Probee's GT2871R LCR

[probee]

When you arrived, not when you left.

hmmm

John/Dave you might put me right here but using an IDC of 83.82% and a flow of 446cc i should be seeing a reading of 218g/s for 12.5:1

to actually have 12.5:1 A/F and an IDC of 83.82% i must be flowing that amount of air but why is it not showing that on the MAF????

 

[probee]

Still not flowing as much air then again ur on boost 7..

Would be nice if we owned a dyno....

81.68 6520 187.86 100 17.3

17.3, isnt that quite alot? Thought u said it was running arround 11?

i find it hard to see a pattern mate.. i dont remember saying it was around 11 but we werent quite sober were we

B7 doesnt change it that much....

 

[DPJ]

Have you measured the ID of your Maf tube? Was it fitted when you did the pre-wmi logs?

 

[DPJ]

Still not flowing as much air then again ur on boost 7..

Would be nice if we owned a dyno....

81.68 6520 187.86 100 17.3

17.3, isnt that quite alot? Thought u said it was running arround 11?

No, you'd expect timing to advance into the 20's at higher RPM - let me find an example....

Clicky

 

[probee]

Have you measured the ID of your Maf tube? Was it fitted when you did the pre-wmi logs?

No i forgot Dave.. it has been fitted for around 8 months now, so the previous logs were with it yes.

ill get out there at lunch with a vernier but i cant see it being too far out... im confused!

 

[Wilko]

I was going to suggest that you use injector duty cycle to calculate actual airflow. I used boost at rpm to give similar numbers to the ones you're calculating.
I would check your maf dimensions. Did you do a reset error codes. There's an adaption channel somewhere in the low hundreds that something like maf correction factor. This may be out.

Have you changed anything like your air filter, removed maf screens or anything that could be upsetting flow across the sensor?

 

[probee]

I was going to suggest that you use injector duty cycle to calculate actual airflow. I used boost at rpm to give similar numbers to the ones you're calculating.
I would check your maf dimensions. Did you do a reset error codes. There's an adaption channel somewhere in the low hundreds that something like maf correction factor. This may be out.

Have you changed anything like your air filter, removed maf screens or anything that could be upsetting flow across the sensor?

at leaset my maths isnt as bad as i thought

ill get out there today and measure the MAF ID but ive had good figures from it since fitting. Nothing at all has changed on the induction side, the MAF housing doesnt have any screens but this hasnt caused a problem in the past... infact my old MAF housing didnt have screens either and that was fine too.

i reset the error codes everytime i do some logs now. Can i go into this adaption channel and reset it manually or can it only be done through resetting fault codes?

 

[probee]

OK the ID of my MAF housing is 74.3mm


i now need to go looking for what it should be

 

[DPJ]

69.5mm for an LCR housing

 

[Skorchio]

So what does the extra size mean? The MAF will not regester as much air going in to the engine?

 

[DPJ]

So what does the extra size mean? The MAF will not regester as much air going in to the engine?

The air actually going into the engine is maf g/s x (74.2/2)^2/(69.5/2)^2

 

[probee]

69.5mm for an LCR housing

Blimey Dave what does that make the figures ive been getting in the past then...

I have definately cleared fault codes since fitting the MAF housing so it should be OK. this sort of explains why the figure is low but it doesnt explain why i had such good figures before.

im also not able to push the timing like i have been able to in the past... i have the car booked in for a leak check on Friday, this may find something i have been missing.

 

[Wilko]

This all adds up now.
Your maf is under reading by around 14% which is the area difference. This means your somewhere around the 210-220g/s mark, which is fantastic for a k04.
Ties up with your IDC and boost levels. I reckon VE at 6400 is around 92% based on all your numbers.

 

[probee]

Thanks for all your help John/Dave i feel like ive wasted your time but i still dont understand how i got the previous figures and why i can no longer push the timing

EDIT: it does seem to be running well at the moment.

 

[probee]

This is the log from before with the corrected figures in

EDIT : scroll to the right

1ML 906 032 A  		1.8l R4/5VT         0001										
												
	Group A:	'003				Group B:	'020					
		RPM	Mass Flow	Load	Ign. Timing		Idle Stabilization	Idle Stabilization	Idle Stabilization	Idle Stabilization		
	TIME					TIME						
MARKER	STAMP	 /min	 g/s	%	 °BTDC	STAMP	 CF	 CF	 CF	 CF		CORRECTED
	40.79	2440	19.03	11.4	33.8	41.19	0	0	0	0		21.6942
	41.59	2480	21.67	12.5	33	41.99	0	0	0	0		24.7038
	42.4	2560	34.44	18	30	42.8	0	0	0	0		39.2616
	43.2	2760	53.39	26.3	27	43.6	0	0	0	0		60.8646
	44	3000	57.25	29	28.5	44.4	0	0	0	0		65.265
	44.82	3240	56.97	26.7	30	45.22	0	0	0	0		64.9458
	45.62	3480	59.47	26.3	30.8	46.02	0	0	0	0		67.7958
	46.42	3720	54.92	23.1	32.3	46.82	0	0	0	0		62.6088
	47.22	3840	60.89	25.9	33	47.63	0	0	0	0		69.4146
	48.03	4200	106.5	89.8	14.3	48.43	0	0	0	0		121.41
	48.83	4640	190.31	100	10.5	49.23	0	0	0	0		216.9534
	49.63	5080	200.78	99.6	9	50.03	0	0	0	3		228.8892
	50.45	5520	206.25	100	9	50.85	0	0	0	3		235.125
	51.25	5960	209.25	100	11.3	51.67	0	0	0	2.3		238.545
												0
	85.85	3600	9.42	6.7	11.3	86.25	0	0	0	0		10.7388
	86.65	3920	101.42	99.6	14.3	87.05	0	0	0	0		115.6188
	87.45	4520	112.31	100	27.8	87.87	0	0	0	0		128.0334
	88.27	5360	206.5	100	10.5	88.67	0	0	0	0		235.41
	89.07	6280	211.25	100	11.3	89.47	0	0	0	0		240.825
	89.88	6760	42.83	9.4	0	90.27	0	0	0	0		48.8262
	90.68	4560	189.28	98	16.5	91.08	0	0	0	0		215.7792
	91.48	5280	205.14	100	5.3	91.88	0	0	0	0		233.8596
	92.28	5520	207.61	100	11.3	92.68	0	0	0	0		236.6754
	93.1	5920	208.56	100	11.3	93.5	0	0	0	0		237.7584
	93.9	6080	0	5.5	6.8	94.3	0	0	0	0		0
												0
	114.82	3880	55.83	25.1	24	115.22	0	0	0	0		63.6462
	115.62	4000	79	35.3	23.3	116.02	0	0	0	0		90.06
	116.42	4360	181.22	100	12	116.82	0	0	0	0		206.5908
	117.22	4880	192.89	99.6	15	117.64	0	0	0	0		219.8946
	118.04	5800	206.25	100	4.5	118.44	0	0	0	0		235.125
	118.84	5680	204.33	100	13.5	119.24	0	0	0	0		232.9362
	119.64	6080	207.92	100	13.5	120.04	0	0	0	0		237.0288
	120.45	5880	80.56	5.5	37.5	120.85	0	0	0	0		91.8384
	121.25	5040	198.08	100	12.8	121.65	0	0	0	0		225.8112
	122.05	5320	202.69	100	15	122.45	0	0	0	0		231.0666
	122.87	5560	203.64	100	15.8	123.27	0	0	0	0		232.1496
	123.67	5800	205.92	100	12.8	124.07	0	0	3	0		234.7488
	124.47	6000	208.25	100	15.8	124.89	0	0	3	0		237.405
												0
	138.95	2120	5.75	3.9	3	139.35	0	0	0	0		6.555
	139.75	2760	7.69	4.7	1.5	140.15	0	0	0	0		8.7666
	140.56	2960	8.75	6.7	33	140.96	0	0	0	0		9.975
	141.36	3000	42.31	19.6	29.3	141.78	0	0	0	0		48.2334
	142.18	3240	36.83	16.5	32.3	142.58	0	0	0	0		41.9862
	142.98	3440	43.64	18.4	18	143.38	0	0	0	0		49.7496
	143.78	3720	56.11	23.5	30	144.19	0	0	0	0		63.9654
	144.59	4240	109.17	98.8	12	144.99	0	0	0	0		124.4538
	145.39	4880	144.69	100	18.8	145.79	0	0	0	0		164.9466
	146.19	5720	204.28	100	16.5	146.59	0	0	3	0		232.8792
	147.01	6280	0	7.1	3	147.41	0	0	0	0		0

 

[DPJ]

No, all interesting stuff Aaron. Keep it coming.

You can see why it's running leaner than normal Revo settings now.

John - is that part of the reason it's making the power?

 

[probee]

No, all interesting stuff Aaron. Keep it coming.

You can see why it's running leaner than normal Revo settings now.

John - is that part of the reason it's making the power?

im glad i havent put you off helping me in the future

any thoughts on previous figures... they look crazy now.

 

[DPJ]

:any thoughts on previous figures... they look crazy now.

Over-reading Maf.

 

[probee]

Over-reading Maf.

LMAO thanks hehe

 

[Wilko]

dave
running leaner will make a little more power, but the turbos shifting plenty of air, and iat's are very low, timing advance is good (for a small port at that boost level), all adding up to good power.

anything in the teens is reasonable timing advance for a small port. With WMI you may get to high teens.