Autothority vs. Wong
#46
Sorry for no reply. I assumed your question was rhetorical.
A chip alone won't allow you to optimize the AFR at 12.6 and hold it
there. It your chip supplier is telling you that, he's got a credibilty
problem. You need a feedback element like a wide band O2 sensor
with its' electronics to control the AFR. A narrow band O2 will only
set the AFR to 14.7 without modifying the fuel injection system with
some front-end electronics.
What provides the simplest approach for racing is to tweak the air
flow meter. This will get you great throttle response without having
to worry about pinging. If you really want performance, the best
approach for optimum AFR for racing is to change the fuel system
to an aftermarket one.
Yes, you do need to have the stock chip modified for an increased
redline. This can be done without affecting the fuel & ignition maps,
though. Autohority (www.autothority.com) and others can
provide you with this capability.
Addtional Note:
Once the throttle reaches about 2/3 to 3/4 full throttle, the air flow
meter maxs out. Since the DME uses the air flow meter & RPM to
determine engine load, the DME can't really deterimne the load
accurately after this point which further compounds the pinging
problem.
A chip alone won't allow you to optimize the AFR at 12.6 and hold it
there. It your chip supplier is telling you that, he's got a credibilty
problem. You need a feedback element like a wide band O2 sensor
with its' electronics to control the AFR. A narrow band O2 will only
set the AFR to 14.7 without modifying the fuel injection system with
some front-end electronics.
What provides the simplest approach for racing is to tweak the air
flow meter. This will get you great throttle response without having
to worry about pinging. If you really want performance, the best
approach for optimum AFR for racing is to change the fuel system
to an aftermarket one.
Yes, you do need to have the stock chip modified for an increased
redline. This can be done without affecting the fuel & ignition maps,
though. Autohority (www.autothority.com) and others can
provide you with this capability.
Addtional Note:
Once the throttle reaches about 2/3 to 3/4 full throttle, the air flow
meter maxs out. Since the DME uses the air flow meter & RPM to
determine engine load, the DME can't really deterimne the load
accurately after this point which further compounds the pinging
problem.
Last edited by Lorenfb; 04-04-2004 at 03:35 AM.
#47
Originally posted by Lorenfb
A chip alone won't allow you to optimize the AFR at 12.6 and hold it
there. It your chip supplier is telling you that, he's got a credibilty
problem. You need a feedback element like a wide band O2 sensor
with its' electronics to control the AFR. A narrow band O2 will only
set the AFR to 14.7 without modifying the fuel injection system with
some front-end electronics.
A chip alone won't allow you to optimize the AFR at 12.6 and hold it
there. It your chip supplier is telling you that, he's got a credibilty
problem. You need a feedback element like a wide band O2 sensor
with its' electronics to control the AFR. A narrow band O2 will only
set the AFR to 14.7 without modifying the fuel injection system with
some front-end electronics.
Originally posted by Lorenfb
What provides the simplest approach for racing is to tweak the air
flow meter. This will get you great throttle response without having
to worry about pinging. If you really want performance, the best
approach for optimum AFR for racing is to change the fuel system
to an aftermarket one.
What provides the simplest approach for racing is to tweak the air
flow meter. This will get you great throttle response without having
to worry about pinging. If you really want performance, the best
approach for optimum AFR for racing is to change the fuel system
to an aftermarket one.
Originally posted by Lorenfb
Once the throttle reaches about 2/3 to 3/4 full throttle, the air flow
meter maxs out. Since the DME uses the air flow meter & RPM to
determine engine load, the DME can't really deterimne the load
accurately after this point which further compounds the pinging
problem.
Once the throttle reaches about 2/3 to 3/4 full throttle, the air flow
meter maxs out. Since the DME uses the air flow meter & RPM to
determine engine load, the DME can't really deterimne the load
accurately after this point which further compounds the pinging
problem.
All this from someone who claims using synthetic oil in a 911 engine is bad and will accelerate valve guide wear as you stated in the following thread. Great going Einstein.
https://rennlist.com/forums/showthre...c&pagenumber=2
#48
"By disconnecting the O2 sensor, or programming the eprom to ignore the it, you can program in whatever part throttle AFR you want at each particular rpm and load point, and it will stay there, all day, all night."
Based on the above quote, I guess engines don't really need an O2 sensor
after all, e.g. 14.7 for optimum emissions. Furthermore, I guess mass air flow
sensors are of no value either, since it's not necessary to worry about the air
density at high altitudes affecting the AFR, since the AFR can be controlled
fully within an EPROM. Too bad the automotive industry hasn't discovered
this yet.
FACT - You can program in any fuel value/quantity, but the air quantity/mass
is a variable somewhat inaccurately measured by an air flow meter (mass air
flow sensor)! Hence the need for a feedback element - an O2 sensor to maintain
an AFR of 14.7 for optimum emissions. THAT'S WHY THEY'RE USED!
Also, remember that the position of the air flow meter is a function of load,
and as a result there are load conditions where 2/3 to 3/4 throttle will yield
a max on the air flow meter. Maybe that's another benefit of mass air flow
sensors.
It can't ping? Tell it to those that have broken piston rings!
Bottomline: Pinging can occur in any engine under certain conditions
without the use of knock sensors. THAT'S WHY THEY ARE USED!
Speaking of EFI 101, someone may have been asleep for that lecture
or doesn't USC ofter that course (They do lack a lot of REAL courses.),
or maybe someone's spent too much time watching scrolling 1s & 0s
or Matrix movies.
So as I said, listen closely on those hot days and check those plugs for that
white metal stuff. Porsche had a reason for not pushing the ignition timing
for max performance, i.e. engine life.
If you really think that you must have a performance chip, then
visit these web sites; www.autothority.com, www.weltmeister.com -
a Dinan chip). Those chips were developed on dynos and not by playing
on a laptop with trial/error chips, e.g. "If your car runs a little rich, we'll
try again and send you another chip. Hey, life's not perfect and you can
help test the chips until we get it right." Remember, as the saying goes;
"You get what you pay for.".
Most Porsche people don't recommend switching to a synthetic oil when
the engine has been run for many years with petroleum based oils,
especially for high mileage engines.
Based on the above quote, I guess engines don't really need an O2 sensor
after all, e.g. 14.7 for optimum emissions. Furthermore, I guess mass air flow
sensors are of no value either, since it's not necessary to worry about the air
density at high altitudes affecting the AFR, since the AFR can be controlled
fully within an EPROM. Too bad the automotive industry hasn't discovered
this yet.
FACT - You can program in any fuel value/quantity, but the air quantity/mass
is a variable somewhat inaccurately measured by an air flow meter (mass air
flow sensor)! Hence the need for a feedback element - an O2 sensor to maintain
an AFR of 14.7 for optimum emissions. THAT'S WHY THEY'RE USED!
Also, remember that the position of the air flow meter is a function of load,
and as a result there are load conditions where 2/3 to 3/4 throttle will yield
a max on the air flow meter. Maybe that's another benefit of mass air flow
sensors.
It can't ping? Tell it to those that have broken piston rings!
Bottomline: Pinging can occur in any engine under certain conditions
without the use of knock sensors. THAT'S WHY THEY ARE USED!
Speaking of EFI 101, someone may have been asleep for that lecture
or doesn't USC ofter that course (They do lack a lot of REAL courses.),
or maybe someone's spent too much time watching scrolling 1s & 0s
or Matrix movies.
So as I said, listen closely on those hot days and check those plugs for that
white metal stuff. Porsche had a reason for not pushing the ignition timing
for max performance, i.e. engine life.
If you really think that you must have a performance chip, then
visit these web sites; www.autothority.com, www.weltmeister.com -
a Dinan chip). Those chips were developed on dynos and not by playing
on a laptop with trial/error chips, e.g. "If your car runs a little rich, we'll
try again and send you another chip. Hey, life's not perfect and you can
help test the chips until we get it right." Remember, as the saying goes;
"You get what you pay for.".
Most Porsche people don't recommend switching to a synthetic oil when
the engine has been run for many years with petroleum based oils,
especially for high mileage engines.
Last edited by Lorenfb; 04-05-2004 at 06:11 AM.
#49
Loren, Until you can show the tests that YOU have done to backup what you are saying, your credibility on chips and synthetic oils are zero. Seems that Porsche remapped their own chip in G cars to be more aggressive and recommends synthetic oils. According to what you have been saying about these subjects Porsche must be wrong. If Porsche had any issues with these they would not have done the more aggressive chip or recommended the use of synthetic oils. Evidently you must be right and Porsche wrong or maybe the other way around. What is it?
#50
For those really interested in race/track car performance fuel injection,
check out this web site (www.electromotive-inc.com). The fuel injection
system provided utilizes O2 feedback to control the AFR for max performance.
This should help explain why you really can't fully control the AFR without
some form of exhaust gas feedback.
check out this web site (www.electromotive-inc.com). The fuel injection
system provided utilizes O2 feedback to control the AFR for max performance.
This should help explain why you really can't fully control the AFR without
some form of exhaust gas feedback.
#51
Originally posted by Lorenfb
For those really interested in race/track car performance fuel injection,
check out this web site (www.electromotive-inc.com). The fuel injection
system provided utilizes O2 feedback to control the AFR for max performance.
This should help explain why you really can't fully control the AFR without
some form of exhaust gas feedback.
For those really interested in race/track car performance fuel injection,
check out this web site (www.electromotive-inc.com). The fuel injection
system provided utilizes O2 feedback to control the AFR for max performance.
This should help explain why you really can't fully control the AFR without
some form of exhaust gas feedback.
Tuning the EGO sensor is the final step in the engine tuning process. Since EGO sensor are only designed to provide a switch-point for stoichiometric operation, it is not recommended that the EGO be used in closed loop mode for anything other than its intended design: part throttle and idling stoichiometric control.
A few things to remember:
• Standard oxygen sensors are designed to provide a switch-point for stoichiometric airfuel operation. They are NOT designed to be able to tell you the exact air-fuel ratio when you are outside the stoichiometric amount (14.64:1 AFR).
• Oxygen sensors have a large degree of inaccuracy when operated at different temperatures. Figure D.4 7 shows a characteristic voltage curve variation with EGO sensor temperature.
• Do not use an EGO authority range that is greater than 10% on a tuned engine. A correction greater than a ten percent increase or decrease to the fuel curve should never be necessary on a tuned engine.
• It is strongly recommended that the High MAP Switch reading be set to a value BELOW 95kPa. This will turn off the oxygen sensor correction at full-load conditions. It will save an engine from having a lean-out condition due to the oxygen sensor reading. Never run a boosted engine in closed-loop during high-boost situations.
• Oxygen Sensors need heat to operate correctly. Readings obtained at idle are often inaccurate due to this fact.
• Although much faith is placed on air-fuel measurement, it is not the sole determining factor for proper engine operation and fuel metering. Unless you know a specific engine’s air-fuel requirements, there is no “target” air-fuel ratio to shoot for. However, ALWAYS run engines on the rich side of stoichiometric when under medium to high load.
Along with these negatives comes a positive: an EGO sensor is typically good at providing a stoichiometric measurement when at idle or part-throttle cruising. When the EGO sensor is turned on (as in closed loop mode), it will try to correct the AFR reading to the values defined in the Desired Air Fuel Ratio Table. It does this by manipulating the fuel injector pulse width. When the EGO sensor is turned off (as in open loop mode), the reading from the EGO is still present, but the sensor is not trying to obtain the values in the Desired Air Fuel Ratio Table.
It is recommended that the EGO sensor be used for its intended purpose: to provide a stoichiometric measurement. Consequently, the EGO should be run in closed loop mode only when the engine should be operating at the stoichiometric mixture. Medium and high load situations MUST be run richer than stoichiometric to prevent engine damage, thus the EGO should be in open loop when these circumstances are met.
Great work for helping restate what I already repeated twice in this thread: that for performance such as at WOT or high load situation, you run 'open loop' which means you DO NOT utilize the O2 sensor feedback.
#54
Originally posted by Lorenfb
It's kinda like not understanding what you've put in your car.
But like most, sure feels good, even though it now makes funny noises!
It's kinda like not understanding what you've put in your car.
But like most, sure feels good, even though it now makes funny noises!
I'm a humble enough person to admit that I'm not an expert in automotive engineering like some others on this board. But I've owned many Porsches have been driving them for years. I'm merely stating that my cars with Steve's chip runs great ...nothing more and nothing less.
One more thing ....my car does not make funny noises.
#56
I do care. That's the great thing about these internet boards. You can check the feedback from other owners before you decide what to put in your car. I think there are enough people here and on the Pelican board that feels the same about Steve's product. I'm not the only one.
I did extensive research on the Upsolute chip before I put it in my 996TT. Alot people said a $500 chip for a twin turbo must not be as good as the $3500 GIAC chip. Well, after enough owners reported excellent results with the Upsolute product, I went ahead and pulled the trigger. My 415hp car now puts out over 500+ hp. I would say it's the best $500 I've ever spent on a car mod, even better bang for the buck than Steve's chip.
I don't try to figure out how Steve or Upsolute programmed their products. I'm just happy with the results. If that makes me different than the 'typical Porsche owner' as you say, so be it.
Have fun,
I did extensive research on the Upsolute chip before I put it in my 996TT. Alot people said a $500 chip for a twin turbo must not be as good as the $3500 GIAC chip. Well, after enough owners reported excellent results with the Upsolute product, I went ahead and pulled the trigger. My 415hp car now puts out over 500+ hp. I would say it's the best $500 I've ever spent on a car mod, even better bang for the buck than Steve's chip.
I don't try to figure out how Steve or Upsolute programmed their products. I'm just happy with the results. If that makes me different than the 'typical Porsche owner' as you say, so be it.
Have fun,
#57
So, what are the long term effects? Don't know, do you.
And for that 996, just wait until it's emissions test time.
Those cars have enough problems as is without mods to
the engine, the DME, and/or the emissions control system.
To use your quote, "even better bang for the buck", beware of those
pistons rings and connecting rods as they get stressed beyond Porsche's
design limits with your performance chips.
Your statements exemplify your naivete. In attemptiing to "squeeze" an
additional 85 HP without knowing the effects to the engine, you do exactly
what I stated in my post, i.e. add-on mods you know little about other than
marketing hype. Furthermore, you and others use testimonials from new
Porsche owners or ones who have little to no technical background when
it comes engine knowledge, only that it "feels" good.
And for that 996, just wait until it's emissions test time.
Those cars have enough problems as is without mods to
the engine, the DME, and/or the emissions control system.
To use your quote, "even better bang for the buck", beware of those
pistons rings and connecting rods as they get stressed beyond Porsche's
design limits with your performance chips.
Your statements exemplify your naivete. In attemptiing to "squeeze" an
additional 85 HP without knowing the effects to the engine, you do exactly
what I stated in my post, i.e. add-on mods you know little about other than
marketing hype. Furthermore, you and others use testimonials from new
Porsche owners or ones who have little to no technical background when
it comes engine knowledge, only that it "feels" good.
#58
Guys, life is to short to worry about engine life. By the way, what is the life expectancy of 88 3.2? My doctor told me that I can have maximum of 10000 ejac! I do not want to save 9800 when I hit 60 years old. Do now
#59
I'll pull a Loren here and ask for proof. I want to see all the Steve Wong chipped engines that have been ruined with pinging and detonation. Post em up!
In the same context, I want to see all the engines ruined by synthetic oil - come on - post em.
In the mean time - I'll just be a satisfied wong chipped customer.
In the same context, I want to see all the engines ruined by synthetic oil - come on - post em.
In the mean time - I'll just be a satisfied wong chipped customer.