switching tunes, shifts weird.
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From: Farmington, MO
switching tunes, shifts weird.
I really havent switched my tunes much, but I did some testing, and when I change tunes, drag/steet/tow, at wot, it will shift at around 4k, and each wot run, it will slowly go up higher, and after about 5-10 wot runs, it will finally shift at 5400, where it should. Is this what you call "learning" for the pcm? I never noticed it untill a while back... Also, it shifts a lot harder when the tune is first put it, then it gets pretty soft, and i have the tune set to max firmness. Im hoping this is normal...
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Originally Posted by built54
I really havent switched my tunes much, but I did some testing, and when I change tunes, drag/steet/tow, at wot, it will shift at around 4k, and each wot run, it will slowly go up higher, and after about 5-10 wot runs, it will finally shift at 5400, where it should. Is this what you call "learning" for the pcm? I never noticed it untill a while back... Also, it shifts a lot harder when the tune is first put it, then it gets pretty soft, and i have the tune set to max firmness. Im hoping this is normal...
Yup - normal.... check out this thread:
https://www.f150online.com/forums/sh...d.php?t=255977
Cheers
Bubba
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From: Farmington, MO
Sounds like its normal, but I thought at WOT it didnt affect the shifting? I hear of people changing tunes in the staging lanes, and run the track... If i did that, i would run about a 20 because it shifts way too soon untill i put about 100 miles on it...
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From: Atlanta, GA
Mine does the same thing, and will finally settle in around, if I really get on it and let it go, 5800rpm. I don't like that, as it has really run out of breathe up there and isn't getting where it needs to, but it does start out around 5000 and wander on up after a few shifts
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This sounds more like the tranny is simply being cooked by doing numerous runs without allowing sufficient cool down time to allow the tranny fluid temps to get back down to 190 or lower before doing another run, thus the fluid gets superheated, etc. This also makes it shift softer, too.
This (where the WOT upshift points occur at) is really not an issue on the newer 2004 & up F-150's with the 4R75E trannies, but can be a little bit of an issue with the earlier 197-2003 trucks - but only from the standpoint that they may need a little tweak, as with those trucks once the PCM sends the signal, the tranny still has to fill the clutches to effect the upshift - and the more power they make, the more rpm they will gain during that time. But in no case will just changing from one tune to another cause a 1400 rpm difference in the WOT upshift point - *something* else is going on that is contributing to that.
See, in the newer trucks the PCM and WOT shift point logic works a bit differently compared to the older trucks - the older trucks will need to settle in their shift points, however, I agree that is NOT going to cause a change of 1400 rpm @ WOT, that is something else going on, whether it's shift solenoids, tranny fluid temps and other things affecting the rate at which the clutch packs fill or other issues - but just changing tunes alone is not the reason for a 1400 rpm difference in the WOT upshift point, something else is at work there.
The more times you pound on it before the fluid cools back down to 190 or colder, the higher (and softer) you can have the WOT shift point get, but that is a problem from superheated tranny fluid causing a reduction in viscosity that increases effective clutch fill times and causing the shift solenoids to act oddly more than anything else. Not once in all our years of tuning have we ever seen any truck or any other vehicle change it's WOT upshift point by 500 rpm, let alone any 1400 rpm - I would start looking elsewhere for the root cause of that,and it may simply be making run after run and super heating the tranny - and if that is the case, that tranny needs to be flushed and it's cooling capacity upgraded, along with a good tranny fluid temp gauge installed.
Start by having a tranny fluid temp gauge with it's probe installed in either the tranny's outgoing fluid line, or in the line pressure test port, (NOT in the pan, ever!), so that you get the hottest possible reading - you need to know the actual temps of the fluid inside the tranny, and remember that the ideal tranny fluid temp is about 170 - for every 20 degrees above 170, you cut the service life of the fluid in half. And if you make 20 passes, you are going to end up with a transmission temperature that is in the stratosphere - and anything above 200 degree fluid temps causes problems, remember.
For example, in just one 1/4 mile run in 75 degree weather, coming up to the line at 170 degrees of tranny fluid temperature, by the end of the 1/4 mile the tranny fluid will be WAY over 200 or so, and even higher in many cases, as much as 230+! Do a half-dozen runs in say, an hour, and you can easily cook that fluid to 280, 300 or even higher.
The bottom line is, it takes far more than just a changing to a different tune of ours to cause a 1400 rpm difference in the WOT upshift point - there isn't anyone who has drag raced as much with our tuning as us, or in as many different vehicles, and not once have we seen even a 500 rpm difference in the WOT upshift point unless the tranny fluid was being cooked due to numerous runs being made without allowing the fluid to come back down to under 190 before starting the next run. This is caused either by simple abuse of too many runs without enough cool down time, or some other mechanical issue - yes, relearn on these older trucks can cause you to need to do a few WOT's to see where they are going to settle in at, and so sometimes an adjustment needs to be made if you want to hit a certain WOT upshift point at the track - and that adjustment is built into the XCal 2 - but having a 1400 rpm variance is a clear indication that something else is contributing to this, that is not the work of just a change from one tune to another, as we have never had that happen, ever.
That's about the best I can tell you at this point.
This (where the WOT upshift points occur at) is really not an issue on the newer 2004 & up F-150's with the 4R75E trannies, but can be a little bit of an issue with the earlier 197-2003 trucks - but only from the standpoint that they may need a little tweak, as with those trucks once the PCM sends the signal, the tranny still has to fill the clutches to effect the upshift - and the more power they make, the more rpm they will gain during that time. But in no case will just changing from one tune to another cause a 1400 rpm difference in the WOT upshift point - *something* else is going on that is contributing to that.
See, in the newer trucks the PCM and WOT shift point logic works a bit differently compared to the older trucks - the older trucks will need to settle in their shift points, however, I agree that is NOT going to cause a change of 1400 rpm @ WOT, that is something else going on, whether it's shift solenoids, tranny fluid temps and other things affecting the rate at which the clutch packs fill or other issues - but just changing tunes alone is not the reason for a 1400 rpm difference in the WOT upshift point, something else is at work there.
The more times you pound on it before the fluid cools back down to 190 or colder, the higher (and softer) you can have the WOT shift point get, but that is a problem from superheated tranny fluid causing a reduction in viscosity that increases effective clutch fill times and causing the shift solenoids to act oddly more than anything else. Not once in all our years of tuning have we ever seen any truck or any other vehicle change it's WOT upshift point by 500 rpm, let alone any 1400 rpm - I would start looking elsewhere for the root cause of that,and it may simply be making run after run and super heating the tranny - and if that is the case, that tranny needs to be flushed and it's cooling capacity upgraded, along with a good tranny fluid temp gauge installed.
Start by having a tranny fluid temp gauge with it's probe installed in either the tranny's outgoing fluid line, or in the line pressure test port, (NOT in the pan, ever!), so that you get the hottest possible reading - you need to know the actual temps of the fluid inside the tranny, and remember that the ideal tranny fluid temp is about 170 - for every 20 degrees above 170, you cut the service life of the fluid in half. And if you make 20 passes, you are going to end up with a transmission temperature that is in the stratosphere - and anything above 200 degree fluid temps causes problems, remember.
For example, in just one 1/4 mile run in 75 degree weather, coming up to the line at 170 degrees of tranny fluid temperature, by the end of the 1/4 mile the tranny fluid will be WAY over 200 or so, and even higher in many cases, as much as 230+! Do a half-dozen runs in say, an hour, and you can easily cook that fluid to 280, 300 or even higher.
The bottom line is, it takes far more than just a changing to a different tune of ours to cause a 1400 rpm difference in the WOT upshift point - there isn't anyone who has drag raced as much with our tuning as us, or in as many different vehicles, and not once have we seen even a 500 rpm difference in the WOT upshift point unless the tranny fluid was being cooked due to numerous runs being made without allowing the fluid to come back down to under 190 before starting the next run. This is caused either by simple abuse of too many runs without enough cool down time, or some other mechanical issue - yes, relearn on these older trucks can cause you to need to do a few WOT's to see where they are going to settle in at, and so sometimes an adjustment needs to be made if you want to hit a certain WOT upshift point at the track - and that adjustment is built into the XCal 2 - but having a 1400 rpm variance is a clear indication that something else is contributing to this, that is not the work of just a change from one tune to another, as we have never had that happen, ever.
That's about the best I can tell you at this point.
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From: Farmington, MO
Ok thanks for that. I do have a temp guage, and I will not go wot with it about 180, hardly ever does it get that hot, It will get amost 200 in traffic in the 90's... When doing these runs and all, its probably lower than 170*. This wont be a problem soon, because fo the new engine and tranny, but that is still a while away before I can come up with funds to finish it.