5R55W/S transmission tuning

I have finally found some of the relevant parameters in the tune. I have way too much time on my hands now being unemployed, so I put it to good use.

Trans Pressure > Target slip time

This will firm up the shifts if the numbers in the table are reduced. It refers to the 1-2, 2-3, 3-4, 4-5 shifts.
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Time to Delay Conv LK after 12 (23,34,45)

Converter lockup times were way too long in stock form. Stock settings were like 30 seconds until converter lock. I backed mine down to under 5 seconds.
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Torque Calculation > Torque Table

I increased these values by over 25% to compensate for the extra power with the turbo. This made a huge difference in shifting.
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Torque Calculation > Torque Table Friction

I also increased the table values here by about 25%.

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Torque Limit > Auto Trans > Torque Converter Torque Limit

Stock was 280 in the entire table . I increased to 500 for my setup.
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I also zeroed the Tip in torque control stuff for timing.

I'm still tweaking these parameters, but they seem to make the biggest changes in shifting.

 

[Jakee]

Very good information. I'd like to add, if you don't mind....

Base N/V and Revs Per mile are good values to have right. There are several other calcs listed below that need to be correct in order to get NV and Revs Per Mile correct.

Example tire size:
235 75 15


235 = Section Width
75 = Sidewall Aspect Ratio
15 = Rim Diameter


Tire Width = Section Width * .03937
Example = 235 * .03937 = 9.25195
Tire Width = 9.25195

Tire Sidewall = Tire Width * (Sidewall Aspect Ratio / 100)
Example = 9.25195 * (75 / 100)
----------(75 / 100) = .75
----------9.25195 * .75 = 6.9389625
Tire Sidewall = 6.9389625

Tire Diameter = Rim Diameter + (Tire Sidewall * 2)
Example = 15 * (6.9389625 * 2)
----------(6.9389625 * 2) = 13.877925
----------15 * 13.877925 = 28.877925
Tire Diameter = 28.877925

Revs Per Mile = 63360 / (PI() * Tire Diameter)
Example:
----------PI() = 3.141592654
----------3.14 * 28.87 = 90.72
----------63360 / 90.72 = 698.39
Revs Per Mile = 698.39 (rounded)

Base N/V = 1 / (0.000947 * ((6.2831853 * (Tire Diameter / 2)) / Rear Gear))
-----------------------------------------(28.877925 / 2) = 14.4389625
----------------------------(6.2831853 * 14.4389625) = 90.72267692725125
---------------(0.000947 * 90.72267692725125) = 0.08591437505010693375
0.08591437505010693375 / Rear Gear of 3.73 = 0.023033344517454942024128686327078
1 / 0.023033344517454942024128686327078 = 43.415129279268227336519245459212
Base N/V = 43.415129279268227336519245459212

Sorry about the decimal places; I was doing this with the windows calc and just copied. If you want to do this the easy way, let me know and I'll send an excel sheet.

To get the shift RPM correct, log acceleration rate. The goal is to keep the rate as consistent as possible thru the shift. If it lowers you shifted early. If it rises, you shifted late. Keep working at it until it has a steady slope. In theory, these will yield the best times.

Last, try and use MPH's as the shift trigger and not RPM's.

 

[Limited02]

Hmmm, is this doable with my SCT3 or will I need James to write me a new tune? I still have a vibration between shifts unless I up the shift pressure up to 15% or more.

I need to take it back to the tranny shop and say, FIX IT!!!

 

[Jakee]

Can you describe the vibration? Is it like VmmmmVmmmmVmmmm

Or

Bmmmbmmmbmmmbmbmbmbmbmbm

 

[mounty03]

Can you describe the vibration? Is it like VmmmmVmmmmVmmmm

Or

Bmmmbmmmbmmmbmbmbmbmbmbm

LOL. If it was only a woman describing that.


Is it a bang when it goes into gear or just seems like it wont shift?


You will need the Pro Racer Package from SCT or you have to pay your tuner to adjust it (unless he's a nice guy). That is the main reason I tune it myself. Unlimitted tune changes!

 

[Limited02]

Well my tranny had the infamous holding of gear on the 2-3 shift and felt like it was slipping. So I had it rebuilt a few months ago and the day after I recieved it, when it shifted from 1-2, 2-3, 3-4 sometimes 4-5 it would have a fast jerking/shudder kind of feel between shifts. It was VERY violent at first and I was like WTF? Called and told them about it and he said I needed to break it in and it should get better. Well it did get better but it still shudders. Took it to him and he had trouble noticing it. But it is noticable!!!!

Since I bought the tuner, I raised the shift firmness up to 15% and it went away. I currently have it set at 5% because the tranny felt less responsive when set at a higher %? So it shudders right now

Another thing is that when at highway speeds, if I mash the throttle, it doesn't do anything for a second and them BAM!!!! it drops a gear VERY hard. It used to be pretty instant and smooth.

The thing that sucks is my dad used these guys for years when he had his auto shop in KCK before moving. Well I happened to move back up here and was haveing some trouble and my dad said they did good work. Did my research before going in and when I mentioned my problems, he was on the money with what could be wrong and even had another Ex in for the same work. Paid for a full rebuild and haven't been happy since.

Sorry for the long post, but if I need to make a vid to better show what's going on, I will. I would like to know what's wrong so that I can go in and say this is what's possibly the deal. I have even thought that the wrong tranny fluid could have been put in(mercon 3 instead of the correct mercon 5?)

Thanks guys')

 

[mounty03]

I'll try to get a video of mine shifting tomorrow. You can compare it to that.

I'll even do a boost launch if I can get the camera mounted up someplace.

 

[Jakee]

I have a feeling, even though this appears to be related to the rebuild, that this can be solved with tuning.

My explorer has over 100K on the engine/tranny and it shift perfect.

My new edge on the other hand has only 15K on the car and I get weird things happening at times. For example, if you mash the gas over half way, then let off the gas a few second before the shift, it shifts and clanks into second. I attribute this to delays and such in the stock tune. I could probably fix but I don't feel like spending the money for another vehicle to be added.

So in short, I bet you can get this solved with a tune and I wouldn't think anything major was wrong right off the bat. You're previous settings may not be optimal for the new improved tranny?

Hey Mounty - How did you come up with the torque variable to add?

 

[Limited02]

Jakee- You are thinking because the tranny is rebuilt, that the factory tune for the tranny is off? Ahhh, I wish one of you two techno nuts were closer so that I can figure this out.

Mounty03- I would love to see some in-cab boost launches We can do a 0-100 run and compare a 200hp motor to a 400hp motor. I need to go find my camera.

 

[mounty03]

OK, I took some video today. The beginning is just some light throttle (about 1/4).

I have a launch from 0-90 mph towards the end.

Here is a link.

 

[Limited02]

Roll up the window Sounds great and looks hella fast!!! The shifting seems really nice as well and much better than mine.

I really like the camera mount that you have. I want to make one for mine, but I have been lazy. I will see about getting a vid of mine in hopes of the shifting problems being noticable enough that you guys may have an understanding on what the problem could be.

Awesome Mounty!!!!(now go run some 12's)

 

[Jakee]

Jakee- You are thinking because the tranny is rebuilt, that the factory tune for the tranny is off? Ahhh, I wish one of you two techno nuts were closer so that I can figure this out.

Mounty03- I would love to see some in-cab boost launches We can do a 0-100 run and compare a 200hp motor to a 400hp motor. I need to go find my camera.

I can't guarantee but it could be a factor. If you post up a huge clank/shudder into the gear then I'll think otherwise but when they rebuilt your tranny they probably used updated parts and the modified settings you had may not be good anymore. There are alot of factors so post up that video so we can see how bad it is.

 

[Limited02]

It's not really "bad" just annoying if anything. I may just need to up the firmness and call it good. I'll get a vid up when I can. Thanks.

 

[Limited02]

Well I went out for a drive to make a vid of the shifting, but it didn't act up But I got a quick 0-85 run in to compare to Mounty03's turbo run. Mine a little bit slower But get this, I was driving and found a nice stretch. I stopped, went to back up into a flat spot on the side and missed it!!!! The Ex started getting really angled and I was like WHOOPS!!! Put it in drive and the front drivers tire was off the ground about 8 inches. So I have to back down even more until all tires were on the ground to take off. Almost got stuck with no phone, in the dark on a country road Jumped out to take a pic to show off, but a car came by and I figured I better get moving. So no picture. Anyway, here is my slow run. EDIT: (really DARK!!! Guess I will have to make a better one)

 

[Jakee]

First thing I see is the shift point between 1 and 2 being so much lower than the other shift points. This is your typical "henson" tranny tune and I don't mean that in a bad way. I think it needs to be raised a little but if you can datalog you'll be able to tell the story.

Another thing that makes a difference is when your torque convertor is set to lock after the shift. In all the tranny tuning I did, the lock and unlock of the torque convertor is where I found the most benifit.

 

[Limited02]

Sorry the vid was dark!!!

If you can see it okay, you will notice at around 75 mph the rpm will actually go down while the speed still climbs to about 80 and then the rpm will rise again before shifting? Does this have anything to do with the torque converter lockup?

I can also datalog. I actually sent a quick one to James when I first got the tuner in hopes of him helping me out with the tranny. I eventually just told him not to worry about it because I knew he was busy and didn't want to waste his time. I do need to get back to him and even send him this thread because it may be helpful? Anyway, thanks for everything so far

 

[Jakee]

Yes, that could be part of it.

The thing about locking and unlocking the torque convertor is this: to get the fastest times you want the torque convertor locked straight after the shift. When you do this, the truck MAY feel slower at first. This is usually because you don’t feel the G’s during the shift anymore; however, you don’t want to feel the G’s during the shift. If you do there’s room for improvement. Hope this makes sense.

Another way to explain is if you feel a jerk into second, it usually indicates you shifted late out of first. The engine RPM went out of it’s range and started loosing power, the shift was made, then the RPM’s dipped back into the power range causing you to ‘feel’ the shift more. VS versa with shifting soon and could result in a bog.

I think for your truck it's just a matter of finding the power range and keep it there thru-out every gear. I just watched the vid again and I see you going up to around 5 grand from 1st to second and then dropping to around 4 grand when in second. From 2nd to third you're closer to 6 grand and dropping down to 4 grand again. Once the shift points are where you want them then you'll have James lock the torque convertor up after every shift. You may already have the right shift points but maybe need to verify when the convertor is locking.

For example:

first to second shift @ 42 MPH
The torque convertor locks @ 44 MPH

The rate at which the convertor locks makes a difference too.

This is all theory so you'll have to find the right pratical application for your truck. Because I didn't see or feel a shudder, I can't help you. ;(

 

[Limited02]

Thanks Jakee. That particular vid will not show a shudder because I was WOT. It only does it during normal acceleration. I have the camera on hand so when the truck starts acting up, I'll be able to get a vid. I will have to email James about what it will take to get the converter locked. Thanks again!

 

[Jakee]

Does it feel like the tranny is shifting back and forth quickly? (getting confused on what gear to be in)

 

[Limited02]

More like if you changed the clutch in a manual tranny and the flywheel was warped. So when you engaged it, it would shake/shudder a little before finally "locking" on.