No plans right now for racefuel testing, but I may move to that as a last resort.

Dwell is currently set to stock (stock LS3 settings) and Granatelli states a change is not needed (but to play around with it if I desire)

SPW's are Taylor 10.4mm

I used grease on the sp side (not the coil side).

 

1000cc inj, ZL1 pump, ADM FPCM... max duty cycle of 64-65%
I am using #10 and #5 Meth nozzles from alky control with 100% meth

 

I didnt expect to see blowout on the plugs, just the dyno graph. I figured I would post pics of my plugs too in case they are running too hot (I wanted opinions too on that).

I run straight meth with Julio's settings from the factory on the pump and controller.

 

For some reason I am not getting notifications of replies.

 

I like pantera's suggestion to switch to race fuel for a next test, thus eliminating the meth as a source of problem.
If you still have an issue i agree to gap the plugs down to see if it clears up. i wouldnt leave them gapped down; just check if it helps then fix the real problem.

 

100% meth shouldn't cause an ignition problem.

 

The meth was fine before. I am hesitant to eliminate the meth as a first option as it will require significant retuning as meth plays a role in my fueling. I will do it if playing with the plugs doesn't show anything. Looked at my logs and took screen shots of various rpms during the pull (including 5700rpm just before I lifted). My fueling was constant and right around my commanded (at 5700rpm A/F was 10.84 and commanded 11.0). At 5400rpm A/f was 10.80 and commanded was 11.04. I mention these rpms as it's right where the trouble spots are. Unfortunately I can't upload pics from my phone, so I'll have to wait until tomorrow.

 

That's a helluva lot of fuel. And are you still using a flip phone??

 

lol. I know, but I am still on the stock bottom I have actually read that high 10's is a good spot to be with meth and gas. If just gas, I'd shift it to 11.5 or so.

 

Easy enough to try new plugs with tighter gaps before going nuts. Make sure coils have a good solid ground. I recommend an extra ground wire to the head to the chassis.

Always the possibility of a weak coil but doubtful being that they are new.

 

Datalogs attached to post #1 of the run on the dyno. You can see the MAF is getting wacky in the spot where it goes weird on the dyno (5000+rpm).

 

1. Whatever your fuel pressure input is attached to, I am sure you notice it drops during the run and spikes (looks like to some 80psi~) when you lift.

2. the wideband in the downpipe does not appear to reflect the a/f ratio on the dyno- a sign that it may be getting too hot or have other issues. It may not be reliable.

3. the clutch slippage or whatever that is obscures the dyno graph makes it difficult to tell what the real problem is related to. for example the maf reading may become obfuscated if engine rpm is bouncing around on a slipping clutch, which affects turbine speed, which affects airflow.

i would say the first thing to do is fix the drivetrain issue and then reduce boost pressure and gradually raise it until an issue is encountered. you obviously cannot get any kind of good performance if the clutch is slipping so I really dont know what engine related changes are going to do for you at this point.

 

Thanks for looking at it. Yes I noticed the fuel pressure spike. I havent dug into yet.

I would trust my WB reading before the dyno WB for multiple reasons:

1. Their first WB sensor was junk (kept registering less than 10.0A/F, and I requested that they swap it out for another one. The second WB is shown on the dyno graph (used sensor, not new). The A/F jived with my sensor, just scaled up since their WB was at my tail pipe (usually reads 0.5-0.75 leaner at the tailpipe then up near the engine).

2. My WB is ~40" from the turbo (but up stream from my cutouts). The WB at the tailpipe is downstream from the cutouts and was probably seeing some false signal.

3. Clutch slippage is the issue for sure that needs to get resolved. I have seen clutch slippage on my logs and it shows a spike in mph/rpm before it settles back down. It definitely is causing havoc on things. The reason I posted this thread is because I have seen other graphs (mainly on import sites) that had loop d loops and it was attributed to spark blowout.

The only thing I can surmise is that it isnt clutch related as it almost feels like I am hitting the rev limiter (physical and audible stumble) during the rpms in question. When the clutch slipped it free rev'd fast/smooth. I am hypothesizing that I have two issues (clutch slip being one).

 

What is worrisome to me is that if people did not look at my dyno graph, and just looked at my log, it would be hard to guess that I didnt get a clean pull (i.e. hard to tell there was a problem other than some MAF variability). This concerns me because without the dyno, I may not be able to notice any changes (i.e. know if I fixed an issue) when logging a 2nd gear pull on the street. 2nd gear pulls happen so quick that i did not notice a top end stutter before the dyno.

 

Oh, the log is from the exact dyno session with the loops? The RPM does not shoot up in the log, i.e. there is no evidence of clutch slip. Maybe if you changed the X-axis of the dyno from RPM to SPEED you might see something to help diagnose.

I looked back and noted the injector duty is dropping from 4900-5000rpm, and so is fuel pressure. Taken together it would stand to reason you are going leaner. The wideband isn't showing this, so either the injectors are enormous (and obscuring the a/f) or the wideband is wrong.

In any case, the series I would take is still:
0. fix/investigate drivetrain and fuel pressure issues.
0.5 verify the injector duty dropped as it shows in the graph, and find out why, it should not drop during a pull. Maybe try speed density. Where is the maf? It should be before the compressor in my opinion.

1. re-dyno with low boost, gradually raise boost until an issue occurs.
2. when the issue occurs, rule out spark plug blowout by gapping down
3. re-dyno with all equal to rule out plug blow out

 

Thanks again for analyzing and trying to advise, its appreciated. Yes it is a portion of the log from the dyno pull.

At 4850rpm, inj dc is 44.2%
At 5036rpm, the inj dc is 46.9%
At 5433rpm, the inj dc is 56.9%
At 5702rpm, the inj dc is 65%

So inj dc does not drop off. You can see it as the green line in the 4th set of graphs, it steadily climbs. Fuel pressure does start to decrease (as the pump s getting near its limits, but I compensate for the pump with large 1000cc injectors and meth.

The WB appears to be good. The A/F is 11.25 @5000rpm (where it jumped lean on the dyno graph), so my WB did show a bump of .5 afr leaner like the dyno shows, then it riches up again like the dyno shows.

MAF is about 12" from TB, and upstream from meth nozzles by about 6 inches. This was the same as last time.

I think I fixed the low boost issue (I couldn't make below 13psi on the dyno where as I could run 8psi before). Unfortunately, due to the layout of the kit, I can't change plugs on the dyno as some of the hot side needs to be removed to get access.

The variables from last time on the dyno (the smooth curves on the dyno chart) are the following:

Head gaskets
Plugs gapped down from .032 to 0.028
Turbo screen instead of air filter
Cutouts 30" downstream from WB (the car did have these high rpm issues with the cutouts closed as well on the dyno that day)
Wastegate dumped to atmosphere
Clutch/driveshaft replaced

The one thing I noticed immediately was a p0300 random misfire code after first start up this spring after all the work was done. I logged misfires and they were bouncing around from cylinder to cylinder with no pattern to it. I desensitized the misfire settings and p0300 went away. I did this after researching and finding threads about lighter clutch/flywheel setups could trigger this misfire code. I am thinking I will put the misfire settings back to stock and log misfires again and see if I can gap down the plugs on the pass side (easier to get to) and see if the misfires are contained to the drivers side only.

 

Is it an HPtuners log? You can upload it , just zip it so reduced file size to very tiny. I can look at it on my scanner and see more clearly. I realize the dc is gradually increasing, what I am looking for is a small adjustment down before it goes back up, like from 44.2 to 43.7%, proof that it drops at any point, however briefly.

 

Log and exported excel file uploaded to first post! The excel file really shows some nice things. You can see weird fluctuations in the rpm during the pull. Thanks.

 

MAF is pretty jumpy. How is the placement? If too close to any bends it results in that.

 

About 6-8 inches from the bend closest to the TB.