Hello,

I been lurking around the forums for 5 years or so and have a question in regards to boost control that I don't see much info on.
I have a Solstice with an LDK motor, S257SXE, on meth and currently controlling boost with the factory solenoid on a Tial wastegate.

I tuned it on meth and it's really getting annoying having to reflash the ECU everytime I want to change between high boost and low boost tunes. The high boost tune the motor works fine in 3rd and 4th but is completely useless in 1, 2 and 5th gear. It just spins in the 2 first gears and then the turbo surges in 5th. I really want to eliminate boost control by the ecu and use a turbosmart Eboost 2 to be able to switch between high/low boost. Also the Eboost 2 has boost by gear which would allow me to use less boost on problem gears and map out the boost curve. Also the low and High boost tunes both use different amounts of meth and this unit has a built-in meth controller that would make thing so much easier for me.
I should be able to edit the load values to keep timing in check between the two boost settings without having to have to reflash the ecu every time. However, my concern are the boost tables on the ECU as this will cause the ecu to show knock when something is not correct. I am not sure how the DAL, Boost pid, MALT and Duty cycle tables will be affected.

Spent sometime messing with the torque tables to try and get boost control to vary on different gears and load value but it just made things more unpredictable.

I was thinking of picking one up and renting a dyno for half a day and trying to figure it out but figured to check to see if anyone has done this before.
All the searches I run return some twincharged kappa but cant much info.

 

You should be able to control the power adjusting the torque by gear, or go into your Optimum Spark tables and reduce the difference in the mid range so it's not such a snap demand for power when you give it partial throttle so you can pedal 1st and 2nd better

 

+1

I actually like the stock optimum spark tables shape because the demand seemed linear for the response to the pedal (better then anything I had created myself). I can reasonably modulate tire spin in 1st/2nd gear with my right foot. So I just used the stock table (optimum - main spark) and multiplied that by 1.1 to make it a tad more lively, but not alter the shape of it.

Also, I use torque X gear (by rpm) as you mention to shape each gear how I want it. I do not use MALT at all though (MALT set to 100% at all rpm points for me), so that only the torque by gear works well. When I tried to have both MALT and torque by gear involved, I did get somewhat unpredictable results that also seemed inconsistent.

OP: I would try the torque by gear again but make sure MALT is set to 100% so it is not also trying to reduce torque.

I get what you want to do. I have tried to think of a way in the tune where I could run a pump gas tune and meth tune both without reflashing. That way I can not worry about running out of meth and then having to stay completely out of boost of that occurs. I thought about trying to trick one of the modifier tables (maybe for temperature since that can affect ignition timing via t least one modifier table to either add or subract) to activate with a simple cabin switch.
That way I could cause the ECU to operate in two different modes that would affect at least ignition timing to have more or less. But I have not figured out a way to do this easily yet.

 

For your meth option a lot of people wire in a level or pressure failsafe and then connect it to the IAT1 sensor and have it set to cause a high temp reading when empty so you can pull timing at excess temperature

 

Hmm,
I will max out the Malt table to play around with the gearing nannies.

 

Cool idea. I will have to look into that and how to get the correct signal piggy backed on the IAT1 input to cause it to read high.

 

Man I miss stand alone ecu's

 

you need a better tuner. cause that tune seems pretty shitty

 

who does this? this is the first iv heard of it on lnf. I want to do it

 

I haven't messed with it on the lnf, but likely if you short to ground the temp wire on the tmap you can reduce timing based on charge temp or you could always use the maf temp wire and do the same based on IAT timing. Don't have hptuners in front of me to remember which tables there are or if both are available. You would also have to find out if the sensor failing to ground would result in a high or low temp (both should give you the control given they have over 100 and -0 temps)