P500 Larger Injector?

[Sam1971]

Hi all,

There is a lot of chat about how the P500 runs lean.

Has anyone tried a slightly larger fuel injector to get more HP? Would a new tune for the P500 be needed.

Regards,
Sam

 

[HondaTech]

A larger injector is only needed when youve maxed out the original. The amount of time the injector is open is what you want to adjust to get more fuel. Only oid your maxing that opening time out and still running lean would you go bigger.

This is what the Power Commander does, holds the injector spray open for longer.

 

[DG Rider]

I think a larger injector by itself would do nothing, since the FI would "see" the increased fuel via the O2 sensor, and simply lean itself out right back to where it wants to be (Approx 14.1 ish). Or it would run out of trim and cut the engine light on.

Anyway, that's like killing flies with a sledgehammer, since the stock injector can flow plenty for this engine IF we can just get it to do so...unless you're planning some huge mods. And if we could load a tune, we'd be able to fix it anyway.

One thing I've been kicking around is an O2 enrichment device. A company called Nightrider used to make them for Harley's, and at one point, had plans on the site for you to make your own.
In essence, it's a tiny resistor than knocks the O2 sensor voltage down a tad, making it look like the machine is running lean to the injection, and having it respond appropriately. You don't want much of a change here, but it would help with the heat and pinging, which my machine has always done under part throttle on crappy AZ gas. That's the main reason I'd want one.

Aftermarket fuelers might also work, but...

Someone on FB (so feel free to disregard it) claimed a while back that a Power Commander guy had basically told him they didn't work so well on closed loop Honda's because the FI would simply shift the fuel trim leaner as the PC tried to go richer, and it ended up being right back where it was.
This is a question I have been wondering about for some time before the comment, but never looked into.
It's my understanding that the tuners "intercept" signals from the stock PGM, and modify them for the desired results. BUT...if the O2 signal isn't changed (and the tuners may well do exactly that) or eliminated all together, I can see where the above statement would be totally true. BUT...id hope the power commander rep would know this?
I've been meaning to start a post on this...or I could just go look at the instructions for the Dobek/PC, I guess.
@snuffnwhisky @Ragnar406 and some others all have experience with these. Maybe they can save me some reading?

 

[DG Rider]

A larger injector is only needed when youve maxed out the original. The amount of time the injector is open is what you want to adjust to get more fuel. Only oid your maxing that opening time out and still running lean would you go bigger.

This is what the Power Commander does, holds the injector spray open for longer.

Looks like you can type faster than me...LOL!

 

[HondaTech]

I think a larger injector by itself would do nothing, since the FI would "see" the increased fuel via the O2 sensor, and simply lean itself out right back to where it wants to be (Approx 14.1 ish). Or it would run out of trim and cut the engine light on.

Anyway, that's like killing flies with a sledgehammer, since the stock injector can flow plenty for this engine IF we can just get it to do so...unless you're planning some huge mods. And if we could load a tune, we'd be able to fix it anyway.

One thing I've been kicking around is an O2 enrichment device. A company called Nightrider used to make them for Harley's, and at one point, had plans on the site for you to make your own.
In essence, it's a tiny resistor than knocks the O2 sensor voltage down a tad, making it look like the machine is running lean to the injection, and having it respond appropriately. You don't want much of a change here, but it would help with the heat and pinging, which my machine has always done under part throttle on crappy AZ gas. That's the main reason I'd want one.

Aftermarket fuelers might also work, but...

Someone on FB (so feel free to disregard it) claimed a while back that a Power Commander guy had basically told him they didn't work so well on closed loop Honda's because the FI would simply shift the fuel trim leaner as the PC tried to go richer, and it ended up being right back where it was.
This is a question I have been wondering about for some time before the comment, but never looked into.
It's my understanding that the tuners "intercept" signals from the stock PGM, and modify them for the desired results. BUT...if the O2 signal isn't changed (and the tuners may well do exactly that) or eliminated all together, I can see where the above statement would be totally true. BUT...id hope the power commander rep would know this?
I've been meaning to start a post on this...or I could just go look at the instructions for the Dobek/PC, I guess.
@snuffnwhisky @Ragnar406 and some others all have experience with these. Maybe they can save me some reading?

You could use an autotune from PC to bypass the stock O2 and make your AFR what you desire.

 

[DG Rider]

You could use an autotune from PC to bypass the stock O2 and make your AFR what you desire.

Didn't think about that. In my case...that's a lot of money for a touch more fuel, though.

 

[HondaTech]

Didn't think about that. In my case...that's a lot of money for a touch more fuel, though.

I've never been a PC fan anyway, they cause more problems then they solve.

 

[Ragnar406]

I think a larger injector by itself would do nothing, since the FI would "see" the increased fuel via the O2 sensor, and simply lean itself out right back to where it wants to be (Approx 14.1 ish). Or it would run out of trim and cut the engine light on.

Anyway, that's like killing flies with a sledgehammer, since the stock injector can flow plenty for this engine IF we can just get it to do so...unless you're planning some huge mods. And if we could load a tune, we'd be able to fix it anyway.

One thing I've been kicking around is an O2 enrichment device. A company called Nightrider used to make them for Harley's, and at one point, had plans on the site for you to make your own.
In essence, it's a tiny resistor than knocks the O2 sensor voltage down a tad, making it look like the machine is running lean to the injection, and having it respond appropriately. You don't want much of a change here, but it would help with the heat and pinging, which my machine has always done under part throttle on crappy AZ gas. That's the main reason I'd want one.

Aftermarket fuelers might also work, but...

Someone on FB (so feel free to disregard it) claimed a while back that a Power Commander guy had basically told him they didn't work so well on closed loop Honda's because the FI would simply shift the fuel trim leaner as the PC tried to go richer, and it ended up being right back where it was.
This is a question I have been wondering about for some time before the comment, but never looked into.
It's my understanding that the tuners "intercept" signals from the stock PGM, and modify them for the desired results. BUT...if the O2 signal isn't changed (and the tuners may well do exactly that) or eliminated all together, I can see where the above statement would be totally true. BUT...id hope the power commander rep would know this?
I've been meaning to start a post on this...or I could just go look at the instructions for the Dobek/PC, I guess.
@snuffnwhisky @Ragnar406 and some others all have experience with these. Maybe they can save me some reading?

@snuffnwhisky might have the answer ... I don’t understand how everything works but I do have the power commander 5 and auto tune for the P1000. The original auto tune came with a plug that you would used to close the loop when you took out the stock O2 sensor but newer PCV do not.. @JTW found a plug online overseas that we both ordered that worked. When we were going back and forth with dyno jet they told us that we needed to run both the Stock and the wide and O2 sensor when running the Autotune and that the pioneer would still make adjustments on the low end... I am running the auto tune with the wideband O2 sensor - and it works.

 

[Hondasxs]

I have a o2 delete in the store.
O2 DELETE for Honda Pioneer

I dont know enough about it to make it read lean all the time.

 

[snuffnwhisky]

A larger injector would require a tune. The stock injector should have plenty of duty cycle left unless you were turboing it. A powercommander is what you would want to richen it up.

 

[lee]

I heard that the first year (2015) the p500 ran lean and you could make the exhaust run red.
The second year was less lean.
And by the third year, although still some what lean (so it is emissions compliant) it was better.
But like @DG Rider says, just because I read it on my computer that dosent make it true.

My 2018 stumbles bad on the 1-2 shift when cold but once it warms up it's good.
Seams like there are other places to apply my efforts first (like getting it out of Ohio so I can ride).

 

[DG Rider]

I have a o2 delete in the store.
O2 DELETE for Honda Pioneer

I dont know enough about it to make it read lean all the time.

Is this just a block off plug or what?

 

[Hondasxs]

Is this just a block off plug or what?

It has a resistor in it to trick machine into thinking it is operating.
Similar to what you mentioned.
330 ohm I think.
But I'm not sure effects if one were to change resistance.

 

[trigger]

Had to add a second O2 sensor when I installed the Dobeck.

 

[Tstover]

I think a larger injector by itself would do nothing, since the FI would "see" the increased fuel via the O2 sensor, and simply lean itself out right back to where it wants to be (Approx 14.1 ish). Or it would run out of trim and cut the engine light on.

Anyway, that's like killing flies with a sledgehammer, since the stock injector can flow plenty for this engine IF we can just get it to do so...unless you're planning some huge mods. And if we could load a tune, we'd be able to fix it anyway.

One thing I've been kicking around is an O2 enrichment device. A company called Nightrider used to make them for Harley's, and at one point, had plans on the site for you to make your own.
In essence, it's a tiny resistor than knocks the O2 sensor voltage down a tad, making it look like the machine is running lean to the injection, and having it respond appropriately. You don't want much of a change here, but it would help with the heat and pinging, which my machine has always done under part throttle on crappy AZ gas. That's the main reason I'd want one.

Aftermarket fuelers might also work, but...

Someone on FB (so feel free to disregard it) claimed a while back that a Power Commander guy had basically told him they didn't work so well on closed loop Honda's because the FI would simply shift the fuel trim leaner as the PC tried to go richer, and it ended up being right back where it was.
This is a question I have been wondering about for some time before the comment, but never looked into.
It's my understanding that the tuners "intercept" signals from the stock PGM, and modify them for the desired results. BUT...if the O2 signal isn't changed (and the tuners may well do exactly that) or eliminated all together, I can see where the above statement would be totally true. BUT...id hope the power commander rep would know this?
I've been meaning to start a post on this...or I could just go look at the instructions for the Dobek/PC, I guess.
@snuffnwhisky @Ragnar406 and some others all have experience with these. Maybe they can save me some reading?

I have the AF AiED from Nightrider on my BMW motorcycle and it works well, and you can adjust how much richer you want the mixture. I did not see anything for Honda on their website though.

As someone else said, simply installing the resistor plug won't work as the brain will adjust to compensate for it.

 

[Duckhunt]

I have the AF AiED from Nightrider on my BMW motorcycle and it works well, and you can adjust how much richer you want the mixture. I did not see anything for Honda on their website though.

As someone else said, simply installing the resistor plug won't work as the brain will adjust to compensate for it.

But the resistor would allegedly be giving a lean signal, so wouldn't it "compensate" by enriching the mixture? From what I've learned the stock system just takes readings at idle-low throttle then adjusts the entire fuel map off that reading. I'm asking more than stating. I think the whole purpose of the wide band O2 sensor like Dobeck or my Autotune for PC-V is to take readings and adjust for entire rpm range.

 

[Tstover]

But the resistor would allegedly be giving a lean signal, so wouldn't it "compensate" by enriching the mixture? From what I've learned the stock system just takes readings at idle-low throttle then adjusts the entire fuel map off that reading. I'm asking more than stating. I think the whole purpose of the wide band O2 sensor like Dobeck or my Autotune for PC-V is to take readings and adjust for entire rpm range.

I don’t know much about it myself. When searching for a solution to the super lean F800GT I bought I read a ton of stuff on this subject (1-1.5 years ago). There was something about the computers relearning with only the resistor in place and remapping to make it basically like the resistor wasn’t there anymore. F800 forums or advrider had good info.

 

[happyfred]

Hi all,

There is a lot of chat about how the P500 runs lean.

Has anyone tried a slightly larger fuel injector to get more HP? Would a new tune for the P500 be needed.

Regards,
Sam

First of all you should read this to understand what you are getting in to"

Piggback vs Standalone ECU Tuning EFI Wiring

Piggy back vs standalone ECU ECM Computers with the pro’s and con’s to each in a article discussing their abilities that make one perform better than the other.

www.enginebasics.com

I have remapped the ecus on my Ducati and Moto Guzzi. Both increased power greatly. The remapping must match your intake (stock or high flow air filter) and exhaust (stock or aftermarket).
I have seen a K&N air filter for the P500. I haven't found many exhausts.
I have gone to the Dynojet site and there is an Auto Tuner available for the P500. It is the single channel unit (one O2 sensor). The Auto Tuner is the best option because it will adjust fuel increases to what the O2 sensor reads.
A Dynojet Power Commander is another option. This is a premapped piggy back unit that will richen the stock fuel intake and exhaust set up.

A third option is an o2 sensor manipulator. This fools the o2 sensor in to reading a leaner condition so the ECU will send more fuel. It works by fooling the IAT (intake air temperature sensor). This is the cheapest way to go but you really need a dynomometer to dial it in. If not you will have to do the old school spark plug reading method. It can be used on either a stock or modified intake/exhaust set up

 

[trigger]

First of all you should read this to understand what you are getting in to"

Piggback vs Standalone ECU Tuning EFI Wiring

Piggy back vs standalone ECU ECM Computers with the pro’s and con’s to each in a article discussing their abilities that make one perform better than the other.

www.enginebasics.com

I have remapped the ecus on my Ducati and Moto Guzzi. Both increased power greatly. The remapping must match your intake (stock or high flow air filter) and exhaust (stock or aftermarket).
I have seen a K&N air filter for the P500. I haven't found many exhausts.
I have gone to the Dynojet site and there is an Auto Tuner available for the P500. It is the single channel unit (one O2 sensor). The Auto Tuner is the best option because it will adjust fuel increases to what the O2 sensor reads.
A Dynojet Power Commander is another option. This is a premapped piggy back unit that will richen the stock fuel intake and exhaust set up.

A third option is an o2 sensor manipulator. This fools the o2 sensor in to reading a leaner condition so the ECU will send more fuel. It works by fooling the IAT (intake air temperature sensor). This is the cheapest way to go but you really need a dynomometer to dial it in. If not you will have to do the old school spark plug reading method. It can be used on either a stock or modified intake/exhaust set up

I have the K&N on mine and had to custom fit an HMF exhaust as there is no slip on available for the P5. Also added the Dobeck AFR+, it is set up with a pre-tune but can also be adjusted. It has a greater amount of air flow now as the muffler doesn't get very hot at all anymore. Found it has more midrange power but decreased my top end by 2mph, used to hit the limiter at 43 now it is 41. Sucks a bit more fuel now too.

 

[happyfred]

I have the K&N on mine and had to custom fit an HMF exhaust as there is no slip on available for the P5. Also added the Dobeck AFR+, it is set up with a pre-tune but can also be adjusted. It has a greater amount of air flow now as the muffler doesn't get very hot at all anymore. Found it has more midrange power but decreased my top end by 2mph, used to hit the limiter at 43 now it is 41. Sucks a bit more fuel now too.

It doesn't get as hot because your new exhaust doesn't have a catalytic converter! Changing just the intake air filter or just the exhaust shouldn't hurt the engine but changing both without a fuel mod may lean it out too much. Honda makes their ECU maps difficult to alter from my experience with their motorcycles. I had an ST1300 with a K&N and Two Brothers exhaust and no remap and it ran fine...I'm still reading about the P500 but am considering changing to a K&N air filter, a custom exhaust and this: Honda Pioneer 500 MAGNUM Dyno-Boost ATV Performance Chip