Stage 1.1 + L Reflash = Problems
03-13-2004, 03:01 PM
#101
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I sounds like the stage 1.1 is to close to being on the edge of self destruction if an exhaust and intake or elevation will cause detonation. Theres a point of getting a ton a power, but then theres a point of going too far for the first stage everyday driver tuning.
03-13-2004, 04:31 PM
#102
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I personally would have at least tried taking the +5 HP (if that!) aftermarket intake off before I gave up the +25 WHP PCM mod, but that's just me. I understand your decision though... you definitely have to maintain the reliabilty of the car above all else. And after all, this all may be a moot point soon anyway, as I'm sure you know that if you really want to add some SERIOUS performance to your '8, Forced Induction will soon be here! :D A'course, you'll most likey lose your warranty...
03-13-2004, 08:48 PM
#103
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Something about this has been bugging me, and I finally put my finger on it. With a MAF rather than a speed density system like we have on our FDs, why would better exhaust and intake flow lean the car out more? With speed density, the ECU just looks at pressure, and if you improve the flow while keeping pressure constant, you're still putting more air molecules in there, and the fuel is the same.
With a MAF system, any increase in the amount of air getting into the engine resulting from improved flow should be measured by the sensor and compensated for by the ECU. Barring something about the intake mods (in this case a drop-in so IMO unlikely) compromising the MAF sensor, any excess power gained by exhaust and intake on the RX-8 should be purely the result of more stuff getting burned, NOT a leaner mixture of stuff.
I'm probably wrong about this in some fundamental way, but I can't find it.
jds
With a MAF system, any increase in the amount of air getting into the engine resulting from improved flow should be measured by the sensor and compensated for by the ECU. Barring something about the intake mods (in this case a drop-in so IMO unlikely) compromising the MAF sensor, any excess power gained by exhaust and intake on the RX-8 should be purely the result of more stuff getting burned, NOT a leaner mixture of stuff.
I'm probably wrong about this in some fundamental way, but I can't find it.
jds
Originally posted by RX-8 friend
2. You are close to sea level, so you have lots of O2 which translates to slightly lean. You caused the mixture to lean a bit more by installing the exhaust. You caused it to lean a bit more still by installing the intake. It was leaned a bit more again by the "L" flash. Then you installed the Stage 1 box, which may have pushed it just a bit too much.
2. You are close to sea level, so you have lots of O2 which translates to slightly lean. You caused the mixture to lean a bit more by installing the exhaust. You caused it to lean a bit more still by installing the intake. It was leaned a bit more again by the "L" flash. Then you installed the Stage 1 box, which may have pushed it just a bit too much.
03-14-2004, 01:07 AM
#104
Originally posted by bureau13
Something about this has been bugging me, and I finally put my finger on it. With a MAF rather than a speed density system like we have on our FDs, why would better exhaust and intake flow lean the car out more? With speed density, the ECU just looks at pressure, and if you improve the flow while keeping pressure constant, you're still putting more air molecules in there, and the fuel is the same.
With a MAF system, any increase in the amount of air getting into the engine resulting from improved flow should be measured by the sensor and compensated for by the ECU. Barring something about the intake mods (in this case a drop-in so IMO unlikely) compromising the MAF sensor, any excess power gained by exhaust and intake on the RX-8 should be purely the result of more stuff getting burned, NOT a leaner mixture of stuff.
I'm probably wrong about this in some fundamental way, but I can't find it.
jds
Something about this has been bugging me, and I finally put my finger on it. With a MAF rather than a speed density system like we have on our FDs, why would better exhaust and intake flow lean the car out more? With speed density, the ECU just looks at pressure, and if you improve the flow while keeping pressure constant, you're still putting more air molecules in there, and the fuel is the same.
With a MAF system, any increase in the amount of air getting into the engine resulting from improved flow should be measured by the sensor and compensated for by the ECU. Barring something about the intake mods (in this case a drop-in so IMO unlikely) compromising the MAF sensor, any excess power gained by exhaust and intake on the RX-8 should be purely the result of more stuff getting burned, NOT a leaner mixture of stuff.
I'm probably wrong about this in some fundamental way, but I can't find it.
jds
03-14-2004, 10:45 AM
#106
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If you free the exhaust you may not necessarily get more flow into the engine, even though you will have a more "vacated" or cleaner combustion chamber for the intake cycle. There may not be enough time for the intake tract to react to the exhaust change (system resonances). Therefore it may be leaner. The intake changes perhaps should be compensated for, but if you introduce turbulance you will mess up the MAF accuracy. The MAF is just a heated varistor. Its' temperature varies the resistance value, therefore the voltage across it. Turbulance will change the rate at which this temperature is changed vs total air flow. I'm getting a headache just trying to figure out how air pressure will affect this cooling of the MAF sensor. That is probably why there is a pressure sensor in the system (altitude compensation). How good is it?
I'd think without care, any change to the intake system could change the way air flows over the sensor. I'm really wondering what happens to those sensors that their owners removed the mesh from. Often these mesh screens are for flame propagation prevention (backfires) and to smooth air flow.
As many aftermarket vendors have been finding, the RX-8 engine has to be treated as a total system. Just changing the exhaust (opening it up even) didn't result in a large improvement, probably because the change reflected back, either physically and/or electronically through the PCM to intake, air/fuel and flow throughout the engine.
Maurice's car has stock intake and exhaust, and the Stage 1 tune was developed under that situation.
I think what is often overlooked is we are now at (stock) 3rd gen RX-7 power levels (with the Stage 1 added). The engine is still the same basic 1.3 L 2 rotor design. Yes, flow has been enhanced, but the change is really just to allow two things:
1. Higher RPM operation to get more power - closer to the turbo engine.
2. Better air flow (both intake and exhaust with less port overlap) so the same flow can be attained without forced induction.
My point being, at this power level we have to be just as careful with this engine setup as we have to be with the 3rd gen RX-7. The 3rd gen may be more difficult to control, and it was definately more expensive (those turbos and their control system are not cheap), but we are just as close to the edge of detonation.
I'd think without care, any change to the intake system could change the way air flows over the sensor. I'm really wondering what happens to those sensors that their owners removed the mesh from. Often these mesh screens are for flame propagation prevention (backfires) and to smooth air flow.
As many aftermarket vendors have been finding, the RX-8 engine has to be treated as a total system. Just changing the exhaust (opening it up even) didn't result in a large improvement, probably because the change reflected back, either physically and/or electronically through the PCM to intake, air/fuel and flow throughout the engine.
Maurice's car has stock intake and exhaust, and the Stage 1 tune was developed under that situation.
I think what is often overlooked is we are now at (stock) 3rd gen RX-7 power levels (with the Stage 1 added). The engine is still the same basic 1.3 L 2 rotor design. Yes, flow has been enhanced, but the change is really just to allow two things:
1. Higher RPM operation to get more power - closer to the turbo engine.
2. Better air flow (both intake and exhaust with less port overlap) so the same flow can be attained without forced induction.
My point being, at this power level we have to be just as careful with this engine setup as we have to be with the 3rd gen RX-7. The 3rd gen may be more difficult to control, and it was definately more expensive (those turbos and their control system are not cheap), but we are just as close to the edge of detonation.
03-14-2004, 01:46 PM
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Originally posted by Omicron
I personally would have at least tried taking the +5 HP (if that!) aftermarket intake off before I gave up the +25 WHP PCM mod, but that's just me. I understand your decision though... you definitely have to maintain the reliabilty of the car above all else. And after all, this all may be a moot point soon anyway, as I'm sure you know that if you really want to add some SERIOUS performance to your '8, Forced Induction will soon be here! :D A'course, you'll most likey lose your warranty...
I personally would have at least tried taking the +5 HP (if that!) aftermarket intake off before I gave up the +25 WHP PCM mod, but that's just me. I understand your decision though... you definitely have to maintain the reliabilty of the car above all else. And after all, this all may be a moot point soon anyway, as I'm sure you know that if you really want to add some SERIOUS performance to your '8, Forced Induction will soon be here! :D A'course, you'll most likey lose your warranty...
dont you have a stage 1.1 with RE intake and a Borla?
if so, have you had any of these problems?
03-14-2004, 02:37 PM
#108
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Originally posted by RX-8 friend
but we are just as close to the edge of detonation.
but we are just as close to the edge of detonation.
As great as the huge hp claims are, I think a lot of people would settle for something a little more tame but proven safe with different setups/cars/altitudes/gas types.
03-14-2004, 02:55 PM
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Maybe it's because the piggy-back is tuned at 5000 ft altitude. If the engine does not knock at 5000 ft altitude, it does not mean it will not knock when you bring it down to sea level.
Another interesting info I have found is that Knight Sports offers stock ECU reflash with their own map. They only claim 6 HP increase. Maybe their map is a lot more conservative.
Chuck Huang
Another interesting info I have found is that Knight Sports offers stock ECU reflash with their own map. They only claim 6 HP increase. Maybe their map is a lot more conservative.
Chuck Huang
03-14-2004, 04:54 PM
#110
Originally posted by Rotary Extreme
Another interesting info I have found is that Knight Sports offers stock ECU reflash with their own map. They only claim 6 HP increase. Maybe their map is a lot more conservative.
Chuck Huang
Another interesting info I have found is that Knight Sports offers stock ECU reflash with their own map. They only claim 6 HP increase. Maybe their map is a lot more conservative.
Chuck Huang
Could it be that the jpm spec ecu is better tuned (or not detuned as the us spec is) and, therefore, less able to be improved upon?
03-14-2004, 05:51 PM
#111
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I don't know if that's the case but I know Knight Sports tuned their ECU to 12.3 a/f under full throttle but Canzoomer's is 13.2 a/f. 0.9 a/f is a big difference.
Chuck Huang
Chuck Huang
Originally posted by red_rx8_red_int
Could it be that the jpm spec ecu is better tuned (or not detuned as the us spec is) and, therefore, less able to be improved upon?
Could it be that the jpm spec ecu is better tuned (or not detuned as the us spec is) and, therefore, less able to be improved upon?
03-14-2004, 06:16 PM
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When it comes to rotary, most tuners keep it around 12.5 a/f on N/A and 11.5 a/f on turbo. Of course you can lean it out more to get more HP but I rather play safe. Most tuners will tune more aggresively on their own cars but they will be more conservative toward customer's cars. Safety margin and maximum HP do not fit into the same sentence.
There are also many negative effects when you run a leaner a/f.
The bottom line is, it's your engine so how far are you willing to go?
Chuck Huang
There are also many negative effects when you run a leaner a/f.
The bottom line is, it's your engine so how far are you willing to go?
Chuck Huang
Originally posted by MazdaManiac
12.3 is way too rich for maximum power on a naturally aspirated engine.
12.3 is way too rich for maximum power on a naturally aspirated engine.
03-14-2004, 06:42 PM
#114
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Originally posted by rudy8
Omicron,
dont you have a stage 1.1 with RE intake and a Borla?
if so, have you had any of these problems?
Omicron,
dont you have a stage 1.1 with RE intake and a Borla?
if so, have you had any of these problems?
03-14-2004, 09:28 PM
#115
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Originally posted by Omicron
RE intake and Borla, yes, but I have not yet upgraded to the new "Stage 1.1" maps. And I have not had these problems with my current setup.
RE intake and Borla, yes, but I have not yet upgraded to the new "Stage 1.1" maps. And I have not had these problems with my current setup.
Do you have any dyno's of your current config?
03-15-2004, 09:22 PM
#117
Originally posted by pr0ber
can the cooling system keep up with a/f ratio's in the 13's??? Very few cars that I know of can without modification.
can the cooling system keep up with a/f ratio's in the 13's??? Very few cars that I know of can without modification.
I imagine, if you spent a long time at WOT it might be an issue.
However, the stock cooling system is very efficient.
03-16-2004, 10:30 PM
#118
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This is getting funny. First, it appears the new Stage 1 is not causing the problems. We're not sure what is wrong with this thread starters car, but something is. Maybe the "L" flash didn't take properly as has happened to a few others.
Second, the "L" flash takes the A/F to 14.5 and leaner in places. Maurice has compensated for this to avoid problems. The tune was developed at an altitude under 3000 ft and if you take the time to compare the air pressure change from sea level to the air pressure change from weather, you will see weather dominates.
There are now lots of "new" Stage 1 users who have no problems and only one we know of who has had a problem. Hence I must now surmise there is something wrong with his car.
I'm prepared to be proven wrong, and we'll see as more and more install the equipment.
Second, the "L" flash takes the A/F to 14.5 and leaner in places. Maurice has compensated for this to avoid problems. The tune was developed at an altitude under 3000 ft and if you take the time to compare the air pressure change from sea level to the air pressure change from weather, you will see weather dominates.
There are now lots of "new" Stage 1 users who have no problems and only one we know of who has had a problem. Hence I must now surmise there is something wrong with his car.
I'm prepared to be proven wrong, and we'll see as more and more install the equipment.
03-16-2004, 10:39 PM
#120
Originally posted by racerdave
That's pretty much my take... I only see this one guy with a problem. Stage 1 still seems like the best mod, especially for the first mod. Thanks.
That's pretty much my take... I only see this one guy with a problem. Stage 1 still seems like the best mod, especially for the first mod. Thanks.
I agree.
03-22-2004, 03:32 AM
#122
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Originally posted by Rotary Extreme
Maybe it's because the piggy-back is tuned at 5000 ft altitude. If the engine does not knock at 5000 ft altitude, it does not mean it will not knock when you bring it down to sea level.
Another interesting info I have found is that Knight Sports offers stock ECU reflash with their own map. They only claim 6 HP increase. Maybe their map is a lot more conservative.
Chuck Huang
Maybe it's because the piggy-back is tuned at 5000 ft altitude. If the engine does not knock at 5000 ft altitude, it does not mean it will not knock when you bring it down to sea level.
Another interesting info I have found is that Knight Sports offers stock ECU reflash with their own map. They only claim 6 HP increase. Maybe their map is a lot more conservative.
Chuck Huang
03-22-2004, 03:52 AM
#123
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Originally posted by Rotary Extreme
When it comes to rotary, most tuners keep it around 12.5 a/f on N/A and 11.5 a/f on turbo. Of course you can lean it out more to get more HP but I rather play safe. Most tuners will tune more aggresively on their own cars but they will be more conservative toward customer's cars. Safety margin and maximum HP do not fit into the same sentence.
There are also many negative effects when you run a leaner a/f.
The bottom line is, it's your engine so how far are you willing to go?
Chuck Huang
When it comes to rotary, most tuners keep it around 12.5 a/f on N/A and 11.5 a/f on turbo. Of course you can lean it out more to get more HP but I rather play safe. Most tuners will tune more aggresively on their own cars but they will be more conservative toward customer's cars. Safety margin and maximum HP do not fit into the same sentence.
There are also many negative effects when you run a leaner a/f.
The bottom line is, it's your engine so how far are you willing to go?
Chuck Huang
03-22-2004, 04:07 AM
#124
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Are you sure? I have a book with an article that they interviewed Knight Sports and it says 12.3 a/f.
Chuck Huang
Chuck Huang
Originally posted by Japan8
Knight Sports is running 13-13.5
Knight Sports is running 13-13.5
03-22-2004, 04:12 AM
#125
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100% positive. This is from their site... http://www.knightsports.co.jp/whatsnew-index.html It says that the results were that 13-13.5 gave the best power. 12.3 WAS the best for a NA engine, however for the 8 taking it low to 13-14 produced more power.