Head Temps
Outstanding HDF Member
Joined: Jan 2007
Posts: 2,598
Likes: 19
From: Naples FL / Pine TWP PA
I didn't know either and figured that is where some of the confusion was coming from and even mentioned it at some point. I didn't mention that my wife has a bone stock 2014 RK and I took it on the exact same ride and her head temps (using IR gun, but close enough) were about 15 hotter than mine. Figured I didn't have a problem but still wanted an answer as to what the differences are.
I loaded my AT results yesterday and made several more test log runs. It's running great and the first run, I had about 15 knock events on the front and 20 on the rear after my initial timing changes. Mostly around 60 map and 2500 rpm range. I timed those out yesterday and managed to only get 1 event and have made the adjustment, just a little lower. I'm pretty aggressive on my timing and only retarded 2 degrees in those areas. I had to go 2.5 degrees for the one that came back.
If weather holds up tonight, I have several more logging runs to make where I can do all out WOT and a couple lugging up the hill to make sure I am spot on. It's nice to know that I can ditch the HeadT gauge and add something else in its place.
Yes, please do send the map when you have time. I'd love to study it as I am learning.
I loaded my AT results yesterday and made several more test log runs. It's running great and the first run, I had about 15 knock events on the front and 20 on the rear after my initial timing changes. Mostly around 60 map and 2500 rpm range. I timed those out yesterday and managed to only get 1 event and have made the adjustment, just a little lower. I'm pretty aggressive on my timing and only retarded 2 degrees in those areas. I had to go 2.5 degrees for the one that came back.
If weather holds up tonight, I have several more logging runs to make where I can do all out WOT and a couple lugging up the hill to make sure I am spot on. It's nice to know that I can ditch the HeadT gauge and add something else in its place.
Yes, please do send the map when you have time. I'd love to study it as I am learning.
Thread Starter
|
Road Warrior
Joined: Jul 2013
Posts: 1,624
Likes: 13
From: Fort Worth
Will do. I wanted the best performance I could get without any knock events so my adjustments were really small over a lot of runs until I got all knock events removed while maintaining maximum timing. Then I worked on closed loop AFR until I got the cylinder head temp where I wanted it without creaming fuel economy. Then I started to play with how much fuel to add when I hit the throttle hard. I stuck close to Jamie's setting but I did get a little more aggressive in a few places for kind of a turbo boost effect. It works well. When I hammer the throttle hard, I can lift the front wheel. Really this is where a dyno would come in handy but just kind of have to do it by the seat of my pants and watch how fast the motor spools up.
Cruiser
Joined: Sep 2010
Posts: 174
Likes: 1
From: Harrisburg, PA
Head Temps
I recently got back from a 3500 mile trip from PA to Florida to New Orleans and back to PA with misc stops and detours along the way. I believe anything worth doing is worth overdoing.. : ) I have the Jagg 10 row cooler installed with fan assist. I also installed the Wards Parts Werks FCS fans.
I did a lot of interstate riding with OAT between 80-90 degrees. Speeds on avg between 70-80MPH. I have Dakota Digital gauges installed and monitor my head temp all the time through the gauges.
Overall with Jason's fans on avg I would see about a 20-25 degree drop by using the fans. My bike would run with the fans on at about 235 to 241 at highway speeds. I turn the fans off and the temp would rise to about 260-265. When I installed the Jagg oil cooler with fan assist I did NOT install their temp switch. I wired it to my acc switch because I wanted to manually control the fan. Jason's fans also cool the oil by cooling the heads. Before I installed either the cooler or the fans my oil would consistently hit 230 degrees. The FCS fans help maintain oil temp and when the OAT is high enough to add a few extra degree to my oil temp I kick the oil cooler fan on and it drops it right now.
I can start the bike and let it idle and it never even comes close to the ETMIS system or whatever they call it which kicks in at about 290 degrees.
If I had to choose one product over the other it would be the FCS Fans from Jason. It helps with the head temps without a doubt!!
I did a lot of interstate riding with OAT between 80-90 degrees. Speeds on avg between 70-80MPH. I have Dakota Digital gauges installed and monitor my head temp all the time through the gauges.
Overall with Jason's fans on avg I would see about a 20-25 degree drop by using the fans. My bike would run with the fans on at about 235 to 241 at highway speeds. I turn the fans off and the temp would rise to about 260-265. When I installed the Jagg oil cooler with fan assist I did NOT install their temp switch. I wired it to my acc switch because I wanted to manually control the fan. Jason's fans also cool the oil by cooling the heads. Before I installed either the cooler or the fans my oil would consistently hit 230 degrees. The FCS fans help maintain oil temp and when the OAT is high enough to add a few extra degree to my oil temp I kick the oil cooler fan on and it drops it right now.
I can start the bike and let it idle and it never even comes close to the ETMIS system or whatever they call it which kicks in at about 290 degrees.
If I had to choose one product over the other it would be the FCS Fans from Jason. It helps with the head temps without a doubt!!
Banned
Joined: Apr 2012
Posts: 648
Likes: 9
From: WV
Unfortunately the only place everything is documented is going to be in the actual definitions written by Delphi for the Motor Company, for us on the outside it is kinda like a big puzzle of putting the pieces together. A short answer for what you are asking is ET is used for most of the lookup tables including the fuel tables and multipliers, while Head Temp is used primarily for spark temp correction.
Banned
Joined: Apr 2012
Posts: 648
Likes: 9
From: WV
I'm not a tuning expert by any means but your "cruise" AFR extends out to 4K RPM, that seems a little excessive to me. With a 6 speed I wouldn't think you would need the cruise AFR much past 3K.
Ultimate HDF Member
Joined: Dec 2010
Posts: 7,776
Likes: 2,252
From: wet coast BC
...................... The second channel is Head Temperature which this is a bit more complex, it is a model the ECM calculates based on the ET sensor, the intake air temp (IAT) and other factors. Head Temp is used within the ECM primarily for Spark Temp correction, for most combination it will run between 260-400F. Note: Heat Temp has been recently added to the PV channel list an is reported as HeadT. The last channel is Coolant Temp which is active on twin cooled and V Rod applications. Hope this info helps...
.................... I need a comprehensive understanding of how and why two different temp readings are being generated from one sensor to express "ET" and "HeadT", which are both another way of expressing CHT. Which PV manual will I find detailed info on HeadT?
I called Dynojet but they weren't up to speed on the HeadT value, he's going to go out in the shop and play with a system to see what he can find out. I'm thinking this value is not going to provide any useful information to the end user, at least for the purpose of moitoring operating temperature.
This now makes sense to me since there is not an actual sensor reading that the head temp, but it can be confirmed with a IR temp at behind the spark plug so it is just a guess made by the software which may well be close to accurate.
There are several temp related channels within the Delphi ECM. The most common channel used is Engine Temperature which is based directly off the 0-5V signal from the ET sensor on the front cylinder head, this channel is reported on the databus as ET. Generally speaking when we speak of engine temp we refer to the data from this channel, we usually consider 240-320F about the normal range relative to conditions, engine mods, and other variables. The second channel is Head Temperature which this is a bit more complex, it is a model the ECM calculates based on the ET sensor, the intake air temp (IAT) and other factors. Head Temp is used within the ECM primarily for Spark Temp correction, for most combination it will run between 260-400F. Note: Heat Temp has been recently added to the PV channel list an is reported as HeadT. The last channel is Coolant Temp which is active on twin cooled and V Rod applications. Hope this info helps...
THIS!!
Thank you Jamie! I know this is a slightly older thread, but, I have recently added the HeadT output on my data log gauges. Yesterday it was up to 380*F and this morning about 340*F. My ET was around 305*F yesterday and 265*F this morning. They're both pretty high, but, the HeadT was making me poop kittens.
Last edited by devildocjames; Jul 22, 2015 at 11:06 AM.
Well I tuned the timing first, got all the knock out, then I worked on the AFR via the 02 sensor bias voltage. I worked on fuel until I got the cylinder head temps where I wanted them. I tuned specifically for cylinder head temp because I care more about reliability than I do max power.
I've been going through my tunes and tweaking them, but, I still get up into the 300's in Southern California weather (70-80's). I only stay under those temps if I'm cruising on the freeway or if it's early in the morning.
Thread
Thread Starter
Forum
Replies
Last Post
Brion B
Sportster Models
5
Oct 8, 2012 10:06 AM