Long term test - 1999 Dakota with LY6/6L90
#1
Long term test - 1999 Dakota with LY6/6L90
When I first put this combination in this truck, I didn't do any tuning. Just drove it. It had some shifting quirks, but did pretty well. Over the summer it ran 9.30 in the 1/8th, but the TM was causing it to shut off briefly at the 60 ft mark.
I bought a Diablosport Intune programmer, and fixed some of the shifting issues, and it drove pretty well.
Last weekend the weather was nice, so I took it to Bradenton for some tuning. Here are the results:
Vehicle: 1999 Dakota club cab
Engine: LY6 with variable valve timing from 2007 GMC Sierra, 130k miles, some bearing wear.
Transmission: 6L90
Tuner: Diablosport
Chassis mods: none
Tires: Federal 255/55-17 @ 30 psi all the way around
Fuel: 93 octane
Weight: 4200?
Temperature: about 78 degrees, sunny with light wind down the track
First pass with canned diablosport tune. Detonation codes and lean in both banks. The traction control also pulled back the throttle at about 60 feet, due to tire slip
After making multiple adjustments, I finally took 2 degrees out of the timing at launch, kept 3 degrees out of the timing at mid and high RPM, and added fuel 2% at launch, 3% at mid, and 5% at high RPM.
This resulted in no detonation, and the best pass of the day
Calculating the HP for weight on Wallace racing calculator, this gives an estimated crank HP of 364.71. Right in line with the estimate.
This is a pretty good street combination. Outruns my G8, and gets 17-18 mpg in mixed driving.
I bought a Diablosport Intune programmer, and fixed some of the shifting issues, and it drove pretty well.
Last weekend the weather was nice, so I took it to Bradenton for some tuning. Here are the results:
Vehicle: 1999 Dakota club cab
Engine: LY6 with variable valve timing from 2007 GMC Sierra, 130k miles, some bearing wear.
Transmission: 6L90
Tuner: Diablosport
Chassis mods: none
Tires: Federal 255/55-17 @ 30 psi all the way around
Fuel: 93 octane
Weight: 4200?
Temperature: about 78 degrees, sunny with light wind down the track
First pass with canned diablosport tune. Detonation codes and lean in both banks. The traction control also pulled back the throttle at about 60 feet, due to tire slip
After making multiple adjustments, I finally took 2 degrees out of the timing at launch, kept 3 degrees out of the timing at mid and high RPM, and added fuel 2% at launch, 3% at mid, and 5% at high RPM.
This resulted in no detonation, and the best pass of the day
Calculating the HP for weight on Wallace racing calculator, this gives an estimated crank HP of 364.71. Right in line with the estimate.
This is a pretty good street combination. Outruns my G8, and gets 17-18 mpg in mixed driving.
#3
But then, with electronic throttle and electronically controlled shifting, this truck kind of does what it wants sometimes.
#4
This was a quote from Mike at Diablosport many years ago. It seems to indicate that torque management (TM) is a combination of maybe TCM and PCM algorithms to protect the transmission.
"TM is basically GM's way of putting an end to the fun before it gets started. There are several different scenarios that bring TM into play. Among these are 'abusive launches' and WOT upshifts/downshifts. When TM is enabled, the PCM thinks you are being abusive, and either pulls timing or closes the throttle body on ETC trucks to kill power. You may drive forever without ever realizing what TM is or does, until you experience a vehicle back-to-back with the TM removed....major difference. Suddenly wheelspin is available at low speeds and WOT upshifts feel much stronger and will produce wheelspin as well. Applying the tunes we make available improve the throttle response in these electronic throttle body vehicles drastically...if you command WOT with your right foot, you get WOT, not what the PCM feels like giving you!
In regards to discussion of a 'delay' in power coming on, some of these GM trucks actually do have a lengthy delay before the PCM will allow you to go into power enrichment mode, meaning you are missing out on alot of acceleration. We recently tested an 07 VortecMax on our dyno, and besides the 25rwhp gains up top, we saw as much as 20rwhp and 25-30(!)ft/lbs of torque between 2500-3500rpm as a result of reducing the PE delay time."
I know that my best time of the day was with TM on and timing reduced in the lowest RPM range. No wheelspin, no shut-down between 2 and 3 shift.
"TM is basically GM's way of putting an end to the fun before it gets started. There are several different scenarios that bring TM into play. Among these are 'abusive launches' and WOT upshifts/downshifts. When TM is enabled, the PCM thinks you are being abusive, and either pulls timing or closes the throttle body on ETC trucks to kill power. You may drive forever without ever realizing what TM is or does, until you experience a vehicle back-to-back with the TM removed....major difference. Suddenly wheelspin is available at low speeds and WOT upshifts feel much stronger and will produce wheelspin as well. Applying the tunes we make available improve the throttle response in these electronic throttle body vehicles drastically...if you command WOT with your right foot, you get WOT, not what the PCM feels like giving you!
In regards to discussion of a 'delay' in power coming on, some of these GM trucks actually do have a lengthy delay before the PCM will allow you to go into power enrichment mode, meaning you are missing out on alot of acceleration. We recently tested an 07 VortecMax on our dyno, and besides the 25rwhp gains up top, we saw as much as 20rwhp and 25-30(!)ft/lbs of torque between 2500-3500rpm as a result of reducing the PE delay time."
I know that my best time of the day was with TM on and timing reduced in the lowest RPM range. No wheelspin, no shut-down between 2 and 3 shift.
#5
Very cool. That is about as quick as my 1999 Formula was on street tires before the cam and heads swap. I had a higher mph though obviously.
Would love to see this in 4WD maybe with a 4L80 tranny. Wonder if the Dodge front axle could take it?
Would love to see this in 4WD maybe with a 4L80 tranny. Wonder if the Dodge front axle could take it?
#7
Hell yeah, but it would have to be a coil spring and 3 or 4 link set up for me. I hate leaf springs on the front end of a truck .
And that might run into some money. There isn't a heavier duty IFS pumpkin that will fit in those trucks, is there?