A long build up leading to a short question
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A long build up leading to a short question
As I had posted in an earlier post, I am going to attempt to start fresh with a stock bin. The first order of business will be to compensate for those big Delphi injectors on the Holley TBI. I checked the color-codes on the old stock TBI, and after a bit of cleaning, a dab of orange and a dab of black paint appeared. So, according to an answer to one of my earlier posts (
) I know that I had 55 lb/hr injectors.
I called Holley tech support today and surprisingly; I connected with a tech that knows this TBI. He told me that the Delphi’s actually have different ratings based on fuel PSI. It ranges for 60 lb/hr @ 12psi to 85 lb/hr @ 21psi. Well a little math shows a 2.7 lb/hr increase per every 1-psi increase between 12 and 21psi.
A while ago I hooked up a fuel pressure gage and got a reading of 14psi, so applying a little more math, I came up with approximately 65lb/hr at 14psi. Ok, so good so far. I calculated the difference in fuel flow between the stockers and the Delphi’s at 15.4%. A pretty significant increase.
Obviously, I need to reduce the fuel flow through the Delphi’s by the said 15.4% to have the equivalent fuel flow of the stock injectors so that I will have a baseline close enough to stock so that the stock AKAJ bin will be happy. AND so that I will have a known baseline to work from.
So there’s the long build up, now here’s the short question: After looking through TunerPro, the closest thing that I can find to an injector constant is the “BPW const for EGR off. This has a value of 135.00, is the value that I need to reduce by 15.4% to lean out the entire fuel map?
If not, can I go through the VE tables and lower each value by the same percentage?
As always, TIA!
) I know that I had 55 lb/hr injectors.I called Holley tech support today and surprisingly; I connected with a tech that knows this TBI. He told me that the Delphi’s actually have different ratings based on fuel PSI. It ranges for 60 lb/hr @ 12psi to 85 lb/hr @ 21psi. Well a little math shows a 2.7 lb/hr increase per every 1-psi increase between 12 and 21psi.
A while ago I hooked up a fuel pressure gage and got a reading of 14psi, so applying a little more math, I came up with approximately 65lb/hr at 14psi. Ok, so good so far. I calculated the difference in fuel flow between the stockers and the Delphi’s at 15.4%. A pretty significant increase.
Obviously, I need to reduce the fuel flow through the Delphi’s by the said 15.4% to have the equivalent fuel flow of the stock injectors so that I will have a baseline close enough to stock so that the stock AKAJ bin will be happy. AND so that I will have a known baseline to work from.
So there’s the long build up, now here’s the short question: After looking through TunerPro, the closest thing that I can find to an injector constant is the “BPW const for EGR off. This has a value of 135.00, is the value that I need to reduce by 15.4% to lean out the entire fuel map?
If not, can I go through the VE tables and lower each value by the same percentage?
As always, TIA!
i dont have tunerpro in front of me but i will assume in "constants" is the BPW or BPC. if you are running 55 lbs at 14lbs FP that BPW needs to be set to the correct number. i believe Monte just posted the formula in TBI sticky.
assuming you are running CL the NB02 will set the A/F around 14.7/1 (assuming not at its limits) and you will have no control over that. further assuming the VE tables are optimized it should allow the PE to hit your commanded A/F. did for me at least on WB(12.1-12.3/1 commanded to 12.5/1). if you change nothing in the .bin i would expect the OL(choke/cold start idle/AE). to be rich as you stated by 15%.
have you run ALDL yet?
assuming you are running CL the NB02 will set the A/F around 14.7/1 (assuming not at its limits) and you will have no control over that. further assuming the VE tables are optimized it should allow the PE to hit your commanded A/F. did for me at least on WB(12.1-12.3/1 commanded to 12.5/1). if you change nothing in the .bin i would expect the OL(choke/cold start idle/AE). to be rich as you stated by 15%.
have you run ALDL yet?
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