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Screamin' Eagle
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Now that I am done with my 95" build break-in, I will be taking it back in for another tune. How low can I safely set my warmed up idle RPM? I would like to set this a low as possible without affecting engine balance and electrics.

Thanks.
 

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ASA Lives
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If you read the service manual, it states that the idle should be no lower than 1000 rpm. This is to provide the proper oil pressure to all areas of the motor. You can set the idle lower, but you do so at risk of damage to components. With the older motors, like the Shovels, Pan, and Knuckle heads, they were very loose. But the newer ones are made to tight tolerances.:corn:
 

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Manuals call for 950-1050 rpm, FLHTs at the upper end. EFI limits lowest to 800 rpm (newer versions of SERT). How far down can you safely go? Well stay with the MoCo's recommendation.
 

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what is the point

ViennaHog said:
Manuals call for 950-1050 rpm, FLHTs at the upper end. EFI limits lowest to 800 rpm (newer versions of SERT). How far down can you safely go? Well stay with the MoCo's recommendation.
of going lower? Am I missing something?
 

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I set mine at 848 rpm with no problems. 95 ci , 37g,bs staggered, sert,9.8:1




ericsenf said:
Now that I am done with my 95" build break-in, I will be taking it back in for another tune. How low can I safely set my warmed up idle RPM? I would like to set this a low as possible without affecting engine balance and electrics.

Thanks.
 

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if your oil pr is as low as 5-10 psi at 1000 rpm, what do you think it is at 800, or 700??

pa-tay-toe...pa-tay-toe...pa-tay-toe
 

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Keep your fuel inj idle between 950 and 100 RPM. If not you risk not maintaining a sufficient charge to the battery. It's my understanding that it's not an oil pressure issue.
 

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I don't remember where I saw it, but somewhere I saw that 912 RPM is what is required to keep the alternator spinning fast enough to keep the battery from discharging while idling.
 

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Idle speed

Got an 05 Springer up in the barn that idles fine at 850 rpms hot and sounds good.Oil pressure runs 20-25 psi depending on oil temp with no problem.Has a feuling pump with Baisley spring in it.Since it does not sit idling a lot, charging is not a problem.
Tom
 

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bigbluff said:
I don't remember where I saw it, but somewhere I saw that 912 RPM is what is required to keep the alternator spinning fast enough to keep the battery from discharging while idling.
With the small time spent at Idle I would think this would not matter. I have heard it is problem with oil getting to everything..but I have mine at 848rpm as well and I still have 10psi at HOT idle..so Im running with it
 

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I read on dtt's website idle rpm under 1000 is possible with their ecu but they caution it should not be done with the stock oil pump. It is not just a pressure issue but since the harley oil pump is a dual pump one portion for oil lubrication the other for the dry sump scavanging. They say the stock pump will not keep the sump dry, not large enough under 1000 rpm. They sugest only using their low rpm mode if you have a high volume pump like a fueling. I read also that the oil spray nozels under the pistons have will not open until 28 psi.
check this link page 3 ( http://www.daytona-twintec.com/download/TCFI2D_Low_Idle_Tech_Note.pdf )
( http://feulingparts.com/wp/feuling/v-twin/harley/support/feuling-twin-cam-engine-tech-memo/ )
 

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cts1950 said:
I read on dtt's website idle rpm under 1000 is possible with their ecu but they caution it should not be done with the stock oil pump. It is not just a pressure issue but since the harley oil pump is a dual pump one portion for oil lubrication the other for the dry sump scavanging. They say the stock pump will not keep the sump dry, not large enough under 1000 rpm. They sugest only using their low rpm mode if you have a high volume pump like a fueling. I read also that the oil spray nozels under the pistons have will not open until 28 psi.
check this link page 3 ( http://www.daytona-twintec.com/download/TCFI2D_Low_Idle_Tech_Note.pdf )
( http://feulingparts.com/wp/feuling/v-twin/harley/support/feuling-twin-cam-engine-tech-memo/ )

Good info, I wonder if the 07+ pumps help since the Moco Claims 20% more flow
 

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I have mine set at 954 and oil pressure is good and never had any charging issues. I dont think I would go any lower with it.-2$en#e-
 

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ericsenf said:
Now that I am done with my 95" build break-in, I will be taking it back in for another tune. How low can I safely set my warmed up idle RPM? I would like to set this a low as possible without affecting engine balance and electrics.

Thanks.

EFI = 950-1050 RPM per service manual. Put it where you want it and if fries then you'll know why the service manual states what it does.


Just My -2$en#e- Worth..................



{salute( :spank: {salute(
 

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cts1950 said:
I read on dtt's website idle rpm under 1000 is possible with their ecu but they caution it should not be done with the stock oil pump. It is not just a pressure issue but since the harley oil pump is a dual pump one portion for oil lubrication the other for the dry sump scavanging. They say the stock pump will not keep the sump dry, not large enough under 1000 rpm. They sugest only using their low rpm mode if you have a high volume pump like a fueling. I read also that the oil spray nozels under the pistons have will not open until 28 psi.
check this link page 3 ( http://www.daytona-twintec.com/download/TCFI2D_Low_Idle_Tech_Note.pdf )
( http://feulingparts.com/wp/feuling/v-twin/harley/support/feuling-twin-cam-engine-tech-memo/ )
Well DTT may say that but for us in the field that have tried it I say Heck NO.
1000 min 1030+ even better
Their ECU doesn't process too well down low and off idle. Case and point, so many of us have found more stability locking out the first two cell blocks from closed loop
 
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