Tuning the 6L80E for a Supercharger: help?!

[Padre]

Well, with the ProCharger D1-SC in and running great, getting the 6L80E tranny tune down has been a problem after 3 visits to the track. It was working great and very consistent with the tune I did for bolt-ons and later for cam. First time out with the old bolt-ons/cam tranny tune, it cut a 10.788, but then went steadily downhill from there.

Basically, it "bucks" or "gasps" as I try to get into it off the line. Here's an example:



Some of the variables I've been looking at: Trans Adapt, Slip, Inertia, Desired Shift Times, Shift Pressures, and misc items.

Part of the problem seems related to the fact that I cannot go wide-open throttle WOT in first gear. Way too much power and spinning.

One thing I did try was to borrow the Inertia, DS Times, and Pressures from a 2011 CTS-V (LSA motor on a 6L90) tune (in the HP Tuners Repository). That feels real nice for daily driving.

Took it back to the track yesterday and the same thing happened. First run was good (11.1 @ 128), but it declined from there. Next three runs were in the 11.4 @ 125 range with more bucking and gasping. Then most of the rest (total of 10) were trash, with only #6 reaching an 11.4 @ 125 again.

Only thing I have not tried is to change the part-throttle shifting. Since it is not at WOT in first gear, it is not yet in PE (Power Enrichment with commanded AFR for WOT) nor is it (I assume) looking at the WOT throttle shift speed and rpm (speed being primary). Looking at the logs, it is not commanding or seeing desired AFR (it seems to be moving in that direction).

Once I'm at the end of 2nd gear and to the end of the run, it's pretty smooth and darn powerful.

Has anyone had to go in and make adjustments to the part-throttle shift speed tables to make it work for a car that cannot go WOT in first (and part of second)?

Any other ideas? Other theories: mechanical (1-2 or 2-3 tranny problems, or blowing through the torque converter), not tuned well for Tranny Adapt, not tuned well for Inertia, Time and Pressure, etc. I tried a lot at thet rack yesterday to no avail.

Of course, it might not be related to the tranny at all but to timing and airflow.

Here's the best run (first):



Padre

[Scott@Bjorn3D]

Looks like TRQ Management in the transmission coming on. Send a PM to Ted Jannetty and see what he thinks.

[Padre]

Originally Posted by Scott@Bjorn3D

Looks like TRQ Management in the transmission coming on. Send a PM to Ted Jannetty and see what he thinks.

I've tuned out torque management a long time ago, but it's possible I missed something.

Padre

[white ZL1]

Have you tried hitting up the guys on the HPT board Padre?

[2SSCAMARO]

You are bouncing off of the rev limiter due to wheel spin. You got suspension work and tire issues to deal with. If you datalog some runs, I think you will see that you are hitting the rev limiter during the 1-2 shifts and probably also the 2-3 shifts to a lesser degree. Cold, Hot, and poorly prepped track surfaces will cause your problem to worsen.

[JANNETTYRACING]

Originally Posted by 2SSCAMARO

You are bouncing off of the rev limiter due to wheel spin. You got suspension work and tire issues to deal with. If you datalog some runs, I think you will see that you are hitting the rev limiter during the 1-2 shifts and probably also the 2-3 shifts to a lesser degree. Cold, Hot, and poorly prepped track surfaces will cause your problem to worsen.

What He Said, You can't Tune an Auto With Wheel Spin.

Also MAF calibration is Crucial to the TCM.

[Padre]

I appreciate the input.

Much of the bucking did not come at the rev limiter, so that's out for the majority of it.

Most of it comes when I am feathering the throttle. Here's an example of what my log looks like:



The bottom green line shows you where the bucking occurs, because the WBO2 (measured) goes lean as it "gulps" for air. The speed (top green line) is pretty steady and does not indicate wheel spin (in other logs, spinning shows up as in increase in MPH followed by a return to pre-spin MPH).

The top light blue line shows what the Electronic Throttle Commanded is doing. I'm pretty sure I'm not in and out of throttle, so is it being commanded to back out? It drops to 60% during and after the "gulps".

The red line shows that I'm no where near the limiter.

Ideas?

Padre

[JANNETTYRACING]

Originally Posted by Padre

I appreciate the input.

Much of the bucking did not come at the rev limiter, so that's out for the majority of it.

Most of it comes when I am feathering the throttle. Here's an example of what my log looks like:

Attachment 351039

The bottom green line shows you where the bucking occurs, because the WBO2 (measured) goes lean as it "gulps" for air. The speed (top green line) is pretty steady and does not indicate wheel spin (in other logs, spinning shows up as in increase in MPH followed by a return to pre-spin MPH).

The top light blue line shows what the Electronic Throttle Commanded is doing. I'm pretty sure I'm not in and out of throttle, so is it being commanded to back out? It drops to 60% during and after the "gulps".

The red line shows that I'm no where near the limiter.

Ideas?

Padre

Also Injector Calibration Should have said that above.

Build a 4 inch MAF Tube at least 12 inches long with Smooth Transitions for minimal turbulence, install a set of ID-850 injectors and use the provided Calibration data, install a ZR-1 Map Sensor, ZR-1 Plugs.

Put all the Transmission Tables Back to Stock, start with Line Pressure only.

This Will Get you headed in the Right Direction.

Ted.

[Padre]

Originally Posted by JANNETTYRACING

Also Injector Calibration Should have said that above.

Build a 4 inch MAF Tube at least 12 inches long with Smooth Transitions for minimal turbulence, install a set of ID-850 injectors and use the provided Calibration data, install a ZR-1 Map Sensor, ZR-1 Plugs.

Put all the Transmission Tables Back to Stock, start with Line Pressure only.

This Will Get you headed in the Right Direction.

Ted.

Thanks Ted! Very helpful information. I'll run it by my tuner.

Padre

[Slowhawk]

You just need the motor tune on. I'll suspect the tune is off which screws with the load tables and then messes with the tranny tune. At part throttle,90kpa+ the car should be in PE.If it is not tuned that way it will mess with the load tables/tranny.

If time is taken on the engine tune there is no need for special injectors or different pipes,maps ect to get it running 100% were it should. I would spend time on what you got before buying more stuff at this time.

[Padre]

Originally Posted by Slowhawk

You just need the motor tune on. I'll suspect the tune is off which screws with the load tables and then messes with the tranny tune. At part throttle,90kpa+ the car should be in PE.If it is not tuned that way it will mess with the load tables/tranny.

Thanks Slowhawk, I was thinking that it had more to do with part throttle and PE than with the tranny tune. Hopefully we'll get it figured out soon.

Padre

[Padre]

Hat tip to Ted Jannetty. He mentioned in another threadabout fuel pressure dropping when low on fuel, because the weight of fuel at the pick-up point is decreased. Well, a light bulb went off and I realized I had been running 1/4-tank like I always do. Never a problem.

But now, not only is the extra power causing the fuel to slosh around, but the new fuel pump (Aeromotive) has no bucket at the pick-up like the stock tank/fuel pump.

So, full tank of gas today, and running 10.9's @ 128mph in 2000+DA ALL DAY LONG.

Thanks gang, and Ted!

BTW, I did also borrow some elements of the tranny tune from a CTS-V 6L90. I like the shift feel better with the V tune than starting with the stock SS tune.

Padre

[JANNETTYRACING]

Originally Posted by Padre

Hat tip to Ted Jannetty. He mentioned in another threadabout fuel pressure dropping when low on fuel, because the weight of fuel at the pick-up point is decreased. Well, a light bulb went off and I realized I had been running 1/4-tank like I always do. Never a problem.

But now, not only is the extra power causing the fuel to slosh around, but the new fuel pump (Aeromotive) has no bucket at the pick-up like the stock tank/fuel pump.

So, full tank of gas today, and running 10.9's @ 128mph in 2000+DA ALL DAY LONG.

Thanks gang, and Ted!

BTW, I did also borrow some elements of the tranny tune from a CTS-V 6L90. I like the shift feel better with the V tune than starting with the stock SS tune.

Padre

Glad I could Help.

Ted.