Miata scroll supercharger (homemade setup)
#61
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That's a tuning fail right there. No engine can sustain detonation for any lengthy period of time.
light det for brief periods you may get over a long period of time, but heavy or sustained det will kill the engine pronto.
Next time invest in some detcans and tune properly rather than assuming it'll all be fine...
light det for brief periods you may get over a long period of time, but heavy or sustained det will kill the engine pronto.
Next time invest in some detcans and tune properly rather than assuming it'll all be fine...
#62
That's a tuning fail right there. No engine can sustain detonation for any lengthy period of time.
light det for brief periods you may get over a long period of time, but heavy or sustained det will kill the engine pronto.
Next time invest in some detcans and tune properly rather than assuming it'll all be fine...
light det for brief periods you may get over a long period of time, but heavy or sustained det will kill the engine pronto.
Next time invest in some detcans and tune properly rather than assuming it'll all be fine...
So how could I stop deto? I can't see the difference with a jackson racing kit and my setup...
#66
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No, it starts with small dimples with rough centers the size of the head of a pin and get larger and can lead to entire rough areas on the surface of the piston. That is unless the rings break quickly and the detonation isn't continued for a prolonged time.
#67
If you haven't thrown them away, check the insulators on the spark plugs. Detonation will leave telltale little ***** of aluminum stuck to the porcelain. The larger the *****, the heavier the detonation, and more ***** means higher quantity.
And I think your ring groove issues are cylinder wall wash down (overly rich condition washing all the oil off the cylinder walls and causing premature wear) causing excessive friction between the top ring and the ring groove. Usually you get really severe skirt damage as well with wash down, but detonation simply wouldn't cause that kind of ring groove damage without absolutely trashing the piston crowns and breaking the top ring land off in places...
And I think your ring groove issues are cylinder wall wash down (overly rich condition washing all the oil off the cylinder walls and causing premature wear) causing excessive friction between the top ring and the ring groove. Usually you get really severe skirt damage as well with wash down, but detonation simply wouldn't cause that kind of ring groove damage without absolutely trashing the piston crowns and breaking the top ring land off in places...
#76
Hello everyone,
I need some analysis on my AFR table.
New engine is running well with the G supercharger (muuuuch better than this autoumn, now I think pistons rings were broken before I put the supercharger on it)
I wanted to make a preservative table, am I on the right way or not?
Yellow dots are the active cases in an WOT accel from 1000rpm to 5000rpm
92kpa = 0 boost
127kpa = 5 psi
162kpa = 10 psi
Thanks for your help
I need some analysis on my AFR table.
New engine is running well with the G supercharger (muuuuch better than this autoumn, now I think pistons rings were broken before I put the supercharger on it)
I wanted to make a preservative table, am I on the right way or not?
Yellow dots are the active cases in an WOT accel from 1000rpm to 5000rpm
92kpa = 0 boost
127kpa = 5 psi
162kpa = 10 psi
Thanks for your help
#78
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Credit to Hustler for that one
The targets look sane if that's what you are asking, but I'm not necessarily the most experienced person in the room with this kind of stuff. Is this thing intercooled yet? I seem to remember you had some insanely high IATs, that'll certainly lead to detonation.
Edit: Yeah, its intercooled. My reading fail. What does your spark table look like?
Last edited by EO2K; 06-07-2012 at 04:48 PM.
#79
The targets look sane if that's what you are asking, but I'm not necessarily the most experienced person in the room with this kind of stuff. Is this thing intercooled yet? I seem to remember you had some insanely high IATs, that'll certainly lead to detonation.
Edit: Yeah, its intercooled. My reading fail. What does your spark table look like?
Edit: Yeah, its intercooled. My reading fail. What does your spark table look like?
For info, yesterday my IAT was 80°F
Spark table is really conservative under boost, I will post it tomorrow.
Thank you
#80
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I posted my AFR and timing table in the thread of complaints that I try to pass off as a build thread. I've fiddled with the timing a bit, and my MS2 based DIYPNP has more resolution than your MS1 based MSPNP, but my timing seems to be close enough to safe with my 9.5:1 1.8 engine that nothing has exploded yet. You could rescale it and use it for reference. Don't just blindly use my (or any) map, that would be A Bad Thing™
Make triple sure your base timing is set/configured correctly. I had mine 3° off when I first started screwing with things. Just for fun, I changed it to be 10° off and the car still started and ran, but the additional 10° would probably have melted something if I had driven it under load.
Last edited by EO2K; 06-07-2012 at 06:26 PM.