Quote:
Originally Posted by TDIwyse
Yes, I have AFR and I'm adding large amounts of H2O/methanol + extra fuel in a progressive fashion after a specific rpm. The base map seems to target ~16:1. Stoichiometry of methanol is significantly lower than diesel. My AFR's get lower than 16:1 in the upper rpm range with ~800 ml/min of 50/50 mix. The H2O portion helps balance the EGT's at these high hp levels.
I haven't seen the KP39 copressor map, but I'm at lower boost psi at the rpm's where it's being primarily used. Hardly above stock levels... It was the big turbo I was mostly concerned with.
In the SCR mod thread I linked some calculators for calculating air flow amounts. The only point I think I may be just off the K26 map based on the analog gauge is at ~3900 rpm. But it's not substantially off the map... But this is also not accounting for the psi drop in the intercooler ... but the measurement is also after the H2O/methanol injectors which are adding dramatic levels of cooling and extra pressure from the extra injected mass...
I should really be measuring the boost directly after the turbo compressor, but didn't think it was worth the extra fussing around to find a good way to tap into that area.
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Fantastic information!
16:1 is going to help keep it on the map. Do you have datalogs, without the modded JBD and H2O/Meth, just remap, you can share? Oh crap, you know what the next question is I am going to ask. Then with?
A while back hotrod182 showed what methanol could do. He was squirting about 120Hp (not in a manner I would want to emulate), by my calculation. Though I'm not sure he was combusting all 120Hp, as I don't think there was enough excess air with the small pressure increase he was seeing. For you, with only 1.3 pounds of excess air (16-14.7) for methanol combustion. Methanol's ~ 6:1 AFR is going to allow you about 11% more power. 400 cc/min methanol is ~ 40Hp. I think that puts you right on the money.
Pressure ratio is defined by inlet and outlet at the turbo. For sure, when everthing is said and done, measuring at the inlets and outs is best. Maybe that is a good use for a spare differential pressure sensor. At full boogie, inlet to the LP turbo won't be at atmospheric pressure, either. Anything that happens to the air after the turbo, cooling etc., doesn't change the operating point on the compressor map. Density ratio changes that you are referring to do effect the "other compressor", the engine.
So, while you didn't answer my question directly, I think I know where you are going. Trying to get back to the boost levels you had before the latest exhaust mods. Did I get that right?