Q45tech....Quote »"Also the O2 sensors react differently to the different space shape [distance to the cats].......they read leaner requiring the ecu to enrichen the cruise mixture dropping the highway mileage by 5-10%..............yes we have tested a few. Not clear why this happens but it does. WATCH OUT that the back pressure doesn't drop so low that the EGR doesn't work as designed!!!!!!!!!!!!!!!!!"[/quote]Dennis....Do you know if the combination of a JWT ECU and Headers will also richen the mixture or does the JWT maintain a specific air/fuel ratio regardless of what my O2 senesors are reading?
If the JWT ECU does not maintain an "ideal" air to fuel mixture, then how do I get the "ideal" air to fuel mixture to get the most benefit out of the headers?
Do I need to contact JWT and ask them about reprograming the ECU for the different O2 sensor readings?
Can I use a Unichip as Ash did and program the parameters this way?
Can I buy one of the MAF sensor adjustment things and reprogram the air/fuel mixture that way?
And final idea ....Should I take it to a performance shop that specializes in ECU tuning and have them reprogram the ECU's air fuel ratio and would I need a baseline OEM or JWT air/fuel ratio mappings for them to get the car back to its maximum performance capabilities?
Thanks again for your "priceless" support and suggestion as you save me and others tons of time and $$.
Headers, O2 sensors, JWT ECU, & air/fuel ratio question
I'll leave the questions to Dennis. Though with the JWT you will be running leaner above 3500ish rpms (?)... so you won't be running as rich as you would with a stock ECU. It should be fine to drive around town, etc. JWT can reprogram your ECU for $100 bucks or so if my memory serves me correct. I'd personally go with the shop you were describing to me though... that is once you have all of your mods done.
Corey
Corey
Thanks for the info....and let me see if I understand this correctly.
The headers will produce more heat (equal more power) and then in turn the extra heat is what causes the O2 sensors to not read correctly and the engine to run rich. Is this correct?
There is a shop here in South Florida that can do all sorts of tuning and remapping, but I don't want them to over tune the car (make it run too lean). Can somebody provide me the air/fuel ratio for a stock or JWT ECU per rpm band. I really have no idea on this stuff and I don't know if every car uses a similar air/fuel ratio so any help is appreciated.
The headers will produce more heat (equal more power) and then in turn the extra heat is what causes the O2 sensors to not read correctly and the engine to run rich. Is this correct?
There is a shop here in South Florida that can do all sorts of tuning and remapping, but I don't want them to over tune the car (make it run too lean). Can somebody provide me the air/fuel ratio for a stock or JWT ECU per rpm band. I really have no idea on this stuff and I don't know if every car uses a similar air/fuel ratio so any help is appreciated.
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Q45tech
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- Car: 1990 Q45 342,400 miles 22 years ownership with original engine
1995 G20t 5 speed 334,000 miles 16" 2002 wheels - 205/50/16 Sr20ve vvl
No!First of all O2 only work [switch back and forth when the base AF is near 14-15-16........they then tell ecu when it is richer [not how much ] 14.7 or leaner than 14.7.The ecu knows they are not linear but doesn't care because it knows from MAF and rpm and tps [by looking in a table what a good injector opening time is then uses the rich and lean to instantly zero in on a pulse width that goes lean, rich, lean, rich, lean, rich.........it starts stepping down in 0.1 steps till the desired switching gets close then switches to 0.01 steps to fine tune into the correct number...........4 firings per rpm [but the banks alternate] means it can get to a correct answer in 100 rpms or so surely within a second.
When ever NON WOT tps and rpm go above a economy cruise speed say 80-85 mph the O2 are ignored and a looked up standard opening time for the MAF voltage is used but it is modified [trimmed] by the the adaptive learning number [+-20% max].
At 80%-WOT no time to calculate so a table that has injector opening time vs MAF vs rpm is just used [the tps is fixed at WOT].Same with ignition advance a number is just looked up vs rpm and used ------only decreased by KS or coolant temp.
JWT just juggles the numbers in WOT tables doing nothing to part throttle tables or calculates.......EXCEPT they increase the ignition timing return rate after the throttle is moved more open.
The oem ecu immediately takes timing out when the throttle is pressed [to avoid tip in knock] and allowes it to return at a degree per 1/10 sec rate.......JWT allows a 2 degree per 1/10 sec rate because they warn you to use nothing but 91 octane.......the factory setting is weaker assuming 87 octane might be used in emergencies.
That's the trade secret the injector opening table and the ignition advance.
Dyno tuning is often in error because the load situation is not the same as on the street. Plus you must consider 100F ambient and gasoline variations [while traveling] unless you haul your own gas around and never buy without analysing in a lab first.
You dyno and find the max then you zero in on what is feasable by driving on the street.
Some of the parameters and tables in ecuhttp://www.tunercat.com/pdfs/pcm_$85.pdf
"Why do exhaust catalysts influence fuel composition?
Modern adaptive learning engine management systems control the combustion stoichiometry by monitoring various ambient and engine parameters, including exhaust gas recirculation rates, the air flow sensor, and exhaust oxygen sensor outputs. This closed loop system using the oxygen sensor can compensate for changes in fuel content and air density. The oxygen sensor is also known as the lambda sensor because the actual air-fuel mass ratio divided by the stoichiometric air-fuel mass ratio is known as lambda or the air-fuel equivalence ratio.
The preferred technique for describing mixture strength is the fuel-air equivalence ratio ( phi ), which is the actual fuel-air mass ratio divided by the stoichiometric fuel-air mass ratio, however most enthusiasts use air-fuel ratio and lambda. Lambda is the inverse of the fuel-air equivalence ratio. The oxygen sensor effectively measures lambda around the stoichiometric mixture point. Typical stoichiometric air-fuel ratios are
6.4 methanol 9.0 ethanol 11.7 MTBE 12.1 ETBE, TAME 14.6 gasoline without oxygenates
The engine management system rapidly switches the stoichiometry between slightly rich and slightly lean, except under wide open throttle conditions - when the system runs open loop. The response of the oxygen sensor to composition changes is about 3 ms, and closed loop switching is typically 1-3 times a second, going between 50mV ( lambda = 1.05 (Lean)) to 900mV (lambda = 0.99 ( Rich)). "
When ever NON WOT tps and rpm go above a economy cruise speed say 80-85 mph the O2 are ignored and a looked up standard opening time for the MAF voltage is used but it is modified [trimmed] by the the adaptive learning number [+-20% max].
At 80%-WOT no time to calculate so a table that has injector opening time vs MAF vs rpm is just used [the tps is fixed at WOT].Same with ignition advance a number is just looked up vs rpm and used ------only decreased by KS or coolant temp.
JWT just juggles the numbers in WOT tables doing nothing to part throttle tables or calculates.......EXCEPT they increase the ignition timing return rate after the throttle is moved more open.
The oem ecu immediately takes timing out when the throttle is pressed [to avoid tip in knock] and allowes it to return at a degree per 1/10 sec rate.......JWT allows a 2 degree per 1/10 sec rate because they warn you to use nothing but 91 octane.......the factory setting is weaker assuming 87 octane might be used in emergencies.
That's the trade secret the injector opening table and the ignition advance.
Dyno tuning is often in error because the load situation is not the same as on the street. Plus you must consider 100F ambient and gasoline variations [while traveling] unless you haul your own gas around and never buy without analysing in a lab first.
You dyno and find the max then you zero in on what is feasable by driving on the street.
Some of the parameters and tables in ecuhttp://www.tunercat.com/pdfs/pcm_$85.pdf
"Why do exhaust catalysts influence fuel composition?
Modern adaptive learning engine management systems control the combustion stoichiometry by monitoring various ambient and engine parameters, including exhaust gas recirculation rates, the air flow sensor, and exhaust oxygen sensor outputs. This closed loop system using the oxygen sensor can compensate for changes in fuel content and air density. The oxygen sensor is also known as the lambda sensor because the actual air-fuel mass ratio divided by the stoichiometric air-fuel mass ratio is known as lambda or the air-fuel equivalence ratio.
The preferred technique for describing mixture strength is the fuel-air equivalence ratio ( phi ), which is the actual fuel-air mass ratio divided by the stoichiometric fuel-air mass ratio, however most enthusiasts use air-fuel ratio and lambda. Lambda is the inverse of the fuel-air equivalence ratio. The oxygen sensor effectively measures lambda around the stoichiometric mixture point. Typical stoichiometric air-fuel ratios are
6.4 methanol 9.0 ethanol 11.7 MTBE 12.1 ETBE, TAME 14.6 gasoline without oxygenates
The engine management system rapidly switches the stoichiometry between slightly rich and slightly lean, except under wide open throttle conditions - when the system runs open loop. The response of the oxygen sensor to composition changes is about 3 ms, and closed loop switching is typically 1-3 times a second, going between 50mV ( lambda = 1.05 (Lean)) to 900mV (lambda = 0.99 ( Rich)). "
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Q45tech
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A typical normal numerical reading for this as displayed on a scan tool will be about 128. If it's higher, the PCM is adding extra fuel to the base calculation because the system is running lean. If the number is lower than 128, the module is subtracting fuel to make up for a rich condition. Integrator is a short-term correction ("SFT"), while block learn is long-term ("LFT") and will only make a change if the integrator has sensed and corrected the same condition for a calibrated period of time.
The 128 value doesn't necessarily represent stoichiometric, but rather the middle of the range of control. The system will always be trying to trim itself back to this, and is more and more unhappy the further it gets from this number. Although theoretically you could see 0 or 255, actual range will usually be between 85 and 170.
To explain further, SFT (or integrator) sees oxygen sensor voltage low more than half the time, it starts marching upward -- 129, 130, 131, 132. LFT (or block learn) watches, then backs up what SFT is doing by going up one. If SFT keeps going -- 133, 134, 135, etc. -- LFT will increase another step. Then, if SET is satisfied that it's seeing O2 signals higher than 450 mV over 50% of the time, it turns around and marches down -- 135, 134, and so on. At a certain point, LFT gets the idea and backs down, too. Remember, both are always trying to stay at 128.
http://www.asashop.org/autoinc...h.htm
http://www.performancetrends.c...o.htm
"The sensor does not begin to generate it's full output until it reaches about 600 degrees F. Prior to this time the sensor is not conductive. It is as if the circuit between the sensor and computer is not complete. The mid point is about 0.45 volts. This is neither rich nor lean. A fully warm O2 sensor *will not spend any time at 0.45 volts*. In many cars, the computer sends out a bias voltage of 0.45 through the O2 sensor wire. If the sensor is not warm, or if the circuit is not complete, the computer picks up a steady 0.45 volts. Since the computer knows this is an "illegal" value, it judges the sensor to not be ready. It remains in open loop operation, and uses all sensors except the O2 to determine fuel delivery. Any time an engine is operated in open loop, it runs somewhat rich and makes more exhaust emissions."
At 500C a 0.88vdc signal could be 14.0AFAt 750C a 0.88vdc signal could be 13.0AFAt 900C a 0.88vdc signal could be 10.2AF
http://www.alamomotorsports.com/fjo_wideband.html
The 128 value doesn't necessarily represent stoichiometric, but rather the middle of the range of control. The system will always be trying to trim itself back to this, and is more and more unhappy the further it gets from this number. Although theoretically you could see 0 or 255, actual range will usually be between 85 and 170.
To explain further, SFT (or integrator) sees oxygen sensor voltage low more than half the time, it starts marching upward -- 129, 130, 131, 132. LFT (or block learn) watches, then backs up what SFT is doing by going up one. If SFT keeps going -- 133, 134, 135, etc. -- LFT will increase another step. Then, if SET is satisfied that it's seeing O2 signals higher than 450 mV over 50% of the time, it turns around and marches down -- 135, 134, and so on. At a certain point, LFT gets the idea and backs down, too. Remember, both are always trying to stay at 128.
http://www.asashop.org/autoinc...h.htm
http://www.performancetrends.c...o.htm
"The sensor does not begin to generate it's full output until it reaches about 600 degrees F. Prior to this time the sensor is not conductive. It is as if the circuit between the sensor and computer is not complete. The mid point is about 0.45 volts. This is neither rich nor lean. A fully warm O2 sensor *will not spend any time at 0.45 volts*. In many cars, the computer sends out a bias voltage of 0.45 through the O2 sensor wire. If the sensor is not warm, or if the circuit is not complete, the computer picks up a steady 0.45 volts. Since the computer knows this is an "illegal" value, it judges the sensor to not be ready. It remains in open loop operation, and uses all sensors except the O2 to determine fuel delivery. Any time an engine is operated in open loop, it runs somewhat rich and makes more exhaust emissions."
At 500C a 0.88vdc signal could be 14.0AFAt 750C a 0.88vdc signal could be 13.0AFAt 900C a 0.88vdc signal could be 10.2AF
http://www.alamomotorsports.com/fjo_wideband.html
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Q45tech
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1995 G20t 5 speed 334,000 miles 16" 2002 wheels - 205/50/16 Sr20ve vvl
Headers usually flow a tiny bit more than oem, otherwise they would have nothing to sell! The extra flow helps remove some of the 10% residual burn gases in the head space after the exhaust valve closes................if the head space is already 10% filled only 90% new air can flow in to cylinder.
Normally a header installation makes the mixture a tiny bit leaner, however moving the position of the O2 even an inch can throw the calibration off.
You really cannot trust the typical wideband O2 sensors dyno operators buy.......because they don't constantly recalibrate because of the expense.
A 10% real error is not unheard of but most might be within 5% STILL thats like 11.7- 12.3.............so always asumme rich is good as it is the most protective and has the least effect on power output.
Being 10% too rich 10.8 vs 12.0 AF only drops power by 3-4% vs 10% too lean which drops power by 10-15%.
Why the oem is extra rich [for safety for cooling] as a single misfire will still be safe bringing the 11.0AF to 14.7 AF at the cat. [11.0/0.75=14.6666].
Above 6500-6700 rpm the oem Q AF goes really really rich, not because the injectors are suddenly open longer but because the air flow suddenly stalls then decreases per rpm gain.After all how much time does it take for the engine to rev from 6500-6900 rpm [even in 2nd gear from 87 mph to 92 mph a second maybe].........the transmission tries to shift before/just at/during the decline.
They optimized things at 5,500-6,000 rpm: Besides shortening the intake runners and or increasing their diameter, changing cams you can't do much about intake air flow.
JWT ecu reprogram leans injection at 6500-7300 MORE and advances the timing MORE to better match the real air flow thus the 5% extra gain in the extreme rpm band over the already leaner and more advanced 3,500-6,000 range.
What really helps is to install exhaust temp sensors very near the exhaust ports [less than 2" inside headers and tune for correct exhaust temps...........more accurate than AF ratio meters.
Normally a header installation makes the mixture a tiny bit leaner, however moving the position of the O2 even an inch can throw the calibration off.
You really cannot trust the typical wideband O2 sensors dyno operators buy.......because they don't constantly recalibrate because of the expense.
A 10% real error is not unheard of but most might be within 5% STILL thats like 11.7- 12.3.............so always asumme rich is good as it is the most protective and has the least effect on power output.
Being 10% too rich 10.8 vs 12.0 AF only drops power by 3-4% vs 10% too lean which drops power by 10-15%.
Why the oem is extra rich [for safety for cooling] as a single misfire will still be safe bringing the 11.0AF to 14.7 AF at the cat. [11.0/0.75=14.6666].
Above 6500-6700 rpm the oem Q AF goes really really rich, not because the injectors are suddenly open longer but because the air flow suddenly stalls then decreases per rpm gain.After all how much time does it take for the engine to rev from 6500-6900 rpm [even in 2nd gear from 87 mph to 92 mph a second maybe].........the transmission tries to shift before/just at/during the decline.
They optimized things at 5,500-6,000 rpm: Besides shortening the intake runners and or increasing their diameter, changing cams you can't do much about intake air flow.
JWT ecu reprogram leans injection at 6500-7300 MORE and advances the timing MORE to better match the real air flow thus the 5% extra gain in the extreme rpm band over the already leaner and more advanced 3,500-6,000 range.
What really helps is to install exhaust temp sensors very near the exhaust ports [less than 2" inside headers and tune for correct exhaust temps...........more accurate than AF ratio meters.
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Q45tech
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- Car: 1990 Q45 342,400 miles 22 years ownership with original engine
1995 G20t 5 speed 334,000 miles 16" 2002 wheels - 205/50/16 Sr20ve vvl
WHY oxygenated fuels get lower MPG:
If the conventional O2 switches at 14.7 and conventional non oxygenated fuel is 14.6 and MTBE is 11.7 a 10% mixture [0.9 x 14.6] + [0.1x 11.7== ~~ 14.31.............14.7/14.31=1.027 more fuel to read correctly..........2.7% more fuel
With ETHANOL a 9.0 is necessary thus [0.9 x 14.6 + [0.1 x 9]= 14.04 ...........14.7/14.04=1.047 ..............4.7% more fuel.
ETHANOLIZATION has decreased the highway mileage by 4.7% at the minimum. Not counting the extra losses [3-4%] from lower btu fuel............8,9,10% less MPG.There is nothing the engineers can do because all the cats are designed for conventional gasoline. Work is under way for an inexpensive fuel analyser to sense gasoline type and make corrections.
Newer Wide Band [after 2002] O2 sensors cost 3 times as much and attempt to reduce the problem.........why they are getting an extra 1 mpg on the highway........running leaner and very very close to 14.7.
The factory warned the EPA what would happen [with ETHANOL]but the corn belt senators need reelection! http://www.kycorn.org/corneduc...d.pdf
Same with power output but MPG doesn't count. expect a 3-4% drop in peak power with Ethanolized vs conventional gasoline!
That's a up to 12 lb/ft of torque and 12 HP loss.
If the conventional O2 switches at 14.7 and conventional non oxygenated fuel is 14.6 and MTBE is 11.7 a 10% mixture [0.9 x 14.6] + [0.1x 11.7== ~~ 14.31.............14.7/14.31=1.027 more fuel to read correctly..........2.7% more fuel
With ETHANOL a 9.0 is necessary thus [0.9 x 14.6 + [0.1 x 9]= 14.04 ...........14.7/14.04=1.047 ..............4.7% more fuel.
ETHANOLIZATION has decreased the highway mileage by 4.7% at the minimum. Not counting the extra losses [3-4%] from lower btu fuel............8,9,10% less MPG.There is nothing the engineers can do because all the cats are designed for conventional gasoline. Work is under way for an inexpensive fuel analyser to sense gasoline type and make corrections.
Newer Wide Band [after 2002] O2 sensors cost 3 times as much and attempt to reduce the problem.........why they are getting an extra 1 mpg on the highway........running leaner and very very close to 14.7.
The factory warned the EPA what would happen [with ETHANOL]but the corn belt senators need reelection! http://www.kycorn.org/corneduc...d.pdf
Same with power output but MPG doesn't count. expect a 3-4% drop in peak power with Ethanolized vs conventional gasoline!
That's a up to 12 lb/ft of torque and 12 HP loss.
Thanks for the info.....
Well as newly designed mods usually go...my headers will not be completed until late next week (Friday) at the earliest.
They are waiting for the machine shop to finish the flanges and should have them by Friday. If everything goes good with the header design and performance, I should have my car back next week June 6th. Otherwise they will redesign the headers another time to see which set works best.
I hope that I don't have to spend any more monies on getting the air to fuel ratio corrected after these headers, but if need be then I will be getting this corrected to get the maximun performance gains.
Well as newly designed mods usually go...my headers will not be completed until late next week (Friday) at the earliest.
They are waiting for the machine shop to finish the flanges and should have them by Friday. If everything goes good with the header design and performance, I should have my car back next week June 6th. Otherwise they will redesign the headers another time to see which set works best.
I hope that I don't have to spend any more monies on getting the air to fuel ratio corrected after these headers, but if need be then I will be getting this corrected to get the maximun performance gains.
I should have my car back late next week. They are going put it on the dyno to see how it is running and look at the AF ratio and adjust it if necessary. I know the dealer reset my AF ratio after the O2 sensors were installed, but I don't know how they do this. Is this a simple procedure to somehow adjust the AF ratio?
I also dropped off my 4.08 to be installed at the same time also becuase these mods are just taking way to long as my patience has worn thin. So I should have my car back with the headers and 4.08 late next week and then off to the 1/4 ET's to see what I got.
Now for the fun part....the guy who is building my headers has a mid 90's Chevy Impala SS (the big sedan taxi like one) and wants to race me really bad after all is said and done. He has some mods including a 4.10 rearend so things gearing wise after my 4.08 should even things up. So my question is....how fast are these cars? He asked me what my car dynos at stock and he seemed impressed at about 225rwhp. So do you all think that this guy will give me a run for my money?
I also dropped off my 4.08 to be installed at the same time also becuase these mods are just taking way to long as my patience has worn thin. So I should have my car back with the headers and 4.08 late next week and then off to the 1/4 ET's to see what I got.
Now for the fun part....the guy who is building my headers has a mid 90's Chevy Impala SS (the big sedan taxi like one) and wants to race me really bad after all is said and done. He has some mods including a 4.10 rearend so things gearing wise after my 4.08 should even things up. So my question is....how fast are these cars? He asked me what my car dynos at stock and he seemed impressed at about 225rwhp. So do you all think that this guy will give me a run for my money?
Can't wait to hear more about your car Rob! As far as the guy with the Impala goes, my best guess is he'll jump on you at the line, but you'll easily be able to pass him after that. He's got a 260hp LT-1 and he's heavier than your Q. His stock ET is 15.6, so if you beat him I say you're running mid to high 14s at worst 
.
Corey
.Corey
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Q45tech
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There is no way to affect the A/F ratio short of reprograming ecu!
The O2 can affect the part throttle non acceleration ratio.
What the ecu learns by adjusting the cruise A/F to 14.7 is used partially in WOT to balance the 2 banks of injectors.
IN acceleration the ecu just looks at the rpm/tps/and MAF and solves an equation for injector open time.......and or compares it to a set of opening times in a look up table.
The ecu always errs on the side of richness as this has the most safety and least effect on power creation. The extra unburned gasoline just blows out the exhaust. 10% extra* fuel would only displace 2-4% of the air........even a 10:1 A/F would only drop power by 10% at the max........any thing between 12.5 and 11 AF is acceptable.
Hey each WOT 6,000 rpm squirt of gas only weighs 74 milligrams,370 cc/minute= 6.2 cc per second corrected for 55% duty cycle= 3.4cc divided by 50 quirts per second of 0.0682 cc per cyclinder per rpm.
The O2 can affect the part throttle non acceleration ratio.
What the ecu learns by adjusting the cruise A/F to 14.7 is used partially in WOT to balance the 2 banks of injectors.
IN acceleration the ecu just looks at the rpm/tps/and MAF and solves an equation for injector open time.......and or compares it to a set of opening times in a look up table.
The ecu always errs on the side of richness as this has the most safety and least effect on power creation. The extra unburned gasoline just blows out the exhaust. 10% extra* fuel would only displace 2-4% of the air........even a 10:1 A/F would only drop power by 10% at the max........any thing between 12.5 and 11 AF is acceptable.
Hey each WOT 6,000 rpm squirt of gas only weighs 74 milligrams,370 cc/minute= 6.2 cc per second corrected for 55% duty cycle= 3.4cc divided by 50 quirts per second of 0.0682 cc per cyclinder per rpm.
Thanks again Dennis for your valuable information and I had thought the same as you stated above that the AF ratio can't be changed without a full ECU reprogram. It was just that the dealer charged me for what they said was the AF ratio needed to be reset after the addition of the new O2 sensors and now these guys said that they would make sure that the car was running the proper AF ratio as well had me wondering what is going on.
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Q45tech
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1995 G20t 5 speed 334,000 miles 16" 2002 wheels - 205/50/16 Sr20ve vvl
The Consult can reset the block learn [adaptive learn] returning each bank to 100%. But the ecu will do that anyway in 10 minutes of cruise driving.
I laugh [feel sorry for] at all those kids who disco the battery overnight after mods.......thinking they are doing something special when the ecu will just readjust quickly.
After all the ecu is designed to quickly compensate for a sudden rain storm and 30F almost instaneous temp drop [3%] or driving up and down mountains where 1,000 feet fast changes occur [3%] in minutes.Their mods make 1% changes at most 2%!
The dealer service writers are not hired for technical expertise but by how well they sell and upsell and upsell and generally placate the customer.
I laugh [feel sorry for] at all those kids who disco the battery overnight after mods.......thinking they are doing something special when the ecu will just readjust quickly.
After all the ecu is designed to quickly compensate for a sudden rain storm and 30F almost instaneous temp drop [3%] or driving up and down mountains where 1,000 feet fast changes occur [3%] in minutes.Their mods make 1% changes at most 2%!
The dealer service writers are not hired for technical expertise but by how well they sell and upsell and upsell and generally placate the customer.
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^ Brilliant. Now it's time to call back the service writer (note I no longer refer to them as "techs") and ask him what exactly they did with the "A/F ratio".
Let him squirm for a while Rob - Then slap him with some Dennis-inspired knowledge.
Bastards.
Dennis, great point re: the ECU quick learning.... instantaneous temp, altitude and barometric pressure changes are not uncommon... Sometimes we get so blinded by technology we fail to apply logic.
Let him squirm for a while Rob - Then slap him with some Dennis-inspired knowledge.
Bastards.
Dennis, great point re: the ECU quick learning.... instantaneous temp, altitude and barometric pressure changes are not uncommon... Sometimes we get so blinded by technology we fail to apply logic.
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Q45tech
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1995 G20t 5 speed 334,000 miles 16" 2002 wheels - 205/50/16 Sr20ve vvl
Think about this:
You are cruising along for a few minutes and the block learn has adjusted the bank to bank variance by say 5% because one injector is a little dirty. 2.8-1.3= 1.5x 0.05= 2.8 & 2.9msYou floor it to pass so the MAF commands things go rich from 2.8 ms to 11.0 ms..........the block learn trims the WOT by the same 5%........one bank 11.0 ms and the other 11.5 ms.........but ecu knows the flow will be more equal at highest flow rates so maybe it then drops the 11.5 to 11.25 and 11.0 all in 0.1 second.
Block learn Adaptive learn is more for diagnostics than for actual correction except at cruise.
Also part of strategy to determine a misfire on OBD2.
You are cruising along for a few minutes and the block learn has adjusted the bank to bank variance by say 5% because one injector is a little dirty. 2.8-1.3= 1.5x 0.05= 2.8 & 2.9msYou floor it to pass so the MAF commands things go rich from 2.8 ms to 11.0 ms..........the block learn trims the WOT by the same 5%........one bank 11.0 ms and the other 11.5 ms.........but ecu knows the flow will be more equal at highest flow rates so maybe it then drops the 11.5 to 11.25 and 11.0 all in 0.1 second.
Block learn Adaptive learn is more for diagnostics than for actual correction except at cruise.
Also part of strategy to determine a misfire on OBD2.
Well...I am still waiting for my car, but I saw the passenger side header completed. It looked great, but what do I really know about this stuff since it all to me looks like a bunch of fancy curvey pipes. The design is a lot different than our Aussy friend Ash as the tubes are more equal length.
Maybe tomorrow (Friday) if the powder coating shop gets it done...otherwise Monday I should have my car back and I will be racing that SS Impala.
Maybe tomorrow (Friday) if the powder coating shop gets it done...otherwise Monday I should have my car back and I will be racing that SS Impala.
My interesting rental car race.....
Well since my car has been in the shop I have been hitching a ride now and then with friends who work downtown Miami with me across the street from my condo and renting a rental car here and there....
My last rental is a Chevy Aveo....never even heard or saw one until Enterprise guy pulled up with one...I can't complain as the cost is only $15/Day through a friend of a friend.
Anyway...last night I decided to take on a Toyota Echo as the two cars are Econo Tree Hugger Death Trap cars....well I got my a$$ handed to me by an Echo. I could not believe it. The one car I decide to pick on and race with this rental that I thought would be even wasted me. The old guy and his wife were laughing their butts off at me and I waived to them back as they kept pulling away from me...we raced from about 40mph to 100mph. This little piece of $hit has 14" wheels which I did not think that they made anymore.
Well since my car has been in the shop I have been hitching a ride now and then with friends who work downtown Miami with me across the street from my condo and renting a rental car here and there....
My last rental is a Chevy Aveo....never even heard or saw one until Enterprise guy pulled up with one...I can't complain as the cost is only $15/Day through a friend of a friend.
Anyway...last night I decided to take on a Toyota Echo as the two cars are Econo Tree Hugger Death Trap cars....well I got my a$$ handed to me by an Echo. I could not believe it. The one car I decide to pick on and race with this rental that I thought would be even wasted me. The old guy and his wife were laughing their butts off at me and I waived to them back as they kept pulling away from me...we raced from about 40mph to 100mph. This little piece of $hit has 14" wheels which I did not think that they made anymore.
The silence before the storm has approached.
I pickup my car tomorrow afternoon (Saturday) with headers, exhaust, 4.08. Finally after 5+ weeks!!!! They had the headers installed this afternoon and were hooking up the rest of the car. They said it sounded very wicked and just like a 4.6L Mustang with just the headers on. It is a little more involved to attach the headers as they had to remove the AC compressor and a unbolt the engine from the mounts to take car of the driver side with the steering shaft. They said all was good with the flanges and new exhaust gaskets...better be as I saw the flanges were like 1/3" thick mounting to the block. I can't wait to just to get my car back let alone feel the new power it had better damn well have....
So if you all hear some fait tire burning exhaust rumbling scretches in the late afternoon tomorrow....it is me
as I will be sure to try to find my first victim to open a can of whoop a$$ (honestly....I am hoping the damn thing just runs half way decent right now).
Also our NICO member 1qsker is here in Miami right now and we will meet up on Saturday and Sunday for some Q'ing around town.
Well enough NICO stuff for now....as I was just taking a party break from Happy Hour and now off to the clubs.
I pickup my car tomorrow afternoon (Saturday) with headers, exhaust, 4.08. Finally after 5+ weeks!!!! They had the headers installed this afternoon and were hooking up the rest of the car. They said it sounded very wicked and just like a 4.6L Mustang with just the headers on. It is a little more involved to attach the headers as they had to remove the AC compressor and a unbolt the engine from the mounts to take car of the driver side with the steering shaft. They said all was good with the flanges and new exhaust gaskets...better be as I saw the flanges were like 1/3" thick mounting to the block. I can't wait to just to get my car back let alone feel the new power it had better damn well have....
So if you all hear some fait tire burning exhaust rumbling scretches in the late afternoon tomorrow....it is me
as I will be sure to try to find my first victim to open a can of whoop a$$ (honestly....I am hoping the damn thing just runs half way decent right now). Also our NICO member 1qsker is here in Miami right now and we will meet up on Saturday and Sunday for some Q'ing around town.
Well enough NICO stuff for now....as I was just taking a party break from Happy Hour and now off to the clubs.
I now have a big smile on my face
The cars runs nice and smooth and has more power than before as I took it up to 145mph with no trouble at all. I had it up to 130 only once before and this time it was much easier and faster. The sound is so sweet....very strong sound only when you are on the gas. I can stand in front of the car when it is idling and I don't hear the exhaust at all. I will post sound video/sound clips this week.
I am going to go back next week and get the dyno numbers done.
The cars runs nice and smooth and has more power than before as I took it up to 145mph with no trouble at all. I had it up to 130 only once before and this time it was much easier and faster. The sound is so sweet....very strong sound only when you are on the gas. I can stand in front of the car when it is idling and I don't hear the exhaust at all. I will post sound video/sound clips this week.
I am going to go back next week and get the dyno numbers done.