Cobb AccessPORT Discussion
04-17-2008, 01:12 PM
#1751
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yes, that would be why some high performance engines ping with lower octanes. Ping is detonation which means the fuel combusted before it was suppose to because of the temperature in the cylinder. So essentially, the higher the octane the more work the ignition system has to do in some respects.
04-17-2008, 01:14 PM
#1753
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Off topic - but hey.
Flame Speed of Gasoline depends on the chemical makeup of the gasoline itself - and has nothing to do with Octane. Think big nasty chemical equation breaking gasoline compounds and oxygen to form new compounds.
Octane refers to what we call sensitivity in the explosives world; which is the initiation of the chemical reaction all by itself (auto-ignition). Once you have a sensitivity rating / octane - does not refer to the power of the reaction - only the amount of initial energy required to initiate it. So a higher sensitivity/octane means it takes XYZ more energy to start the breakdown. That is why you can advance ignition et al - because the heat from the compression of the mixture is less likely to be high enough to initiate the explosion.
That is why we can run around with military dynamite in a backpack; but you can't do that with civilian dynamite - but they are both the same explosive force.
Flame Speed of Gasoline depends on the chemical makeup of the gasoline itself - and has nothing to do with Octane. Think big nasty chemical equation breaking gasoline compounds and oxygen to form new compounds.
Octane refers to what we call sensitivity in the explosives world; which is the initiation of the chemical reaction all by itself (auto-ignition). Once you have a sensitivity rating / octane - does not refer to the power of the reaction - only the amount of initial energy required to initiate it. So a higher sensitivity/octane means it takes XYZ more energy to start the breakdown. That is why you can advance ignition et al - because the heat from the compression of the mixture is less likely to be high enough to initiate the explosion.
That is why we can run around with military dynamite in a backpack; but you can't do that with civilian dynamite - but they are both the same explosive force.
Now back to the topic...sorry I interrupted
04-17-2008, 02:19 PM
#1756
04-17-2008, 02:33 PM
#1757
That's bad. If you actually read this thread you would know that 10 to 15 degrees above ambient is normal
04-17-2008, 02:58 PM
#1759
[QUOTE=Razz1;2412412]That's bad. If you actually read this thread you would know that 10 to 15 degrees above ambient is normal[/QUOT
so what is a normal ambient temp? I realize that it is hard to narrow my question down because there are so many different variables, but what is a good range while driving and at idle after driving? thanks
so what is a normal ambient temp? I realize that it is hard to narrow my question down because there are so many different variables, but what is a good range while driving and at idle after driving? thanks
04-17-2008, 03:05 PM
#1760
The Professor
so what is a normal ambient temp? I realize that it is hard to narrow my question down because there are so many different variables, but what is a good range while driving and at idle after driving? thanks
The stock Rx8 comes with a CAI setup so you will most likely see better temps if you went back to stock.
Colder air is higher reliability and greater power.
04-17-2008, 03:47 PM
#1761
Drive Master
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The previous owner of my AP was seeing a 5+ HP difference on stage 1. I just did a baseline on the factory maps. Next Dyno Day in my area I'll get numbers for the MM map I wind up running at the time.
04-17-2008, 04:01 PM
#1763
Jeff (MM),
would I benefit more from using my stock intake vs. k&n intake and the AP?
04-17-2008, 04:03 PM
#1764
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I hope to get those #'s. I could care less about MPG, I only drive 20 mi. a day.
04-17-2008, 05:50 PM
#1766
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04-17-2008, 05:54 PM
#1767
NA.
No. I'd like to. I'll have to schedule something.
I don't have a "baseline" with that car, though the owner has a DynoJet pull from last year that could probably be used as a comparison.
I'll be putting a 4-port AT with the GReddy turbo on the dyno on Monday.
No. I'd like to. I'll have to schedule something.
I don't have a "baseline" with that car, though the owner has a DynoJet pull from last year that could probably be used as a comparison.
I'll be putting a 4-port AT with the GReddy turbo on the dyno on Monday.
04-17-2008, 06:13 PM
#1769
Asspl0de? Probably not.
Rotary motors go out with a whimper, not a bang.
That said, the Grand Am cars want to run on 93 and they are tuned within an inch of their teeth, so 89 on the street with conservative ignition timing will probably not asspl0de.
Rotary motors go out with a whimper, not a bang.
That said, the Grand Am cars want to run on 93 and they are tuned within an inch of their teeth, so 89 on the street with conservative ignition timing will probably not asspl0de.
04-17-2008, 06:19 PM
#1770
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question. I know that once we get the AP from you then based on locatioin and intake and exhaust and what not you send us our maps accordign to our car. My question is is that once we get those maps and get it close, if we send you a graph of a datalogged pull, could you make a custom map for our car from that? I ask this knowing that everyone will want to do this and you will be making a million maps, but would the graph from a run give you enough info for a more exact tune for that one specific vehicle?
04-17-2008, 06:33 PM
#1773
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good call, also if things go as planned i will be putting in a request for mine next friday. Any idea on when it would ship out? or is this a longer line then the ignition solution?
