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SlantSixDan
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PostPosted: Sun Jul 20, 2008 8:04 pm 
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Dan, isn;t there actually more energy available in regular? Doesn;t it burn faster than high test?
No, neither. The only significant differences between regular and high-test are:

1. High-test is more resistant to spontaneous combustion (ping/detonation)
2. High-test costs more.

My truck has no knock sensor or any other way of determining the octane rating of the fuel being used...but driveability is better with regular. Or at least it was before the last round of mods. Haven't tried high-test since the mods...no pinging, so no reason to do so.
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This ECU does have a knock sensor circuit, and the engine has a GM knock sensor installed and working a gauge. It seems to work correctly.
Interesting. Knock sensors and solid lifters generally don't get along well, since the tap of even correctly-adjusted solid lifters closely mimics spark knock. Probably just as well your knock sensor isn't hooked up to the ECU; it can be really tough to avoid unwanted spark retard due to the knock sensor mis-hearing tappet tick as ping.

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Sam Powell
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PostPosted: Mon Jul 21, 2008 7:22 am 
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The gauge shows knock only when it is there. Would the tappet noise be worse under hard acceleration? This is when the gauge lights up. All other conditions leave it dark. Would the ECU pick up feedback more sensitively? The gauge works withs LED's. The center one lights up at the first hint of knock. Then the ones around the gauge light up from left to right as the preignition gets worse, and as it lasts longer. So you see the lights sweep around the face of the dial like an LED tachometer.
had
I have one other guy tell me the same thing about solid lifters, so you are in good company. However, the behavior of this gauge would suggest maybe it might work out.

Sam

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Dart270
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PostPosted: Mon Jul 21, 2008 8:07 am 
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Ehrenberg also said they had no trouble with solid lifters on the Green Brick w/knock sensor.

Lou

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Sam Powell
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PostPosted: Mon Jul 21, 2008 7:07 pm 
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That's good news Lou. If I can figure out how to wire it up, I will give it a try. I have had other, bigger fish to fry up until now. They are using the same ECU. I wonder if they could give me info on how to wire it. Do you have an e-mail for them?

Sam

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Dart270
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PostPosted: Mon Jul 21, 2008 7:18 pm 
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I would go to moparaction.com and send Ehrenberg a PM or email from there.

Lou

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Shaker223
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PostPosted: Mon Jul 21, 2008 7:35 pm 
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Dan, India? I gotta hear about this...
Well, start here. Product development nightmare...big boss specified 3rd-world manufacture for a new lamp, because everyone knows that's how you save money. Except we are now 9 months behind, we don't have lamps to send to our customers, and we've wasted enormous amounts of time and money on pathetic samples from India. The trip idea (not mine) is that I'll wave some kind of a magic wand I don't actually have, and *presto*, the Indians who for most of a year have been lying and sending us garbage that doesn't even come a little bit close to meeting our specs, will suddenly become capable of first-world quality. It's completely freakin' idiotic. We could have had super premium, top-flight, military-spec, USA and/or Canadian manufacture for less than we've wasted on this fiasco with Indians who very obviously have no capability or intent to do what they claimed they could. This is what happens when we disregard the difference between price (the number the Indians put on the quote) and cost (the pile of money we've wasted chasing that "price").

22 hour plane flight there...two days there...22 hour plane flight back. I said I'd bring back a souvenir. I hope it's not dysentery. :roll:
Mgt. seems to believe outsourcing is the answer...not. Our help desk was outsourced to India...needless to say, I'm on 3 weeks for something that used to take an hour. I feel for ya.
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Wizard
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PostPosted: Mon Jul 21, 2008 8:12 pm 
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turbo/supercharging/high compression engine runs on any kind of gas but they run much hotter and higher compression so these calls for higher octane fuel to get best use of the engine's potiential. Oh yes you can tweak the engine with the rounding edging and etc to get fuel burning all the way to the whole area of cylinder instead of boucning off "walls" or sharp corners and waste fuel.

It's all in compromises.

Cheers, Wizard
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Twisted Sixer
 Post subject: Knock sensors
PostPosted: Tue Jul 22, 2008 3:58 pm 
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With megasquirt its my understanding that you tune the knock sensor threshold based on how noisy the engine is under normal conditions (no knock) the noisier the engine (mechanical cams etc..) the higher the chance a slight spark knock will be ignored but you would really need a lot of noise before the computer would ignore the kind of death rattle the people in the car next to you can hear.

The 3.4l dohc v6 in my t100 has a knock sensor and the valvetrain is direct acting bucket lifters. The factory computer in it ignores the knock sensor until 3000 rpm when the valvetrain quites down enough for the knock sensor to be useful. If it sees knock above 3000 rpm it will take timing out of the lower rpm's just in case.

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