Please critique my 3 bar tune.

[HRD]

This is my first attempt at a tuning a boosted engine. It is a budget build 5.3L with twin 67mm turbos, LS7 cam, 80 lb injectors, Holley hi-ram intake, and ported heads, 4L80E. I have the SD 3 bar OS. I know it is way rich especially in the upper MAP and the timing appears to be quite low by the log especially when it goes into boost. Otherwise, driveability seems pretty good. It's just a dog when in the positive MAP, probably due to the low timing and being overly rich.
I'm getting quite a bit of knock retard that I can't seem to figure out. It doesn't look like it should be knocking, all things considered. I know I need to work on the VE table.
TIA for help and feedback.
t7 2-20-14.hpl 54 Chevy PU 3bar t7.hpt

resized_DSCN8416.JPG

[gn2beatu]

Your AFR is 10.1 - that alone is enough to cause knocking (Rich Knock). Lean it out to 11.2 up to peak TQ, and to 11.5 by Peak HP. You also didnt mention what plugs your running, I hope its two stages colder to start. Set your rev limiter to 4000rpm and tune to that point and get your AFR right. You dont want this thing to spool and get away from you. Tune it 1000rpm at a time.

You didnt mention what fuel your running either. I wouldnt be starting at 16 degrees to start with twins on 93. You can always add timing, but it only takes one bad instance of Knock to destroy that 5.3 - Id start at 10 degrees if your on 93, especially with twins, as your moving allot more CFM in the upper RPMs.

On an 11:0 - 1 compression LS2 with a T88 I was only able to run 9 degrees of timing at peak torque but still made rediculous TQ in a 5200lb truck that did 0-60 in 3.0sec and ran 11.0 as it was AWD. This was on 93 octain as well with A2W setup and superchiller. But we have crappy reformulated gas in WI. This just goes to show with todays efficient combustion chambers and boost you dont need allot of timing. So start off slow and creep up on it. Once you find your KR point subtract two degrees from it for safety.

[HRD]

NGK TR6 plugs.
93 Octane pump gas

Thanks for your help.

I noticed that I was quickly reaching the 1.2g/cyl limit in the timing table so I have scaled the tune 50% hopefully the right way. I just cut the injector flow rate in half then halved the VE values and shifted the timing table up to account for the lower recorded airmass. I then did some driveability work in the lower RPM and MAP range. Here is the new tune and datalog from today. I noticed that I am still getting a lot of knock retard even at very low loads with decent A/F and what I believe to be reasonable timing.

t9 2-22-14.hpl t9.hpt

[HRD]

Here is my Config file. Gen III 3bar.cfg

[umrjmac]

While I don't know enough (yet) to know for certain, I believe that there may be a bit more to injector scaling than those 3 steps to do it right. Below is a link to a writeup that DSteck created and shared with Injector Dynamics to put on their website. I would read through it and see if anything resonates with you.

http://injectordynamics.com/articles...ation-scaling/

[RonSSnova]

I read the scaling info by DSteck from the ID site. If I got it right this is needed for the later ECM because the injector size has a hard limit,
Is the process the same for the Gen3 ECM?

I've tried to find good info for the need to scale based on hitting the 1.2gm/cyl limit in the spark tables, but haven't had much luck.
I see how easy it will be to hit this limit.

In this case, is scaling as was mentioned above necessary?

I'm just about to start my 5.3 turbo....

Ron

[Bill@HPTuners]

maf dtc's are wrong, needs to be fixed, first thing.

[HRD]

maf dtc's are wrong, needs to be fixed, first thing.

Could you please elaborate a little bit? I'm running pure speed density, no MAF.

[Bill@HPTuners]

http://www.hptuners.com/help/vcm_edi...to_user_sd.htm

[HRD]

I read the scaling info by DSteck from the ID site. If I got it right this is needed for the later ECM because the injector size has a hard limit,
Is the process the same for the Gen3 ECM?

I've tried to find good info for the need to scale based on hitting the 1.2gm/cyl limit in the spark tables, but haven't had much luck.
I see how easy it will be to hit this limit.

In this case, is scaling as was mentioned above necessary?

I'm just about to start my 5.3 turbo....

Ron

A lot of that write up has to do with the Gen IV stuff and MAF. Since I am gen III and SD only, a lot of that does not apply. I hit the 1.2g/cyl limit very easily. If you scale by 50% you need to move your timing table rows up to half the original g/cyl to start with.

[RonSSnova]

I have the 3 bar tune loaded. Glad I popped in here because I had the MAF DTC's set wrong too......
I need to understand more about this scaling for the Gen III.
Eventually I'd like to get to 20psi.

With help, I tuned my LS1 very nicely, but this turbo stuff is all new to me.
Car is a 69 Nova.

Ron

[Bill@HPTuners]

I have the 3 bar tune loaded. Glad I popped in here because I had the MAF DTC's set wrong too......
I need to understand more about this scaling for the Gen III.
Eventually I'd like to get to 20psi.

With help, I tuned my LS1 very nicely, but this turbo stuff is all new to me.
Car is a 69 Nova.

Ron

Yeah its a very common mistake.

When people ask me to critique their tunes the first thing I look up is how they have the maf setup ie first I check the maf fail frequency, if its stock I know the maf dtc's probably shouldn't be changed, if its been modified HIGHER they are probably trying to keep the maf active so the maf dtc's probably shouldn't be changed, if its been modified to 0 or 1hz then the maf dtc's should be changed so I always check to see how they've been changed, if any of the 3 was set to no error reported thats the first mistake and if theres one theres usually more so I stop looking there until that gets fixed because until thats fixed the pcm won't properly fall into SD mode.

[HRD]

I changed all three of the MAF DTC's to MIL on first error and unchecked the SES. The below tune is where I am at right now. It's set to run open loop. It just developed a large exhaust leak at the V-band of the downpipe coming out of the turbo that I believe is skewing the wideband O2's. I plan to fix it tomorrow and do some test driving. I've noticed that in all of my logs, I am getting a lot of knock retard that comes on about 3000 rpm regardless of the A/F or the timing. I didn't get a chance to drive it today, but I did crank it up and log some free revs. You can see at 42 seconds I roll into the throttle and at only 11% throttle and 3300rpm I'm getting 8deg of knock retard. This is free reving with no real load. I've disabled the burst knock. Interestingly at 1:50 when I stab the throttle I'm getting zero KR.
Any ideas of what is going on?

Any suggestions?

TIA.
t13 rev.hpl 54 Chevy PU 3bar 50% t13.hpt Gen III 3bar.cfg

[RonSSnova]

Possibly picking up mechanical noise?

[HRD]

Possibly picking up mechanical noise?

Probably. I've been all over the exhaust looking for rattles. It does have a leak, but no rattles.

[HRD]

Here is where I am now.
54 Chevy PU 3bar 50% t15.hpt t15.hpl t15 idle after drive.hpl
I still have a ton of false knock. I say its false because I'm getting a lot of knock at low loads, like at 2.52 in the first scan.
The big problem I am dealing with is the fueling is very inconsistent. I can drive it and the fueling looks decent, but slowly gets richer as I drive it. When I turn it off and restart it after only a couple of minutes it is very lean with no changes made. The first scan was driving it home from work. At 1.50 it's idling at about 14.7 AFR with 208F engine temp and 81F IAT. At 12.4 it is idling at about 13.6 AFTR with 210F engine and 64F IAT. I shut the engine off for about 2-3 minutes and restarted it (see t15 idle after drive) the AFR was 16.5 with 210F engine temp and 88F IAT.

[RonSSnova]

I saw KR at 1200 rpm, 8% TPS.......
Solid engine mounts?
Perhaps a bad knock sensor?
Have you tried reducing the sensitivity?
Have you tried a log with key on, engine off and just tapped on things with a whammer looking to see how sensitive things are?
Seems like pretty much all it does in knocks. Seems like you should solve this first.

[gn2beatu]

Go to at least a 7series NGK plug, a 6 is NA territory for high compression LS2. This will lower EGT's and help with KR some. If your goona really lean on it may even need to go colder down the road - with a single 88 on my LS2 I tried a 9 series but ended up on an 8 series plug. Two stages colder can lower EGT's by ~200-250degrees and helps KR more than you think.

I agree with the others, if your getting KR at 8% throttle, somethings not right. Im not a fan of reducing sensitivity much though. Did you over-tighten the KR sensor? I know some sensors can get hyper-sensitized this way.

[HRD]

I've been trying to nail down where I'm getting all the KR from, but haven't had much luck. No rattles, not solid motor mounts (although I do run solid motor mounts with the LS7 in my Camaro and have no issues with KR).
I desensitized the crap out of the sensors today and got zero KR with not even a hint of audible pinging and I'm pretty good at picking up on detonation by ear.
The thing that seemed to do the trick was to make the Knock sensor Tip in max TPS zero. My question is does zeroing this field completely keep the knock sensors from working or is it just for tip in as the heading suggests?

[Smoky68]

Have you made any more progress with this setup? I am in the process of trying to figure out how to scale my tune also, and would like to make sure that I avoid as many problems as I can.