I have been playing with the custom tuning on my pulse, but I am not really sure what I am doing. Can someone break it down for me and let me know what each option does.

- Boost Scaling

- Timing (what is a safe number)

- Timing Scale

- Max Pump Stretch

- TPS Pump Max

- TPS Pump Min

- TPS Can Max

- TPS Can Min

 

Anyone have any input?

 

This was posted by Quad back when custom tune was first enabled. It should get you headed in the right direction.


Ok, I am going to give a rundown about how each tuning parameter works. I am going to do my best to explain this in plain english.

To start with, the test file I sent you is pretty mild but, can be made into the COMP file really easily. For the most part the actual fuel maps are the same across the board. Yes, there are a few different ones out there and when we actually go live with custom tuning we will also have more downloads that offer nothing more than map changes.

Pump Stretch.

This will make the biggest difference in overall power and smoke. This is the amount of time the injector is actually opened and spraying fuel into the cylinder. I have this set pretty low on the 1000 tune that I sent you. The COMP file is set to 1800. More than 1800 creates more torque and a lot more smoke but, actually makes less power on the upper end based on all the trucks I have had on the dyno. This is where the COMP file is set to. Feel free to run it to 2400 anytime you want lots of low end power and smoke but, realize you are giving power up on the top.

This does not mean you will get this amount of fuel all the time. There is a map, in percentages based off of this number as the maximum. Beyond that the map is also scaled by the TPS. So even if the map commands 100% but, you are at 50% throttle you will be getting 50% of the max stretch. If the map calls for 25% and you are at 50% TPS you will be getting 12.5% of the max stretch.


TPS MIN. For both CAN and Pump fueling.

This allows you to make the throttle lighter or more responsive. Basically it gives you a fudge factor that allows you to get a minimum amount of the max fuel stretch all the time. If you set this to 10% you will never get less than 10% of the fuel map. So if the map calls for 100% (1800) but, you are at 5% throttle you would normally get 5% of the map. If you set this parameter to 10% you will get 10% even though the mapping algorithm calls for 5%.

You have to be somewhat careful with this or you will be fueling way too much at light throttle. This is set to 0% on the tune I sent out.


TPS MAX. Both CAN and Pump Stretch.

This allows you to determine what throttle position you will see max fueling at. It also re-scales the entire map based on what you select. This is set to 100% on tunes I sent out. This means that you will not get 100% of the map unless you are at 100% TPS. If you set this at 80% TPS that means you will get 100% of the fueling at 80% TPS. It also means that 80%=100% and the map is scaled between 0% and 80% but, on a 0-100 scale. In other words the map moves in increments of .8% instead of 1%.

This can be really useful for those that drive light but, want power on tap earlier in the pedal but, not necessarily right off idle.


Timing MAX

Sort of goes without saying. 0 means we do not add any timing. 10deg means if the map calls for 100% you will get 10deg added over stock.

I never go over 7.5%. In my opinion that is more than plenty. If you are going for only mileage and are going to be easy you can use 10 deg and it should be great for mileage. The problem is that under much boost it could easily cause headgasket damage.


Boost Scaling.

This function is more of a smoothing function of the map. There are 20 positions that this function controls. Think of it at columns. Until boost equals a certain amount, then it is in a certain column. It takes more or less boost to move to different columns.

So if you set this to 20, then each column is changed by 1psi. If you scale it to 40psi then every 2psi it changes.

While this can make things more or less responsive or smooth it out slightly it does not make huge differences because not necessarily every column is more or less aggressive than the next. There have been maps in the past and there will be maps in the future where they will be more boost reliant. For now we do not rely on boost that much other than as this scaling function.



Hope that helps. If you have questions please let me know.

To turn your custom tune I sent you via email into a COMP tune follow these guidelines:

Timing = 7
Fuel Stretch = 1800
TPS MIN = 0 (both can and pump_
TPS MAX CAN = 100
TPS MAX Pump = 70
Boost Scaling = 25

Wholaa, COMP tune