How to get e4od 7.3 to downshift more often?

85_305 · Oct 25, 2012

Hey guys. So heres the deal. Basic OBS auto w/ beans custom chip, and 35" tires w/ stock speedo programming. I know these speedo are programmed and the 35's throw the tires off, but its only roughly 5%. My beans tunes help shifting a ton, but still have a few issues.

First.. if I'm cruising say 20mph (on the speedo... prolly like 22-23mph actual w/ the 35s) and I punch it.. the ****er doesn't downshift, it just lugs out 2nd gear. Then other times I catch it just right, and it will catch 1st and peg out real nicely.

Same results at other speeds that I dont have memorized. Just wondering how I can fix this lack of a downshifting strategy?

I plan to do a good vb/tc next summer along with stage 1s... i'm wondering if those mods combined with reprogramming the tranny will result in a truck more willing to downshift and not just lug out?

JDub · Oct 25, 2012

It's pretty easy to reset the speedo for the proper tire size if you wanted to try it and see how it affected things...

"First, you'll need to know the actual height of the tires, not the nominal height of 35" that's printed on the sidewall. To get that, make a mark on the edge of the tire at the ground, and mark the ground directly under the mark. Now, roll the truck far enough for the tire to have made three revolutions. When your mark on the tire is at the very bottom, near the ground, mark the ground again, and measure the distance between the two marks on the ground. Divide that distance by three, since there were three revolutions of the tire, then divide that number, (which is the circumference of your tire,) by 3.14. The answer you have is the true height of your tire. Write that number down, because you'll need it for the next step. Divide 30282 by your actual height. If your true height is 34", the math goes something like this: 30282/34.5=891. That would be your speedometer calibration code." "To set the calibration, ground the single wire connector under the glove box it says PSOM (Programable speedometer Opdometer Module). "Yes there is only one and it has a spade type plug on the end". I used a wire with clips on both ends to ground the plug to a screw under the dash or try a test light and use the clip end to the PSOM and the other jam in a dooe hinge. Now look at your speedometer on the face of your dash while sitting in the drivers seat and there should be a "reset" button and a "select" button. While holding the reset button in on the trip meter, turn the ignition to 'on' while the wire is still grounded. Let go of the reset button. The speedometer display will sweep once and will show a code of some kind then push in again the "reset" button and the existing code will be displayed with RECAL?, mine said 976 RECAL? Now you enter your new code you came up with by dividing the rolling measurement by PI or 3.14 by pushing the "select" button until it gets to the new calibration code number. You may have to push "select" a whole bunch of times until you get to your code. If you turn off the key at this point the original code will not be changed or any of the 6 lives will not be used. To store your new code press "Reset". Turn off the key. Unplug the ground wire."

85_305 · Oct 25, 2012

Yep I'm aware of the process n its a real bitch lol. But I HIGHLY doubt the 2-3mph my speedo is off at only 20mph is NOT going to impact the downshifting strategy.....

SPEEDDEMON31176 · Oct 25, 2012

85_305 said:
Yep I'm aware of the process n its a real bitch lol. But I HIGHLY doubt the 2-3mph my speedo is off at only 20mph is NOT going to impact the downshifting strategy.....

Well it seems as though every time someone with the knowledge to help you gives you the right information you tell them they are wrong. If that is the case, then why are you asking for help. Instead of arguing with people every time they try and help you try and take their adivce for once. The information you just got came directly from one of the tuners that are on here. There is a damn good chance he knows what he is talking about.

85_305 · Oct 25, 2012

SPEEDDEMON31176 said:
Well it seems as though every time someone with the knowledge to help you gives you the right information you tell them they are wrong. If that is the case, then why are you asking for help. Instead of arguing with people every time they try and help you try and take their adivce for once. The information you just got came directly from one of the tuners that are on here. There is a damn good chance he knows what he is talking about.

If you had any sense in reading comprehension, he offered me advice in how to reset the speedometer, implying that perhaps I wasn't aware how. He didn't say anything such as "oh, your problem is the speedometer" or "the fix to your problem is your tires". He merely stated how to correct my speedometer, which was fine and nice of him, but certainly not why my truck wont downshift all the time @ 20mph.

jschildm · Oct 25, 2012

Put a 302 in your truck. I had F150 with a 302 and a E4OD and I couldn't get the stupid thing not to down shift ... haha.

Bobby@cp · Oct 25, 2012

A couple mph off can effect shifting....

Sent from my PC36100 using Tapatalk 2

Wackerjr · Oct 25, 2012

85_305 said:
If you had any sense in reading comprehension, he offered me advice in how to reset the speedometer, implying that perhaps I wasn't aware how. He didn't say anything such as "oh, your problem is the speedometer" or "the fix to your problem is your tires". He merely stated how to correct my speedometer, which was fine and nice of him, but certainly not why my truck wont downshift all the time @ 20mph.

And you sir are a tard....

1MPH will effect shifting....

A OBS truck is all 100% shifted of MPH and TPS... If your tuner is asking for downshifts at 20... and your speedo states 21.... it aint gonna downshift...

simple as that....

You cant fix a electrical issue with mechanical items...

fix your speedo... then if it still isnt shifting where you like have your tuner adjust it... that is your only options.

85_305 · Oct 25, 2012

jschildm said:
Put a 302 in your truck. I had F150 with a 302 and a E4OD and I couldn't get the stupid thing not to down shift ... haha.

Lol!!!!!!!!!!!!! Thats funny man

Countryboyrob said:
A couple mph off can effect shifting....

Sent from my PC36100 using Tapatalk 2

But 1st gear lasts until what...35-40mph? Even a few mph off should still force a downshift @20mph.

Bobby@cp · Oct 25, 2012

Shifting depends on your mph....

Sent from the doughnut shop

85_305 · Oct 25, 2012

Wackerjr said:
And you sir are a tard....

1MPH will effect shifting....

A OBS truck is all 100% shifted of MPH and TPS... If your tuner is asking for downshifts at 20... and your speedo states 21.... it aint gonna downshift...

simple as that....

You cant fix a electrical issue with mechanical items...

fix your speedo... then if it still isnt shifting where you like have your tuner adjust it... that is your only options.

But 21mph and 20 mph are still FAR below the downshift point of 30mph+. That point should 30mph or so. If I'm wrong, I'm wrong. And I'd be tickled to get my speedo fixed to help with the shifting... but being so low in the RPM band I wouldn't think the 1-3mph TOPS that my speedo is off would prevent a downshift. Especially if it does it every other time.

85_305 · Oct 25, 2012

Countryboyrob said:
Shifting depends on your mph....

Sent from the doughnut shop

right, but these trucks downshift at 30mph +/- stock... so 20mph is 10mph below the shift threshold.

Bobby@cp · Oct 25, 2012

You're still not getting it, the truck can shift from first to second at 10mph.... Or later due to the speed.

:banghead:

Sent from the doughnut shop

85_305 · Oct 25, 2012

Countryboyrob said:
You're still not getting it, the truck can shift from first to second at 10mph.... Or later due to the speed.

:banghead:

Sent from the doughnut shop

yes I know that it can shift at low speed... but when the truck is going like 30mph and under, its supposed to downshift @ 3/4throttle or more. Some days it will, some days it wont. I'm thinking the tires aren't the reason.

Countryboyrob said:
Btw the tc dep

Sent from the doughnut shop

So you are saying its a TC thing that controls this? Or did I misread that?

Bobby@cp · Oct 25, 2012

85_305 said:
Lol!!!!!!!!!!!!! Thats funny man

But 1st gear lasts until what...35-40mph? Even a few mph off should still force a downshift @20mph.

And no thats not first gear, that's more than likely your tc locking at thay speed.

Since you won't listen and you think we are all wrong then why dont you call your tuner.....

Bobby@cp · Oct 25, 2012

85_305 said:
yes I know that it can shift at low speed... but when the truck is going like 30mph and under, its supposed to downshift @ 3/4throttle or more. Some days it will, some days it wont. I'm thinking the tires aren't the reason.

So you are saying its a TC thing that controls this? Or did I misread that?

The tc post was an error post between fat thumbs and tapatalk....

85_305 · Oct 25, 2012

Countryboyrob said:
And no thats not first gear, that's more than likely your tc locking at thay speed.

Since you won't listen and you think we are all wrong then why dont you call your tuner.....

I'm talking during a WOT run 1st gear taps 35-40mph. A downshift is supposed to take place from like 30-32mph somethign like that.

SPEEDDEMON31176 · Oct 25, 2012

Actually the things that are taken into consideration for shift strategies are speed(mph), RPM, line pressure, tc locked or unlocked, gear ratio, and a few other things. Specifically the fact that your MPH is off even 2 mph is a major factor in how it shifts. If you correct your speedometer, which is what the PCM uses in order to command the transmission, you will definitely help to correct your shifting issues. The other issue you have is that with the larger diameter tire and still using the same gears in the differentials, you will never get the shifting back to exactly where it was before you changed tire size.

85_305 · Oct 25, 2012

SPEEDDEMON31176 said:
Actually the things that are taken into consideration for shift strategies are speed(mph), RPM, line pressure, tc locked or unlocked, gear ratio, and a few other things. Specifically the fact that your MPH is off even 2 mph is a major factor in how it shifts. If you correct your speedometer, which is what the PCM uses in order to command the transmission, you will definitely help to correct your shifting issues. The other issue you have is that with the larger diameter tire and still using the same gears in the differentials, you will never get the shifting back to exactly where it was before you changed tire size.

What does my rear end gears have to do with anything in terms of shifting strategy?

As far as everything else, I'm going to take your guys advice on this and reprogram the speedo and see what happens. I guess thats the next logical step.

SPEEDDEMON31176 · Oct 25, 2012

85_305 said:
What does my rear end gears have to do with anything in terms of shifting strategy?

As far as everything else, I'm going to take your guys advice on this and reprogram the speedo and see what happens. I guess thats the next logical step.

Because the PCM is programmed for the gear ratio you have in your truck which would either be 3.55:1 OR 4.10:1. Once you change tire size, either bigger or smaller, it changes what the computer expects to see from the VSS/PSOM. This in turn will change the shift parameters that the computer sends to the transmission during its commands. Basically the tone ring in the rear will either spin faster or slower than it would with the "correct" size tires on the vehicle. This in turn basically confuses the computer. It will try to compensate but will not be correct until you correct the faults to the best of your ability such as changing the code for the PSOM.