowing every nuance of every part of every task, equipment and responsibility.  At least at the MotoAmerica level.  I end up too worn out if I do too much myself.  And hating it.  It's a process, and I'm honestly good at getting good at processes (if that makes any sense).  I just have to keep learning and pushing and knowing what is what and who is what.  I'll get it...  But yes, sorting through the "expertise," ego, drama, and bullsht involved in motorsport racing experts has certainly been tough cookies.  It's like a goddamn soap opera for men.  I guess that's a whole 'nother thread, but I hear you.  Lots of cats to heard and landmines to avoid (and it seems I just lost a leg...)...  Everyone talks sht about everyone else and everyone has the solution to all of your problems.  (On that note, that's part of why I may even keep this tuner.  He's at least smart and honest and listens to me and isn't an ego queen.  Yeah, he may have screwed this up, but he listens and cares and is modest.)

Well, I was hoping the engine / bike wouldn't be so much trouble!  Again, it ran great last year, and it was on it's third season.  Yes, these two engine builds were a bit "hotter," but not so much that they should have failed like they did.  I'll get some new engines, learn a bit more about how to get them right, do a better job at managing their tuning, and give it a go.  If I fail at the process again, maybe I'll get an RS660.  I don't want to do any class bigger or faster as, well, they're just too damn fast!  I like these twins and think I can be half-decent at MotoA, once I get the groove of things...

Thanks again for your input.  This has all been great help.

Edited June 16, 2022 by jb.junior

[M. Hausknecht 361]

92HP, that's what my current motor reached on the KWS dyno with Sunoco 100 octane, 4%oxygen fuel. My sense is that there is probably 3-4HP attributable (directly and indirectly) to the fuel I'm using over the VP MGP (94 oct, 2.5% oxygen) MA mandates you use.

Notwithstanding my complaints about aRacer and its lack of english-language support, short of the Yamaha "kit" I've heard talked about in hushed tones, its probably still the best option. 

Well JB, you sound undaunted, so keep on keeping on. This year may just have to be your big learning year. Good luck!

 

 

[jb.junior 95]

Just now, M. Hausknecht said:

92HP, that's what my current motor reached on the KWS dyno with Sunoco 100 octane, 4%oxygen fuel. My sense is that there is probably 3-4HP attributable (directly and indirectly) to the fuel I'm using over the VP MGP (94 oct, 2.5% oxygen) MA mandates you use.

Notwithstanding my complaints about aRacer and its lack of english-language support, short of the Yamaha "kit" I've heard talked about in hushed tones, its probably still the best option. 

Well JB, you sound undaunted, so keep on keeping on. This year may just have to be your big learning year. Good luck!

 

 

So it sounds like your tune is slightly mellower than mine were.  But again, it's hard to compare dyno-to-dyno.  I guess we'd have to compare internals.  But that's great fuel.

I appreciate that!  It is what it is!  Yes, good learning!  I was really amped on doing a full season of MotoAmerica this year, thinking that my interests or abilities may wane, so I've put a lot of pressure on myself to rush "cram" it all in this year.  I'm still very intersted in racing and will just take a more "medium" term view.  Next year will be better!  I should still be able to make Brainerd, Jersey, Pitt and Barber, this year, which should be fun.  Thanks again.

My superbike "back-back-back" up option just fell through.  So I'm goin to buy a stock engine or two and start from scratch again.

Edited June 16, 2022 by jb.junior