Heres a post from Sean on the Viper forum about the vec2 and vec3:
Hi Everyone,
Sorry I didn’t come on here earlier and address this topic. I really did intend to.
Here it is in a nutshell.
The VEC3 is a progression from a VEC2 in regard to the circuit board components and interface. The processor, drivers, etc are the current state of the art components. Does that make it any better than the VEC2? A little, in that the components are now more robust and it uses a USB cable to communicate (allowing for an additional set of inputs in the back). Is that a reason to change over from an earlier VEC2? No.
With the new box release, we also introduced new firmware and software versions. The firmware is the program the processor uses to operate and the software is the interface you use to write different fuel curves, timing curves, etc.
During the last twelve to sixteen months, we’ve been working on making the operating system and software better. To that end, here are the changes that have been made over firmware 5.108 and software version 3.5.0 (dataset 106).
- Intake Air Temperature input function. There’s a new page within the fuel table to offset the final injector output pulse as it leaves the box. You can leave the offset at 0, or scale the fuel up as the air is cooler and down as it gets hotter. It doesn’t take much of an adjustment. The stock PCM’s IAT input is not disabled to make the VEC’s work. They both work together. It makes no difference on the year of the vehicle. It’s just an offset to the final injector pulse time. If the pulse out was about to be 10ms and you have a hot day with a 2.5% decrease at 140 degree IAT, the output pulse will be 9.75ms instead. Simple as that.
- For the Gen 3 cars, we’ve added a function that eliminates the problems associated with the stock PCM’s holding closed loop operation for the first 1.5 seconds of full throttle. Closed loop is the operating condition where the PCM monitors the oxygen sensor voltage and alters the injector pulse in order to achieve a specific voltage / air to fuel ratio. It does this on the fly and instantly. If you have a 2003+ car, are cruising along and slam the throttle, the stock PCM will continue to monitor and a adjust the injector pulse to achieve the optimum (for emissions) 14.7:1 air / fuel ratio for 1.5 seconds. That’s not so great in a lot of different ways for a lot of different reasons. Suffice it to say “LEAN†at full throttle is bad for engine life. We put in a function that clamps that down and keeps it from adjusting the AFR on the 2003+ cars. Very beneficial for naturally aspirated and necessary for forced induction, unless you have an aftermarket flashed PCM where it’s been turned off (not too many people know about this problem).
- In the logging, we’ve added a horsepower and torque graphing function. Utilizing this function along with an air / fuel ratio sensor input allows you to do full tuning without having to go to a dyno. It won’t necessarily produce the exact same numbers as a dyno, but is just as useful for tuning. Any area where the ignition advance or air / fuel ratio is not optimum will show up as a lower power area. It’s pretty slick really.
Any other changes made in the firmware and software have been made as a matter of evolution. This is the best to date.
All VEC2’s can do the same thing as a VEC3. The only real difference is in the input configuration. A VEC3 has an Analog 4 input on both master and slave board, where a VEC2 does not (the VEC2 uses that port for serial cable communication). On the VEC3’s I use the new AN4 input for the IAT input.
Assuming you have a VEC2 (silver box, where a VEC3 is black), should you update or not? Here are the facts, pro’s and cons:
If you have a 1992-2002 car, the only benefit of significance is the IAT input function. Not all “need†this function. If it isn’t broke, don’t try to fix it. A stock Viper has a wide fluctuation in its AFR due to IAT’s, but most people never see it because they don’t start monitoring their AFR until after they’ve modified the engine.
There are some 2000-2002 cars with stock PCM’s that hit 100% injector duty cycle output, which can screw up an older firmware VEC2 (causes a miss at about 5,500 RPM in hot weather). Those would benefit from the firmware update, even if they didn’t use the IAT function.
If you have a 2003+, yes, you should update your VEC2 and wiring harness to the newest frimware / software. These cars have a bad program from the factory that turns the fuel up way too much when the air is hot. Just kills the power and fuel economy. Additionally, you’ll want to get the closed loop delay eliminated. Makes better throttle response and is better for your modified engine (will help keep it alive if you happen to punch full throttle at 4,500 RPM or so by allowing the AFR to come down to where it should, not go lean for 1.5 seconds).
The downside to the update is compatibility and wiring. The new software is version 3.6.11 and the dataset is S108. It’s not compatible with the older S106 version. If your VEC2 is updated, your box will not read the S106 cards any more. You’ll need to have the cards changed over and need new software if you have the S106 version. You’ll also need a set of IAT wires and or additional wires if yours is a Gen3. Is it the end of the world to do this, no, but it is a little time consuming if you’re on the end of the desk thinking about the 850+ VEC’s out there
So, if you’re thinking about doing it, let me know in advance of sending anything in. We don’t mind doing it and helping everyone out, but we may have to charge something for it since that will be a lot of work and time spent.
Hope I didn’t miss anything. If I did, I’ll try and pop back on soon.
Regards,
Sean
Hi Everyone,
Sorry I didn’t come on here earlier and address this topic. I really did intend to.
Here it is in a nutshell.
The VEC3 is a progression from a VEC2 in regard to the circuit board components and interface. The processor, drivers, etc are the current state of the art components. Does that make it any better than the VEC2? A little, in that the components are now more robust and it uses a USB cable to communicate (allowing for an additional set of inputs in the back). Is that a reason to change over from an earlier VEC2? No.
With the new box release, we also introduced new firmware and software versions. The firmware is the program the processor uses to operate and the software is the interface you use to write different fuel curves, timing curves, etc.
During the last twelve to sixteen months, we’ve been working on making the operating system and software better. To that end, here are the changes that have been made over firmware 5.108 and software version 3.5.0 (dataset 106).
- Intake Air Temperature input function. There’s a new page within the fuel table to offset the final injector output pulse as it leaves the box. You can leave the offset at 0, or scale the fuel up as the air is cooler and down as it gets hotter. It doesn’t take much of an adjustment. The stock PCM’s IAT input is not disabled to make the VEC’s work. They both work together. It makes no difference on the year of the vehicle. It’s just an offset to the final injector pulse time. If the pulse out was about to be 10ms and you have a hot day with a 2.5% decrease at 140 degree IAT, the output pulse will be 9.75ms instead. Simple as that.
- For the Gen 3 cars, we’ve added a function that eliminates the problems associated with the stock PCM’s holding closed loop operation for the first 1.5 seconds of full throttle. Closed loop is the operating condition where the PCM monitors the oxygen sensor voltage and alters the injector pulse in order to achieve a specific voltage / air to fuel ratio. It does this on the fly and instantly. If you have a 2003+ car, are cruising along and slam the throttle, the stock PCM will continue to monitor and a adjust the injector pulse to achieve the optimum (for emissions) 14.7:1 air / fuel ratio for 1.5 seconds. That’s not so great in a lot of different ways for a lot of different reasons. Suffice it to say “LEAN†at full throttle is bad for engine life. We put in a function that clamps that down and keeps it from adjusting the AFR on the 2003+ cars. Very beneficial for naturally aspirated and necessary for forced induction, unless you have an aftermarket flashed PCM where it’s been turned off (not too many people know about this problem).
- In the logging, we’ve added a horsepower and torque graphing function. Utilizing this function along with an air / fuel ratio sensor input allows you to do full tuning without having to go to a dyno. It won’t necessarily produce the exact same numbers as a dyno, but is just as useful for tuning. Any area where the ignition advance or air / fuel ratio is not optimum will show up as a lower power area. It’s pretty slick really.
Any other changes made in the firmware and software have been made as a matter of evolution. This is the best to date.
All VEC2’s can do the same thing as a VEC3. The only real difference is in the input configuration. A VEC3 has an Analog 4 input on both master and slave board, where a VEC2 does not (the VEC2 uses that port for serial cable communication). On the VEC3’s I use the new AN4 input for the IAT input.
Assuming you have a VEC2 (silver box, where a VEC3 is black), should you update or not? Here are the facts, pro’s and cons:
If you have a 1992-2002 car, the only benefit of significance is the IAT input function. Not all “need†this function. If it isn’t broke, don’t try to fix it. A stock Viper has a wide fluctuation in its AFR due to IAT’s, but most people never see it because they don’t start monitoring their AFR until after they’ve modified the engine.
There are some 2000-2002 cars with stock PCM’s that hit 100% injector duty cycle output, which can screw up an older firmware VEC2 (causes a miss at about 5,500 RPM in hot weather). Those would benefit from the firmware update, even if they didn’t use the IAT function.
If you have a 2003+, yes, you should update your VEC2 and wiring harness to the newest frimware / software. These cars have a bad program from the factory that turns the fuel up way too much when the air is hot. Just kills the power and fuel economy. Additionally, you’ll want to get the closed loop delay eliminated. Makes better throttle response and is better for your modified engine (will help keep it alive if you happen to punch full throttle at 4,500 RPM or so by allowing the AFR to come down to where it should, not go lean for 1.5 seconds).
The downside to the update is compatibility and wiring. The new software is version 3.6.11 and the dataset is S108. It’s not compatible with the older S106 version. If your VEC2 is updated, your box will not read the S106 cards any more. You’ll need to have the cards changed over and need new software if you have the S106 version. You’ll also need a set of IAT wires and or additional wires if yours is a Gen3. Is it the end of the world to do this, no, but it is a little time consuming if you’re on the end of the desk thinking about the 850+ VEC’s out there
So, if you’re thinking about doing it, let me know in advance of sending anything in. We don’t mind doing it and helping everyone out, but we may have to charge something for it since that will be a lot of work and time spent.
Hope I didn’t miss anything. If I did, I’ll try and pop back on soon.
Regards,
Sean
