Scanner Data questions on a 11.40 @ 118.97 pass

[slarsen47]

Finally had a chance to get to the Friday night street legals and made two passes.

Full tank fuel, stock wheels front and back, full exhaust and weight in street trim.

Spun a bit on the first 11.48 (1.68 sixty foot). The 11.40 was assisted with a 1.62 sixty foot.

Launch is from idle. Seems to work good with 255/50R16 MT drag radial.

Anyway some strange looking data in some areas as per the chart.

Timing bouncing around a bit after burnout and staging car. Maybe just scaling looks worse than is.

I charted the input/output shaft rpm ratio to check transmission "slip" to see where the 3.06 changes to 1.62 and then to 1.0

According to the chart it is taking a long time to shift??

For example the 1-2 change from 3.06 starts at 1:07.547 seconds and 1.62 is not reached until 1:09.238

Similarly the 2-3 change from 1.62 starts at 1:10.408 and 1.00 is not reached until 1:12.978

However when you play back the run in real time in the gauge view the shift rpm drop seems pretty normal.

The converter slip chart shows dropping to 9.5% at the 1-2 shift and then increasing to 15.4% after the shift and and then down to 7.8% at the 2-3 shift, then dropping momentarily to 4.8% before stabilizing around 10.5% before it finally shows input/output shaft rpms the same. But then converter slips jumps up to 17.4% dropping down to 6.8% at the last WOT position.

Seems to me the input/output shaft rpm's ratio should match the transmission ratio's a lot better than what this data is showing.

Am I reading the data wrong or is there a transmission fault/ bad setting or is the data wrong?

Without looking at this data, I would never be aware that there could be a problem because it shifts and drives perfectly!!

Another curious piece of data is the TCC mode and TCC duty cycle sometimes showing engaged (not locked) and 99.2 percent. Lockup is not permitted at WOT.

Posting a scanner image, scanner log and tune file for review and comment.



11.40 scan data.jpg

1140.hpl

Aug 4a 2023 add fuel wrote.hpt

[kingtal0n]

I would at least log force motor current so you know what kind of internal pressure is being commanded to the PR valve
The slope of the rpm drop is a not as sharp as I would prefer for a performance shift
You have disabled torque management which I think will cause your poor 4l60e much abuse
You have zero'd out the torque % tables per timing which can influence other tables besides just torque management, I've heard.
The IAT rises quickly, if this is turbo I recommend boost leak pressure testing, find all leaks, but I have feeling this is not turbo based on boost drop during shift
did you mean to zero out the pressure multiplier table, did it come that way, those tables being zero kind of scare me. Consider at least to make them all = 1.00


When you supply these data you should also supply more info on the engine and setup, such as torque converter make, diameter, and stall. Whether the trans is built or not, and if so what is done to it.
How much boost did you intent to run, does the map match the boost gauge
What type of fuel, this could be alcohol or gasoline, based on the timing I would guess gasoline E10 its about right for that. But you didn't say so?
Year of engine, model, what is done there

[slarsen47]

I would at least log force motor current so you know what kind of internal pressure is being commanded to the PR valve
The slope of the rpm drop is a not as sharp as I would prefer for a performance shift
You have disabled torque management which I think will cause your poor 4l60e much abuse
You have zero'd out the torque % tables per timing which can influence other tables besides just torque management, I've heard.
The IAT rises quickly, if this is turbo I recommend boost leak pressure testing, find all leaks, but I have feeling this is not turbo based on boost drop during shift
did you mean to zero out the pressure multiplier table, did it come that way, those tables being zero kind of scare me. Consider at least to make them all = 1.00

Transmission settings were done by professional. I have not yet discussed this data (just ran Friday night with the weekend and holiday monday the shop is closed).
Without doing some research into your comments can't say I understand.
The engine tuning is DIY.............being fairly cautious.

When you supply these data you should also supply more info on the engine and setup, such as torque converter make, diameter, and stall. Whether the trans is built or not, and if so what is done to it.

Yank power adder series 9.5 inch 3600 stall.
Level IV transmission, basically everything except 5 element planetary.
Yes, I am aware the 4L60e has limitations but my goals for this Camaro are modest.
I am well underway with building a 98 turbo car with a cammed LQ4 and 4L80e and a Circle D converter.

How much boost did you intent to run, does the map match the boost gauge

With stock pulley was expecting 6-7 psi..........may switch pulley later to get 10-12 max. Just enough to run a 10.95!

What type of fuel, this could be alcohol or gasoline, based on the timing I would guess gasoline E10 its about right for that. But you didn't say so?

Pump gas 94 octane with small bottle of "boostane".

Year of engine, model, what is done there

2002 Camaro basically stock LS1 with a Comp 54-426-11 (222/224 and .566/.568) 1800-6800 operating range
Long tube headers, deatchwerks 60 pound injectors
D1SC stock 4.38 inch pulley 8 rib belt, ATI balancer with crank pulley 7.65

3.70 gears in Moser 9 inch.
255/50R16 MT drag radial


Transmission temperature was always low as per data log.
It was hot and so the twin intercoolers were likely heat soaked.

Note shift rpm was purposely set relatively low.
Will try and raise once transmission uncertainty is resolved.

Other than lots of street driving it only has two hard passes with gear selector in 3.

[SiriusC1024]

Idk about taking a so-called professional at face value. Look at the pressure modifier table. 1-2 and 2-3 have been adjusted, but then the multiplier is zeroed? Why do both? Nonsense.

I think you need to experiment with torque reduction re-enabled as stock. If that works then find the minimum.

[edcmat-l1]

If it's a "level IV" trans you shouldn't have to do anything as far as tuning to firm up the shifts. You should be able to run stock pressure tables and even stock shift times and it should shift firmly and quickly. If it doesn't take it back to the builder.

A really loose converter which Yanks are known to be will soften the shift feel but it won't cause it to shift slowly from one gear to the next.

[slarsen47]

All great comments, appreciate the input. Continuing to learn.

In 20/20 hindsight..................I could have framed my question differently in the original post.

I should have asked for input/output shaft data that others are getting with their 4L60e's for comparison purposes.

To see what is typical or normal. Does nobody data log transmission input and output shaft rpm's?

If I use engine rpm peak just before shift to lowest engine rpm after shift, I get 0.430 seconds for both shifts.

But using the engine rpm change does not mean that the shift has completed.

So the question of apparent transmission "slip" remains. Perhaps my scanner data is inadequate.

My input/output shaft PID polling was at 200 ms which is probably way too coarse to use as data for shift timing??

200 ms is 0.2 seconds............a long time when measuring shift time.

Next time I do a WOT test, I will change the polling interval to be much shorter to better capture actual shaft rpm's vs time.

I will revisit some of the transmission tune entry values that were questioned.



Edit: I looked at some part throttle upshifts and the same basic pattern takes place. It takes time to slow down the input shaft to where the two shafts are "locked in gear". As you would expect it takes longer to go from 3.06 to 1.62 than it takes from 1.62 to 1.0 for full no slip engagement. Bottom line........the clutches are slipping for much longer than you may realize on each shift, even though you do not feel it when driving. The more torque you apply against the input shaft through the converter the harder it will be to complete the shift "lockup". And hence the use of torque reduction to reduce slip and shorten the time to "lockup". Seems to me that removing torque reduction will have minimal effect on quarter mile ET but decrease life of the clutches.

[kingtal0n]

You need to look at
1. commanded EPC PWM aka EPC Milliamps (mA of current to the EPC solenoid)
2. Shift command vs shift finished & begin of RPM drop
3. RPM drop differential

-1. The Commanded EPC will tell you if the pressure regulator is getting a (commanded, hypothetical) full complement of pressure
-2. Shift command to shift finished is how long the shift takes total. Shift command to begin of RPM drop is the time it takes for valve to move and initiate the clutch pack begin to grab the next gear.
-3. RPM Drop differential is the rate of RPM Drop over time (dD/dT). A higher rate of drop means less slippage. Low rate is lots of slippage. You would compare this with say, a stock shift, and a performance tuned shift from a known good vehicle

[slarsen47]

Looking at the 2-3 shift input to output shaft ratio.

2-3 starts at about 1:10.603 and completes at 1:12.977. That is 2.37 seconds of clutch slip under a lot of torque.

How much will torque reduction reduce the time to gear change completion?

The chart view clearly shows the slow rate to complete the shift completion.

Notice the converter slip increases at the moment the shift completes for 1:1 input/output shaft.



3rd gear shift completion.jpg

[slarsen47]

Exported the hp tuner scanner file to excel and charted the apparent transmission slip.


Around 540 ft lbs torque.

1140 1-2 shift slip.jpg

Is 1.577 seconds too long for a 1-2 shift?

1140 2-3 shift slip.jpg

Is 2.659 seconds too long for a 2-3 shift?

[kingtal0n]

There you go, good f@#(*# job.

Now compare the rates to other cars. Export other logged data from stock and performance vehicles.

Its hard to determine strictly from the raw data whether something is 'good' or 'bad' without prior experience and inspection of the (transmission/engine) components after such data was generated.

In this case, you have clutch materials and shafts/bushings/bearings to consider. 'good' just means reasonable slip without harsh abuse on those components. 'bad' is either too harsh or too much slip, wearing out the clutch materials prematurely. Torque management can help with both, thats why its super useful. You'd probably get a much faster RPM drop and greatly extend the life of the clutches and components.

I'm impressed for your ambition and willingness to go the distance, just a little bit farther.