ZL1 Pulley ... No gain ...???

[ChargerFan1]

I've tuned a ZL1 on ID850/E55 a few month ago.
Then add a 2.55 pulley, E74.

Timing is 23 to 26, Lamba 0.75 steady 12PSI boost ...

results ... WTF ??? no gain ? How it is possible? I'm scratching my head for hours ...



PULLEYLOG2.hpl

Timing, AFR are okay ... but no improvement with the Pulley ....

[ChargerFan1]

TunedE85.hpt

[GHuggins]

What's it do with about 4 to 5 degrees pulled out?

[gmtech16450yz]

Couple things I see...

You're commanding .74 then go to .71 at 5k rpm. That's a little rich and you generally want to lean out the top end, not richen it up more. The weird thing is that your PLX is reading a super steady 12.80? It's weird that it's that steady and it's also weird that it's reading 12.80 when you're commanding 10.5 to 10.9. I'b betting that your mixtures aren't what you think they are. Log your narrowbands so we can see what they are reading. Also, can you get an external (tailpipe) wideband reading when you're at that dyno?

You also want ignition timing to climb with rpm, not drop or even stay steady. Take a few degrees out of the middle and let the timing climb to a peak of 24-26 degrees.

IN GENERAL, high torque numbers with low hp numbers means the engine is having a hard time making power. In other words, it's not "efficient" (used as a relative term). Those numbers are telling me that engine isn't happy with how it's running and it CAN be better.

[ChargerFan1]

This was a quick tune because I'm installing headers and wanted to do a before/after headers.
So yes I have rapped PE table, the PLX is not installed, I've used the WB dyno (not hooked to hptuners), 0.75 lambda flat, so don't focus an afr/lambda

I've used the scanner and begin with -5 degree overall, I was 20 hp less on the whole table (minus the bump at the beginning).
so yes, I was got too much timing from 2000-3000 ... but the hp level didn't grow up in the whole range.

I'm very surprised how the curbs looked very similar

[GrannySShifting]

Looks like it started making alot more boost... and then belt slip?

[gmtech16450yz]

Looks like it started making alot more boost... and then belt slip?

The log that he posted showed no belt slip, the boost level looked fine. The log didn't jive with the dyno chart with the hump though, maybe that one was a different log? That doesn't even make sense because the fuel cutoff in the attached log was at 6500, which does jive with the dyno trace with the hump. I think it's a trick!

[10_SS]

How much more MAP KPA or Airflow have you gained with new pulley? Can you post both logs, before pulley and after pulley?

Regarding the additional power down low, looks like something was working right for a minute...

And, could you have Rich After Flash occuring? THis shows -18% fuel being pulled at idle before entering PE, prob unrelated.

[ChargerFan1]

Logs are in the first post.
12 psi steady.
9 before. (i haven t saved the logs).

I think there is too much timing in the wot transition. I will try different combos on the dyno with the arh headers.

Are the stock headers a restriction at this power level?

[10_SS]

Logs are in the first post.
12 psi steady.
9 before. (i haven t saved the logs).

I think there is too much timing in the wot transition. I will try different combos on the dyno with the arh headers.

Are the stock headers a restriction at this power level?

I have your first log, was hoping to compare boost, AIRFLOW, timing, injector, etc to the before pulley log. You should also be able to see if you have a header restriction from comparing logs, but that should not net 0hp difference.

Actually just noticed you dont have Injector Pulse or AFR connected or logged, so it would be very helpful to add those, then go make a WOT run, then could you put the stock pulley back on and make another WOT run? Post both of those files.

[10_SS]

I have your first log, was hoping to compare boost, AIRFLOW, timing, injector, etc to the before pulley log. You should also be able to see if you have a header restriction from comparing logs, but that should not net 0hp difference.

If you have a massive restriction in our exhause then it's possible you could have more BOost pressure but no more airflow... which I highly doubt happened.

[ChargerFan1]

yes unfortunately it was a quick tune to compare before/after headers.

Injectors IDC were 75% before Pulley and 85% after (wanted to see if the pump pump would be enough).