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Lean out under partial loads and partial boost


Plumbs
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Hi , 2005 territory 1000 cc Bosch injectors Barra fg turbo motor. 98 fuel 

crusie is great 15-16.1 afg on 1 lambda fuel base and anything 1/2 to wot is hitting target lambda of .82-.78 . 11 psi full boost .

but at light throttle say 30 % I’m still getting 5 psi and stf is showing .98 lambda which’s showing 14.1 af . I’m commanding .83 ish on those cells 2500 rpm to 4000 rpm . It has an fg NA manifold and ported head ( 283 cfm ) .would that be causing the issue with the slope sd tables . Eg is this where I need to look at to fix this slight lean out under partial boost ? 
regards Graham. 

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Ok , don’t worry, all good ! So I logged the cam angle and rev’s to find the relevant cells to change the slope speed density tables and yep it worked ! Reduced each cell by 3% and was hitting my stft. Well close ! 
Still don’t know what I’m doing haha 😆😆😆

So now I have a really good tune with the btr box doing what I want . Getting  9 to 10 Lts per 100 Km’s and using 20 rwhp per psi boost. It did 320 rwhp at 6 psi gate pressure  . Now 100 % duty 11 psi = 100 rwhp so approx 420 rwhp .  And it feels like it !  Just need to replace the abortion of the intercooler set up and replace it with the Plazman territory kit and done !! Been nearly 18 months in the making ! With rebuilding the motor twice because I stuffed up the rings gaps first time round using a grinder , Doh!
Working out that the turbo is clocked nearly 45 deg with the drain back , to avoid the territory engine mount . Porting the head which took me 20plus hours . Also that it’s a  good idea to also change the valve stem seals when doing the springs , especially out of the car ! 
And the Barra engine is huge ! It’s longer than the territory opening and has to nearly come out east west . And this fg Na manifolds looks really cool and flows well in the mid range . But are the biggest pain to bolt on the motor in the car and are a tight fit . And installing injectors in the fg Na rail and manifold is a beeping pain ! 
 

Was a heart in month thing when it was taken to Forced to be thrown to the whims of the dyno for the base tune ! Thanks Jamie for doing the hard work for me ! 
So finally I think I have achieved a little bit of Barra heaven ! Been a lot of challenges. 
Cheers very happy little veggemite! 
 

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  • 1 month later...

Ok update . After backing off timing in the .8 to 1.0 to force the pedal more towards the floor . To force the desired lamda under partial boost . 
so under 3-6 psi , AF would be 14.3 at about 25 % peddle. Move peddle a fly spec more and then it would go to about 11.8 which was what I was commanding . I was worried about burning out exhaust valves ect ! 
 

I found aufo476 which is the fuel base TPs Axis . Disclaimer I’m learning so I don’t know how to say it correctly but I get the gist of it . So for the pros I may get things jumbled. So see how I go ? 
This fuel base tps seems to be the tps calibration . In the Na tps axis it’s totally in my opinion, incorrect for boost as Ad count doesn’t even come in till 300! And cell 3 was only being read ( if I’m correct!)  So boost was spooling but only around stoic AF . Ok for NA but not for boost . 
so I looked up the xr6t stock file and just copied. 
well hey presto problem fixed ! I’ve now put timing back in below boost and a little bit above . So hope this helps ! 

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Edited by Plumbs
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Yep they can make a couple of hundred rwkw at 14.7:1 afr if you don't adjust it.

If the timing is safe it won't detonate but it will introduce a lot of heat into the combustion chamber and surrounding areas. If you were towing for a long time with those unfavourable conditions, you would likely destroy your cat, o2 sensor and anything else that is close to the exhaust, which will be glowing red after a while.

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1 hour ago, Puffwagon said:

Yep they can make a couple of hundred rwkw at 14.7:1 afr if you don't adjust it.

If the timing is safe it won't detonate but it will introduce a lot of heat into the combustion chamber and surrounding areas. If you were towing for a long time with those unfavourable conditions, you would likely destroy your cat, o2 sensor and anything else that is close to the exhaust, which will be glowing red after a while.

A bit off topic but some interesting info.

The new euro standards (In china they are already doing this) will require lambda 1.0 at ALL times. This includes extended WOT power runs, you cannot rely on enrichment for power anymore in china, same will happen in the US and Europe soon. One benefit of this is it will mean easy power gains for the aftermarket but it does also prove it can be done.

From the calibrator I was speaking to they said the engine generates about 10% more heat at lambda than your typical WOT enriched cooling lambda, coupled with a particulate filter (like the diesel ones) that they are now running in china they had to do a few things for reliability. Bigger radiator, more cooling passages around the cylinder walls, higher temp valves and a different catalytic converter design. They also have a lot of cooling failsafes to pull the throttle back etc to stop things melting.

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  • 1 month later...
On 9/19/2021 at 11:04 AM, Puffwagon said:

Yep they can make a couple of hundred rwkw at 14.7:1 afr if you don't adjust it.

If the timing is safe it won't detonate but it will introduce a lot of heat into the combustion chamber and surrounding areas. If you were towing for a long time with those unfavourable conditions, you would likely destroy your cat, o2 sensor and anything else that is close to the exhaust, which will be glowing red after a while.

ill just add to this. My terry low/mid load points are still fairly std so it will be doing 1Afr while spooling/on boost. I have towed a 2T caravan with it like this, without fault, water temp never reaches 100 deg c.

My timing is factory, i haven't been game to touch it without knock ears. 

id say we have been like this 2 years, cause the kid just turned 2. I had to replace the wideband sensor (at around the 1.5 year mark) and i think i need to give it a new narrowband soon (but i have never changed it, so god knows how old it is)...

wideband could have cooked because of hot exhaust,  or because its on with car on - i really need to give it a startup delay.

 

ill take these points with note and add some more low/mid throttle fuel in.

 

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  • 2 months later...

Ok , I finally figured out how to fix this ! It’s in the open loop to close loop transition. Just have to adjust the Ad ( analogue to digital count I believe) on the pedal to be more partial boost friendly.  Around 3000 rpm pedal count is in the 200-150 count and then scaled on through the rest of the rev range . Then go and test. 
Works a treat , as I was seeing like 10 psi depending on what boost I was commanding in open loop 14.5-15.2 af on partial throttle. 
if your doing a NA conversion, you really need to find it in the open loop tables and change. 
I’ll take a pic and post ! 

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It is highly recommended to adjust this table when running anymore than factory boost levels. You can get 14.7 AFR with 12psi just cracking the throttle open towing a trailer very easily otherwise. It will use more fuel however you will keep the temperatures under control and avoid knock this way.

It will also be noticeably pokier when driving around.

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