Lean running Legnum on the dyno

whats_doing

QLD Events Manager
Location
QLD
First Name
Sam
Drive
98 PFL Black Legnum - SOLD
MY15 Hyosung GT650R
Just go for a short drive up to NT where they have gotten their unrestricted highway again.

Or just say bugger it and do 180/200 on a private road.

edit: we don't condone illegal driving on this forum
 

ripn2u

Idling at the Lights
Location
Queensland, Australia
First Name
morrie
Drive
2001 Vr4 v-spec, Santa Fe 2013
I'll like to see if this is fixed the issue of knocking fuel issues etc. Are you able to post a update bro
 

Kaldek

2 AYC Bars
Premium Member
Location
Melbourne
First Name
Ed
Drive
2000 Legnum VR4 Manual, Ford Territory family runabout, BMW K1300R.
I'll like to see if this is fixed the issue of knocking fuel issues etc. Are you able to post a update bro
Yeah sorry mate I've just not had any time to get the wideband fitted. The car is running OK at the moment and is decidedly quick, but I do know I need to get the data together eventually and update the tune.

Soon, hopefully!
 

Kaldek

2 AYC Bars
Premium Member
Location
Melbourne
First Name
Ed
Drive
2000 Legnum VR4 Manual, Ford Territory family runabout, BMW K1300R.
Just as an update I've got my wideband fitted after all this time and seen that the car is now super rich - 10.2 at WOT on occasion. This is fairly expected now since I fixed all the likely sources of the car running lean since I had the tune done in 2014. Map tweak coming at some point.
 

Kaldek

2 AYC Bars
Premium Member
Location
Melbourne
First Name
Ed
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2000 Legnum VR4 Manual, Ford Territory family runabout, BMW K1300R.
Been over the log data again. The lean problem is surely fixed - at 4,000rpm and 153 load I'm getting AFR of 11. Interpolating the 140 and 160 load cells (11.1 and 10.8 AFR) gives me 10.95 AFR - pretty spot on to 11 I'm recording at the wideband.

I'm amazed just how accurate the Mitsubishi volumetric efficiency and fuel injector scaling is. Some boffin engineer has run the math on a motor in good condition and used those for fuel map calculations based on metered air.

All I need now is @TME_Steve to show me what to tweak in my ROM. *Cough* reminder *Cough*
 

Kaldek

2 AYC Bars
Premium Member
Location
Melbourne
First Name
Ed
Drive
2000 Legnum VR4 Manual, Ford Territory family runabout, BMW K1300R.
It's tuned for 16, but I did say 4,000 rpm not peak torque rpm. Unless I am missing something?
 

jungle

3 AYC Bars
Lifetime Member
Location
QLD
First Name
Simon
Drive
1 PFL & 1 FL Legnum
153 load on an stock turbo, stock cammed car is around 11-12 spi. 16psi should be up round 190-200
 

Kaldek

2 AYC Bars
Premium Member
Location
Melbourne
First Name
Ed
Drive
2000 Legnum VR4 Manual, Ford Territory family runabout, BMW K1300R.
153 load on an stock turbo, stock cammed car is around 11-12 spi. 16psi should be up round 190-200
Five minutes later I did another run and pulled 180 load at 4,900rpm.

Mind you it immediately dropped from 180 sharply past 5,000rpm. Odd.

Strange pull..png
 

Kaldek

2 AYC Bars
Premium Member
Location
Melbourne
First Name
Ed
Drive
2000 Legnum VR4 Manual, Ford Territory family runabout, BMW K1300R.
I will say that on the day of the tune, Steve said that my old exhaust was severely holding me back. Not sure if that would have affected the way he tuned the desired load/boost tables. I don't know enough yet to put the pieces together on how the boost is controlled.
 

Kaldek

2 AYC Bars
Premium Member
Location
Melbourne
First Name
Ed
Drive
2000 Legnum VR4 Manual, Ford Territory family runabout, BMW K1300R.
Actually the graph doesn't look so bad when you zoom it to that single event. Total time of ~3.5 seconds between peak load of 180 at 4,900rpm and the tail off to 6,700rpm.

not so strange pull when zoomed.png
 

jungle

3 AYC Bars
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QLD
First Name
Simon
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1 PFL & 1 FL Legnum
I will say that on the day of the tune, Steve said that my old exhaust was severely holding me back. Not sure if that would have affected the way he tuned the desired load/boost tables. I don't know enough yet to put the pieces together on how the boost is controlled.
Five minutes later I did another run and pulled 180 load at 4,900rpm.

Mind you it immediately dropped from 180 sharply past 5,000rpm. Odd.

I don't know your mods, but load dropping past 5000 is fine if your exhaust is a restriction. The engine make peak power around 5200-5500. The oem cam turbo combo can't flow enough air past 5500 so boost and hence load will drop from there. But the load should remain pretty constant from around 2800-5500
 

jungle

3 AYC Bars
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QLD
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Simon
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1 PFL & 1 FL Legnum
I will say that on the day of the tune, Steve said that my old exhaust was severely holding me back. Not sure if that would have affected the way he tuned the desired load/boost tables. I don't know enough yet to put the pieces together on how the boost is controlled.
A restrictive exhaust just won' flow so you can't put much timing into & it won't make as much power. Some will take the timing but just won't make the power due to,the restriction. Every engine of the same type is different
 

TME_Steve

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NSW
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Steve
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2010 nt did pajero tow car / 2000 6spd gc8 wrx tarmac rally car / 2000 Manual Subaru Outback 2.5 just a car
Got your stuff Ed. Will go through it later today
 

Kaldek

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Location
Melbourne
First Name
Ed
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2000 Legnum VR4 Manual, Ford Territory family runabout, BMW K1300R.
As long as I can fix the rich mixture I'll be able to work on the airflow issues separately. Before this car goes to Steve for its rebuilt motor I want all the other restrictions resolved. The exhaust should no longer be a restriction as it's 2.5 inch front pipes feeding into a 100 cell cat and Fujitsobo Super R. Intercooler is next, it's an Autobahn88 being replaced with a HDi GT2.
 

NuffNuff

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Lifetime Member
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Victoria
First Name
Damian
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GTI, GTI, FL Manual Legnum VR4
600 x 300 x 80mm vs 590mm x 200mm x 70mm cores (edit: GT2 is the bigger one)


no idea if either one flows better than the other, size difference is pretty big overall
 

Kaldek

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Premium Member
Location
Melbourne
First Name
Ed
Drive
2000 Legnum VR4 Manual, Ford Territory family runabout, BMW K1300R.
What was wrong with the 88?
Steve also said at the time of the tune that the intercooler was fairly small. For the price, I'd rather deal with this now than have the motor built up and find on the day that there is yet another restriction somewhere.

Everything the previous owner did was badly thought out.
  • Custom "3 inch exhaust" - garbage. It used 2 inch resonators welded (if you could call it that) to 3 inch pipe and a shitty muffler
  • "Hand built high flow turbos" - wasted. I've removed the rear one and measured it, there is zero difference in inducer and exducer size on either wheel
 

Kaldek

2 AYC Bars
Premium Member
Location
Melbourne
First Name
Ed
Drive
2000 Legnum VR4 Manual, Ford Territory family runabout, BMW K1300R.
So you running a pissy 11-12 psi :LOL:
Just did some runs at lunch. I can hit 16psi in 4th gear but not so much in 3rd unless I'm going uphill.

I'm not sure I understand the physics behind this.

Right now my brain is along the path of the turbo able to make pressure at lower airflow and it's at that lower flow for longer going uphill - due to the load on the engine. In an unloaded state - say, going downhill where most of my runs are - it quickly gets to too high an airflow for the little TD03 to keep boost up?

And then maybe we are adding an inefficient intercooler. My brain starts to melt after that.
 
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