2012+ WR450F Camshaft Upgrade Info.

[revelc]

Not all cars have a MAF. I think it's a lot like the speed density system that some cars use but without the O2 sensors.

Uhhhh... Yeah. Did I say they all had MAF sensors?

02 sensors tell the ECU how lean/rich things are so it's nothing like that. From what Kah described it sounds like it just adjusts the initial mix for elevation with the MAP sensor but the ECU still doesn't know how rich/lean its running and only retards things when it gets too hot.

You can still ride fast enough to keep the coolant temp low but cause damage from a lean condition. But if taking little risks like that make you feel alive, then by all means go right ahead.

I work on big rigs and cars for a living so I have somewhat of an idea as to what I'm talking about.

2014 WRR R.I.Pieces

2012 WR450F ECU, GYTR tuner, Yoshi RS4, MSR rad guards, Cycra Pros, and a growing wish list...

Edited September 8, 2014 by revelc

[MidlifeCrisisGuy]

OK, lets discuss this.

 

Carburetors don't measure air flow.  Fuel flow varies some what versus air velocity through the carburetor bore, but mostly fuel flow is determined by how wide the slide is open, because that opens the needle.

 

Open loop fuel injection actually measures the air going into the engine and delivers fuel accordingly.  The measurement on the WR450F is based on engine RPM, intake air temp, throttle position and manifold pressure.  Basically, the ECU looks the readings for all these things and says there must be X amount of air flowing into the engine.   It then meters out the fuel for X amount of air.

 

So when you change the muffler, more air flows.  The FI computer senses more flowing based on a lower manifold pressure and delivers fuel appropriately.   

 

A carburetor doesn't do this.  A carburetor only knows slide position and velocity through the carburetor bore.  The fuel that gets pulled into the air stream doesn't change linearly with the air velocity and thus jetting changes have to be made when the air flow for a given slide position changes.

 

MAP changes on the Yamaha fuel injection systems serve to tell the computer to add or subtract fuel from what it calculates should be needed for the calculated air flow.  Effectively it is richening or leaning out the mixture from that the ECU thinks is ideal.

 

So when one changes the air flow through the engine by running an aftermarket exhaust or installing a cam, the ECU knows that the engine is flowing more air and delivers fuel accordingly.   As long as it is accurately measuring how much air is going into the engine, the mixture is going to be fine across changes to the engine.  And if it isn't, that is what the GYTR tuner is for.

 

Like any engine, richening or leaning out the mixture affects how the engine runs.   I'm not saying the stock map is perfectly optimal, but it has never been so bad that I had the impetus to change things, mixture wise.  FWIW, this has saved me a lot of time not having to rejet a carburetor.  I ride with guys who are rejetting with ever engine mod and spring and fall to boot.   And they are mentioning that their jetting is less than optimal when the temperature and elevation changes.   I'm not feeling that.  Aside from the lean idle mixture, I'd give Yamaha a 9/10 on the WR450F fuel injection system.  

 

I've run the stock MAP in my bike from stock until now.  I am now running an FMF muffler and the 08 exhaust cam.  I use it at elevations from 2,000 feet to 8500-9,000 feet at temperatures from near freezing to about 90F.  In these conditions the mixture has been really good.  I can't ever say that its run poorly.   

 

 

The off idle response and engine heating was a different story.  Changing C1 made a big difference on my bike, but that (sub 3,000 RPM) isn't affected by the map.  

 

I had the plug out when I changed the cams. Its a gray bown color, perfect in my books.  

 

FWIW, people make a point to say that the WR450F needs to be uncorked for optimal performance.  They go on to list removing the throttle stop screw, installing the competition ECU and an aftermarket exhaust system.  What those people don't realize is that the WR450F exhaust cam is part of the restrictive system and it too needs to be addressed to get the full potential from the engine.  While map changes can affect how the engine runs, no map change is going to affect how the engine breathes and it turns out that changing how it breathes makes a huge difference in its character.

 

At the start of this thread certain people jumped all over the notion that changing the cams in a 2012 WR450F could do anything to improve it, especially in a tight woods situation.  After all, who needs more power than what a WR450F has ?

 

It turns out that there is way more to a cam swap than peak power.  It affects every aspect of the engine's character.  Engine braking, overheating, throttle response, both part and full throttle, lugging ability, over rev, peak power, etc. 

 

I'm very happy to say that installing an 08 YZ cam improves the entire character of the engine, especially for woods riding.  I verified this yesterday first hand by completing our usual 20 mile test ride way, way faster than I ever have, while using way less energy than I ever have before.  I'm usually pretty tired at the end of the 20 miles.   Yesterday I was ready to ride a second lap.  If that doesn't verify that the 08 YZ exhaust cam makes the WR450F a better bike for tight woods, I don't know what does. 

 

I also lost my buddy riding a KTM 200XC twice.  Usually we are the same speed.

 

I think the biggest change was in snotty and really technical conditions.   The bike is so much easier to control.

Edited September 8, 2014 by MidlifeCrisisGuy

[MidlifeCrisisGuy]

I don't know if its making more bottom and mid torque and power or if it just seems that way because its smoother and responds better.  I'll do some roll ons against a bike I frequently drag race (for kicks) and see.   The front end sure seems lighter though.

[MidlifeCrisisGuy]

02 sensors tell the ECU how lean/rich things are so it's nothing like that. From what Kah described it sounds like it just adjusts the initial mix for elevation with the MAP sensor but the ECU still doesn't know how rich/lean its running and only retards things when it gets too hot.

 

Krannie wasn't describing a speed density system.  There are 2 common ways to measure air going into an engine.  One is by a Mass Air Flow sensor.  Ie hotwire.  GM uses them on the fancy intakes.  The other method is by speed density, which is what I was describing above.  Its cruder, but it works and you don't have a sensitive, expensive MAF sensor to deal with.

[cracker please]

Uhhhh... Yeah. Did I say they all had MAF sensors?

02 sensors tell the ECU how lean/rich things are so it's nothing like that. From what Kah described it sounds like it just adjusts the initial mix for elevation with the MAP sensor but the ECU still doesn't know how rich/lean its running and only retards things when it gets too hot.

You can still ride fast enough to keep the coolant temp low but cause damage from a lean condition. But if taking little risks like that make you feel alive, then by all means go right ahead.

I work on big rigs and cars for a living so I have somewhat of an idea as to what I'm talking about.

2014 WRR R.I.Pieces

2012 WR450F ECU, GYTR tuner, Yoshi RS4, MSR rad guards, Cycra Pros, and a growing wish list...

Narrowband O2 sensors found in most cars are used mostly to read stoich.  You need a wideband sensor to get a good reading of "how rich/lean"  The O2 sensor keeps the idle and cruise mixture accurate but doesn't have much influence on open loop fueling.  The ECU on the bike doesn't know how rich/lean the engine is running but neither does a car ECU in open loop. 

[cubera]

This advice is absolutely true.....and absolutely wrong as well.

 

If you do not have enough skill to ride better than your buddy, more power and better handling can ( not will, but can) help you.

 

The bottom line is, LEARN HOW TO RIDE, not how to read specs and shop. 

Consider every ride a practice session, and  improve your skills with every ride.

Dang it.....now I want another trials bike.....

[cubera]

OK, lets discuss this.

 

Carburetors don't measure air flow.  Fuel flow varies some what versus air velocity through the carburetor bore, but mostly fuel flow is determined by how wide the slide is open, because that opens the needle.

 

Open loop fuel injection actually measures the air going into the engine and delivers fuel accordingly.  The measurement on the WR450F is based on engine RPM, intake air temp, throttle position and manifold pressure.  Basically, the ECU looks the readings for all these things and says there must be X amount of air flowing into the engine.   It then meters out the fuel for X amount of air.

 

So when you change the muffler, more air flows.  The FI computer senses more flowing based on a lower manifold pressure and delivers fuel appropriately.   

 

A carburetor doesn't do this.  A carburetor only knows slide position and velocity through the carburetor bore.  The fuel that gets pulled into the air stream doesn't change linearly with the air velocity and thus jetting changes have to be made when the air flow for a given slide position changes.

 

MAP changes on the Yamaha fuel injection systems serve to tell the computer to add or subtract fuel from what it calculates should be needed for the calculated air flow.  Effectively it is richening or leaning out the mixture from that the ECU thinks is ideal.

 

So when one changes the air flow through the engine by running an aftermarket exhaust or installing a cam, the ECU knows that the engine is flowing more air and delivers fuel accordingly.   As long as it is accurately measuring how much air is going into the engine, the mixture is going to be fine across changes to the engine.  And if it isn't, that is what the GYTR tuner is for.

 

Like any engine, richening or leaning out the mixture affects how the engine runs.   I'm not saying the stock map is perfectly optimal, but it has never been so bad that I had the impetus to change things, mixture wise.  FWIW, this has saved me a lot of time not having to rejet a carburetor.  I ride with guys who are rejetting with ever engine mod and spring and fall to boot.   And they are mentioning that their jetting is less than optimal when the temperature and elevation changes.   I'm not feeling that.  Aside from the lean idle mixture, I'd give Yamaha a 9/10 on the WR450F fuel injection system.  

 

I've run the stock MAP in my bike from stock until now.  I am now running an FMF muffler and the 08 exhaust cam.  I use it at elevations from 2,000 feet to 8500-9,000 feet at temperatures from near freezing to about 90F.  In these conditions the mixture has been really good.  I can't ever say that its run poorly.   

 

 

The off idle response and engine heating was a different story.  Changing C1 made a big difference on my bike, but that (sub 3,000 RPM) isn't affected by the map.  

 

I had the plug out when I changed the cams. Its a gray bown color, perfect in my books.  

 

FWIW, people make a point to say that the WR450F needs to be uncorked for optimal performance.  They go on to list removing the throttle stop screw, installing the competition ECU and an aftermarket exhaust system.  What those people don't realize is that the WR450F exhaust cam is part of the restrictive system and it too needs to be addressed to get the full potential from the engine.  While map changes can affect how the engine runs, no map change is going to affect how the engine breathes and it turns out that changing how it breathes makes a huge difference in its character.

 

At the start of this thread certain people jumped all over the notion that changing the cams in a 2012 WR450F could do anything to improve it, especially in a tight woods situation.  After all, who needs more power than what a WR450F has ?

 

It turns out that there is way more to a cam swap than peak power.  It affects every aspect of the engine's character.  Engine braking, overheating, throttle response, both part and full throttle, lugging ability, over rev, peak power, etc. 

 

I'm very happy to say that installing an 08 YZ cam improves the entire character of the engine, especially for woods riding.  I verified this yesterday first hand by completing our usual 20 mile test ride way, way faster than I ever have, while using way less energy than I ever have before.  I'm usually pretty tired at the end of the 20 miles.   Yesterday I was ready to ride a second lap.  If that doesn't verify that the 08 YZ exhaust cam makes the WR450F a better bike for tight woods, I don't know what does. 

 

I also lost my buddy riding a KTM 200XC twice.  Usually we are the same speed.

 

I think the biggest change was in snotty and really technical conditions.   The bike is so much easier to control.

Without mapping info on the Competition ECU all your cam info is worthless. I'm beginning to think this whole thread is FOS.

[FORMA MOTO]

Nearly everything above describing how the Keihin FI system works, is incorrect.

 

 

 

You need to do some more research on Keihin Throttle bodies and how they work.

They are electronic carburetors that need to be jetted (mapped) for each change in application.

They have nothing to do with the FI used on JetSkis, Snomobiles, Lawn mowers or Cars.

 

Keihin uses a modified Speed-density Open loop system.

It cannot cope with changes in intake or exahaust, but only minor changes in air pressure and temp.

 

http://www.motorcyclecruiser.com/how-electronic-fuel-injection-efi-works-how-to

 

 

There is no sensor in the TB that allows the ECU to change maps as the motor is running.

There are no variable maps either.

There is no way for the ECU to know how to change anything, other than from temp and barometric pressure data from the sensors, or a manual change to the maps.

None of it is real time, accept during a re-set procedure.

[MidlifeCrisisGuy]

Without mapping info on the Competition ECU all your cam info is worthless. I'm beginning to think this whole thread is FOS.

 

Stock map.

 

Don't shoot the messenger.   What did you think was going to happen when you install a less restrictive exhaust cam in an engine ? <shrug>  <palm to forehead>  Why is this earth shattering to people ?

Edited September 8, 2014 by MidlifeCrisisGuy

[MidlifeCrisisGuy]

From Krannie's link.

 

 

 

On the other hand, electronic fuel injection systems employ a variety of sensors that tell a computer exactly what the engine is doing at any given moment. After comparing that information to a set of known parameters called a map, the computer determines exactly how much fuel is required to maximize power while creating the lowest emissions, then adjusts the air/fuel ratio accordingly.

 

Yep.  The map is used to adjust the A/F mixture, not determine how much baseline fuel is injected.

 

You don't need to remap for changes.  The computer figures it out, as long as it can accurately measure the air flow.  If it was running 13:1 before the mod, it will run 13:1 after, except if there are measurement issues.  If you want it to run 12.5:1 or 14:1 there, change the map.

Edited September 8, 2014 by MidlifeCrisisGuy

[cubera]

Stock map.

 

Don't shoot the messenger.   What did you think was going to happen when you install a less restrictive exhaust cam in an engine ? <shrug>  <palm to forehead>  Why is this earth shattering to people ?

So you're running the stock ECU? What a joke.

[MidlifeCrisisGuy]

So you're running the stock ECU? What a joke.

 

Stock map in the comp ECU.  Check out my signature.

Edited September 8, 2014 by MidlifeCrisisGuy

[revelc]

Stock map in the comp ECU. Check out my signature.

The comp ECU has its own map. So MLCG is not running the stock ECU map

2014 WRR R.I.Pieces

2012 WR450F ECU, GYTR tuner, Yoshi RS4, MSR rad guards, Cycra Pros, and a growing wish list...

[cracker please]

I think Keihin just makes the throttle body.  The ECU has a yamaha symbol on it and says "moric" which I think is yamaha's motor electronics division.

[FORMA MOTO]

K

 

From Krannie's link.

 

 

 

 

Yep.  The map is used to adjust the A/F mixture, not determine how much baseline fuel is injected.

 

You don't need to remap for changes.  The computer figures it out, as long as it can accurately measure the air flow.  If it was running 13:1 before the mod, it will run 13:1 after, except if there are measurement issues.  If you want it to run 12.5:1 or 14:1 there, change the map.

 

...but not for the kind you have.

That is for closed loop or multi cylinder versions that have constant manifold pressure that can be relied upon.

The single cylinder Keihin FI is not 'real' FI, because it cannot alter FI past the +/- range of the base map.

[cubera]

Settings on the Comp ECU out of the box are all balls (0000000). It's not that bad but not nearly as good as the FMF or Aussie maps. Not even close.

So the perceived benefits of the '08 YZ exhaust cam cannot be fully realized without commensurate changes to tuning.

I'm a tediously slow methodical simpleton. Help me understand why mapping changes are not included with cam swap impressions and recommendations.

[MidlifeCrisisGuy]

Settings on the Comp ECU out of the box are all balls (0000000). It's not that bad but not nearly as good as the FMF or Aussie maps. Not even close.

So the perceived benefits of the '08 YZ exhaust cam cannot be fully realized without commensurate changes to tuning.

I'm a tediously slow methodical simpleton. Help me understand why mapping changes are not included with cam swap impressions and recommendations.

 

Because I make one change at a time and I didn't have time to be testing a bunch of maps yet ? 

 

I haven't ridden it enough to find a weakness where I would even want to change the map.  It runs awesome the way it is.  Everywhere.  Maybe in a month I'll get bored and try boosting it somewhere.  Because you never know when you'll need more power on these things.  LOL.

 

Maybe I need to repeat how awesome it is now ?   Install one, you'll see what I mean.

Edited September 8, 2014 by MidlifeCrisisGuy

[cubera]

Fair enough. It takes all of 5 minutes to change mapping. I'm interested in how the '08 cam responds to fuel and ignition adjustments.

 

I'm trying to anticipate what I'll need when the head goes off for porting.

[MidlifeCrisisGuy]

I'll report when I do it, but I don't think I'm riding next weekend.

 

What would be really interesting is if you need to port the head on these things.  I would have tried cams first.

[cracker please]

So you could just let the MAP sensor hang in the atmosphere and plug the hole and it would have no effect on performance?