SYNC ERRORS

[kevdachev]

David, thank you very much for all your info. I am slowly getting a better understanding of this. I can see how the launch control is set up against the x axis of RPM but cannot understand what happens after launch and I want the engine to rev without restriction .Also why the launch control is on all the time. I thought it would only activate with the trans brake button. I think Sean was a bit puzzled with this part as well.
KEV

[David Ferguson]

I think without wheelspeed sensors you should disable launch control. I missed something that needs to be set to disable launch control -- you need to have Adjust->Functions->Traction Control->Setup->Control Method = 0 as well.

With the above set, it shouldn't matter that Digital Input 1 is configured (in Adjust->Digital Inputs Functions->Dig 1 In->Function) to be TC Enable/Disable.

I am not a drag racer, but perhaps this has been setup to create a "two-step" rev-limiter, using the TransBrake as the TC disable, so works as Sean described -- only when the Launch knob is in position 0 - 2, and the TransBrake is active (of that's connected to Dig 1 In). You then use the Knob position to decide what RPM to leave the line with.

Can you tell us how this has worked in the past, or what you are trying to achieve? Is it still not reving past 2500?

If you use the menu View->View Sensors and go to the "Status" tab, what is the "Digital Input 1" and "TC Disable" when you switch the TransBrake on and off. If it still won't rev, what is the state of "TC Launch Ctrl Act" (found on the same screen), when the limiter is active?

[Sean]

Kev, going back a step, has this vehicle been successfully rundown the track with this config? Or are we looking at something that has not yet actually worked? The massive steps in the proposed 2 step rpm imply that the values are notional values for setup only as there's now way you'd be using such coarse adjustments if everything was dialled in.

If (big IF) the 2 step works with the dial in setting 0 to 2 and not above that I believe there's a work around. Bear in mind that if you roll the throttle in when you go to the 2 step the revs will go way high then come back down to the target when you pass the 15% throttle arming threshold that is set.

[kevdachev]

Sean/David, to clarify a few issues the truck was set up 4 years ago. It has run very well since running a best of 8.7 at the strip. There is more power in the engine but I chose to be conservative to preserve the engine. I have always had it in mind to learn about the ECU but as the truck was pretty reliable didnt. I had a problem with the turbo and damaged the motor as well. Normally on a run, depending on track conditions I set launch control between 2-5 and boost control the same. I pull up to the line push the trans brake button and put the throttle pedal to the floor. On launch the truck revs to 6000 or 6500 and I then shift gear. Hope this the info you want.
Kev

[Sean]

Your launch control has been nagging at me (and I couldn't help myself) so I got out a wiring harness , M800 and a few bits and did some testing.

If the TC disable switch is wired with the transbrake as we think, yes it will work, it will turn off the TC system and the engine will rev to high limit. It doesn't leave launch mode as far as I can see, just turns the TC system off. Needs to power cycle or reset the ecu to leave launch mode once it's entered.

In the supplied configuration, launch control activates only in dial setting 0 and 1 ONLY. This is because to activate the channel value (in this case dial setting) has to be below 1/4 of the maximum value. The reason 2 isn't accessible I believe is because 9/4=2.25, which rounds to 2. 2 = 2 so it's not below.

To access all the settings in the launch rpm table you can do a mod to the table, adding a value of 50 as the last value. 50/4=12.5, which rounds to 12, which is greater than 9.

Kev table mod.jpg (23.71 KiB) Viewed 5831 times

Do you have logged data from these runs? Boost settings appear to be 2 = 8 psi, 5 =21 psi, does this seem right?

[Sean]

Kev, next question, does the boost control actually work? In the logged data supplied it appears not to. I will add the qualifier that I know not much about the Motec boost control system, however......

At one point target boost is 57 kpa (8.2 psi) and actual boost is 216 kpa (31 psi), that is 159 kpa (23 psi) over target.
See plot below of aim boost versus manifold pressure.

kev boost.jpg (189.61 KiB) Viewed 5813 times