Who's running 80# injectors?
- Thread starter KidMoney
- Start date
I'm running them in my car with no issues, Drives like stock...
+1,had them for 2 seasons now and no issues at all,drives like stock as well.
Who did your tune?
I see Larocca did yours. I'm trying to find someone who can tune them to get my car to drive normal.
Dennis Gomes from Tasca tuned mine..
Yes,plenty of options imo, but Dennis Gomes from Tasca like kleen93gt is a great option!I know a few guys that worked with him for there cars and they're really happy on the results!
these injectors behave the same as stock, we have use them on most of our builds without ever having any issues,
I've run them in a turbo car I had before this that made a lot more power and they worked fine in it as well. I don't see why they would be different in this car.
I am also running them in my car, which isnt currently running to do the p2195 lean code and doubt its because of the 80lb injectors. When it was running, it was flawless.
I have been tuning the 80lb Siemens Deka injectors since they came out in February of 2009. I tuned them on Steve Turner's car, my own car, and a few customers cars. The first set I did was off, even though I had what was supposed to be the correct data from the Ford flow lab. I later found out the injector characterization changed from the pre-production injectors to the production injectors, so the Ford data originally published for 80s was incorrect. Once I had the right info, it was better, but the 80s still have some quirks.
Side note:
To fully characterize an injector you have to run it across the entire operating pulsewidth, at different pressures, battery voltages, and offsets. You end up with about 6 tables that get plugged into the PCM and interpolated on the fly based on various PCM inputs (like rail pressure and bat voltage). This type of baseline data can only be properly defined on a sophisticated flow bench, it's not something you do on a car. There seems to be a belief on the internet that a good tuner can figure out anything, but a tuner is only as good as his data.
The 80s were originally designed for a race car that would see a 1/4mile at a time, FRPP needed an inexpensive injector that performed at wide open throttle. The 80s do this quite well. I was made aware early on by an FRPP engineer that the 80s did not like to idle below 2msec pulsewidth and would become non-linear. Guess where a GT500 likes to idle with that big of an injector? around 1.5ms on gasoline.
Side note:
E85 has a 30-40% higher fuel requirement by volume so that brings the injector back up into the linear range and they run great at idle and part throttle.
When an injector gets into the non-linear range it does not open and close consistently. This results in poor fuel delivery, usually erring to the rich side. The PCM tries to compensate but cannot get any control. Often the short term fuel trims will “stick” from the O2s not switching. At that point you can only tune the car with a wideband, but you’ll find that a small tuning changes results in an extreme air/fuel change due to the injector being non-linear in the area you trying to adjust.
This is what the actual data from the car looks like on my GT500 with 80lb injectors:
The left side is the car idling, notice that fuel pressure has been lowered to 30psi to increase injector pulsewidth and get them back into the linear range, one of the ‘tricks’. Spark has been lowered to increase engine load and thus injector pulsewidth, another tuning technique. Load at idle is 23%, for this set of 80s that is the threshold of linear operation. As soon as the car is free-revved in neutral the load drops to 15% and the fuel trims flat line (purple line at top). We can visually see where the 80s go non-linear and the engine goes rich. The red line is Analog 1 from a lab-grade AFM1000 wideband air/fuel measuring device installed in the vehicle’s exhaust before the cat. When the load drops, the A/F goes from close to stoich, to 11:1, which is richer than you would want the car to be even at WOT. So what do you do? you try and get it close, but there are still trade-offs in driveability.
Below is an analysis of Siemens-Deka 80lb injector across its operating range courtesy of Paul Yaw at Injector Dynamics. He owns a very sophisticated flow bench that can generate OE-quality injector characterization data.
You can see the very sharp curve around 1.5msec, when the PCM tries to modulate injector pulsewidth to keep air/fuel ratio in the stoichiometric range during closed-loop operation, it would have a very hard time doing so with such a drastic change in flow rate, once it gets over the first hump, flow drops back off and then comes up again at what is still somewhat of a sharp angle.
Another issue with 60s and 80s is that they are highly variable from one injector to the next and one batch to the next. I have seen flow reports that have indicated a variance of 20-30% from one injector to the next at low pulsewidths, once you go WOT and get into the high-slope they are fine so it does not result in any engine damage. Most people will never have the data available to them to quantify this since they are not tuning on an individual cylinder basis, but when a problem is suspected and the injectors are dynamically flowed at high and low pulsewidths it becomes apparent.
You can not always lower fuel pressure to 30psi to try and trick the 80s into running better, with the ethanol in the fuel these days it will boil in the rail very easily. Ford goes to great extremes to prevent fuel boiling (often called vapor lock) by chrome plating the rails and now insulating the rails on newer cars. Raising fuel pressure also raises the boiling temperature. On 05-10 returnless fuel cars (and 07-13 GT500) the computer actually has a temperature sensor in the fuel rail so pressure can be raised to prevent boiling. The other trick, lowering spark, only works at idle, once you start revving the engine up you have to increase spark advance.
My car ran alright with 80s, after I put cams in, driveability became that much more important, and a higher quality more precise set of injectors made a big difference. I believe that the people who posted in this thread also have cars that run alright, but without data show that everything is working as Ford intended "no issues" is a very subjective measurement.
Side note:
To fully characterize an injector you have to run it across the entire operating pulsewidth, at different pressures, battery voltages, and offsets. You end up with about 6 tables that get plugged into the PCM and interpolated on the fly based on various PCM inputs (like rail pressure and bat voltage). This type of baseline data can only be properly defined on a sophisticated flow bench, it's not something you do on a car. There seems to be a belief on the internet that a good tuner can figure out anything, but a tuner is only as good as his data.
The 80s were originally designed for a race car that would see a 1/4mile at a time, FRPP needed an inexpensive injector that performed at wide open throttle. The 80s do this quite well. I was made aware early on by an FRPP engineer that the 80s did not like to idle below 2msec pulsewidth and would become non-linear. Guess where a GT500 likes to idle with that big of an injector? around 1.5ms on gasoline.
Side note:
E85 has a 30-40% higher fuel requirement by volume so that brings the injector back up into the linear range and they run great at idle and part throttle.
When an injector gets into the non-linear range it does not open and close consistently. This results in poor fuel delivery, usually erring to the rich side. The PCM tries to compensate but cannot get any control. Often the short term fuel trims will “stick” from the O2s not switching. At that point you can only tune the car with a wideband, but you’ll find that a small tuning changes results in an extreme air/fuel change due to the injector being non-linear in the area you trying to adjust.
This is what the actual data from the car looks like on my GT500 with 80lb injectors:
The left side is the car idling, notice that fuel pressure has been lowered to 30psi to increase injector pulsewidth and get them back into the linear range, one of the ‘tricks’. Spark has been lowered to increase engine load and thus injector pulsewidth, another tuning technique. Load at idle is 23%, for this set of 80s that is the threshold of linear operation. As soon as the car is free-revved in neutral the load drops to 15% and the fuel trims flat line (purple line at top). We can visually see where the 80s go non-linear and the engine goes rich. The red line is Analog 1 from a lab-grade AFM1000 wideband air/fuel measuring device installed in the vehicle’s exhaust before the cat. When the load drops, the A/F goes from close to stoich, to 11:1, which is richer than you would want the car to be even at WOT. So what do you do? you try and get it close, but there are still trade-offs in driveability.
Below is an analysis of Siemens-Deka 80lb injector across its operating range courtesy of Paul Yaw at Injector Dynamics. He owns a very sophisticated flow bench that can generate OE-quality injector characterization data.
You can see the very sharp curve around 1.5msec, when the PCM tries to modulate injector pulsewidth to keep air/fuel ratio in the stoichiometric range during closed-loop operation, it would have a very hard time doing so with such a drastic change in flow rate, once it gets over the first hump, flow drops back off and then comes up again at what is still somewhat of a sharp angle.
Another issue with 60s and 80s is that they are highly variable from one injector to the next and one batch to the next. I have seen flow reports that have indicated a variance of 20-30% from one injector to the next at low pulsewidths, once you go WOT and get into the high-slope they are fine so it does not result in any engine damage. Most people will never have the data available to them to quantify this since they are not tuning on an individual cylinder basis, but when a problem is suspected and the injectors are dynamically flowed at high and low pulsewidths it becomes apparent.
You can not always lower fuel pressure to 30psi to try and trick the 80s into running better, with the ethanol in the fuel these days it will boil in the rail very easily. Ford goes to great extremes to prevent fuel boiling (often called vapor lock) by chrome plating the rails and now insulating the rails on newer cars. Raising fuel pressure also raises the boiling temperature. On 05-10 returnless fuel cars (and 07-13 GT500) the computer actually has a temperature sensor in the fuel rail so pressure can be raised to prevent boiling. The other trick, lowering spark, only works at idle, once you start revving the engine up you have to increase spark advance.
My car ran alright with 80s, after I put cams in, driveability became that much more important, and a higher quality more precise set of injectors made a big difference. I believe that the people who posted in this thread also have cars that run alright, but without data show that everything is working as Ford intended "no issues" is a very subjective measurement.
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Thanks Justin ! That was an injector 101 class . It is fun to learn more about these great cars .
Justin - does this mean the only "good" injector option is Injector Dynamics? It's hard to swallow nearly $1k for injectors.
It means id injectors are the best.
This!! This is exactly my point. What did people use before the ID's?? There are a ton of high hp street cars not running them.
There are tons of blow engines do to injector failure and having injectors not flow matched because one injector ran rich the other injector ran lean. Choose what you must. No one says you have to buy id. But if you want the best on the market an easiest to tune then id are the way to go.
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