Of note to those of you that are trying to get PE injectors tuned
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Pr0n King
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Of note to those of you that are trying to get PE injectors tuned
Originally posted by AZScoobie
Some of the guys have given you good advice in that you need to use a wideband and a good dyno tune will help.
We have spent alot of time calibrating the PE injectors for use on the WRX.
The PE injectors are a two stage design and they a very different then the stock or STI units in design. Because of this they will never work correctly with a stock ECU and Utec. People have done it, I have done it, I have tuned many cars with the PE's. It works, sorta....
If you run the stock ECU map and the Utec, what you will find is that on low injector times your 800's will flow less then a stock injector. The 800's are leaner then the 650's at idle and cruise. You will have to make positive corrections to the fuel map based on your AF correction readings. Then, when you aproach that magical number on injector time the flood gates open and the fuel dumps in. This is no doubt the hesitation that you are experiencing.
The band aid way of fixing this is to tune the Utec out to mask the cross over point on the injectors, add fuel down low and remove ALOT on boost. Values of -16 to -18 are not uncommon on boost and values of +4 are common on lower scales of the fuel map. Because of this wide correction the stock ECU is unhappy and will no doubt switch to the Hi det fuel map. Many times peopel dont even know this is happening because they do not have the tools to view the ECU's rom file as the car is running. When you switch to the Hi det map, more fuel to be dumped in. Then, people see this as a half point to a point on the AF meter and remove a bit more fuel. Now the car runs great again with a nice AF. The ECU comes out of the Hi det map and goes into the low det map and less fuel is being injected. uh, oh.. I am a bit lean now..... And the cycle continues.
What you end up with is an inconsistant car that needs alot of attention. Guys that are very Utec Savy and have widebands can make a few adjustments here and there to keep the car running decent but in the end this is a band aid.
We spent hours and hours and hours tuning the PE injectors on the Factory STI and US ECU's. We learned some things by trial and error and when we put our heads together we figured out how to calibrate them to the Factory ECUs. Once this change is made to the ECU Rom file the injectors act exactly like they should. They are no longer lean at low injector times and the switchover point is no longer abrubt. Utec values all of the sudden go smooth needing slight negative values in most of the map and - values of -9 to -14 on boost (with smallish turbos). The ECu is very happy and never switches to the Hi det fuel map and it can now do its job of of tuning part throttle and idle via AF correction. After these changes to the ROM in the ECU, the PE's are a pleasure to tune with the Utec.
As an option you can set your Injector scaling in the Rom file to offset the larger injectors and then you need even less utec correction. This is not required with the Utec but it makes for less work in Utec programming.
HTH
CT
Some of the guys have given you good advice in that you need to use a wideband and a good dyno tune will help.
We have spent alot of time calibrating the PE injectors for use on the WRX.
The PE injectors are a two stage design and they a very different then the stock or STI units in design. Because of this they will never work correctly with a stock ECU and Utec. People have done it, I have done it, I have tuned many cars with the PE's. It works, sorta....
If you run the stock ECU map and the Utec, what you will find is that on low injector times your 800's will flow less then a stock injector. The 800's are leaner then the 650's at idle and cruise. You will have to make positive corrections to the fuel map based on your AF correction readings. Then, when you aproach that magical number on injector time the flood gates open and the fuel dumps in. This is no doubt the hesitation that you are experiencing.
The band aid way of fixing this is to tune the Utec out to mask the cross over point on the injectors, add fuel down low and remove ALOT on boost. Values of -16 to -18 are not uncommon on boost and values of +4 are common on lower scales of the fuel map. Because of this wide correction the stock ECU is unhappy and will no doubt switch to the Hi det fuel map. Many times peopel dont even know this is happening because they do not have the tools to view the ECU's rom file as the car is running. When you switch to the Hi det map, more fuel to be dumped in. Then, people see this as a half point to a point on the AF meter and remove a bit more fuel. Now the car runs great again with a nice AF. The ECU comes out of the Hi det map and goes into the low det map and less fuel is being injected. uh, oh.. I am a bit lean now..... And the cycle continues.
What you end up with is an inconsistant car that needs alot of attention. Guys that are very Utec Savy and have widebands can make a few adjustments here and there to keep the car running decent but in the end this is a band aid.
We spent hours and hours and hours tuning the PE injectors on the Factory STI and US ECU's. We learned some things by trial and error and when we put our heads together we figured out how to calibrate them to the Factory ECUs. Once this change is made to the ECU Rom file the injectors act exactly like they should. They are no longer lean at low injector times and the switchover point is no longer abrubt. Utec values all of the sudden go smooth needing slight negative values in most of the map and - values of -9 to -14 on boost (with smallish turbos). The ECu is very happy and never switches to the Hi det fuel map and it can now do its job of of tuning part throttle and idle via AF correction. After these changes to the ROM in the ECU, the PE's are a pleasure to tune with the Utec.
As an option you can set your Injector scaling in the Rom file to offset the larger injectors and then you need even less utec correction. This is not required with the Utec but it makes for less work in Utec programming.
HTH
CT
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Pr0n King
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Anybody that can do Ecutek and/or Cobb ECU.
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From: Lastweek Lane - Watertown, NY
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You know, I still don't understand short term fuel trim vs. long term. I want to be able to control exactly how long my injectors pulse down low, during daily driving.
I just went to Kaneohe, MCBH exchange and observed 2 things. I went through over a 1/4 tank of gas never revving past 3000rpm, and when I was driving up the steepest parts of the climb (near the tunnel, going east bound), the car had no power in 5th or 4th gears, and my EGT's would climb to about 1525 degrees.
More and more I'm disliking piggybacks, but my dislike of them doesn't outweigh my fear of having to go through what Mitch went through with his link.
I just went to Kaneohe, MCBH exchange and observed 2 things. I went through over a 1/4 tank of gas never revving past 3000rpm, and when I was driving up the steepest parts of the climb (near the tunnel, going east bound), the car had no power in 5th or 4th gears, and my EGT's would climb to about 1525 degrees.
More and more I'm disliking piggybacks, but my dislike of them doesn't outweigh my fear of having to go through what Mitch went through with his link.
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Pr0n King
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From: The Land of Rocks
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Fuel tuning on the UTEC (currently) is just through MAF voltage modification. Look at your fuel map - you are adding/removing fuel with a constant amount that the UTEC converts into MAF voltage modification.
The UTEC is basically lying to the stock ECU about how much air is coming into the engine to modify the AFR.
The computer applies a short term and long term trim to the fueling it decides to give based upon previous usage/monitoring- however the first post discusses a high-det and low-det map, not the same as fuel trim.
If the car develops values that it is internally adding or subtracting to the fueling that it's deciding to give the car based on MAF voltage - the end result can vary from when you originally tuned the car.
From my understanding of what's being discussed that's why if you are a stickler for precise a AFR # it's important to do a complete Vishnu reset before your final fuel tuning. This gives you an even playing field, or a blank canvas as it were. Also make sure you don't run into det. events during fuel tuning as this can set your stock ECU onto the "high-det. map" and change your AFR again.
Tuning the Scooby sure ain't easy!
Re: the standalone issue - Tuning a race car/weekend warrior on a dyno with a stand-alone ROCKS. Tuning a daily driver/every day car on the road with no access to a dyno running a stand-alone ECU is no fun.
For clarification on the above see the "active ignition timing" thread posted by Ecutek on NASIOC or "the other board", Pat. It's all in there.
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The UTEC is basically lying to the stock ECU about how much air is coming into the engine to modify the AFR.
The computer applies a short term and long term trim to the fueling it decides to give based upon previous usage/monitoring- however the first post discusses a high-det and low-det map, not the same as fuel trim.
If the car develops values that it is internally adding or subtracting to the fueling that it's deciding to give the car based on MAF voltage - the end result can vary from when you originally tuned the car.
From my understanding of what's being discussed that's why if you are a stickler for precise a AFR # it's important to do a complete Vishnu reset before your final fuel tuning. This gives you an even playing field, or a blank canvas as it were. Also make sure you don't run into det. events during fuel tuning as this can set your stock ECU onto the "high-det. map" and change your AFR again.
Tuning the Scooby sure ain't easy!
Re: the standalone issue - Tuning a race car/weekend warrior on a dyno with a stand-alone ROCKS. Tuning a daily driver/every day car on the road with no access to a dyno running a stand-alone ECU is no fun.
For clarification on the above see the "active ignition timing" thread posted by Ecutek on NASIOC or "the other board", Pat. It's all in there.
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Pr0n King
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IMHO, YMMV, AFAIK, ad nauseum... I'm not a pioneer here, just a nut trying to tune a squirrel. 
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Last edited by IS2Scooby; May 26, 2003 at 10:01 PM.
Thread Starter
Pr0n King
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Yeah... I feel your pain, just when I think the 650 Map I've done for a customer is coming along, it starts to get bogus out of no where. I'm slowly working that 500-3000 RPM area trying to map that transition point when the injectors decide to spew their guts out.
Someone needs to find a single stage 650 we can use. these dual stage injectors are a PITA!
Someone needs to find a single stage 650 we can use. these dual stage injectors are a PITA!
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From: Lastweek Lane - Watertown, NY
Car Info: 02WRXpseudoSTiWannabeWagon
Originally posted by Nolimit
Pat, ... remind me to talk to you later.
Pat, ... remind me to talk to you later.
Originally posted by gpatmac
You're gonna have to email me...or maybe we could all get together sometime before I leave.
You're gonna have to email me...or maybe we could all get together sometime before I leave.
Basically, .... DON'T fear a standalone. (or is it Don't fear to stand alone??
)You need to spend some time with Blake and I and watch what goes on tuning the AEM on his car.
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