Help, I either need new engine or new knowledge!

[mr.prick]

Don't be too concerned with the oil consumption, these motors are notorious for that
especially with the type of racing you are into.
Post up pics of the plugs.
IMO you are too lean for this type of racing, are you using race fuel?

[WeathermanShawn]

Overall, outside of a mechanical reason I agree with Mr. Prick that basically you are just too lean..With those hot ECT's/IAT's, cylinder pressures, racing, etc., just commanding ~12.5 AFR would usually cure most legitimate knock.

Ken, unless I have a few things backward..when in PE Mode your Commanded Fuel will be the richer of B3605 or B3618 when below 4000 Rpm's. Above 4000 Rpm's, B3618 dictates your Commanded Fuel. So, in PE Mode above 4000 Rpm's, if you are Commanding 12.7, but your wideband reads 13.0, your correction ultimately is applied directly to those corresponding MAF Frequencies found in Table B5001.

Granted a log off the track is not a true representation of your tuning challenge, but it might be a good 'control' run to compare.

[Mr. P.]

Sorry for butting in here,

If this car is using "about 1.5 quarts over 2 days and 100 laps".
Then the engine is in a serious state IMO...

I know that I'm a little late to this thread, but I have to agree completely this motor sounds like it is under duress. When your oil control issues are bad enough that you are being black-flagged it's a problem.

kwhiteside - what is your PCV system like? is it still stock? If so I would HIGHLY encourage you change that as follows:
1) install a catch-can in the line from the PCV valve to the intake manifold
2) install a vented oil-fill breather/cap (like this one http://www.summitracing.com/parts/CEI-103032/)
3) permanently remove the stock fresh-air PVC hose from the motor (the hose from the throttle-body to the valve cover) and cap off both bungs with 3/8" vacuum caps

Assuming you use a quality catch-can, this will *absoutely* prevent oiling into the intake via the PCV circuit on a naturally aspirated motor.

Following this, if you see visible oil consumption as you let off the throttle (high manifold vacuum) then you are pulling oil down the intake valve stem seals, they need to be replaced; this is common on high-mileage motors.

If you see visible oil consumption as the RPM goes up, that is ring-flutter.

Get your oil consumption under control, inhaling that crap makes the fuel octane nosedive not to mention on a competition car being a quart low will work the hell out of the oil still left in the pan plus you risk the oil pump gulping air in an extended high-G maneuver.

My 2-cents.

Mr. P.

[kwhiteside]

I know that I'm a little late to this thread, but I have to agree completely this motor sounds like it is under duress. When your oil control issues are bad enough that you are being black-flagged it's a problem.

kwhiteside - what is your PCV system like? is it still stock? If so I would HIGHLY encourage you change that as follows:
1) install a catch-can in the line from the PCV valve to the intake manifold
2) install a vented oil-fill breather/cap (like this one http://www.summitracing.com/parts/CEI-103032/)
3) permanently remove the stock fresh-air PVC hose from the motor (the hose from the throttle-body to the valve cover) and cap off both bungs with 3/8" vacuum caps

Assuming you use a quality catch-can, this will *absoutely* prevent oiling into the intake via the PCV circuit on a naturally aspirated motor.

Following this, if you see visible oil consumption as you let off the throttle (high manifold vacuum) then you are pulling oil down the intake valve stem seals, they need to be replaced; this is common on high-mileage motors.

If you see visible oil consumption as the RPM goes up, that is ring-flutter.

Get your oil consumption under control, inhaling that crap makes the fuel octane nosedive not to mention on a competition car being a quart low will work the hell out of the oil still left in the pan plus you risk the oil pump gulping air in an extended high-G maneuver.

My 2-cents.

Mr. P.

I'm running exactly what you describe already.

[kwhiteside]

So, in PE Mode above 4000 Rpm's, if you are Commanding 12.7, but your wideband reads 13.0, your correction ultimately is applied directly to those corresponding MAF Frequencies found in Table B5001.

1'st read, did not compute in my brain. So I'm .3 lean in PE mode, how does B5001MAF factor in?

Ok, so I did a log run a little while ago. New TR6 colder plugs gapped .040. I did NOT flash the new tune we've worked up. Wanted to see how the plugs and straight line stuff affected. Not good. See the attached log. Still lots of knock (again, same tune as at track still). Temps did get similar to track time as I drove the car around for 40 min before doing a log run. Unless any further suggestions, I suppose flashing the tune is next step.

[WeathermanShawn]

Ken, I usually plot my LTFT's and PE AFR Error using Table B5001. I use a MAP that shows what MAF Frequencies correlate to what AFR. I adjust it accordingly. But, there are many ways to do it.

However, I agree that is too much KR to operate your engine. Your AFR's looked fine, but basically my conclusion would be that either pre-ignition, detonation or a massive valve-train harmonics is contributing.

While the initial KR looks 'false' in that is so abrupt and massive, it does repeat and seems to occur around the same RPM range.

Does the car seem slower?

[joecar]

SS,

Hey bro, you're not butting in, your comments are welcome...

Yes, cyl #7 is known to run hotter, I was hoping to see a close up picture of #7 plug.

Good point about the rear steam vents being blocked off from the factory... if Ken doesn't like to grind off the structural stability ribs on the underside of the manifold, then he could instead install a front crossover steam pipe at the rear, and plumb it to the front using a T fitting and some heavy duty hose.

Hmmm... if he's RR'ing then an engine oil cooler may be a good idea in general.

Sorry for butting in here,

If this car is using "about 1.5 quarts over 2 days and 100 laps".
Then the engine is in a serious state IMO.

Also with the one plug being off-colour to the others, that you indicate as coming #7 seems to point to the problem.

Number 7 cylinder always runs hottest and is the most prone to detonation. Often failing or giving trouble in some way, usually by cracking or breaking the piston.

IMHO I'd have had the head pulled by now.

If what I think has happened has, then no amount of tuning will make a difference.

If that is the case, see below.

1. To avoid detonation problems in #7 fit the cylinder head steam pipes Part Number 12562169 "Pipe Bleeder" These were fitted to the early LS1 V8's only. The "fix" is a GMPP recommendation picked up from Katech when road racing.
If fitting this you will need to grind parts of the ribs on the underside of the LS6 intake to clear the pipe and allow the intake to fit.

2. Consider fitting forged pistons.

Apologies if I'm off-target and sounding like LS1Tech.

p.s. 207f or 97c for track work is pretty normal and re-doing fan speed settings or changing the stat won't make a bit of difference. A decent-sized stand-alone engine oil cooler positioned with a 1" airgap in front of the A-C condenser would though!

[kwhiteside]

I just couldn't help myself guys. I flashed the tune and went for another run. I'm very surprised what a difference it made. My new tune and recent log attached.

I could go a little richer on PE if necessary. Any other suggestions welcome. Of course the goal is to get my timing back up to 22 degrees area.

[kwhiteside]

Ken, I usually plot my LTFT's and PE AFR Error using Table B5001. I use a MAP that shows what MAF Frequencies correlate to what AFR. I adjust it accordingly. But, there are many ways to do it...WeathermanShawn..

Hey Shawn, walk me thru that map please. I have a LTFT Ben and LTFT Avg that I got from Mr. Prick already in my logs.

Data?
Column?
Row?
paste row values from b3618 I assume.

Thanks in advance.

[kwhiteside]

SS,

Hey bro, you're not butting in, your comments are welcome...

Yes, cyl #7 is known to run hotter, I was hoping to see a close up picture of #7 plug.

Good point about the rear steam vents being blocked off from the factory... if Ken doesn't like to grind off the structural stability ribs on the underside of the manifold, then he could instead install a front crossover steam pipe at the rear, and plumb it to the front using a T fitting and some heavy duty hose.

Hmmm... if he's RR'ing then an engine oil cooler may be a good idea in general.

I'm running a FAST92 Intake so I'm not sure if those ribs exist?

I'm running a Dewitts Rad/EOC combo unit. Now those plugs were in for many days of hotlanta tracking before I got the EOC. Oil temp was up to 295 before the EOC , since then it runs stable around 245 degrees in the scorching sun.