Well.......I drive a Camaro, a Tahoe, and a Saab.........

 

I guess they would stand out in a Chelsea parking lot.

You work in Warren? Milford? Mesa? Nurinburgring? All of the above?

I've been reading about your F-bod. You know that Bret's my son, right?

Jon

 

Update to Knock Issue:

I logged a brief WOT and cruise yesterday to baseline again before trying race gas mixed with toluene. I was still on Sunoco 94, and had ZERO knock the whole time! So, it looks like I have an intermittent issue causing real or false knock. That's the only time I've watched data and had no knock whatsoever, so the condition is not frequent. No sense running race mix until it returns. More driving today.

Despite the tuner's statement about max 20* at WOT, I saw 27* advance at WOT after a delay. Had a mild missfire around 6400 rpm, sort of felt like revlimiter. I'll send this one to Benji. I still haven't recieved my registration code for Tunercat.

[IMG][/IMG]

 

OldSS: Warren, sometimes MPG and Mesa, too. Haven't made it to the 'ring, yet.

Yes, I do know the relationship. As for you, Mr. Bauer - well, I guess if Bret learned a lot of what he knows from the old man, but isn't done pickin' your brain yet and still delivered the results I got (with LE of course).....let's just say I'm honored to be able to discuss things with you.

 

JP

Thanks, but now I'm learning from him. For years he has tried to "think like an engine" in order to determine what the engine wants. That has helped him with engine design. ECA software still relies on good input; no Artificial Intelligence at affordable prices yet. You can open up the box and ask it to look at a range of combinations you might not specifically persue. Sometimes there are surprises or Aha! moments.

Fortunately I get to design and make some bespoke CNC parts for him and act as consulting engineer. Most special parts he makes for himself on a Bridgeport and manual lathe. Without formal training as a machinist, but with some as an artist and economist, he 'sculpts' quite well in aluminum and does a good job running his business. Again, you might hear otherwise from those who really don't know.

He has also hooked up with some specialists who are extremely good in their field. He buys their labor or parts and incorporates them into his engines. Even our Generous Mother figured out you can't always do everything in house. Back in the day, not that much stuff came from outside, or at least not exclusively.

If you read much on this forum you may hear a different view from some folks. Mostly they like to hear themselves talk, but the jousting is a diversion for me, with a thinly-veiled ulterior motive. The particular thread has brought in quite a few new customers as well as probably turned away some. The net is positive.

Regards,

Jon

PS: Back when I was with an OEM division, one of my contemporaries was an very good young engineer with the initials JP. JPP actually because we all used 3 initials like the boss did.

 

good #'s.

Should make peak HP at 6100-6200 RPM and hang on until 6600-6700 RPM before losing more than 5 HP.

I would check rocker adjustment, rocker geometry, plug wires, plugs, opti and then focus on tuning.

Lloyd

 

Thanks, Lloyd. Nice to hear from you.

Yes, it made the power just as you described on my 1st run on the final tune, then developed the fall-off for the rest of the runs. Based on that, I think something broke or moved during the best run. So, I doubt it's rocker geometry, but I'll look again. Roller patterns on valves looked pretty good, I do have pics.

I'll try the rocker adjustment again, too. That is the part of my setup I was least confident about, but with engine running method (most recent adjustment, 1/4 turn) it seemed pretty straightforward. All above mentioned parts are new. Eventually I guess I might have to tear into the new opti to make sure all is still tight and clean inside. I'll save that joy for last.

 

I checked out both logs and all I can say is that you need to verify whether or not the knock is true or false. I really didn't see any patterns except that most of it is at lower rpm's and idle (as your histograms showed). If I had to put money on it, I'd say that it was false. You're not really putting much of a load on the car when it is pulling timing and half the time it doesn't pull any timing at all.

You're definitely only getting 27* of timing at WOT, which is just crazy. All in all, I'd still like to see the tune. I'll make some changes (more timing) and give it back, then have you log the car. We'll see if the knock retard changes at all. I still can't believe you put down over 400 at the wheels running 27* of timing at WOT.

 

I really appreciate you taking a look ond offering to help tune, thank you!!!

I tend to agree it is false, as well, after today's experience. I had the tank on E and the toluene fuel mix ready to go in tonite, made a baseline run, and at the end of my 3 mile run, did 2nd gear WOT to 6k. Pulled great. Funny thing is, after that WOT, the knock was GONE. That's the second time I have seen this happen. I drove for 15 or so more miles, through 3 ignition cycles and putting a little gas in, with knock mostly at zero, 1-3 degrees just a couple of times, otherwise zero or blank. There is normally a very brief flare to 10-12 degrees retard if I blip the throttle from idle, and that didn't happen again at all. So, it was improved somehow during the WOT. Still not showing knock, but I bet it will again tomorrow AM.

This seems like a very telling symptom, if only I could figure out what it means! I can only think of maybe 3 possible causes that could fit the circumstances:
1) Something mechnaically changes during the WOT, like a dirty lifter becoming unstuck of something.
2) Oil is slowly building up in the intake, and gets cleaned out during the WOT. Intake was wet inside, but smelled like gas, not oil. I'll look for an oil separator just in case that helps.
3) An electrical connection is getting vibrated enough to temporarily improve.

Does any of this sound plausible?

 

I think you may be stretching this a little bit. Those are all possiblities, but the chance that any of them are happening are extremely slim. If it's false, I think it just comes down to harmonics. The knock sensor is nothing but a piezoelectric microphone, picking up all the sounds the engine makes. If the knock module then determines that the sound is in the correct frequency range, it sees that as knock and will retard the timing. That's why knock retard can be a funny thing and why I completely disabled on my own car (not recommended unless you know what you're doing). Now, on the other hand, if the knock is true, then the explanation for not seeing any knock at WOT is that you're only running 27* of advance.

 

Well, it looks like the knock is false. Good call, Benji. I appreciate you sticking with this thread. I hope it will be an educational example of debugging knock on a new motor, when it's all done.

Tonite I ran two gallons of 50/50 toluene/93 added to a tank on E, and knock didn't change as far as I can tell. Should have been around 98 octane if there was one gallon left in the tank. Also, I repeated the WOT event a couple of times, and the knock didn't go away this time. So, that's not repeatable, although the only times I've seen no knock retard are after WOTs. Coincidence maybe.

I also noticed the knock counts increment very rapidly while the off-idle blip is causing 8-12 degrees of knock retard. Thousands of knock counts in less than a second. Could that mean this might be calculated knock retard, as opposed to knock-sensor-based retard? Does anybody even really know what knock counts are used for, and how? Or if the sensor can increment them?

Today I saw my first codes, open ESC and shorted ESC. I've been checking codes each drive, so I know it happened this AM and did not repeat after that. I found one pin on the ICM that is open a little too wide from probing it and won't bend back perfectly, so I will replace the pigtail. And test the ICM wires. Opti connector looks good, but I'll try to test those wires, too. I understand that these codes can be an OPTI symptom, but I'll try wiring first. Remember, it's a brand new OPTI. It's a Summit 850060.

I think I need to get rid of this false knock before tuning the spark.

 

maybe try a new knock sensor? I know when i ran open longtubes for a month, that caused my knock sensor to go HAYWIRE. a simple sensor swap and all was well again

I'm impressed with your numbers (so far get that thing on a dynojet w/ some tuning changes!!) and hope you pinpoint the false knock issue and can start to have worry free hours of driving that beast :thumbup:

 

Hybrid,

I guess I will throw a new one of those at it, considering your fix. Thanks for the tip.

 

My car threw the DTC 43 ESC Failure, which is why I no longer use my knock sensor. I checked the wiring (thanks Shoebox), the knock sensor (which I replaced), and still couldn't get it to not throw that code. Just to let you know, if the PCM is showing/storing that code, then it defaults and pulls the maximum allowed (max value in the knock retard tables) timing for knock retard. It's a safety thing. Get this issue resolved and get back with us. I'll still look at the tune and get you something ready for when you figure out the problem.

 

UPDATE:

Milan event was rained out, so no times yet.

Knock is mostly gone. Bench tested sensor for a/c volts while tapping it, and resistance check. Both ok. Did not replace. Moved Knock Sensor wire to cross perpendicular to +wire for the starter, to minimize EMI sensitivity between the two (less interference, if wires are parallel they are get more). If I get more retard, I'll try the old LT1 module again.

Relashed valves again to be sure they were right. They were - I marked the nuts, and the most any of them changed was less than 1/16 turn.

BLMs seem to still be improving, even though it's been a few hundred miles since I fixed the AIR hose leak. Cell 7 was hanging around 109, now up to 115ish. How long can the BLMs take to stabilize?