duty cycle - can it be converted to e85 from 91 reading?

[tuned2boost]

hi guys.
98 ws6 5.3 t76 turbo 13psi 60# injectors 91oct

my current set up is limited to 550trq due to clutch and would like to hit that
I think my 60# injectors can make it up to that point and very well be max out or close to it.

but im unsure of my current power at the moment. and not sure how far i am.
(in comparison i raced a stock 07 gt500 and walked away slowly(3/3) so i think im around 450rwhp ish?)

at the current pressure im at 80% IDC
is the conversion straight forward? like multiple by 1.3 since it requires 30% more fuel?
in which case just switching would put me at 104% (would not be of any use.)

or not?


what im looking to gain is take advantage of e85 cooling and knock deterant.
aswell as raised the boost more and get to 550whp.
that and e85 doesnt leave me smelling like gas when i drive the car.

im thinking around 17-18psi will get me there?


and yes i know 80# would be a better fit but considering that my clutch is a limiting factor im thinking 80# would be an upgrade later when i change out the clutch and build the engine(its 100% stock 5.3)
if the 60# deka can handle it im ok with it near max or?

[gofastwclass]

If you are at 80% duty cycle, you are at the maximum safe duty cycle for the current injectors. Some may disagree, but that has been my experience from what I've seen which has been backed up by what I have read in books and gleaned from experienced tuners.

If you move to e85 you will need larger injectors and potentially a larger (higher volume) fuel pump. If you are currently running out of pump (pressure or volume) you will appear to run a higher duty cycle because the PCM holds the injectors open longer to compensate for the lack of flow. If you are going e85, you need a solid fuel delivery system due to the increased volume of fuel required.

I say this because I thought you only needed around 45lb injectors for 550 while 60lb injectors are good for 700 - 750 on gasoline. I could be incorrect since this information was from an internet based injector calculator I use periodically as a baseline before I purchase parts.

In short, I would check your fuel pressure at WOT and see what the drop is, the number may surprise you.

[tuned2boost]

If you are at 80% duty cycle, you are at the maximum safe duty cycle for the current injectors. Some may disagree, but that has been my experience from what I've seen which has been backed up by what I have read in books and gleaned from experienced tuners.

If you move to e85 you will need larger injectors and potentially a larger (higher volume) fuel pump. If you are currently running out of pump (pressure or volume) you will appear to run a higher duty cycle because the PCM holds the injectors open longer to compensate for the lack of flow. If you are going e85, you need a solid fuel delivery system due to the increased volume of fuel required.

I say this because I thought you only needed around 45lb injectors for 550 while 60lb injectors are good for 700 - 750 on gasoline. I could be incorrect since this information was from an internet based injector calculator I use periodically as a baseline before I purchase parts.

In short, I would check your fuel pressure at WOT and see what the drop is, the number may surprise you.

fuel pump is 320lph aem-e85 friendly.
yes ideally 80% but i dont mind going up higher. however i wouldnt want to pass 100% just wanted to see if there is room with e85

[tuned2boost]

fuel pump is 320lph aem-e85 friendly.
yes ideally 80% but i dont mind going up higher. however i wouldnt want to pass 100% just wanted to see if there is room with e85

for future reference. making the switch does infact multiply current IDC by 1.3

I made the switch and was at about 105%
80# are in order....