After completing tuning of the GTI’s Shuenk IS38+ turbocharger on 93 octane with an EQT custom ECU tune I began thinking of another project that would build on the work currently done modifying the GTI.
With recently completing a long DSG tuning effort with Stratified I inquired about the possibility of an ECU tuning project that would include modifying the IS38+ to accommodate the Garrett Turbocharger Speed Sensor. Stratified was open to this proposal and suggested an Ethanol mixture as a way to produce some additional output from the existing setup.
Note: The existing setup is mostly stock fueling with an HPA HPFP.
This path sounded good to me and I began discussing with Sheunk the process of modifying an IS38+ to accept the Garrett sensor.
In the meantime I have begun moving forward with adding an Ethanol content analyzer to the GTI and starting the ECU tuning, which will be the subject of the remainder of this post.
Prior to receiving the first tune I submitted the GTI modification list to Stratified. Standard for ECU tuning I received back a list of variables to log with the Cobb Accessport and instruction for how to collect the data.
Soon after I received the first file targeting an Ethanol content of 30%.
The Fuel-It! analyzer has an accompanying App that includes a simple calculator for estimating the ratio of Gasoline to Ethanol for a given size fuel tank.
After adding the suggested amount of Ethanol to the tank I flashed the ECU with the Stratified E30 tune and then started the engine to monitor the change in Ethanol content.
I was expecting it to take a minute or two for the Ethanol content percentage to change. To my surprise it took a bit longer, several minutes of driving around my neighborhood were needed before the Ethanol content started to tick upward.
Eventually the percentage rose to 30% (nailed it!) and the GTI was taken out to record data.
A third gear full throttle acceleration was made and the data produced is shown on the following charts:
To gauge progress of the tuning effort the acceleration time from 3500 to 6300 rpm is calculated using the Cobb data. Comparing with results on 93 octane, during warmer weather, is made on the next chart. The blue bars are on 93 octane, the red bar on the E30 mix.
Comparing results between different atmospheric conditions is not preferred, but in the interest of progress is acceptable.
Tuning is off to a good start. Results have been positive and there’s room to push things further.