First dyno session ever the other day, just a couple back-to-back runs

Power was lower than I was expecting/hoping and I'm curious about what's going on with the top of the curve
The AFRs are from the shop's tail pipe sniffer, so not super accurate. When the guy let off the gas at the end of each pull, there was a puff of unburned fuel that came out the exhaust

Modifications:
Intake/exhaust/SMIC/PFC/HKS Twinpower
Boost and wg duty are set the same as the base map on stock sequential twins. 11.5psi I believe
I just tuned what I could on the highway (using a wideband and Chuck's notes), which obviously didn't show the power level bouncing at the end

Any ideas what would cause that?

 

you have a Datalogit? You did take logs while you were doing the pulls right? Can you post a chart of your boost (PIM) and wastegate duty (WG% and PC%) + the raw data

It would help to see the raw curve. That power curve is corrected and smoothed so that's going to affect how noisy it looks and the shape of that oscillation. Can you ask the shop to send you the dynojet run files? You can download the Dynojet WinPEP software and view them yourself, looking at different correction factors and chart scaling.

 

Is "volt 2" suppose to represent boost or AFR?

 

Volt 2 is supposed to be AFR from the tail pipe, but it doesn't look very accurate

I have a Datalogit and I was logging the runs, but the logs (and my tune) are on my laptop. I'll try to post them either tonight or tomorrow.
Unfortunately my LC-1 stopped working a couple days before the dyno session, so I wasn't able to log AFRs properly (the LC-1 only gives either 0 or 5V now, nothing in between :thanksobama: )

 

I have run dual innovate widebands, one in the tailpipe , one in the downpipe on our dyno, there was no difference in reading at all.

Really need better data to determine what the issue is. The AFR reading on that sheet starts out pig rich and then leans out.

 

Looks like it is related to the wastegate... but I have no idea how to adjust it away
The duty cycle setting isn't very intuitive imho
Knock never went over 30 fwiw
When my LC1 was working last week, it read boost as being ~11.5 AFR +/- 0.3

 

It might help if you post up the map.

 

Sorry, the file is here:
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The only change from that is the rev limit, which is now higher (as to not be reached)


PIM looked like this (from the unedited 5 minute datalog driving onto the dyno, then getting the pulls, then driving off)


Edit- I had to change the max value higher to show the rest of the values

 

Nothing glaring in the map, which means there is a problem with; a solenoid, check valve, vacuum line routing, turbo ( or all of the above) for the secondary turbo operation.

It is not a tuning/PFC issue

 

Thanks Banzai

 

The boost pattern and afr's look
Fine so based on that power curve(jagged lines)id say ht leads or plugs.ive had exactly the same break up on a 99 spec fd, it produced 270-then 320 after changing the leads.

 

The boost pattern and afr's look
Fine so based on that power curve(jagged lines)id say ht leads or plugs.ive had exactly the same break up on a 99 spec fd, it produced 270-then 320 after changing the leads.

 

Smoothing is set to 5, so it's much worse.
I normally set dyno to smoothing 3.
very abrupt lines are generally a sign of ignition while wavy lines are boost related.

You've got too much fuel at beginning of the pull.