Dyno tuning the new 3.9 lz9 setup.

[The Dark Side of Will]

Great job, mang! Congrats!

Great to hear the turbo spool!

[Shaun41178(2)]

According to my plan, I will set up the boost control to be able to run at 175, 200, and 225 kPa, and then I will tune those three rows (maybe other rows, depending on how much time it takes). I set up the table with 225 kPa at the top row, because I want to run the engine with that amount of manifold pressure. I suppose that with 7.4 compression and water injection, it should be possible.

That said, I realize that plans can change!


I have a bunch of resolution in the low-load low-RPM range, because that's where much of the "daily driving" happens, and smooth daily driving is a priority for me. On high-RPM decel, the engine will hit 12 KPa, so I wanted the tables to go all the way down there.

I understand you want tables that to 12 kpa but you dont need to. Granted I dont know how you ve map looks but your timing map is the same from 32kpa and down. If your ve map is the same from 32 and lower than you can repurpose those rows. Your timing is the exact same at 17 kpa as it is at 32. If your engine is ever below 32 it just uses the 32 row. And since your timing is the same from 32 to 12, you can repurpose those rows for resolution somewhere else.

Did you tune each high-boost row (160, 180, 195, 210, 230) or did you just tune around your 8 psi boost, and then you adjusted the rest of the ignition map to fit with the area you tuned?

I tuned multiple rows at once. So where my 8 psi run and 160 kpa, I tuned VE and timing tables in the kpa and ve table above and below 160kpa. So I wpuld make changes in the 150, and 180 kpa cells. Thats because the computer interpolates from 4 different cells at one time so the adjacent values must be close.

So for instance if one cell at 160 kpa and 5k rpm is at 20 degrees, and the 150 kpa and 5k rpm is at 10 degrees of timing, your computer might be around only 15 degrees of timing when you datalog your run. Yes I might be traveling through the 160 kpa cell, but it might actually be 169 kpa. Or it might be 155 kpa. So the computer grabs from 4 diff cells and takes the average.

So I think my timing table is.

180kpa
160 kpa
145kpa

If at 160kpa boost and I wanted to change the timing at 160 by 1 degree, I bumped timing in all 3 kpa ranges because like I said the computer interpolates four cells at a time. If my ups is at 165, it will use the 160 and 180 ups range. If I only hit 155kpa, the computer will interpolate between the 145 and 160. If I only bump it by 1 degree at 160, I wont see a full degree change unless I change the values in the neighboring cells. Same goes for VE

If you use megalogviewer to look at your datalogs you will see what I mean with the color change of the four cells its averaging from.

Thats the best I can explain how I made my changes on the dyno and street tuning

[pmbrunelle]

Cool, I understand your tuning process now.

Yes, you are correct that based on my ignition table, the lower-kPa rows I have are useless.

VE keeps dropping off as kPa goes down, so I wanted to capture that in the VE table:

Fuel VE.jpg (243.39 KiB) Viewed 4483 times

My ignition table is only that way in order to be consistent with the VE table.

[Shaun41178(2)]

Video on YouTube

https://youtube.com/shorts/5DHKb7vjvrc?feature=share

[ericjon262]

video is missing the curve/numbers...

[Shaun41178(2)]

video is missing the curve/numbers...

Thats why I posted it here

[eHoward]

Congrats Shaun. How is this not in tech?

[Shaun41178(2)]

My last dyno thread I put in this section so I figured id do the same with this one.

I added a wastegate spring and am now running 14.5 lbs all the time now.

Also ordered a heat exchanger or the intercooler setup.

[Shaun41178(2)]

In case anyone here hasnt seen it yet. Short video of the 8 psi pull and dyno numbers review. Chart is shown

https://youtu.be/aGAvBQepXo0

[pmbrunelle]

When tuning on the dyno, do you rely more on the dyno's wideband oxygen sensor versus your own?

Is it just more convenient to use the dyno's wideband, since the measurement appears on the same datalog as the hp/torque?

Do your wideband and the dyno's agree with each other?

[Shaun41178(2)]

When tuning on the dyno, do you rely more on the dyno's wideband oxygen sensor versus your own?

Is it just more convenient to use the dyno's wideband, since the measurement appears on the same datalog as the hp/torque?

Do your wideband and the dyno's agree with each other?

So in my case I was watching the wideband readout on the dyno. Thats because a couple of the leds in my gauge are burnt out which makes reading the decimal places difficult. I used mine while street tuning obviously and cross referenced my gauge readout with my catalog of what the computer was seeing.

But yes after the pull the dyno has the wideband readout on the chart so its easy to see where changes need to be made.

My wideband and the dyno was close enough. Within a tenth or 2 points. That is something that should be confirmed before doing pulls.

I also pulled plugs on the dyno to verify the timing mark on the ground strap to see if I should add or takeaway timing.

[Shaun41178(2)]

so I have a dragy and I need to test it but I took it for a drive today. It pulls pretty good in the cool air. DA was about -500 today with temps about 50

I had to use my datalogs and from 60 to 115 it took 6.2 seconds. The headlight doors popped up and scared me as I forgot they do that and which is why I let off. I am assuming 60-120 would fall in the upper 6 to loq 7 second range somewhere. not terrible imo.

[Honest Don]

Slap the dragy on the defrost vent and see what it do!

[Shaun41178(2)]

Well I plan to go back and redyno in the next couple of weeks.

I will be on e85 this time. I will be around 15-16 psi but I want to get the ebc dialed in too so I'd like to hit 18-19 lbs if possible up top.

Give me your guesses on 15 psi and your guess on 19 psi if I can get there.

I did 450 on 13 lbs and 15 degrees of timing on 93

Still bone stock lz9

[ericjon262]

90,520,444.94 M&M's/hr at 16 PSI

97,120,894.05 M&M's/hr at 19 PSI.

or would you prefer cheeseburgers/hr?

[pmbrunelle]

Using an estimated stock LZ9 = 216 whp, and two points with boost in this thread.

The "x" axis is the manifold pressure in atmospheres.
The "y" axis is SAE whp.

Soooo, when I think of interpolating three points, I think, PARABOLA!

Quadratic regression.png (17.45 KiB) Viewed 1717 times

Oops, around 2.3 atm whp is going down... that doesn't look right.

Inverse:

Inverse regression.png (17.79 KiB) Viewed 1717 times

Looks nice enough...

15 psi:
x = 2.021
y = 714.73 - 498.67/2.021 = 468 whp

19 psi:
x = 2.293
y = 714.73 - 498.67/2.293 = 497 whp

Doesn't look like the numbers increase fast enough in the higher boost areas.

b7e.jpg (57.27 KiB) Viewed 1717 times

Instead, I'll try to linearly extrapolate from these points:
(8, 392)
(13, 450)

473 whp
520 whp

I don't super-trust linear extrapolation either, so I'll take the average of the above two methods:

Final answer
470 whp @ 15 psi
508 whp @ 19 psi

[Shaun41178(2)]

Final answer
470 whp @ 15 psi
508 whp @ 19 psi

Pretty good guess. On 93 octane I'd say you would be pretty close. I am hoping e85 adds 20 hp by itself. Cooler, denser charge as well as being oxygenated usually gives a decent bump with boost by itself without timing being added.

This test showed a 6% gain from e85 alone vs race gas with no timing change. If my results are similar that should put me around 477. More timing could make it another 15-20. And that's still on the same 13 lbs of boost.
https://youtu.be/Z0Ac72xQvAo

I am thinking 490 whp on 15 isn't far fetched. If I can get more boost out of it, I think low 500s is there. I'll put my number at 530 on 19 if I can get there. I think my stock camshaft is really holding me back.
I guess we shall see

[The Dark Side of Will]

On 93 octane I'd say you would be pretty close. I am hoping e85 adds 20 hp by itself. Cooler, denser charge as well as being oxygenated usually gives a decent bump with boost by itself without timing being added.

110 octane doesn't hurt either.

I think my stock camshaft is really holding me back.
I guess we shall see

You had aftermarket cam + crazy intake stack on you 3.5 right? I've assumed that dramatically enhanced its top end.

[Shaun41178(2)]

You had aftermarket cam + crazy intake stack on you 3.5 right? I've assumed that dramatically enhanced its top end.

Yea I had a 220ish duration cam in that 3.5. Not sure of exact specs off the top of my head. But yea the lx9 power was still climbing at 6500 rpm. I never found out where true peak was. I was out of injector.

If I had known at the time a microsquirt would have run that engine, I would have kept it and installed 1100cc injectors and reved higher.

My 3900 stock cam peters out hard @ 5600

[Shaun41178(2)]

Thursday the 30th if all goes well I'll have something to report