LS9 Injector Limit on E85

[02pewterz28]

Hey guys have a bolt on C6 Z, it has a ported msd manifold headers etc basically a FBO car. I was going to use ID850's on the car but plans changed and I ended up selling the ID's to a buddy who needed them on his blower car top get it tuned. I was thinking they might be over kill for me anyway, my question is... I can get a set of ls9 injectors from dstek on here for a good deal but I'm wondering if that would be enough fuel?

From what I've seen with the internet calcs ~530whp on E85 says its going to need 65lb injectors to be at 90% DC but I have heard of people running this setup without issue. Does anyone have expereince on what an ls9 injector will max out at on a bolt on ls7 with pure e85 and what duty cycle i'd be looking at or be safe going to?

[DSteck]

Upper 500s NA is where they start to run out on ethanol.

[GHuggins]

For what it's worth and I honestly have no idea how it's even possible - I typically see LSA / LS9 injectors max at 130% DC even though it shouldn't be mathematically or physically possible... I don't like seeing anything above 80%, but like I said - for whatever reason they'll go into the low 100's on DC and still control fueling even with the same pump output...

[02pewterz28]

Upper 500s NA is where they start to run out on ethanol.

That's with 58psi as opposed to what the zr/ZL1 run which is like 87 at full boost?

[02pewterz28]

For what it's worth and I honestly have no idea how it's even possible - I typically see LSA / LS9 injectors max at 130% DC even though it shouldn't be mathematically or physically possible... I don't like seeing anything above 80%, but like I said - for whatever reason they'll go into the low 100's on DC and still control fueling even with the same pump output...

That's insane...so safe to say I'd be fine at say 540whp with e85 just don't want to burn up the coil in the injector or run out of fuel

[DSteck]

That's with 58psi as opposed to what the zr/ZL1 run which is like 87 at full boost?

Correct.

That's insane...so safe to say I'd be fine at say 540whp with e85 just don't want to burn up the coil in the injector or run out of fuel

The whole "burn up the coil" thing is hooplah. There's a hard coded 0.8ms reset time on each cycle.

[07GTS]

Mowton put a injector calculator in this thread it may help

http://www.hptuners.com/forum/showth...-injector-size

[02pewterz28]

Correct.


The whole "burn up the coil" thing is hooplah. There's a hard coded 0.8ms reset time on each cycle.

Thanks dave so you think ~530whp on pump would translate to being ok for ls9 injectors with e85? if so could you shoot me a pm with a price on a set of 8?

[dreksnot]

For what it's worth and I honestly have no idea how it's even possible - I typically see LSA / LS9 injectors max at 130% DC even though it shouldn't be mathematically or physically possible... I don't like seeing anything above 80%, but like I said - for whatever reason they'll go into the low 100's on DC and still control fueling even with the same pump output...

Not trying to sidetrack the conversion, but how is this possible but still fueling is happy, somewhat?

[02pewterz28]

Not trying to sidetrack the conversion, but how is this possible but still fueling is happy, somewhat?

Nice what was the setup on that scan log?

[GHuggins]

I honestly believe that there's something up or unique to the injector data for those injectors. Out of all the ls motors stock injectors, the LSA ones are the only ones that I've seen do this which is why I believe something throws off the duty cycle calculation for them. The cars I've pushed them to the limits on before swapping them out did have variable output pumps to boost pressure slightly. Perhaps that plays into as well, but at exactly 127 to 130 percent duty cycle is where I would start seeing fueling not respond to changes in the air models. Like I said though - I don't like to see anything above 80 percent duty cycle.

[GHuggins]

I just double checked - the two customers vehicles that I did that wanted to see if it was possible to keep the lsa injectors on - I've already deleted those logs with the lsa injectors - all I have are the last logs with the ID injectors - would have like to have posted them for you, but can't as I don't have them any more...

[dreksnot]

Nice what was the setup on that scan log?

Personal vehicle, as in the sig:
LS3 on E85 (was 70% in the log) ID-1000s on LPE Twin-Fuel KB BAP

I really thought I was riding the edge with the ID-1000's IDC over 80% on E85, then 90%, next was 100% but I figured I'd try pushing it until the fuel started getting lean then back off. I didn't hit that wall, but I did decide to stop before having an impromptu garage sale in the left lane of the quarter. There does have to be something screwy with the IDC calculations in HPTuners...