TTS - idle - open or closed loop

[07heri]

Typical Texas summer again.  I love being able to ride all year so I guess I'll take it over snow.

Anyway, I've read of some folks going open loop at idle to try to keep the heat down.  After reading the TTS tuning manual it appears that this already happening.

3.11.
EITMS - Engine Idle Temperature Management System
The EITMS system was developed to reduce heat buildup during prolonged idling times and controls heat buildup in two stages:
1. Mode 1 – AFR Enrichment
2. Mode 2 – Skip Fire / Rear Cylinder shutoff

Mode 1 will be activated under the following conditions:
1. The engine temperature exceeds 142 °C (Sportsters 230 °C)
2. The Engine RPM is less than 1200 RPM

Mode 2 (Big Twins only) activates if Mode 1 is active AND
1. The engine temperature exceeds 155 °C
2. The vehicle speed is less than 1-2 KPH

Note that Sportster temperatures are much higher due to the location of the temperature sensor and only use EITMS Mode 1 (AFR enrichment).

So, if I end up at long red light, or any condition below 1200 rpm's, what is the AFR programmed to in mode 1?  When I stop I will obviously be below 1200 rpm's and the temp above 142 degrees, here in Texas anyway.

Is it even necessary to go open loop at idle if the EITMS is already programmed to enrich at these parameters?  What the tuning guide didn't say was what the AFR is under these conditions, which is what prompted this question.

Remember guys, this Texas.  It's not uncommon to see 105-110 degrees in the later parts of the day.  If I was in a cooler part of the country I would just keep it closed loop and ride on.  But down here there has to be something that will work best with the temps we see.

[strokerjlk]

sure there is a big advantage to going open loop at idle.

now the rest of the stuff your kinda off on. the temps are C not F so it isnt what your thinking
when you actually start to hear/feel the affects of  EITMS, it's time to get moving

[Ohio HD]

sure there is a big advantage to going open loop at idle.

now the rest of the stuff your kinda off on. the temps are C not F so it isnt what your thinking
when you actually start to hear/feel the affects of  EITMS, it's time to get moving

Yep, when the EITMS comes on, your seconds away from a blast furnace between your legs. I have the idle area set to 13.8 AFR. Runs cool there, and idles just fine.

[07heri]

Why is it in Celcius and not Farenheit? Seems it would be easier to follow...

Anyway, I'll leave it at 13.8 and press on.

Thanks 

[glens]

I've open-looped the idle area in the past, too.  But this time I've left it closed and have not had much EITMS activity.  The thing that concerns me, being a huge fan of closed-loop tune maintenance/protection, is not knowing where the AFVs are in my calibration or whether an area would lose all their benefit by going open and possibly "stranding" an AFV.  I've asked the question of the "power that be" many times and have never gotten an answer.  And I'm too lazy to spend all the time it would take, or spend the money on the extra gear it would take, to find out for myself.  I think it's a reasonable question to ask...

Steve:  Would/could going open-loop in just one small area, especially on one end or the other of the "spectrum", cause an AFV to become inactive, and if this happens, will that area lose all open-loop fuel modification that would otherwise result from the AFV's activity?  Or would the adjacent "active" one pick up the task and maintain such coverage for the area in question anyway?

[Steve Cole]

AFV's effect an area, not just one value so if in that area you need several different corrections your going to be in trouble. Going Open loop may or maynot effect things differently based on how good of a job you did when tuning. As I've said before how the AFV's are setup is something we do not share. It is one of the pieces of the puzzle that we spent many many hours on developing for our base calibrations.

[Sporty 48]

I have closed loop at idle.
It is too difficult to anticipate the variables or control idle conditions at set AFR.
Heck, that ECU should be good for something, and it is; too rich, too lean, too rich, too lean, how many times per second? More than I can count.

[strokerjlk]

I have closed loop at idle.
It is too difficult to anticipate the variables or control idle conditions at set AFR.
Heck, that ECU should be good for something, and it is; too rich, too lean, too rich, too lean, how many times per second? More than I can count.

what did you use to determine ..that it is difficult to control idle in open loop?
tuning ve's with a narrow band to stoich, and then changing the AFR to something other than 14.6 ? 

[hrdtail78]

I have closed loop at idle.
It is too difficult to anticipate the variables or control idle conditions at set AFR.
Heck, that ECU should be good for something, and it is; too rich, too lean, too rich, too lean, how many times per second? More than I can count.

I agree.  Let the ECM do it's job.

[07heri]

I have closed loop at idle.
It is too difficult to anticipate the variables or control idle conditions at set AFR.
Heck, that ECU should be good for something, and it is; too rich, too lean, too rich, too lean, how many times per second? More than I can count.

Can you elaborate a little more on what you're talking about?  I'm asking about trying to cool this thing down at idle in 100+ degree temps.  My knowledge is limited, but I can understand the basics of how closed loop can have it's advantages in changing situations.  I guess I just don't see the advantage of idling at 14.6 or whatever in CL when the bike should run cooler at say 13.8 in OL.  It's should transition back to CL at whatever cells I have set to 14.6 right?  If it gets hot it's going into OL anyway right?  Why not just run it open loop from the git go and avoid it getting hot to start with?

I'm hoping some of the tuners weigh in on this.  Did tuners set up bikes to idle at 14.6 BEFORE the CL system came around?  If yes, why so?  If no, why so?

Hopefully this question wasn't taken as to start a debate.  I'm just trying to learn what's best for the engine during the hot summers.         

[Thumper Buttercup]

07heri,

   If you look at my Cals that Mayor made you will see we went to open loop
at idle to cool down our bike, we had too.  It's much better now.

[strokerjlk]

I have closed loop at idle.
It is too difficult to anticipate the variables or control idle conditions at set AFR.
Heck, that ECU should be good for something, and it is; too rich, too lean, too rich, too lean, how many times per second? More than I can count.

Can you elaborate a little more on what you're talking about?  I'm asking about trying to cool this thing down at idle in 100+ degree temps.  My knowledge is limited, but I can understand the basics of how closed loop can have it's advantages in changing situations.  I guess I just don't see the advantage of idling at 14.6 or whatever in CL when the bike should run cooler at say 13.8 in OL.  It's should transition back to CL at whatever cells I have set to 14.6 right?  If it gets hot it's going into OL anyway right?  Why not just run it open loop from the git go and avoid it getting hot to start with?

I'm hoping some of the tuners weigh in on this.  Did tuners set up bikes to idle at 14.6 BEFORE the CL system came around?  If yes, why so?  If no, why so?

Hopefully this question wasn't taken as to start a debate.  I'm just trying to learn what's best for the engine during the hot summers.       

Sounds like you understand just fine 

[aharp]

 

I have closed loop at idle.
It is too difficult to anticipate the variables or control idle conditions at set AFR.
Heck, that ECU should be good for something, and it is; too rich, too lean, too rich, too lean, how many times per second? More than I can count.

Can you elaborate a little more on what you're talking about?  I'm asking about trying to cool this thing down at idle in 100+ degree temps.  My knowledge is limited, but I can understand the basics of how closed loop can have it's advantages in changing situations.  I guess I just don't see the advantage of idling at 14.6 or whatever in CL when the bike should run cooler at say 13.8 in OL.  It's should transition back to CL at whatever cells I have set to 14.6 right?  If it gets hot it's going into OL anyway right?  Why not just run it open loop from the git go and avoid it getting hot to start with?

I'm hoping some of the tuners weigh in on this.  Did tuners set up bikes to idle at 14.6 BEFORE the CL system came around?  If yes, why so?  If no, why so?

Hopefully this question wasn't taken as to start a debate.  I'm just trying to learn what's best for the engine during the hot summers.       

Sounds like you understand just fine 

[Onthefence]

I tried 13.8 in the map rpm cells where idle is.  No measured change in engine temps. 

[Ohio HD]

I think unless we calibrate our VE tables against a gas / air analyzer, we don't know if 13.8 is really giving us 13.8. Maybe try a lower value.







Brian

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[Steve Cole]

Only TTS base calibrations richen the mixture at idle as long as EITMS is left on. So if your running closed loop control at idle, as the temperature climbs the system will begin to richen the mixture automatically to TRY and help with cooling. It will continue to richen as long as the temperature rises and it will then begin to skip fire the engine to again cool the engine.

Some people thing that running in Open loop at a richer mixture will solve the heat at idle issue, they are sadly mistaken as it doesn't work. In our testing running closed loop idle versus open loop idle and allowing the bike to run in a normal idle not moving test the variation from what I would call dead rich (12:! open loop) to closed loop was about 5 seconds difference. It slowed the heat up by about 5 seconds but it still got just as hot either way.

[rbabos]

Seriously, 5 seconds .  me, I've heard it all now.
Ron

[Onthefence]

Only TTS base calibrations richen the mixture at idle as long as EITMS is left on. So if your running closed loop control at idle, as the temperature climbs the system will begin to richen the mixture automatically to TRY and help with cooling. It will continue to richen as long as the temperature rises and it will then begin to skip fire the engine to again cool the engine.

Is Skip fire really cooling anything?  Once skip fire kicks in the ET rises fairly quick.  What is happening on the rear cylinder?  Is it holding steady or rising slower?

Some people thing that running in Open loop at a richer mixture will solve the heat at idle issue, they are sadly mistaken as it doesn't work. In our testing running closed loop idle versus open loop idle and allowing the bike to run in a normal idle not moving test the variation from what I would call dead rich (12:! open loop) to closed loop was about 5 seconds difference. It slowed the heat up by about 5 seconds but it still got just as hot either way.

You shouldn't let measurements and facts get in the way internet myths

[Steve Cole]

Skip fire allows the engine to draw air only into the cylinder and then push it out on the exhaust stroke. This cools the cylinder and head. Yes it really does work but we do not just cut the rear cylinder only as HD does as that just places all the load on the front cylinder. So by skip firing both cylinders it pulls heat from each one to slowly cool the entire engine down.

Only TTS base calibrations richen the mixture at idle as long as EITMS is left on. So if your running closed loop control at idle, as the temperature climbs the system will begin to richen the mixture automatically to TRY and help with cooling. It will continue to richen as long as the temperature rises and it will then begin to skip fire the engine to again cool the engine.

Is Skip fire really cooling anything?  Once skip fire kicks in the ET rises fairly quick.  What is happening on the rear cylinder?  Is it holding steady or rising slower?

Some people thing that running in Open loop at a richer mixture will solve the heat at idle issue, they are sadly mistaken as it doesn't work. In our testing running closed loop idle versus open loop idle and allowing the bike to run in a normal idle not moving test the variation from what I would call dead rich (12:! open loop) to closed loop was about 5 seconds difference. It slowed the heat up by about 5 seconds but it still got just as hot either way.

You shouldn't let measurements and facts get in the way internet myths

[strokerjlk]

Seriously, 5 seconds .  me, I've heard it all now.
Ron

Ron
Better bookmark this one for later ....the BS is thick

[glens]

I ended up spending a fair amount of time riding in and around town early this evening in triple digit temperatures.  Got my fairing lowers on and am running closed-loop idle with a 103 running SE255 cams.  The idle speed did lower a little once or twice, but the skip fire never once occurred.  No BS, just FYI.  According to a lot of what I've been reading lately, I'd have expected molten aluminum to be drizzling down out of my frame...

[Jeffd]

my idle is in closed loop and it has never been an issue as far as I can tell.  the bike fires up and settles in at 1000 rpm and never wavers.  I have not been in 115* temps but have been in Sturgis traffic at 100*.  I eimts enabled but not sure if it has ever kicked on.  2011 rgu with 20,000 miles. 

[HogMike]

my idle is in closed loop and it has never been an issue as far as I can tell.  the bike fires up and settles in at 1000 rpm and never wavers.  I have not been in 115* temps but have been in Sturgis traffic at 100*.  I eimts enabled but not sure if it has ever kicked on.  2011 rgu with 20,000 miles.

I've got my idle set at 1056, just cause I like it there. I never thought/knew about the skip fire, I just thought the TTS cut the rear cylinder like the stock system.
My bike does not go to etims that I am aware of......triple digits Southwest weather. Oil temps get to a max about 260-275 that I had stored in the memory. Just never think about it. Bike just runs fine.

[rbabos]

my idle is in closed loop and it has never been an issue as far as I can tell.  the bike fires up and settles in at 1000 rpm and never wavers.  I have not been in 115* temps but have been in Sturgis traffic at 100*.  I eimts enabled but not sure if it has ever kicked on.  2011 rgu with 20,000 miles.

Skip fire is a function of where the iac point is set withing the ecm constants. Depending on how iac points are determined with tune , settings etc it might never hit the ecm point. Last time I looked that point was adjustable, so most likely skip fire can be set to a given temp . Smoking hot, my iac point would not drop below 14, yet the skip was set to 12. At the time I was reading 300 on the head temp which is too damn hot, period. I might add, there was not detectable enrichment happening either.
Ron

[guydoc77]

In another 5 seconds or so there would have been Ron.