Best injector latency for e85 12 STi

Alin

Diehard Car Enthusiast!
[MENTION=4577]TK-421[/MENTION] [MENTION=9]HolyCrapItsFast[/MENTION]

I think it depends on what your power goals are and what psi youre aiming for.
 

Alin

Diehard Car Enthusiast!
I believe holycrapitsfast suggests an aeromotive 340 for e85 and we shall see what he says about injector size.
 

HolyCrapItsFast

Drinks beer!
Latency needs to be provided to you by the manufacturer of the injector. If not then you have to find the latency and that is not a totally simple task

What injector brand? If I know that, I will probably be able to find you something to get you started.
 

milehighsubie303

New member
Injectors dynamics 1000cc they did provide the latency for them, but it was for 91 octane. Looked on other forums, but everyone has different numbers on them
 

HolyCrapItsFast

Drinks beer!
Injectors dynamics 1000cc they did provide the latency for them, but it was for 91 octane. Looked on other forums, but everyone has different numbers on them

Latency is not effected by fuel type. It is the same for all levels of gasoline, race fuel, or E85. :tup: It is however effected by pressure. I'm a little concerned for you and your car. If you don't know this I feel you should not be tuning your car

Regardless here is the data taken directly from ID website. For stock fuel pressure use the row for 43.5 PSI. Also divide the numbers at each voltage by 1000 to get milliseconds...


ID1000 Dynamic Flow Data

Fuel PressureOffsetSlope
(psid)(?sec)(cc/min)
8 Volts10 Volts12 Volts14 Volts16 Volts
40.0248516301210970800980
43.52600167512409908051015
45.027201705129510008101035
50.028551750135510258151085
55.030151815140010558201135
60.031951880144010808451180
65.033701960148511008801225
70.035502050153011259251265
75.0N/A2155158011559751305
80.0N/A22801625119510201345
85.0N/A24351675124510601390
90.0N/A26101725130510951435
95.0N/A28001775137011251485
100.0N/A29951855144011551530
 
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milehighsubie303

New member
Latency is not effected by fuel type. It is the same for all levels of gasoline, race fuel, or E85. :tup: It is however effected by pressure. I'm a little concerned for you and your car. If you don't know this I feel you should not be tuning your car

Regardless here is the data taken directly from ID website. For stock fuel pressure use the row for 43.5 PSI. Also divide the numbers at each voltage by 1000 to get milliseconds...


ID1000 Dynamic Flow Data

Fuel PressureOffsetSlope
(psid)(?sec)(cc/min)
8 Volts10 Volts12 Volts14 Volts16 Volts
40.0248516301210970800980
43.52600167512409908051015
45.027201705129510008101035
50.028551750135510258151085
55.030151815140010558201135
60.031951880144010808451180
65.033701960148511008801225
70.035502050153011259251265
75.0N/A2155158011559751305
80.0N/A22801625119510201345
85.0N/A24351675124510601390
90.0N/A26101725130510951435
95.0N/A28001775137011251485
100.0N/A29951855144011551530

Thanks for the helps guys, is the number underneath the fuel pressure would that be the flow to scale he injectors at?
 

HolyCrapItsFast

Drinks beer!
Thanks for the helps guys, is the number underneath the fuel pressure would that be the flow to scale he injectors at?

No... The Slope is the flow rate of the the injector but is not necessarily your scaler. Offset is the Latency values and Fuel Pressure is just that. I highlighted the row you should be concerned about if you have a properly adjusted FPR.

What are you using to tune the car? OpenSource or Cobb AccessTuner Race?

Typically you apply a 27% change to the injector scaler when you are converting to E85. in OpenSource, you need to reduce the scaler by 27%. For AccessTuner Race you need to increase the scaler 27%.

So if you have 1000cc as the scaler in OpenSource for gasoline, you need to apply a multiplier of .73 to get a scaler of 730cc

In AccessTuner Race if you have a scaler of 3300 per say for gasoline, you apply a multiplier of 1.27 to get 4191.

That will get you pretty close to where you need to be but you will need to adjust that for the blend of fuel you are actually using. The proper procedure for converting to E85 is to have a perfect gasoline tune first. Then all it would take is a few adjustments here and there to convert. To find the actual scaler value, using the Gasoline tune and having a gasoline only in the tank, you need to record your fuel trim at idle for both A/F Corrected and A/F Learned and add them together to get the total trim. The car should be fully warm and you should drive around a little before you record a log. Then when you convert to E85, using the base E85 tune and emptying the tank of all gasoline and filling with e85, you simply adjust your total fuel trims at idle to match that of the gasoline tune by adjusting your scaler.

There are other adjustments to consider like your cranking and warm up tables and Tip-in. These will all need to be adjusted as well.

Seriously though this is not something you should be doing on your own because serious damage can occur if you forget just one thing or lack then knowledge and understanding of what effects what. Also you need to understand the relationship between e85 and timing and boost and the roll that each of them play.
 
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milehighsubie303

New member
No... The Slope is the flow rate of the the injector but is not necessarily your scaler. Offset is the Latency values and Fuel Pressure is just that. I highlighted the row you should be concerned about if you have a properly adjusted FPR.

What are you using to tune the car? OpenSource or Cobb AccessTuner Race?

Typically you apply a 27% change to the injector scaler when you are converting to E85. in OpenSource, you need to reduce the scaler by 27%. For AccessTuner Race you need to increase the scaler 27%.

So if you have 1000cc as the scaler in OpenSource for gasoline, you need to apply a multiplier of .73 to get a scaler of 730cc

In AccessTuner Race if you have a scaler of 3300 per say for gasoline, you apply a multiplier of 1.27 to get 4191.

That will get you pretty close to where you need to be but you will need to adjust that for the blend of fuel you are actually using. The proper procedure for converting to E85 is to have a perfect gasoline tune first. Then all it would take is a few adjustments here and there to convert. To find the actual scaler value, using the Gasoline tune and having a gasoline only in the tank, you need to record your fuel trim at idle for both A/F Corrected and A/F Learned and add them together to get the total trim. The car should be fully warm and you should drive around a little before you record a log. Then when you convert to E85, using the base E85 tune and emptying the tank of all gasoline and filling with e85, you simply adjust your total fuel trims at idle to match that of the gasoline tune by adjusting your scaler.

There are other adjustments to consider like your cranking and warm up tables and Tip-in. These will all need to be adjusted as well.

Seriously though this is not something you should be doing on your own because serious damage can occur if you forget just one thing or lack then knowledge and understanding of what effects what. Also you need to understand the relationship between e85 and timing and boost and the roll that each of them play.

Thanks for that info, I'm using open source. I'm not doing this on my own. My car has been tuned E85 before. It was running fine. Then It started to give me the code P0171, the tuner I had couldn't figure it out what it was. The code kept coming back.
Then that tuner just didn't want to work on my car said he didn't know how to get rid of the code, I did everything possible that was mechanical. (O2 sensor, maf sensor, checked fuel pump, and leaks)

I asked around found a guy who tunes subarus but hadn't really dealt with e85 fuel. He told me that my fuel trim was off and that was causing the code to come up. Right now have I have a decent tune( idle 14.7afr and at wot it's like 11.1-11.3. The code hasn't come up again but the fuel trims are still not perfect.

Also my car doesn't feel as powerful, that's the reason I was asking here to have some one with more experience with the fuel to give me, I guess A common way to scale injectors and latency that way I can get the best of the fuel.

Thanks a lots Holycrapitsfast.
 
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