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Old 07-03-2015, 02:04 PM   #1
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Default First run on a dyno - how's my strategy look?

Hi all

So I'm heading to the dyno next week with my newly VVT'd NA and would like some feedback on my starting points, and my planned strategy. My setup is a 52k mile 02 engine in my 95, with an MS3 Basic (Rev built), square top manifold, RB header, borla catback, no cat, and the 3d printed ABS cold air intake from alec moody.

First, my starting points. I haven't touched the VVT or injector timing values from Reverent's baseline tune. Found the AFR target table on here and have autotuned VE on the street - the car seems to run really well. I have also enabled time-based and enhanced acceleration enrichment. I've messed with the time-based on the street but left the eae at the default values - the car feels good at steady state and under transient throttle, but I also have ego enabled

I'll be using a load-bearing Mustang dyno, with det cans, and I have up to 4 hours if I need it. After reading all over, I think my strategy will be this: First, run through all the cells with VEAL to make sure that is spot on. Then, lock RPM and run through load cells, adjusting timing in degree increments as I go (adj fuel as needed). Do this for RPM columns from 2000rpm to 6000rpm (every other column, ~every other load cell?). Interpolate between columns and load cells. 60 second break between columns. Adjust the upper cells through WOT runs, with 60 second breaks in between.

Next would be accel enrichment. I've read all through the EAE thread here as well as the AE resources from msextra - just use the AE wizard to put inputs in at varying TPSdot, adjust curve to get best feel w/ reasonable AFR. Slow increasing throttle input on EAE atw, decreasing on sfw until I get stable AFR's going both ways.

If I'm not exhausted by then, I'd like to continue on to the VVT tuning. Step one would be to see how well actual cam angle matches what's in the table. For this, how close is close enough? Here is a log from the street:
I'm open to suggestions here - not sure what direction I should go or how to tune it.

And finally... injector timing. Reading through the other thread here, it looks like I should tune it similarly to ignition timing, except my goal is to maximize AFR. Once I've got that for every cell, run VEAL a last time and go home.

Is this too much? Sound good? Bad? Thanks!
Edit: Should AE come before ignition tuning?

Last edited by Uncle Humjaba; 07-04-2015 at 02:04 AM.
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Old 07-07-2015, 08:08 AM   #2
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Heading up there tomorrow. Anyone? Beuller?
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Old 07-07-2015, 11:56 AM   #3
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<p>post #7 of this thread has a good overview.&nbsp;</p><p></p><p>&nbsp;</p><p>Your&nbsp;plan seems like a good one. If it's your first time you will probably get overloaded with trying to multitask and juggle so many tasks. It's a bit overwhelming at first. Just take your time and don't rush it. I'd set your IAT, Coolant and any other parameter you want to watch with the proper warning color thresholds before time so you can glance at your gauges and know when you need to back off and let it cool off for a bit.&nbsp;</p>
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Old 07-07-2015, 09:32 PM   #4
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As cyotani mentioned thats a little to much for first attempt and only 4 hours of dyno time.
First things first ! If you want to do it correctly:
1. Set reasonably conservative timing (approx minus 5-7deg below MBT)
2. Quick tune fuel
3. Tune injection timing
4. Quick fuel re-tune
5. Tune VVT
6. Re-tune fuel
7. Tune ignition timing
You have to work very quickly on the dyno to finish your tune in time. You can do most of the fueling on the street though, on the dyno i would concentrate on ignition timing and maybe VVT. Injection timing is not that noticeable (power wise). Don't waste your expensive time on acceleration enrichment settings on the dyno. Tune it in the last place after the engine is completely mapped.
To make things quicker, remap VE and Ign. tables axis values to lower resolution and even numbers.
KPa: 20, 30, 40, 50, 60, 70, 80 and 100. Believe me, you don't need more.
RPM: 500, 1000, 1500, 2000, 2500, 3000, 3500, 4000, 4500, 5000 and so on ....
At first tune full throttle then part throttle.
In steady state do it every 20KPa (40, 60, 80) and every 1000rpm (2000, 3000, 4000, 5000). INTERPOLATE THE REST. It will save a lot of time and give very good results.
Adjust ignition timing in 2 degrees increments for full throttle and 3 for steady state low loads (30-60KPa).
Regarding VVT PID setup, make sure its working perfectly before you hit the dyno. I would say 0.1-0.3deg (max 0.5) target error is expected and acceptable.
Always do dyno pulls with same coolant and intake temperature (+-5C) for best repeatability.
I am able to achieve 0.3-0.5 HP/Nm repeatability for N/A engines on my Dynapack dyno.
Hope this helps.

Last edited by Laimis; 07-07-2015 at 10:08 PM.
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Old 07-08-2015, 10:09 AM   #5
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Thanks for the feedback. I can leave enrichment for the road. As far as vvt tuning goes, what values do you compare? The only thing cam or vvt related I can see to log are vvt target and vvt angle and they're not of the same magnitude. They follow each other very closely in shape when looking at a log but they don't appear to be the same calculation.

Assuming the pid settings are okay, how do you go about tuning vvt? Same as ignition timing? (advance in column/load ranges until peak power or minimum throttle angle)

I posted my ignition table - is this a good starting point? For wide open throttle runs, should I advance the whole rpm range and dial individual rpm cells back as they dip lower on a power trace than the previous run?

Also, with re-binning, what do I do with the extra cells? Set to high rpm/load and ignore? Then rescale them back when I finish?

Thank you!
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Old 07-08-2015, 08:52 PM   #6
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Well my trip to the dyno was rather surprising.
For WOT, on the baseline, I ran a pretty steady 12.6-12.8 up to about 6000RPM, falling to 12.4ish at redline according to Logworks (digital reading from the wideband).

I tried leaning it out a little bit at the top and didn't gain any power. So, onto WOT ignition timing... Tried advancing 2 degrees, and HP went down by about 1hp. Reset. Retarded by 2 degrees, HP goes down by about 0.5hp. Reset. Try advancing by 2 degrees again and it goes down again. All of this 200F coolant, 115F intake temp. Looks like Reverent's base timing was spot on for me...

Onto VVT table. I added 2 degrees of overlap from 5000RPM on and made an extra 1hp... dyno plot looked to taper off more towards the end, added another degree to the 7000rpm bin and made another .5hp. Good enough.

So I didn't bother with partial load VE or timing. I tried experimenting with locking the dyno at a certain speed and changing values, looking at a change in the TPS required to produce a certain MAP value and it didn't look like there was enough resolution in the TPS reading to make a difference.

So, in summary: Reverent's base ignition map was spot on. VEAnalyze was pretty much spot on. And I made way more power than I was expecting.
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First run on a dyno - how's my strategy look?-llctfwm.jpg  
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