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The Renesis does NOT run rich

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Old May 13, 2010 | 04:16 PM
  #26  
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Ahh. That's nothing. Take a look at the AT's 1/2 table:





8.27:1
Attached Thumbnails The Renesis does NOT run rich-clipboard01.jpg  
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Old May 13, 2010 | 04:19 PM
  #27  
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I don't even run the safest FI base calibrations that rich.
Obviously, Mazda was very concerned with knock on the AT at high load/high RPM.
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Old May 13, 2010 | 04:19 PM
  #28  
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Originally Posted by MazdaManiac
Sorta.
Though the stoichiometric ratio is the usual target for cruise, you will actually get slightly better mileage a bit rich of that point (around 13.8:1 for gasoline).
why is that ?
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Old May 13, 2010 | 04:22 PM
  #29  
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@MM, ah standard units is what to check if you wants ATR to display the same - duh.

holy freaking wow! thats RICH
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Old May 13, 2010 | 04:23 PM
  #30  
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Originally Posted by Brettus
why is that ?
i think it will have something to do with flamefront speed
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Old May 13, 2010 | 04:29 PM
  #31  
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Stoich produces "ideal" combustion theoretically, but a point richer produces more torque.
The additional torque is generally greater, as a percentage, than the fuel used.
MBT>stoich
It is flame speed and combustion efficiency. At stoich, there is still a lot of left over oxygen.


BTW - In reviewing the tables above, keep in mind that "commanded" values don't always equal "output" values.
Mazda was less concerned with "nailing" the MAF calibration than we are since they had such a wide deviation to deal with.

Last edited by MazdaManiac; May 13, 2010 at 04:31 PM.
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Old May 13, 2010 | 04:40 PM
  #32  
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Originally Posted by MazdaManiac

BTW - In reviewing the tables above, keep in mind that "commanded" values don't always equal "output" values.
Mazda was less concerned with "nailing" the MAF calibration than we are since they had such a wide deviation to deal with.
the same reasoning i threw the disclaimer here
still though, its rich
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Old May 13, 2010 | 06:47 PM
  #33  
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Originally Posted by MazdaManiac
Stoich produces "ideal" combustion theoretically, but a point richer produces more torque.
The additional torque is generally greater, as a percentage, than the fuel used.
MBT>stoich
It is flame speed and combustion efficiency. At stoich, there is still a lot of left over oxygen.
.
is it a waste of time tuning for that or are there some real mileage gains (more than a few %) ?
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Old May 13, 2010 | 07:16 PM
  #34  
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Well, If you can make it happen consistently, it's good for 20 - 40 highway miles per tank.
YMMV
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Old May 14, 2010 | 05:02 AM
  #35  
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Well, my mileage is fantastic! I spend a lot of time cruising north of 6,000rpms and i still get 20+ And at american highway speeds I can get better than 25 pretty easily. My only relavent mods are coils, cat delete, and tune.

and FWIW my compression is nice and balanced, but a bit on the low side. IMO this car can make 30mpg. I've had 27 a few times. I think with the addition of the right choice in wheels, clutch/fly/PP, removing the 120lbs in my trunk, and a few other minor things - that this car could make 30

Last edited by paulmasoner; May 14, 2010 at 05:05 AM.
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Old May 14, 2010 | 12:34 PM
  #36  
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Originally Posted by MazdaManiac
Well, If you can make it happen consistently, it's good for 20 - 40 highway miles per tank.
YMMV
A 15% gain sounds about right in a cruising situation. My airplane engine charts show that for a given horsepower output, that's the difference in fuel flow between the "best economy" and "best power" mixture settings. The two roughly correspond to lambdas of 1.15 and 0.85. The reason that the difference doesn't scale by 115/85=35% is that for a given rpm and manifold pressure (related to MAF) the lean setting will result in less power, therefore requiring a higher MP (more throttle) to maintain the same output power.

Are the tables only divided into the 1-2-3 and 4-5-6 pieces? Is there a way to do a 1-2-3, 4-5, and 6 map? If so, it would leave an option of creating a cruising-only 6th gear map where one could push the lean limit.

Perhaps another way to eliminate lambdas under 12.5 or so would be to water/meth inject, to get a higher octane for detonation-prevention. However that would require a fairly sophisticated method of determining when that injection should occur.
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Old May 14, 2010 | 12:39 PM
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Originally Posted by paulmasoner
Well, my mileage is fantastic! I spend a lot of time cruising north of 6,000rpms and i still get 20+ And at american highway speeds I can get better than 25 pretty easily. My only relevant mods are coils, cat delete, and tune.
It would be very interesting if you could share what tables you are using now to achieve that!
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Old May 14, 2010 | 12:40 PM
  #38  
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Originally Posted by HiFlite999
Are the tables only divided into the 1-2-3 and 4-5-6 pieces? Is there a way to do a 1-2-3, 4-5, and 6 map? If so, it would leave an option of creating a cruising-only 6th gear map where one could push the lean limit.
No, they are in groups of two - 1/2, 3/4 & 5/6.

However, there are some tricks that can be done with the MAF curve and the way it overlays with the fuel maps.
Also, the overall "engine Ve" table allows you to trim certain conditions.
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Old May 14, 2010 | 02:06 PM
  #39  
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you'd have to ask that^^ man, and i doubt he's telling

Originally Posted by HiFlite999
It would be very interesting if you could share what tables you are using now to achieve that!
but i'll bet, being the curious person he seems, that he will go looking at my calibrations in his records now
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Old May 14, 2010 | 08:00 PM
  #40  
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Originally Posted by paulmasoner
Well, my mileage is fantastic! I spend a lot of time cruising north of 6,000rpms and i still get 20+ And at american highway speeds I can get better than 25 pretty easily. My only relavent mods are coils, cat delete, and tune.

and FWIW my compression is nice and balanced, but a bit on the low side. IMO this car can make 30mpg. I've had 27 a few times. I think with the addition of the right choice in wheels, clutch/fly/PP, removing the 120lbs in my trunk, and a few other minor things - that this car could make 30
i personally got 28 mpg average driving from wv to fl from what cobb ap said and i was running stock tune ....the 8 had 88000 miles, aem cai with cat knocked out and exotic speed exhaust dont remeber how old the plugs were but coils had only 3000 miles aprox.....also i was doing about 80 the whole way in 6th gear and whats that about 4500 rpm or close to it
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Old May 14, 2010 | 09:00 PM
  #41  
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Classic arrgh ...
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Old May 14, 2010 | 09:07 PM
  #42  
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Originally Posted by TeamRX8
Classic arrgh ...
???
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Old May 14, 2010 | 09:32 PM
  #43  
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Have you asked your spark plugs lateley?

They will tell you PIG RICH.
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Old May 15, 2010 | 06:30 AM
  #44  
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Originally Posted by TeamRX8
Classic arrgh ...
Originally Posted by FoxRacer600RR
???
i think he may be referring to the OP
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Old May 15, 2010 | 06:32 AM
  #45  
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Originally Posted by FoxRacer600RR
i personally got 28 mpg average driving from wv to fl from what cobb ap said and i was running stock tune ....
OE tune? now THAT is impressive
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Old May 15, 2010 | 06:40 AM
  #46  
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WV to FL is mostly downhill.... I got 40MPG last time I did it in a Tercel mind you.... but still.

All the Fuel Maps can have a cruising area set up - since the load and RPM create the scales.

Even in 3rd gear, a load of less than 30% constitutes cruising in most situations...
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Old May 18, 2010 | 07:02 PM
  #47  
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Originally Posted by Kane
WV to FL is mostly downhill.... I got 40MPG last time I did it in a Tercel mind you.... but still.

All the Fuel Maps can have a cruising area set up - since the load and RPM create the scales.

Even in 3rd gear, a load of less than 30% constitutes cruising in most situations...
lol down hill true, and 28 is huge for me. im used to 12-15
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Old May 18, 2010 | 09:37 PM
  #48  
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Originally Posted by MazdaManiac
No, they are in groups of two - 1/2, 3/4 & 5/6.

However, there are some tricks that can be done with the MAF curve and the way it overlays with the fuel maps.
Also, the overall "engine Ve" table allows you to trim certain conditions.
doesn't that depend on the year? early cars had three maps, newer ones had less IIRC.

(I'm just going by what some older builds of ATR offered, but I assume it follows the stock pcm logic)

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Old May 18, 2010 | 09:45 PM
  #49  
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Originally Posted by secret8gent
doesn't that depend on the year? early cars had three maps, newer ones had less IIRC.

(I'm just going by what some older builds of ATR offered, but I assume it follows the stock pcm logic)
You are correct.

The 2006 and up have them grouped 1/2/3 & 4/5/6.
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Old May 18, 2010 | 10:20 PM
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Nothing a mixture of regular and E85 won't solve ....
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