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Old 23-01-2018, 12:05 AM
rotrex rotrex is offline
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Join Date: Jan 2014
Location: Germany
Posts: 187
Default Re: Injection amount vs E85

Hello Peter,
Ears, a TurboXS knocklite and later a J&S Safeguard plus gauge.
No Motec or Syvecs capability, but in a early Elise you can hear it knocking pretty well as there is no sound insulation and the engine sits close behind your head.
Now at least my puny SC Rover K made less power on rather rich AFRs and knocked with less advance. Could be exhaust valves getting hotter or whatever. Lot's of nonlinearities.
Maybe I was all wrong and should have drowned that bugger in fuel despite it performing rather poor.

You also posted similar observations on way rich not being any good in the past.
You advocated AFRs of 11:1 and higher.
I can dig out a few examples from you, but can't be bothered on a ipad.
From: http://rotarycarclub.com/rotary_foru...p/t-10423.html
"*At full boost pressure* The AFR on average is 11.3:1 with the current WI setting, it only goes towards 11.4:1 at revs past 7400rpm to stop the power from falling off where I need to hold rpm to say 8300rpm to save making a gear change be it on a straight or hold out 5th gear for 200+mph top speed as my car is geared for too . Lower boost pressures (0.5bar to near 1.0bar) the AFR is around ~12.0:1 setting (more so because any more excess fuel is not required, especially with water injection or even without) Anything with more excess fuel really takes away allot of power. My EGT was always around 980 deg C or so with the correct ign timing, this set fuel mixture, and WI rate. Anything outside of these settings results in lower power, too high an EGT, misfire, or and less measured performance (< too over cooled *fuel or combination of fuel and water*, or not enough ignition advance especially) in my standard 90-140kmh testing I do."

"Default Re: Injecting water into a rich a/f mixture is not a good id
Quote:
Originally Posted by Richard L
Not so long ago, a user of our WI system has lost some 40+ WRHP during a dyno tuning session, not surprise to know that he was quite disappointed. Only after a few months later and have discovered that his engine is tuned to run an a/f ratio of around 10.5:1.

I would really like to hear from anyone if they have suffered the same experience?
Great thread Richard !

I have seen this in my own current car, but I put it down to non audible misfires. When I have had a super strong ignition system on various other cars I have done I have not seen losses in that magnitude but they def do exist.
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In the end, it won't matter as long as you can extract the most from a given set-up. :-)
You have also worked on lower boost levels at the time you posted you observations.
Could very well be that at 30PSI and higher things look different these days.
I went NA for 2018 :-)

Last edited by rotrex; 23-01-2018 at 12:08 AM.
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