idle rpm goes up some times

[hendrixgr]

Hi.
Lately i am experiencing a strange problem, after a 5th or 6th speed pull when i close the throttle and engage the clutch
my idle rpm stays to 1500-1800 rpm before it starts to creep down very slowly.
Even if i select the neutral without pulling the clutch it does the same.
I have the strange feeling that this started after i cleaned the plenum injectors with ultrasounds.
If anyone has experienced this i would like to know how he solved it.

Btw yesterday i changed the oil from Redline to Motul 300v (all 10W40)
Here are the differences i noticed (when both oils were fresh from the bottle):

1) smoother and quieter operation with warmed up engine at least for now that the Motul 300V oil is still fresh, the Redline did
not show any deterioration over the 4000km i had them on the bike, in fact when i took them out they looked almost like new.
Note: the oil, magnetic oil plug and filter did not had any metal fragments in them.

2) I can hear the cam chain when the bike is cold but the noise goes away when the engine heats up
With Redline i couldn't hear the cam chain in any case.

3) Gear changes are smoother when the engine is up to operating temperature.
With Red line when the engine was up to temperature gear changes were a bit rougher,
It almost looks like the Redline oil does not like to get hot.

Chris

 

[Boosted Cycle Perf]

Hayabusas have something called ram air compensation that activated in 5th and 6th gear. Basically it makes up for the extra air coming in the ram air tubes at speed', so it injects I think like 7-9% more fuel.

If it doesn't do in in any other gear then 5-6 I'm sure that's what it is. Why you pulling in your clutch at speed in 5 or 6th anyways?

 

[hendrixgr]

Hi.
When i had enough from a high speed run (or the road is shrinking fast ) i always pull the clutch until the speed comes down to normal cruising speed (applying brakes or simply rolling, it depends on the road left) where i engage the clutch again, is this wrong?
I have the ram air compensation disabled by checking the "turbo" check box in ecueditor for gen1 bikes.
My initial guess is that the throttle plates which are synchronized have bend a little or maybe a vacuum hose sucks air
but i am not that sure that this would cause only a 500rpm rise.
Chris

 

[nosbig]

I would think that the bike would slow faster with the transmission helping. Opposed to just costing to a stop. Maybe I am wrong I am not a turbo guy.

 

[hendrixgr]

I would think that the bike would slow faster with the transmission helping. Opposed to just costing to a stop. Maybe I am wrong I am not a turbo guy.

You are right but the autotune module i have installed wants me to disengage the engine while slowing down in order to make correct predictions.
I used to use the engine for braking but now it became a habit of mine to just let the bike roll while pulling the clutch.
Chris

 

[hendrixgr]

I want to share an idea i had just now.
I suspect that when i pull the clutch and close the throttle the turbo still spins because of the BOV valve and still provides some pressure above ambient for a while.
This in turn raises the idle a bit (more air and somewhat rich a/f) until the turbo spools down.
Is this possible or the turbo stops spinning the moment i close the throttle?
Chris

 

[Boosted Cycle Perf]

I hope you're not auto tuning and boost.

I'd also disable the auto tune and then go out and see if it does it. Your sure ram air is disabled? Are your maps unified?

 

[hendrixgr]

I hope you're not auto tuning and boost.
I'd also disable the auto tune and then go out and see if it does it. Your sure ram air is disabled? Are your maps unified?

I use the autotune module with great success especially in the transition range between no boost and low boost but i have it disabled
in the vacuum range under 4800 rpm so it shouldn't interfere with the idle.
Of course i had the engine tuned prior enabling the autotune module.
The AEM failsafe gauge (and it's log) i have shows the A/F to be a completely flat line at 11.3 on boost an d 13.2 on the vacuum side.
In fact the bike has never been performing stronger and smoother than it does now.
About the Ram air compensation, yes i do have the ram air compensation disabled, i just checked, but i noticed that i also have unchecked the "IAT disable for dyno" which enables the IAT corrections
(Usually i have it at "IAT fixed at 24C") so could this add some idle instability when the engine warms up?
About the maps, they are unified but maintaining the offset between cylinders 1-4 and 2-3, I have tried unifying them completely but i didn't like the outcome so i reverted back to maintaining the offset.
Should i try unifying them one more time just to check?
Chris

 

[Boosted Cycle Perf]

You've gotten lucky if you haven't melted the engine yet.

If you don't unify fuel and ignition maps the ecu uses multiple fuel and ignition maps. Unifying makes it so the ecu uses 1 ignition and one fuel map.

And on a side note how much boost are you running? Don't y'all have 98 octane over there? 11.3 under boost is pretty fat.

 

[hendrixgr]

I am running 12 psi max and i also have a water/air intercooler with 4 additional injectors an external Bosch fuel pump and an aeromotive 1:1 fuel regulator so there is no problem whatsoever.
See here: https://www.hayabusa.org/forum/turbo/182536-finally-i-went-turbo.html
I know that i can go up to 12:1 easily with 100 octane (your 98 i think) fuel which i can get everywhere here but i prefer to loose some power and be extra safe instead.
I will try with unified maps also then...
Chris

 

[Boosted Cycle Perf]

We only have 93 here.

And with air to water, you absolutly do not need meth injection, specially at that boost level. 11.8 on your guys fuel is still overly safe. Like wearing 3 condoms safe. but seriously, there's not need for meth and downing it with fuel.

 

[OZBooster]

Your 93 is pretty much the same as our 98

slight throttle body plate imbalance or vac leak may raise the idle

also check your throttle bodys are not lifting out of the rubbers or rubbers not lifting off the head

 

[hendrixgr]

Your 93 is pretty much the same as our 98

slight throttle body plate imbalance or vac leak may raise the idle

also check your throttle bodys are not lifting out of the rubbers or rubbers not lifting off the head

I will check those parts for sure this week, i am leaning on the throttle plates....
Chris

 

[hendrixgr]

We only have 93 here.

And with air to water, you absolutly do not need meth injection, specially at that boost level. 11.8 on your guys fuel is still overly safe. Like wearing 3 condoms safe. but seriously, there's not need for meth and downing it with fuel.

You are correct, i have been thinking of raising this to 11.8 for a long time, maybe it is time to actually do it

 

[Boosted Cycle Perf]

Your 93 is pretty much the same as our 98

slight throttle body plate imbalance or vac leak may raise the idle

also check your throttle bodys are not lifting out of the rubbers or rubbers not lifting off the head

Thought that too, but he said it happens in 5-6th. That's what got me to say what I did.

 

[Boosted Cycle Perf]

You are correct, i have been thinking of raising this to 11.8 for a long time, maybe it is time to actually do it

Do it!!! You'll pick up 20hp or so. Don't pull any timing ither.

 

[Kevin Jones]

Is 11.8 safer because of his intercooler or just that much safe in general? Ive been 11.1-11.3 since Johnny built that limp **** map.

 

[hendrixgr]

Do it!!! You'll pick up 20hp or so. Don't pull any timing ither.

It is done, i am now at 11.7 and yes it picked up power as expected but the bike became a bit nervous
Btw i conducted some tests today and i am pretty sure that the throttle barrel plates are sticking a bit...
Chris

 

[Boosted Cycle Perf]

Is 11.8 safer because of his intercooler or just that much safe in general? Ive been 11.1-11.3 since Johnny built that limp **** map.

Realistically 12-12.2 is still safe on pump fuel with an intercooler. 11.1-11.3 is overly safe on a non intercooled stage 1 bike. 11.5-6 is still safe no intercooled.

It is done, i am now at 11.7 and yes it picked up power as expected but the bike became a bit nervous
Btw i conducted some tests today and i am pretty sure that the throttle barrel plates are sticking a bit...
Chris

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