greddy timing recommendations ?
#26
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I have not had detonation under "normal" driving conditions; I had to red line 1,2,3. It's possible I guess that my car doesn't like the Shell gas from the last fill up. I usually get Amaco, but the Shell was convienent.
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Don't think so because I can wind out 3 without detonation. It's when I go 1-2-3 that it happens. Might have been a fluke, I haven't repeated the test. The math shows that my injectors have enough flow potential (but it's close) and I've got a 190 lph hp feeding them. AFR shows rich.
Dunno. EMU or MS with 560s is on the horizon.
Ben
Dunno. EMU or MS with 560s is on the horizon.
Ben
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If it happens after a run up through a few gears, but not while winding out merely one gear, than your on the ragged edge of audible detonation (you may be getting some inaudible detonation even in the one-gear-pulls), and the intercooler is getting heat-soaked to the point of audible detonation on the longer pulls.
That's a timing issue.
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Winding out 1st (if you can really call it that) and 2nd are pretty different than going all the way in 3rd. You are in boost a lot longer. I suspect that your intake temps are simply getting too high, and your IC wasn't keeping up maybe. Pull more timing.
Either that or you have a fuel delivery issue. Maybe the pump is running out of steam when you run high boost for a prolonged amount of time. Do you have a fuel pressure gauge in the car?
Jay
Either that or you have a fuel delivery issue. Maybe the pump is running out of steam when you run high boost for a prolonged amount of time. Do you have a fuel pressure gauge in the car?
Jay
#32
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So, to follow-up:
I had actually been running more timing retard than I remembered. I have a base of 12° pulling 8° in the 2500-3800 RPM range. A bit much for the 7-8psi I've been running, maybe, but it had been working fine that way for some time.
So I experimented this weekend with pulling only 5°, and was met with a decent amount of pinging once the full 8psi was attained. Even at 6°, there's still a touch of ping if it overshoots and hits a little over 8psi. So, at the 7.0-8.0psi level, it would seem 6° is running very close to detonation, and may even have some inaudible detonation.
Granted, this is with a relatively small MX-6/Probe intercooler, but it's bigger than the Saab (probably roughly similar to the 2nd-gen RX-7 intercooler), so I have no idea how Ben, for example, is running 9psi through a Saab intercooler and pulling only 6-7° from a base of 13°; I would think you'd be getting some pretty good ping.
And, Magna, even with your water injection setup, I would think you'd be getting at least some inaudible ping, what with no timing being pulled and no A/A intercooler, at 12psi of boost. You've gotta be on the ragged edge.
I had actually been running more timing retard than I remembered. I have a base of 12° pulling 8° in the 2500-3800 RPM range. A bit much for the 7-8psi I've been running, maybe, but it had been working fine that way for some time.
So I experimented this weekend with pulling only 5°, and was met with a decent amount of pinging once the full 8psi was attained. Even at 6°, there's still a touch of ping if it overshoots and hits a little over 8psi. So, at the 7.0-8.0psi level, it would seem 6° is running very close to detonation, and may even have some inaudible detonation.
Granted, this is with a relatively small MX-6/Probe intercooler, but it's bigger than the Saab (probably roughly similar to the 2nd-gen RX-7 intercooler), so I have no idea how Ben, for example, is running 9psi through a Saab intercooler and pulling only 6-7° from a base of 13°; I would think you'd be getting some pretty good ping.
And, Magna, even with your water injection setup, I would think you'd be getting at least some inaudible ping, what with no timing being pulled and no A/A intercooler, at 12psi of boost. You've gotta be on the ragged edge.
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Winding out 1st (if you can really call it that) and 2nd are pretty different than going all the way in 3rd. You are in boost a lot longer. I suspect that your intake temps are simply getting too high, and your IC wasn't keeping up maybe. Pull more timing.
Either that or you have a fuel delivery issue. Maybe the pump is running out of steam when you run high boost for a prolonged amount of time. Do you have a fuel pressure gauge in the car?
Jay
Either that or you have a fuel delivery issue. Maybe the pump is running out of steam when you run high boost for a prolonged amount of time. Do you have a fuel pressure gauge in the car?
Jay
For grins n giggles, I could snap in my super cool MAC fuel injection pressure set (it literaly pops in) and go for a ride.
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So, to follow-up:
Granted, this is with a relatively small MX-6/Probe intercooler, but it's bigger than the Saab (probably roughly similar to the 2nd-gen RX-7 intercooler), so I have no idea how Ben, for example, is running 9psi through a Saab intercooler and pulling only 6-7° from a base of 13°; I would think you'd be getting some pretty good ping.
Granted, this is with a relatively small MX-6/Probe intercooler, but it's bigger than the Saab (probably roughly similar to the 2nd-gen RX-7 intercooler), so I have no idea how Ben, for example, is running 9psi through a Saab intercooler and pulling only 6-7° from a base of 13°; I would think you'd be getting some pretty good ping.
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