Boy that is a rough one. Not sure how I could figure out what RPM I am at during the different stages. The 1/8 mile would be easy to figure out because I have a mph for that. I am afraid the others would be a little hard for me to come up with.

 

Interesting opinion. I presume you have a lot of dyno tuning experience?

I saw the changes being made, and I saw the results. I've seen the same results on several different LS1s, 2 different tuners, 3 different dyno shops.

 

I have noticed the easier i come off the line the better the 60 ft. time. way better 1.7s

 

The conditions that cause the ECM (and aslo the TCM on the auto-tranny) to invoke Torque Management don't occur on the dyno because
(1) acceleration is gradual, not abrupt and
(2) the rear wheels don't spin because the rear is strapped down

So eliminating TM entirely won't show an increase in power on the dyno. But it certainly shows up in measured acceleration, where the absence of TM means you get to use all the power of the motor rather than sacrificing 10% or so on launch and shifts in a TM toll.

Ranger

 

What he said.

 

i don't think spinning wheels has anything to do with tm unless wheel hop spikes torque when wheels land

 

That is a very big unless. I suspect that the sensor inputes that are interpreted by the ECM as wheel hop are at much lower thresholds than a driver can sense seat-of-the-pants. And of course wheel hop (abuse mode) is only one of the conditions that invokes TM.

Fact remains. Most operators don't launch the car on the dyno and don't make strong shifts. But another look back at Post #210 on this thread might remind everyone that an M6/M12 strongly shifted on the dyno (imagine that) does cause TM to intervene and the power reduction is about 10%. Thanks again to Brett Hunter for those dyno graphs.

And yet some folks still say that TM may not exist or is minimal on manual-tranny C6s.

Ranger

 

Was your C5 an automatic? I know with 01-04 C5 automatics the torque was purposely limited to 360 lb.ft via programing compared to 6spd cars being allowed to generate 375 lb.ft. If your C5 was an automatic that may have been what you were seeing on the dyno.

 

Ok I'll make everyone a deal. I keep very detailed records of my drag strip results and try to apply a methodical approach to making improvements. If we can get 65 people to pay pal me $10, I'll buy HP Tuners enhanced version and log my runs, both with and without TM, and with varying amounts of TM and post what I'm changing and the results thereof!

I'm probably not the best person to do that, truth be told. I'm just a hack with 30 years of reading Hot Rod and other magazines under my belt. But I would CERTAINLY chip in the $10 if someone (Ranger ???) wants to do this!

Then we can stop just bench racing and see real results!!

 

To further this, every dyno run I have ever watched they just put the car in the gear with a 1:1 ratio (fourth on a manual car), hold steady at a "start" rpm, then floor the accelerator and hold it to redline. This would not invoke TM.

I cannot picture "banging" shifts or doing a "launch" on a dyno. That would be way out of the norm for a dyno run. I'm thinking that with the car strapped down, and the drum having to be what moves, it would be a real good way to break some expensive parts.

 

You mean that for $10 a person, we could put an end to this debate? Now why would we want to do that? So we can go back to asking each other what color interior we should get with our red.....no, black.....oh, what about Lemans Blue.............

 

everyone knows LeMans Blue gets ebony interior. duh ?!

 

I did!!

I actually came 'this' close to hitting send on the HP Tuners purchase this weekend just so I could do this on my own, but I was supposed to get tuned this Friday by Mike Norris. However, I just got news today that doesn't look like it's going to happen now (is American Racing EVER going to ship C6 headers??????).

Hmmm. Does anyone know how fast HPTuners gets shipped?

 

If your stating that changes to the PCM tune were done while on a dyno and then saw torque increases related to TM it had nothing to do with the TM value changes when using a non load bearing dyno in 1:1 gear ratio with no launching, shifting, decel, etc.

It was more to the PCM after being flashed is now in a relearn adjust state.

All C5s if a coupe or a Z06 has the same PEAK torque value of 350 ft/lbs
as the TM trip point in PCM for maximum delivered torque.
Peak though has nothing to do with smoothly exceeding that value but a sudden peaking of that via free wheeling of tires would allow a sudden increase of flywheel torque and cause TM to kick in.

 

Ranger i misunderstood your post
(2)the rear wheels don't spin because the rear is strapped down.
i thought you were say hell i don't no what you were saying
seriously i thought the tm worked under good traction conditions or on shifts and it measured it by rear tire speed and air flow via air flow meter and someway off the converter .

 

When the ABS/ETC control module senses spin from the drive wheels due to too much engine torque for the road conditions, it enters the traction control mode.
The ABS/ETC module monitors both front and rear wheel speeds through the wheel speed sensors. If at any time during acceleration the ABS/ETC module detects drive wheel slip, it will request:
• The PCM, via the spark retard circuit, to retard the amount of spark advance.

• The PCM, to restrict transmission downshifting.

• The throttle relaxer control module to reduce the engine throttle opening by a certain percentage to bring engine torque into a specific range.
The throttle relaxer control module accomplishes this by commanding the throttle relaxer to override the accelerator pedal cable and physically reduce the throttle body butterfly opening by winding the throttle cable back.
This is achieved via two high speed Pulse Width Modulated (PWM) circuits between the ABS/ETC module and the throttle relaxer control module.

The ABS/ETC control module sends a message to the throttle relaxer control module on the requested throttle position (DKR) circuit.
The throttle relaxer control module then reports the modified throttle position opening back to the ABS/ETC control module via the actual
throttle position (DKI) circuit.
Simultaneously with engine spark retard and throttle position intervention, the ABS/ETC control module will activate the ABS isolation valves, turn on the ABS pump motor and supply brake pressure to the over spinning wheel(s).

The isolation valves isolate the front brake hydraulic circuits from the master cylinder and rear brake hydraulic circuits. Once the rear brake hydraulic circuits are isolated, pressure can be applied to the rear wheels without
affecting any other brake hydraulic circuits.

The ABS/ETC module opens the priming valve, allowing fluid to be drawn from the master cylinder to the pump motor, turns on the ABS pump motor to apply pressure, begins cycling the ABS assembly's inlet and outlet valves, and closes the switching valve, ensuring fluid is directed to
the wheel not back into the master cylinder.

The inlet and outlet valve cycling aids in obtaining maximum road surface traction in the same manner as the Anti-Lock Brake mode. The difference between Traction Control and Anti-Lock Brake mode is that brake fluid pressure is increased to lessen wheel spin (Traction Control mode), rather than reduced to allow greater wheel
spin (Anti-Lock Brake mode).

If at any time during Traction Control mode, the brakes are manually applied, the brake switch signals the ABS/ETC module to inhibit brake intervention and allow for manual braking (throttle reduction and spark retard intervention can still occur if necessary).

Engine Spark and Throttle Position Intervention
Simultaneously to brake intervention, the ABS/ETC control module communicates with the Powertrain Control Module (PCM) and the throttle relaxer control module requesting the PCM to retard the spark advance and for the throttle relaxer control module to reduce the throttle opening.

With the engine running, the PCM continually supplies and monitors a 12 volt pull-up to the spark retard circuit.
The ABS/ETC control module requests spark retard by pulling this voltage low. The PCM then responds by reducing the spark advance of the engine and restricting transmission downshifting.

The ABS/ETC control module constantly sends a Pulse Width Modulated (PWM) signal at 90% with a frequency of "lOOHz to the throttle relaxer control module on the requested throttle position line (DKR).
This signal is to indicate to the throttle relaxer control module that the traction control system (ETC) is in a state of readiness.

With the engine idling, the ABS/ETC control module constantly sends a Pulse Width Modulated (PMW) signal with a duty cycle of 90% to the throttle relaxer control module via the requested throttle position line (DKR).
The throttle relaxer control module responds on the actual throttle position line (DKI) with a PWM signal with a duty cycle of 9%.

When the ABS/ETC control module determines that a reduction in throttle is required, it reduces the PWM signal on the requested throttle position line (DKR), from 90% (no throttle reduction) to as low as approximately 14% (maximum throttle reduction).
The throttle relaxer control module then drives the throttle relaxer motor, overriding the accelerator pedal command (drivers foot), pulling the throttle cable back, and thus, closing the amount of throttle opening.

 

boosted_z06, it would he helpful if you were to provide a source for the info you provided in Post #316 above. TIA.

Ranger

 

My C5 is an M6. Pulls were done as described, in 4th gear, from 2200 RPMs up to redline.

 

That comes directly from GM service document so this is a quote (copy/paste)

 

Is this the current documentation, e.g. 2006? If not, what year?

Ranger