lz9 3900 V6 buildup

[Shaun41178(2)]

She is running.

https://youtu.be/uGjWBgK_S18

[Honest Don]

Nice!

[The Dark Side of Will]

Bam!

[pmbrunelle]

Fast idle with 55 kPa manifold pressure.

Radical!

[ericjon262]

nice to see it running, hopefully I can figure out my throttle issue this week and get my heap making good noises again.

[Shaun41178(2)]

Took it for a drive today. I dont have any turbo piping hooked up but its making more tq than my old lx9. In second gear half throttle she has some get up and go even off boost.

Its gonna be fun

[Shaun41178(2)]

Cold. Side piping is hooked up and it hit 5 lbs today. Felt good. Dialing in the fuel ve table.

I used autotune to give me.an idea of where the ve table needs to be.

Autotune is a nice feature.

[Honest Don]

Cold. Side piping is hooked up and it hit 5 lbs today. Felt good. Dialing in the fuel ve table.

I used autotune to give me.an idea of where the ve table needs to be.

Autotune is a nice feature.

Autotune is great stuff for getting close!

Unrelated, but it's also good for getting you home when the fuel pump gets weak.

[pmbrunelle]

I think that Autotune will work better if you can dwell on each cell, vs. hanging out in between.

For autotuning boost, I do pulls with the boost pressure set to correspond with a certain MAP row in the table, traversing the RPM columns. Ideally in the highest gear possible, so the RPM isn't changing too fast... I use different boost control settings to do each MAP row.

For autotuning vacuum (and low boost), I maintain RPM constant with my left foot on the brake pedal, and I slowly open the throttle, traversing the MAP rows. This technique cannot be easily used in boost; in 2nd gear at WOT on my Fiero the front tires just lock up and skid.

Your engine will be much more powerful than mine; I imagine that at some point it becomes difficult to collect useful data without needing to use higher gears and higher speeds -> sketchy?

I imagine that renting time on a constant-speed dyno becomes an attractive proposition at some point

[Shaun41178(2)]

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Some logs. It builds boost fast. I started in 3rd gear at 1300 rpm and has 1 lb of boost by 2000 rpm. By 3k its at 4 lbs but the wastegate was opened well before slowing boost build.

I'm having fun with this stuff

[pmbrunelle]

It may be interesting to try things such as ignition timing at TDC in the WOT zone below 2500 RPM or so.

While this would reduce the torque on the crankshaft, hotter exhaust gas would leave the engine, which could spin up the turbine faster.

Just an idea you could have fun playing with on a programmable ECU.

I haven't tried that particular idea myself; maybe next summer.

[Shaun41178(2)]

Got done with around a 14 mile drive. Did some tuning on the fly. Got the air fuels pretty good for driving around town and the highway. She runs good at steady and part throttle. Tip in is also pretty good. Wot pulls are smooth and steady. Did some pulls in 4th up to 4600 rpm.

Gotta dyno tune the rest of it most likely. Speeds get too high otherwise. Or try and to some third gear pulls.

Ahe holds boost at 5 lbs. Iats get up to about 130 by 4500 rpm on a 5 second pull. Ambient was about 80 degrees. Intake reading around 95 before boosting. This is non intercooled

Microsquirt working great so far.

[pmbrunelle]

Iats get up to about 130 by 4500 rpm on a 5 second pull.

Ehhh, careful about taking that sensor reading for the truth.

In reality, as soon as the air molecules are compressed together (once you hit regulated boost), they are hot.

The temperature trace should reflect the boost pressure. If the sensor reading is steadily rising over a number of seconds, that's just the sensor lag you're seeing.

********************************************************************************

On my Fiero, I decided that I didn't want the ideal gas law calculation to be performed using seconds-old temperature information, so I put the sensor pre-compressor to avoid sensor response problems.

The reduction of air density due to boost-induced temperature rise ends up being baked into my VE table, which is computed based on MAP and RPM (which are fast).

The compensation due to variation in ambient temperature still works in the usual MegaSquirt way (Charles's law).

[Honest Don]

Gotta dyno tune the rest of it most likely. Speeds get too high otherwise. Or try and to some third gear pulls.

3rd gear and maybe find a long incline? I like using on-ramps

[ericjon262]

Gotta dyno tune the rest of it most likely. Speeds get too high otherwise. Or try and to some third gear pulls.

3rd gear and maybe find a long incline? I like using on-ramps

Pretty sure he's in FL, so long inclines aren't really a thing.

[Honest Don]

Gotta dyno tune the rest of it most likely. Speeds get too high otherwise. Or try and to some third gear pulls.

3rd gear and maybe find a long incline? I like using on-ramps

Pretty sure he's in FL, so long inclines aren't really a thing.

Oh!

[Shaun41178(2)]

It may be interesting to try things such as ignition timing at TDC in the WOT zone below 2500 RPM or so.

While this would reduce the torque on the crankshaft, hotter exhaust gas would leave the engine, which could spin up the turbine faster.

Just an idea you could have fun playing with on a programmable ECU.

I haven't tried that particular idea myself; maybe next summer.

It spools fast enough already. 5 lbs by 3k rpm in 3rd gear is pretty quick imo. I am already looking at a larger turbo

[Shaun41178(2)]

She is rollin

Maybe have it dynoed by end of Feb

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[Shaun41178(2)]

Started installation of the intercooler setup.

Tank will be mounted here. It holds 2.5 gallons.

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[ericjon262]

Pretty sure I mentioned it in a comment on one of your youtube videos, but be careful with the lid on the tank, it's easy to get them too tight and hard to remove.

I'm working on a drawing of the LZx plenum flanges, it would be really easy to machine a couple chunks of aluminum and maybe direct port N2O?