A lot of you guys have figured out something that I haven't I reckon. I cannot seem to get anymore power out of this combo without running into knock reduced timing. The dyno says we have about 40ftlbs of torque improvement but only about 5-10 hp. Trying for anymore than this we get knock or charge temps over 125*. I plan to upgrade the intercooler here in a few weeks but what else have you guys done to increase knock resistance?
Knock.hpl
Can't look at the log right now, but an intercooler really goes a long way.
I expected so. The only issue is, during the summer it will be 100* already. If I cant deal with 125* charge temps I guess Ill be slow until winter lol. Race Gas?
E30 or E85 is always an option, if you don't mind dropping the coin on a bigger HPFP, which you'll probably have to do anyway.
Like me, you're probably at the edge of the stock fuel system anyway. lol
e30 ftw.Originally Posted by seishuku
Or water-meth.
Those intake charge temps really aren't very high. It looks like what's happening is your combustion chamber is heating and causing pre-ignition. The cure for that is even more enrichment up top, like 0.8 lambda. Problem is your fuel isn't stable in the first place. RPM increases, EQ commanded rises, then knock retard occurs. I can't tell what's making the fuel jump around, but it looks like it's due to throttle movement.
Have you tried Pedal Pos WOT Start/End to 389/500? Disable popcorn air limit source?
Also maybe try a stage colder plug.
Last edited by SiriusC1024; 11-15-2022 at 09:57 AM.
I'm no where near maxing out the turbo I hope. Barley asking anymore than stock for now until I'm sure that its safe to push higher. I made a previous post asking about the commanded enrichment swinging around
but I don't think we gat anywhere. I see that the reported fueling stays at .82 regardless of the swing but In not sure why or what that is about. I have not tried either the wot pedal start/end or the popcorn airlimit. What do these do exactly and why do we want to use them? Do you see them being beneficial to my fueling issue or the throttle issue? Appreciate the input guys!
Oh and ethanol is not an option around here unless I drum it in for myself. What about race gas or boosters? I know that ethanol period increases power out put so it would be the ideal fuel, I just dont have access.
As far as I can determine, Throttle Pos Start/End makes the throttle go WOT and override driver demand throttle calculations.
Ok, looked at the log... Yeah, you're no where near maxing out the turbo and honestly the charge air temps really aren't that bad, I think I've had it over 150f before on my stock intercooler and made more power.
Do yourself a favor though, log individual cylinder knock, knock correction is just a global variable that the ECU uses to track overall timing correction... Not really an indication of how much knock is actually occurring.
But your air load is basically still stock, desired load is always maxing out at 2.2.
In Engine->Air flow->Speed density->Maximum load, try increasing anything that says 2.2 to 2.8 and see where things go (you'll have to go through all the mapped points tables).
Might need to increase desired air mass max load as well (Engine->Airflow->General, max load)
After that, LSPI HI table will be limiting things.
What's your detailed explanation for changing from 2.0 to 2.8 in SD? How did you arrive at that number?
No detailed explanation, max load for speed density, as far as I know that will limit air load (desired or actual)... Though I've not witnessed it myself, I've always raised it before it would be a problem.
Granted LSPI HI table is 2.29 and might have been already riding that, but it'll be another hurdle anyway. Might as well get it out of the way.
But desired air load was exactly 2.2 in the log, could be a rounding error and it was actually 2.29 (LSPI limit), in which case I'm wrong about SD max load.
Just wanted to reiterate what @SirciusC1024 said. I use water-meth injection and I will regularly see my IAT2 temps go from 90*+ to 50* during a WOT pull.
By going going WOT you mean that it will no longer close due to over shooting Desired TIP and Desired Load? I don't produce enough tq yet to reach the requested driver demand tq.
Logging individual cylinder knock and spark correction, Ok I'll see what that tells me. Also I'm not running up the power until this knock situation is under control. No need too if all it is going to do is push me into negative timing.
Keep in mind that these engines don't run a lot of advance under load, I think the highest I usually see is 4 to 6 degrees BTDC at full load.
I usually see knock of about -2 on cylinders 3 and 4, but it's always bouncing between adding and removing timing, that's just how the system works.
Throttle Angle Source is TQ Red. < Driver Demand. There is a limiter happening, but can't tell what that may be. Probably something to do with torque vs air load. Could be cylinder pressure, which popped up briefly in Spark Source right before the timing drops in the first pull. The idea is that the throttle angle limit will be ignored by commanding WOT. Try it and see.
Last edited by SiriusC1024; 11-16-2022 at 02:59 PM.
4-6* at what load or pressure level? Im at that right now at 2.2 or 20lbs of boost. I just don't know how much can be pulled before It becomes an issue.
I'm currently using the LSPI Table to cap me at 2.20 Load for now until I get more comfortable. I wonder if triggering the throttle blade to ignore the spikes and over run would trigger the wastegate to jump into action faster
Untitled-1.png
Log file here:
https://forum.hptuners.com/attachmen...9&d=1668289385
This is on completely stock engine, the only thing I currently have is a single 3" catback and aftermarket blow-off valve.
Last edited by Seishuku; 11-16-2022 at 05:14 PM.
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