Journeyman28778

"And this one is just right" ~ Goldilocks
Joined
Aug 13, 2017
Messages
732
Location
Swannanoa, NC 28778 USA
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'11 Rocket III Roadster
Because the stock ECU will correct within limits.

What however I do see is a change in ABSOLUTE intake manifold pressure running (cruising) at (say) 80mph at sea level and 1000metres. And can totally feel a different throttle response. But Nev is, as always, correct - we all tend to over think. I stand guilty - but it keeps me sane.
Funny you should mention 80 mph. At 3,000 rpm, which is 80 mph in 5th I'm getting a gentle thump in my left foot peg. Same in 4th at 3k. I haven't noticed it in lower gears or other rpms. I don't hear anything, just feel it. Where I got the bike tuned is at 600 ft. elevation. Where I live is 2400 feet. Other than that she runs like a beast.

I'm going to do a separate post on this. My tuner asked me where I tend to cruise- well, I don't do a lot of cruising, but I said about 80. Wondering if he leaned it out there and that's what I'm feeling. Look for a thread - "Knock, knock" I'm about to post if you have a theory.
 

barbagris

Mad Scientist
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Aug 1, 2010
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13,009
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On the verge of insanity
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2009 R3 - 1979 Guzzi V1000G5 - 2018 KTM 790 Duke
Look for a thread - "Knock, knock" I'm about to post if you have a theory.
Prior to theorizing: data, data, data. With a PCV and AUTOTUNE - consider seriously the acquisition of a POD-300. Then get in a shackload of booze because when you start to look at ALL THE DATA - you are going to need it. That or really good shrink.
 

Speedy

Supercharged
Joined
Apr 23, 2007
Messages
342
Location
Wisconsin
The barometric pressure sensor, located on the top corner of the airbox under the seat, and the intake air temp sensor allow the ECU to adjust mixture for both altitude and temperature changes, albeit they both have limits and are subject to non-linearity and manufacturing variations. As you go up in altitude the absolute pressure drops so the ECU adjusts and injects less fuel to maintain AFR. The result is that with 20% less air, and fuel, the bike produces 20% less power and likely even less. Why: because the intake and exhaust tracts are designed, or tuned, as is cam timing, for air density near or at sea level. Denser air conducts sound faster than thinner air so the farther away from sea level the less in tune those systems become. The result is even greater power loss than just the change in air pressure would indicate.

The position of the air temp sensor is critical. If it gets much heat from the radiator, or engine itself, it will result in a leaner running motor. So when climbing a mountain, the engine makes less power the higher you go, has to work harder due to the grade and creates more heat for the radiator to dissipate and the engine to radiate. Slow down to drive through a town and the bike can run like crap if the temps sensor is getting heat other than from the air flow in the intake system. Even when properly placed, the air flow through the intake is so low at near idle throttle openings that the whole air cleaner gets heat soaked. (This statement is made under the supposition that the O2 sensor is not active. The O2 sensor can compensate for this heating affect so long as it remains with the scope of the O2 sensor operating range.)

As to the thump: Did the driveshaft universal joint get inspected when the bevel box was changed? A bad u-joint can bind at a given rotational position and induce a vibration into the drive system. Is the thump episodic or is it constant and rhythmic? Does it change under different loads? Test the load condition by riding the brake; does the vibration change at all? A failing torsional bearing may exhibit episodic vibration whereas a failing u-joint would be prone to rhythmic vibration.
 

Journeyman28778

"And this one is just right" ~ Goldilocks
Joined
Aug 13, 2017
Messages
732
Location
Swannanoa, NC 28778 USA
Ride
'11 Rocket III Roadster
The barometric pressure sensor, located on the top corner of the airbox under the seat, and the intake air temp sensor allow the ECU to adjust mixture for both altitude and temperature changes, albeit they both have limits and are subject to non-linearity and manufacturing variations. As you go up in altitude the absolute pressure drops so the ECU adjusts and injects less fuel to maintain AFR. The result is that with 20% less air, and fuel, the bike produces 20% less power and likely even less. Why: because the intake and exhaust tracts are designed, or tuned, as is cam timing, for air density near or at sea level. Denser air conducts sound faster than thinner air so the farther away from sea level the less in tune those systems become. The result is even greater power loss than just the change in air pressure would indicate.

The position of the air temp sensor is critical. If it gets much heat from the radiator, or engine itself, it will result in a leaner running motor. So when climbing a mountain, the engine makes less power the higher you go, has to work harder due to the grade and creates more heat for the radiator to dissipate and the engine to radiate. Slow down to drive through a town and the bike can run like crap if the temps sensor is getting heat other than from the air flow in the intake system. Even when properly placed, the air flow through the intake is so low at near idle throttle openings that the whole air cleaner gets heat soaked. (This statement is made under the supposition that the O2 sensor is not active. The O2 sensor can compensate for this heating affect so long as it remains with the scope of the O2 sensor operating range.)

As to the thump: Did the driveshaft universal joint get inspected when the bevel box was changed? A bad u-joint can bind at a given rotational position and induce a vibration into the drive system. Is the thump episodic or is it constant and rhythmic? Does it change under different loads? Test the load condition by riding the brake; does the vibration change at all? A failing torsional bearing may exhibit episodic vibration whereas a failing u-joint would be prone to rhythmic vibration.
I did not inspect the universal joint when I changed the bevel box. The thump comes right in at 2900 - 3,000 rmp , but not a constant rhythmic thing. It often seems very specific to a certain exact RPM, so hard to keep it going... but, it is not keeping time (rhythmic)- seems a bit random. So, not like a bad tire or something that would present at a constant rate.

I moved this discussion to a new thread "Knock, knock." Knock, knock!
@warp9.9 mentioned the torsional bearing there too and suggested that I drop the sump pan at my next oil change. I hate to ask what is involved in changing that out.

I'll copy and paste your post over there, if you don't mind. I greatly appreciate the input.
 

Kevin frazier

Widowmaker!
Joined
Dec 22, 2018
Messages
4,237
Location
Nashville
Ride
2008 Triumph rocket 3 touring
I did not inspect the universal joint when I changed the bevel box. The thump comes right in at 2900 - 3,000 rmp , but not a constant rhythmic thing. It often seems very specific to a certain exact RPM, so hard to keep it going... but, it is not keeping time (rhythmic)- seems a bit random. So, not like a bad tire or something that would present at a constant rate.

I moved this discussion to a new thread "Knock, knock." Knock, knock!
@warp9.9 mentioned the torsional bearing there too and suggested that I drop the sump pan at my next oil change. I hate to ask what is involved in changing that out.

I'll copy and paste your post over there, if you don't mind. I greatly appreciate the input.
Rocket scientist has a great thread on that. Hoping youre good our engines and trannys are very similar and id guess our riding style too, but model differences ofcourse, with your fat tire and my fat arse it’s probably real equal on drive train. hope its nothing and goes away, when did this start?
 

Journeyman28778

"And this one is just right" ~ Goldilocks
Joined
Aug 13, 2017
Messages
732
Location
Swannanoa, NC 28778 USA
Ride
'11 Rocket III Roadster
Rocket scientist has a great thread on that. Hoping youre good our engines and trannys are very similar and id guess our riding style too, but model differences ofcourse, with your fat tire and my fat arse it’s probably real equal on drive train. hope its nothing and goes away, when did this start?
I noticed it several months ago. I had a lot of crap going on in my life and just ignored it, but afraid I'm tearing something up. Amazing how often I hit that 3k rpm groove when I'm not on the back roads. I convinced myself it was a tune issue, as it didn't seem to make sense mechanically, but wiser minds on here are indicating otherwise. We'll see. I need to put some extra octane in and see what that does.
 

Thedogsbollocks

Turbocharged
Joined
Aug 20, 2016
Messages
751
Location
Florida via Liverpool.
Ride
Rocket Roadster 2018
I borrowed a PC III when my tuner did his thing after my rebuild and it seemed to give him trouble. He advised next time to get a PC5. The tune is 85-90% spot on, but has a couple of bad spots.

I'm considering getting a PC 5 (if anyone has one for sale, btw, let me know). My question is how much more/less can I do with that PC5 than with Tune ECU alone?

Those of you with a PC5, do you leave it on the bike, or convert the tune over to TuneECU?

Will the PC5 allow tuning to specific gears, or is that just for some bikes, like Harleys?

Autotune- an extra device? Available for the Rocket 3? If I had that would I need to revisit the tuner, as I'm close with the current tune?

I know someone will chime in to say "find a tuner that uses TuneECU," but not in my area, so let's take that out of the equation, plus the guy I've found is good at what he does.

Thanks, in advance...
Well, I live in die hard Harly country in Crystal River Fl. After deleting the air, installing DP shorties in ran like crap and sounded like Romels whole Panzar corp was on my tail. Went to a couple if recommended tuners here but they really are only into Harleys...they showed no interest. Anyway went with the PCV and autotune and love the results. It's as good as it gets IMHO short of a full dyno. I've been very pleased.
 

Journeyman28778

"And this one is just right" ~ Goldilocks
Joined
Aug 13, 2017
Messages
732
Location
Swannanoa, NC 28778 USA
Ride
'11 Rocket III Roadster
Well, I live in die hard Harly country in Crystal River Fl. After deleting the air, installing DP shorties in ran like crap and sounded like Romels whole Panzar corp was on my tail. Went to a couple if recommended tuners here but they really are only into Harleys...they showed no interest. Anyway went with the PCV and autotune and love the results. It's as good as it gets IMHO short of a full dyno. I've been very pleased.

I have a custom tune that is 95% there. Based on what you say, I think the autotune will improve on that and get me where I need to go- thanx.
 

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