Tuning for water injection: fuel, ignition, and EGT

[dlheman]

Originally Posted by RICE RACING

Final note, some knock is good! generally the closer any engine runs to destruction the better its performance will be! so its not uncommon with Life Racing electronics to run the engine on the verge of this point all of the time to extract the most power and highest efficiency. Water Injected cars will allow you to run closer to this point without then quickly leading to pre igntion, this is no one really talks about, but is one of the key things that WI allows (not higher ratios of meth than 50% cause that will lead to far inferior performance FYI)

I was told, when fine tuning REVO software for VW's TFSI engine, the guideline stated to keep adjusting the fuel, timing and boost until the knock retard value reads -3.0 because that's when the engine makes the most power. Maybe it is safe to do that in TFSI engine which comes with forge piston standard.

[dlheman]

Originally Posted by arthurtoo

I'm running an aquamist HSF-2 kit for my JDM 2006 Subaru STI. injecting only water at 42% IDC onwards. car runs great!

but i realized that there is a very very minor knock during initial injection and it's persistent throughout my logs. should this be of a concern or is there anyway to totally eliminate this?

thanks.

On my STI, I find 42% IDC (12 o'clock position) is a bit too late and choose to go for 10 o'clock which injects at around 25% to 30% IDC (I need to look at my HFS3 flow vs FIDC flow datalog). But I am using TMIC so injecting sooner is never a bad idea and I never saw any knock correction.

What is the value of you knock correction during the initial injection anyway? -1.4?

[arthurtoo]

Originally Posted by dlheman

On my STI, I find 42% IDC (12 o'clock position) is a bit too late and choose to go for 10 o'clock which injects at around 25% to 30% IDC (I need to look at my HFS3 flow vs FIDC flow datalog). But I am using TMIC so injecting sooner is never a bad idea and I never saw any knock correction.

What is the value of you knock correction during the initial injection anyway? -1.4?

base on my datalogs injecting at 25%-30% FIDC is around 300-400rpm earlier. what benefits are to be expected for injecting earlier?

yes, the knock correction is -1.4 during the initial injection. few days back i tried advancing more timing where knock is recorded during initial injection, and its at 0 knock now. perfect!