Super Chip and Shift Points
Thread Starter
|
Member
Joined: Nov 2003
Posts: 14
Likes: 0
From: Goose Creek, SC
Super Chip and Shift Points
I installed the "performance" program (Super Chip 1715) in my 2003 F250 4x with a 5.4L - I finally flushed out all the old 87 octane, so, I feel sure that I'm running 93 octane fuel. Nice easy acceleration at 2000 rpm steps me up through the gears (automatic) with plenty of speed. She "kicks" in to overdrive about 42 mph. Where I drive, the speed limits are typically 45 mph (usually pushing 50)... I find the truck shifting back and forth between "drive" and "overdrive" too often. So, I adjusted the shift points for 2-3 and 3-4 to "minimum". I don't really notice any difference...
What is a "shift point" ? - I assumed a lower shift point would lower the speed at which the transmission shifts to the next gear, up and down. (I didn't change "shift pressures" in any range.)
Is this one of those cases where I need to drive it for a couple a hundred miles before I notice any change?
Any advise would be appreciated.
What is a "shift point" ? - I assumed a lower shift point would lower the speed at which the transmission shifts to the next gear, up and down. (I didn't change "shift pressures" in any range.)
Is this one of those cases where I need to drive it for a couple a hundred miles before I notice any change?
Any advise would be appreciated.
Former Sponsor
Joined: Mar 1998
Posts: 13,385
Likes: 4
From: Virginia
Hi Tom,
You're not going to alter that behavior successfully like that - this really gets far too involved to type this all out, so you'll need to call your dealer or the manufacturer and have them explain this to you in proper detail.
Briefly.........
You're using Overdrive in conditions where it's not appropriate, is the bottom line. Turn it off if you aren't going to be driving at speeds of about 48-50 mph or higher in these trucks & SUV's.
What you are adjusting are the *full-throttle* upshift points with the Micro Tuner. Now it is true that if you adjust the full-throttle shift points far enough, that will start to affect part-throttle shifts as well - and can also affect downshift points, too. (That can get you into a a real driveability problem if they are twisted out of whack, for example.)
The point being, it's *not* something that you can just go in and change an extremely light-throttle part-throttle shift point to make it happen at a specific speed - part-throttle shift points don't work like that. Only full-throttle shift points can be set to occur at basically the same speed all the time - part-throttle shift points must vary based on load, speed, throttle position, & other factors - so they can never be the same speed for all conditions.
The only time it's going to go up into Overdrive by just 42 mph is at very light throttle, when you are giving it just barely enough throttle to move the vehicle up to speed - and using Overdrive just really isn't appropriate under those driving conditions anyway. We recommend for best driveability and fewer shifts, if you're not hitting at least 48-50 mph or better then just turn Overdrive off. When you drive at very light throttle, it's going to shift into the next gear as quick as it possibly can, because you aren't asking the engine for any real power - you're just putting along at very low speeds and at extremely light throttle - and it will always upshift as quick as it can under those conditions. Turn O/D off at those low speeds, that's your best bet not only for better light-throttle performance but also for best transmission life.
If you feel you do not have a good understanding of shift points & how they work, you'll probably want to hold off making any changes to them until you understand them properly. The little bit I went over here may help your understanding of this enough to help you for this situation (and I just touched on it very briefly), but if not then please don't hesitate to give your dealer or the manufacturer a call and have them go over this with you, OK?
Have fun & enjoy your turkey day!
You're not going to alter that behavior successfully like that - this really gets far too involved to type this all out, so you'll need to call your dealer or the manufacturer and have them explain this to you in proper detail.
Briefly.........
You're using Overdrive in conditions where it's not appropriate, is the bottom line. Turn it off if you aren't going to be driving at speeds of about 48-50 mph or higher in these trucks & SUV's.
What you are adjusting are the *full-throttle* upshift points with the Micro Tuner. Now it is true that if you adjust the full-throttle shift points far enough, that will start to affect part-throttle shifts as well - and can also affect downshift points, too. (That can get you into a a real driveability problem if they are twisted out of whack, for example.)
The point being, it's *not* something that you can just go in and change an extremely light-throttle part-throttle shift point to make it happen at a specific speed - part-throttle shift points don't work like that. Only full-throttle shift points can be set to occur at basically the same speed all the time - part-throttle shift points must vary based on load, speed, throttle position, & other factors - so they can never be the same speed for all conditions.
The only time it's going to go up into Overdrive by just 42 mph is at very light throttle, when you are giving it just barely enough throttle to move the vehicle up to speed - and using Overdrive just really isn't appropriate under those driving conditions anyway. We recommend for best driveability and fewer shifts, if you're not hitting at least 48-50 mph or better then just turn Overdrive off. When you drive at very light throttle, it's going to shift into the next gear as quick as it possibly can, because you aren't asking the engine for any real power - you're just putting along at very low speeds and at extremely light throttle - and it will always upshift as quick as it can under those conditions. Turn O/D off at those low speeds, that's your best bet not only for better light-throttle performance but also for best transmission life.
If you feel you do not have a good understanding of shift points & how they work, you'll probably want to hold off making any changes to them until you understand them properly. The little bit I went over here may help your understanding of this enough to help you for this situation (and I just touched on it very briefly), but if not then please don't hesitate to give your dealer or the manufacturer a call and have them go over this with you, OK?
Have fun & enjoy your turkey day!
