Dyno tuning the new 3.9 lz9 setup.

[Shaun41178(2)]

Bone stock lz9. Heads never been off. Using an lnj camshaft which is basically a stock cam but not a vvt like stock in the LZ.

Factory rating of 240 hp.

Gonna Dyno on 8 psi and 93 octane.
72mm BW turbo.
Microsquirt ecm

Place your guesses. Dynoing on Fri. 6 days from now

[jdv]

519hp

[ericjon262]

quick math suggests about 377 hp,

240hp*(1+8psi/14psi)=377 ish hp.

that being said,

LZ9 output was at the crank, yours will be at the tire

LZ9 with accessories, which yours will have too, but not the same parts, so maybe better, maybe worse.

LZ9 has emissions, you don't, this is probably where significant gains will come in,

LZ9 has a full exhaust, last I saw you had a dump, no muffler at all, which plays in your favor.

hard to nail down a number, but if I were to guess, I'd say somewhere close to 400 hp, more boost quickly changes that though.

[pmbrunelle]

240hp*(1+8psi/14psi)=377 ish hp.

I'm basically going with the same sort of logic, but I'll use 0.9 as a transmission loss fudge factor, 14.696 psi as the standard atmosphere, and then round up to 350 hp cause it's a nice round number.

[Shaun41178(2)]

I too am thinking 330-350whp.

Its supposed to rain in the morning which might put a damper on getting the car to the shop since its on drag radials.

[Emc209i]

It's 5pm. They're closed now. So what happened?

[Shaun41178(2)]

Final numbers on 8 psi were 400whp and 424tq. da was 2200 ft

SAE numbers were 392 whp

Dynoed in 4th gear

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[jdv]

nice

[Emc209i]

400 whp is greater than 312...

[pmbrunelle]

Nice. Was that with ice in the icebox?

[Shaun41178(2)]

I was using my little ice packs. They melt pretty fast I was just trying to prevent runaway intake temps vs actually having the water ice cold.

I think I used 20 packs and two 2 liter bottle of frozen water

I ran some datalogs and IATs were around 110f. It was hot in the dyno. I think I saw 94 degrees readout.

First pull made 352 whp at around 5200 and the power dropped off fast. Too much fuel after 5500. 10:1 af ratio.

After some tweaks I got it in the 11.8 range up top. Then I added some timing and at 6500 I picked up 40 hp. Between the fuel and timing changes it worked out to about a 75 hp gain at 6500 rpm.

Tweaks of fuel and timing near peak hp gained another 40 hp at about 5500 rpm making 392 whp

The factory cam is a peanut cam and was holding me back. Prob down 60hp peak to peak At 8 psi. But this just goes to show what a bone stock 3900 engine will do. They respond real well to boost. 200 hp gain at the crank on 8 lbs of boost equals about 20hp per lb of boost. That's good.

At the end I did one last run on 13 lbs with the boost controller and it made 450whp. Thats where we quit

[ericjon262]

so, closest without going over wins right? you made 392 at 8 pounds? that's badass!

[pmbrunelle]

When you're on the dyno, do you find it helpful to make the value in the MAP bin equal to the actual boost pressure your engine is running at?

Timing Map.jpg (212.9 KiB) Viewed 4497 times

In this way, as the RPM goes up, you would be sweeping right over the center of the cells, and not somewhere in between rows.

I haven't gone to the dyno yet, so I'm wondering about hints/tricks that can make the process go more smoothly.

[Shaun41178(2)]

Video of the dyno. Hope you have Facebook.

https://www.facebook.com/21895900153293 ... 858830845/

[Shaun41178(2)]

When you're on the dyno, do you find it helpful to make the value in the MAP bin equal to the actual boost pressure your engine is running at?

Timing Map.jpg

In this way, as the RPM goes up, you would be sweeping right over the center of the cells, and not somewhere in between rows.

I haven't gone to the dyno yet, so I'm wondering about hints/tricks that can make the process go more smoothly.

So the MS is gonna interpolate from cells around it. Thats the way the software is setup. So even if you have consistent boost control, its gonna share cells with the other cells that the boost curve as its moving left to right across the ve table. Same goes for timing tables.

So on your ve table you posted , at 175 kpa, if the kpa is actually 173, its gonna interpolate from the 175 cell as well as the 150 kpa cell and interpolate that. Dont worry about it traveling straight through the cell. Its almost impossible.

So on my setup on the dyno I would adjust the cells at the 175 kpa, as well as the cell above and below at the rpm. So I was changing timing in 3 different cells. One of my kpa values is 8 psi. So when I wanted to adjust ve and timing I would change the values in the one below 8 psi and the one above.

I suppose I could post my ve table at some point in time

[Shaun41178(2)]

In this way, as the RPM goes up, you would be sweeping right over the center of the cells, and not somewhere in between rows.

I haven't gone to the dyno yet, so I'm wondering about hints/tricks that can make the process go more smoothly.

Forgot to ask, how much boost do you plan to run? your ve table has your boost table going up to 225 kpa which is about 18 psi of boost. you ever gonna run that much? If not than you can drop that to a lower number and gain back some resolution.

your table has 16 rows for vacuum and boost resolution. youre only using 5 for boost and 12 for vacuum and 1 for when you are at 0 boost and vacuum(100kpa)

I would prob go with 8 for vacuum, 1 for 100 kpa, and then 7 for boost. depending on how much boost you plan to run. if only 10 psi then you only need 3 or 4 on the x axis for boost.

[Shaun41178(2)]

here is my spark table

dyno final timing table.jpg (193.97 KiB) Viewed 4471 times

[Shaun41178(2)]

450 hp Dyno. 13 psi.

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[Honest Don]

Do you guys use the quick rescale feature?

https://youtu.be/dSkXBI0cSH0



Nice numbers, btw! That was way more than I expected for 8psi

[pmbrunelle]

Forgot to ask, how much boost do you plan to run? your ve table has your boost table going up to 225 kpa which is about 18 psi of boost. you ever gonna run that much? If not than you can drop that to a lower number and gain back some resolution.

your table has 16 rows for vacuum and boost resolution. youre only using 5 for boost and 12 for vacuum and 1 for when you are at 0 boost and vacuum(100kpa)

I would prob go with 8 for vacuum, 1 for 100 kpa, and then 7 for boost. depending on how much boost you plan to run. if only 10 psi then you only need 3 or 4 on the x axis for boost.

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!

Eisenhower-_planning_vs_plans.jpg (101.98 KiB) Viewed 4441 times

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.

My fuel VE and AFR tables have the same RPM/kPa bins. I like to keep things consistent between the different tables.

here is my spark table

dyno final timing table.jpg

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?

Do you guys use the quick rescale feature?

https://youtu.be/dSkXBI0cSH0

I didn't know about that; that's pretty nifty.

When I've had to do operations like that, I manually copied the cell values into an Excel spreadsheet, did whatever I had to do in Excel, and then manually copied back the data into the tuning software.