I know I was just giving you a hard time .028 isn't that wide but with 2x15 nozzles you will find your weak point in your ignition system. Try .020" or so and leaning it out. I've had similar issues when adding meth injection. I went through plug gaps, plug wires, dwell time and coils. Everything helped but in the end I feel my stock coils were weak as I gained a lot of power swapping to better coils (truck coils with heat sink).

 

10.5 afr on 93? or E85?

on gas that's insanely rich. I would go to a 8plug & aim for 11.4-11.5 on gas

 

Its 93 and meth with truck coils. Il try the .020 gap.

 

I wonder if its rich because the spark might be blowing out. Does that make sense?

What's odd is that the no meth run at 10psi and low 11 afr looks the worst

 

Is there any chance at all the dyno graphs are messed up? The car runs so good if I had never dynod id have no suspicion some thing is wrong.

I didn't get a good look at the graphs while dynoing because i was paying by the hour and they were not showing rpm just mph. They just auto saved after each run and I kept on tuning.

Couple questions, does it matter which plug wire they go off for the dyno?

I was looking the verter on the dyno, am I supposed to have pmw on or off? I pressed both tcc solenoid and the pmw on.

 

Too rich. should be 11.2-11.8 A/F. Also print the graphs by MPH so you can see more.
I run 8's at .025. They are fine but I run LS3 coils.

Here is a graph that is MPH. Gives you a better look of whats going on.

 

10.5 AFR is costing you 30-50hp compared to 11.0 AFR..

Been there, done that..

 

I made a .050 change in pe table and it didn't make much differenece in afr on the dyno. Was still around 10.5. I'm going to check spring seat pressure tomorrow. I barrowed a moroso on car tester. If those are good I'm putting the stock rockers back on.

I wonder if its floating and causing it to be rich. So I'm not going to make tune changes again untill I eliminate the valve train. Ill also tighten the gap from .028 to .020 or so.

Man I wish I had a dyno in my back yard. At these levels its hard to make a high way pull to 6500 and actually tell if some thing has changed.

The car feels awesome the way it sits. Id have never know they may be an issue if i didn't put it on the dyno.

Il post up the graph in mph tomorrow to see if helps shed some light.

 

Interesting. At what point is there diminishing returns from leaning it out?

 

Lean is always going to make more power, up until the point of failure. I like mid 11's. 12.0 will make more power as well, but its on the way to hurting parts.

 

If you're running roller rockers there is a good chance it's valve float. Stock rockers will solve that. What heads, valves, rockers and cam lobes are you running? You said it happened on the first pull with no meth.

 

Stock ported 241 heads,stock size valve with aftermarket exhaust valves,1.7 roller yellaterra and xer lobes. I know the xer are not ideal.

On second look all those runs are on Meth. I need to see if they still have the no meth pull.

 

Aftermarket roller rockers have much more mass over the tip of the valve and are the main cause in almost all valve float problems. Stock rockers are the lightest setup you can run. I'm confident your issues will go away when you swap to the stock rockers. Good luck and keep us updated.

 

That was my point. Without meth, I hit roughly 11.5-11.8 afr in boost, and with the meth/water, it comes down to 10.8-11.2. To me it's not worth leaning it out back to the 11.5-11.8 range because the extra power isn't worth the chance that something could happen if the meth/water injection were to hiccup and send me upwards of 12.2-12.5 afr.

I was just curious of approximately how much power I was leaving on the table running 10.8-11.2 vs. say 11.8-12.0.