RPM Level V tuning

[custosonlinux]

Hi,

I need help to find the right values for my new installed transmission.
It's a RPM Level V with tripple disk lockup PI 2600 stall converter.
The car is making about 505 RWHP and 533 lbft with an A&A Supercharger.
The transmission shifts fine, and I've set the shiftpoints to my needs.
As RPM told me, I changed the pressure back to stock and added 10 percent to all values in the shift pressure upshift tables.
I've nice and firm shifts and it seems everything is ok.

Last weekend I've done some tests to adjust the TCC tables, because of the higher stall, I had to find the matching
values for my style of driving.
For that I've done done some pulls with 70 to 100% throttle in 3rd gear.
At 4500 U/min, where the supercharger reaches good pressure, I noticed some slip in the drivetrain.
First I thought that it could be the TCC, which was closed at this time, but it was the transmission.
I had the same issue with opened TCC, when I maxed out the fileds in 3rd gear.

Now I think that the transmission has not enough line pressure to hold the clutches for the 3rd and it slips.
When it slips, and I just reduce the power of the engine, (release just the right foot) it stops slipping and RPM and speed rises up normally.

Now my question: How can I see the pressure of the transmission when no shift is in progress (maybe it's calles holding pressure ) and
how can I rise it up to give the transmission more power for the clutches?

Are these the "force motor" tables?

I've sent the question about the values to RPM, but it's a bit more complicated, because they didn't use HPTuners.

Anyone here with the same transmission who could share his tune with me?

Thank you and kind regards

Birger


Attached the tune, I'm using at the moment.

[custosonlinux]

anyone?

[custosonlinux]

Hmm anything wrong with my question?
No ideas?

[jimmyblue]

I thought most of the higher performance transmissions
were set up with vacuum modulation. In that case the
line pressure settings don't matter.

[NTIMID8]

Only 42lb (@3bar) injectors?
Base force motor current table is where you need to be, but I suspect another issue as well.
RPM transmissions maintains electronic controls.

[custosonlinux]

Only 42lb (@3bar) injectors?
Base force motor current table is where you need to be, but I suspect another issue as well.
RPM transmissions maintains electronic controls.

Hi, yes I'm using electronic controls.

What do you mean with 42lb injectors? For the engine? Installed are 60lb as delivered with the A&A kit.

[jimmyblue]

Force motor table is the tail of a long chain of calcs,
based on modeled motor torque.

I'd begin with scanning for Delivered Torque - Trans,
commanded line% and force motor current for the
pressure side, and the input & output shaft ratios
and TCC slip RPM for the result side.

If you figure that a stock motor is good for maybe
350lb-ft, you ought to see (MAP/100kPa)*350 for the
delivered torque. Somewhere above 300 lb-ft you
ought to see line% go full-on, clip to the limit value,
and force motor current go to 90mA or zero. But the
"interesting" area is likely to be more in the mid-range,
where GM thought to go stingy on the pump load ->
line pressure profile and any air mass error to the
short side, may hold off your line pressure too much
as torque rises.

[custosonlinux]

Force motor table is the tail of a long chain of calcs,
based on modeled motor torque.

I'd begin with scanning for Delivered Torque - Trans,
commanded line% and force motor current for the
pressure side, and the input & output shaft ratios
and TCC slip RPM for the result side.

If you figure that a stock motor is good for maybe
350lb-ft, you ought to see (MAP/100kPa)*350 for the
delivered torque. Somewhere above 300 lb-ft you
ought to see line% go full-on, clip to the limit value,
and force motor current go to 90mA or zero. But the
"interesting" area is likely to be more in the mid-range,
where GM thought to go stingy on the pump load ->
line pressure profile and any air mass error to the
short side, may hold off your line pressure too much
as torque rises.

Hi,
is there a way to recalibrate the tables for the torque calculation?
I think after installing the Supercharger, the PCM is not calculating the right values for delivered torque.
When I compare the scans with the results from my dynosheet, the dyno shows between 100 and 200 lb-ft more than the PCM.

The MAP is on its limit.... 104kpa most of the time, but the PCS just gives about 61% line pressure at the max (0,53 Ampere)

[jimmyblue]

I don't think we have access to anything besides the
torque reduction vs retard table. I wish.

But I think the main questions are

- is your PCS current down to 0mA by the time you get
to (say) 300lb-ft indicated Delivered Torque (never mind
the inaccuracies there)

- With the force motor and general pressure set up to
give her all it's got, are you seeing any slip in the frictions
(see input/output shaft RPM ratio, vs nominal gearbox
ratio for current gear)?

[NTIMID8]

Hi,
is there a way to recalibrate the tables for the torque calculation?
I think after installing the Supercharger, the PCM is not calculating the right values for delivered torque.
When I compare the scans with the results from my dynosheet, the dyno shows between 100 and 200 lb-ft more than the PCM.

The MAP is on its limit.... 104kpa most of the time, but the PCS just gives about 61% line pressure at the max (0,53 Ampere)

Its using to low of an injector scaler for the combination. The only way to generate proper fueling was to reduce the MAF/VE data which will generate a low torque number.
So now you have a condition where not only do you have enough pressure dialed into it for the combination (if it were seeing full load) it only using about 1/2-2/3 of the normal pressure output. This is why I asked about the Injector size.

[skinnypimp-ss]

they say to set all the line pressures and shift speeds to stock, all that stuff if changed in the trans when they build it. adjust slightly to your liking from there.

[custosonlinux]

Hello,

last Weekend I had time to do some tests and to check every hint and idea I got from you and RPM Transmissions.
First I checked the fluid level. -> It's OK, little fluid trains out when you remove the screw in the pan (engine running and selector in P or N)
Second I checked MAF sensor wires and any error codes. -> wires and conectors OK no errors


After that I've done some testdrives so find answers to your ideas and questions

I scanned for the PCS current and it never goes down to 0mA.
At 300lb-ft (sorry I've to translate it to NewtonMeter every time) the PCS is 620 mA.
I've to do some math for the question about slipping.

When I compared the results from my dyno sheet, the torque shown in the HPtuners scans, are always to low.
As NTIMID8 identified, my tuner scaled the maf and ve tables for the new injectors instead of changing values for the injectors.

So I think I have only two choices:

a) to go back to my tuner and let him tune the car again with the right values for the injectors (for which I have to pay for)
b) scale down the other tables which have to do with torque in the transmission.

I think I will go with b), because I can do this on my own.

I started with the pressure values and the next scan on sunday was a lot better.

What do you think: I would set the shift pressure values to max (96) starting from 300 lb-ft, if you think that at this point the real torque is more than 400 lb-ft. The fields below 300 would be filled smooth down to zero and above 300 I set only full pressure.

I compare these to the vacuum modulated line pressure. As I understand the vac system, the selenoid sets full line pressure when the vacuum is low or zero. In a supercharger setup, this could be already at low rpm and at any boost level.


So, thank you very much for your support!
You pushed me into the right direction so find a solution.

Next steps will be the modification of the shift pressures, as it is the only table with values in combination with torque.
I'm going to do some testdrives and increase the pressure to my needs. As I can see, the base pressure in each gear is interpolated from the shift pressure tables.

I'll post my results when I'm ready, that others could use them.

Kind regards

Birger

[NTIMID8]

Force Motor Current table

[custosonlinux]

Thanks!

Wohow... seems like a hard calibration.
I'll try it, but I think I will let some mA in the 61-100 fields than setting it to 0.

I see that you set the shift times to values between 0,5 and 0,250.
I've set it to 0, because of many discussions here in the forum about this tables. Some say to zero these tables, and let the tranny do what pressure allows and some said to set it at 0,2 or lower.
This discussions where about the shift kits (i've transgo HD-2 in the Level V) and that the pcm could be confused about the fast shift times the transmission could to.

What is your opinion about that?

Thanks and kind regards

Birger

[custosonlinux]

Hi there,

I'd like to give you an update about the problem I had with the power loss at 4500 U/min.

First of all: It wasn't a problem with the transmission.

Because of the way, my tuner scaled table for MAF, injector size and VE, I had to rescale the transmission tables for shift pressure and the force motor table.
The calculation of engine load was to low, as NTIMID8 identified. I've seen this in a lot of tests. I changed the force motor table to give full line pressure at about force motor 66 and above, because values about 72 were the maximum I've seen in the logs.
(OK when it shifts, it gives a short 96 value)

After changing these Tables the tranny shifts fine, fast and chrisp at WOT, without slamming into the gears.
I can't detect any slippage in the logfiles after these changes.

But the problem is still there.

I took the car to another tuner, who has a lot of knowlege about engines.
He drove the car and said that this is valve float.
We looked at the fresh installed pressure gauge and it was at 8 psi when valve float starts.
So we changed the valve springs to C5Z06 springs (we had no better springs at this time) and the problem changed to 5000-5300 U/min.
Now I'm going to change them with Comp 918 springs in the near future.


Thank you very much for your ideas, that helped me to find the solution.

kind regards

Birger