Conversion ratio for engine load% > MAF/HP?

[Brav]

I know we use a factor of .8 for HP to MAF.. and since combined MAF logs top out at 364 when combined, I track the torque to see how the power continues. I ran a few logs tonight to see how everything was running since I put my car back together.. thing is definitely faster! At the dead end street by my office I run at late at night, I actually got air and traction control went nuts over a slight rise. She was pulling hard. But sometimes power didnt come on quite as smooth. And actual boost seemed to sometimes trail behind requested, but not always. Could my 710s e leaking? I hit almost 190% - seems pretty high. 3rd gear pulls are crazy.

The below log- i see timing drop off around 4700 RPM then come back. This is also about where peak engine load comes in, and my peak boost. boost trails off after that a bit. normal?

I forgot - I got 2 error codes for MAFs now - upper limit exceeded. Will this hinder performance?

[Brav]

	Engine Speed	Mass Air Flow	Throttle Valve Angle	Ignition		Lambda Control	Lambda Control	Lambda Control	Lambda Control		Engine Speed	Engine Load	Boost Pressure	Boost Pressure
TIME	(G28)	(G70 + G246)		Timing Angle	TIME	Bank 1 (actual)	Bank 1 (specified)	Bank 2 (actual)	Bank 2 (specified)	TIME	(G28)		(specified)	(actual)
STAMP	/min	g/s	%	°BTDC	STAMP	V	V	V	V	STAMP	/min	%	mbar	mbar
107.06	3320	31.22	9.4	48	107.23	0.255	0.1	0.665	0.095	107.4	3320	21.8	1000	1040
107.58	3320	35.14	10.6	46.5	107.75	0.09	0.095	0.08	0.15	107.92	3360	72.9	1980	1010
108.09	3400	165.11	94.5	21.8	108.26	0.24	0.26	0.695	0.675	108.43	3560	130.8	2180	1610
108.61	3640	310.44	98	3.8	108.78	0.775	0.8	0.8	0.79	108.95	3800	178.9	2170	2150
109.12	3920	311.67	100	1.5	109.29	0.815	0.835	0.83	0.825	109.46	4120	177.4	2150	2090
109.64	4200	342.92	100	5.3	109.81	0.815	0.83	0.825	0.82	109.98	4400	185	2150	2160
110.15	4480	364.08	100	1.5	110.33	0.815	0.83	0.83	0.82	110.5	4640	188	2150	2130
110.67	4760	364.08	100	-3	110.83	0.82	0.84	0.84	0.83	111.01	4920	185	2080	2100
111.18	5040	364.08	100	2.3	111.35	0.83	0.845	0.845	0.835	111.53	5200	179.7	2050	2050
111.7	5240	364.08	100	1.5	111.86	0.82	0.84	0.835	0.835	112.04	5400	173.7	2040	1970
112.21	5480	364.08	100	4.5	112.39	0.83	0.85	0.855	0.85	112.57	5640	172.2	2060	1930
112.75	5720	364.08	100	6	112.93	0.825	0.85	0.85	0.85	113.1	5880	165.4	2100	1870
113.27	5920	364.08	100	8.3	113.44	0.83	0.85	0.86	0.86	113.62	6080	161.7	2130	1860
113.79	6120	364.08	99.6	12.8	113.97	0.83	0.855	0.86	0.86	114.14	6280	157.1	2140	1830
114.32	6320	364.08	100	12.8	114.49	0.83	0.86	0.86	0.86	114.66	6440	155.6	2170	1840
114.83	6480	364.08	100	11.3	115	0.835	0.86	0.855	0.855	115.18	5760	170.7	2110	1880
115.36	4880	364.08	97.6	-7.5	115.54	0.825	0.855	0.85	0.85	115.71	4560	182	2170	1970
115.88	4600	333.69	100	4.5	116.05	0.83	0.855	0.855	0.855	116.23	4720	189.5	2120	2160
116.39	4720	364.08	100	0	116.56	0.825	0.85	0.845	0.85	116.74	4800	191.7	2090	2190
116.9	4800	364.08	100	0.8	117.08	0.83	0.855	0.855	0.855	117.26	4880	191.7	2070	2170
117.43	4880	364.08	100	2.3	117.61	0.815	0.85	0.845	0.85	117.78	4720	35.3	1000	2030
117.95	4760	9.72	5.9	52.5	118.13	0.775	0.83	0.815	0.82	118.31	4760	13.5	1000	1190
118.48	4760	26.42	8.2	6	118.66	0.485	0.785	0.635	0.8	118.84	4680	12	1000	1100

[4everRS]

Log looks pretty good Brav. Diverters could be causing the trail in boost you see. As far as MAF logs, I think it's block 2 that will show the values of both Mafs independently. Then you can add them together and know what the true MAF reading is.

[4everRS]

And you should post that log for us to see!

[ttboost]

In troubleshooting my problems lately, I have been logging block 2 (separtates the MAF's, so you can what EACH one is doing) and blocks114 & 115 for boost and block 120 for actual engine TQ. I believe block 120 is teribbly inaccurate for a flashed car, but you can at least see the consisitancy....
On kill, I am seeing MAF's in the low 430's, but not always at peak boost.

My actual boost lags way behind my requested boost also....and I noticed my N75 consistantly maxxes out at 95.3%. It was brand new last year, wondering if its expiring already?

[Brav]

looks like boost holds well up to 5400 RPM then it trails off. Sign of leaking DVs? What engine torque / load % are you guys hitting? I will try to log my N75 on the way to work..

[Brav]

02, 114 and 115

	Engine Speed	Engine Load	Mass Air Flow	Mass Air Flow		Engine Load	Engine Load	Engine Load	Wastegate (N75)		Engine Speed	Engine Load	Boost Pressure	Boost Pressure
TIME	(G28)		(G70) Bank 1	(G246) Bank 2	TIME	(specified)	(spec. corrected)	(actual)	Duty Cycle	TIME	(G28)		(specified)	(actual)
STAMP	/min	%	g/s	g/s	STAMP	%	%	%	%	STAMP	/min	%	mbar	mbar
0.17	2760	27.1	16.42	16.03	0.34	172.2	170.1	27.1	0	0.01	2760	27.1	1010	1060
0.68	2760	31.6	23.58	22.81	0.85	172.2	170.1	35.3	0	0.51	2760	27.1	1010	1050
1.2	2760	69.9	57.28	52.78	1.37	172.2	170.1	82	99.2	1.03	2760	38.3	1150	1050
1.71	2840	99.2	79.22	69.33	1.88	172.9	171.6	109.8	99.2	1.54	2840	91	2250	1230
2.23	2960	130.1	106.92	91.36	2.4	173.7	171.6	141.4	84.3	2.05	2920	119.5	2250	1620
2.74	3040	154.1	104.94	105.81	2.91	174.4	173.1	151.1	78.8	2.57	3040	151.9	2270	2050
3.27	3200	147.4	101.89	113.58	3.44	175.2	173.1	148.9	79.6	3.09	3120	148.1	2280	1960
3.79	3280	148.9	113.47	117.17	3.97	175.9	174.6	150.4	80.4	3.61	3240	148.9	2300	1940
4.32	3440	156.4	115.14	132.19	4.49	175.9	174.6	158.6	81.2	4.14	3360	154.1	2310	1980
4.84	3560	166.2	131.75	146.86	5.02	176.7	174.6	167.7	82.4	4.66	3520	162.4	2320	2070
5.36	3680	170.7	131.58	156.86	5.53	177.4	174.6	173.7	85.5	5.19	3640	167.7	2340	2140
5.88	3800	182.7	159.39	173.14	6.05	177.4	176.1	187.2	88.6	5.71	3760	178.2	2340	2240
6.39	3960	191.7	168.47	190.67	6.56	178.2	176.1	191.7	85.1	6.22	3880	191.7	2360	2390
6.91	4080	190.2	162.5	183.08	7.08	178.2	176.1	188.7	83.9	6.74	4040	191.7	2350	2400
7.42	4200	185.7	166.89	186.17	7.59	178.9	176.1	187.2	85.1	7.25	4160	186.5	2310	2270
7.93	4320	189.5	175.36	192.42	8.11	178.9	177.6	186.5	81.6	7.77	4280	188	2270	2270
8.46	4400	182.7	149.89	166.89	8.62	178.9	177.6	69.9	0	8.28	4400	184.2	2220	2200
8.97	4280	12.8	11.28	5.53	9.13	178.9	177.6	13.5	0	8.79	4360	17.3	1010	1540

[Brav]

	Engine Speed	Engine Load	Mass Air Flow	Mass Air Flow		Engine Load	Engine Load	Engine Load	Wastegate (N75)		Engine Speed	Engine Load	Boost Pressure	Boost Pressure
TIME	(G28)		(G70) Bank 1	(G246) Bank 2	TIME	(specified)	(spec. corrected)	(actual)	Duty Cycle	TIME	(G28)		(specified)	(actual)
STAMP	/min	%	g/s	g/s	STAMP	%	%	%	%	STAMP	/min	%	mbar	mbar
80.65	3600	72.9	75.92	71.64	80.81	176.7	174.6	91.7	99.2	81	3720	112.8	2380	1490
81.17	3800	140.6	147.17	142.31	81.34	178.2	176.1	164.7	85.5	81.51	4000	183.5	2410	2340
81.68	4080	191.7	177.69	190.86	81.85	178.9	177.6	191.7	90.6	82.02	4280	191.7	2290	2390
82.19	4400	191.7	191.31	203.06	82.37	178.9	177.6	191.7	82.4	82.54	4560	191.7	2180	2240
82.71	4680	191.7	195.44	200.28	82.88	179.7	177.6	185.7	79.6	83.05	4840	181.2	2090	2030
83.23	4920	175.9	191	196.5	83.39	179.7	177.6	172.9	87.5	83.56	5080	173.7	2030	1950
83.73	5200	176.7	203.03	206.75	83.9	179.7	177.6	175.9	91.8	84.08	5360	175.2	2020	1980
84.25	5440	174.4	210.11	216.08	84.43	179.7	177.6	172.2	97.6	84.59	5560	172.9	2030	1940
84.77	5640	171.4	206.08	213.67	84.95	178.9	177.6	169.9	96.5	85.12	5800	168.4	2070	1900
85.29	5880	166.9	206.5	218.67	85.46	177.4	176.1	166.2	95.7	85.64	6000	164.7	2110	1860
85.81	6040	164.7	208.42	216.97	85.99	176.7	174.6	163.2	95.3	86.16	6160	162.4	2140	1860
86.34	6240	160.2	208.92	211.81	86.51	175.2	173.1	158.6	95.3	86.68	6360	157.1	2160	1830
86.86	6400	157.1	209.14	215.22	87.03	174.4	173.1	157.9	95.3	87.21	6480	160.2	2170	1890
87.39	5880	169.2	206.69	218.89	87.56	179.7	177.6	177.4	56.9	87.73	4600	182.7	2160	2150
87.91	4560	179.7	150.25	166.69	88.09	179.7	177.6	164.7	91.8	88.26	4640	169.9	2140	1960
88.44	4680	178.9	175.36	190.67	88.61	179.7	177.6	183.5	84.3	88.78	4760	186.5	2110	2100
88.97	4800	189.5	192.25	200.61	89.13	179.7	177.6	191.7	83.5	89.31	4840	191	2070	2150
89.48	4880	190.2	191	201.17	89.65	179.7	177.6	188.7	79.6	89.82	4920	175.2	2060	2070
89.99	4920	178.9	173.11	193.03	90.17	179.7	177.6	51.9	0	90.33	4800	11.3	1010	1570
90.51	4720	10.5	10	5.75	90.68	179.7	177.6	12	0	90.85	4560	12	1010	1150
91.03	4480	12	11.58	13.67	91.19	178.9	177.6	12.8	0	91.37	4200	12.8	1010	1090

[Brav]

	Engine Speed	Engine Load	Mass Air Flow	Mass Air Flow		Engine Load	Engine Load	Engine Load	Wastegate (N75)		Engine Speed	Engine Load	Boost Pressure	Boost Pressure
TIME	(G28)		(G70) Bank 1	(G246) Bank 2	TIME	(specified)	(spec. corrected)	(actual)	Duty Cycle	TIME	(G28)		(specified)	(actual)
STAMP	/min	%	g/s	g/s	STAMP	%	%	%	%	STAMP	/min	%	mbar	mbar
229.79	3320	48.9	35.11	36.06	229.96	175.9	174.6	62.4	72.5	229.62	3280	48.9	1000	1190
230.3	3480	104.5	104.78	98.28	230.47	176.7	174.6	124.1	99.2	230.13	3400	89.5	2330	1220
230.83	3760	172.2	166.86	163.69	231.01	177.4	176.1	185	90.6	230.65	3640	148.9	2360	1920
231.36	4080	191.7	172.86	189.5	231.53	178.9	177.6	191.7	88.6	231.19	3960	190.2	2390	2400
231.87	4400	191.7	191.06	195.61	232.05	178.9	177.6	191.7	80	231.7	4280	191.7	2280	2380
232.39	4680	185.7	179.86	190.67	232.57	179.7	177.6	177.4	81.2	232.22	4600	191.7	2180	2210
232.91	4960	169.2	179	192.78	233.07	179.7	177.6	172.9	87.1	232.73	4880	171.4	2070	1980
233.42	5240	176.7	198.28	211.81	233.59	179.7	177.6	173.7	91.8	233.24	5160	173.7	2020	1980
233.94	5480	171.4	209.06	214.81	234.1	179.7	177.6	172.9	97.6	233.76	5400	173.7	2030	1970
234.45	5720	169.9	208.36	215.39	234.62	178.2	176.1	166.9	96.1	234.28	5640	171.4	2050	1910
234.96	5960	166.2	209.06	211.25	235.13	176.7	174.6	163.9	95.3	234.79	5880	166.2	2080	1880
235.48	6160	160.9	214.58	215.22	235.69	175.9	174.6	157.9	95.3	235.31	6080	162.4	2120	1870
236.03	6400	157.1	212.28	208.42	236.21	174.4	173.1	156.4	94.9	235.86	6320	156.4	2150	1820
236.56	6520	157.1	209.39	210.11	236.72	176.7	174.6	169.2	60	236.38	6480	157.1	2170	1860

[Brav]

So.. I see boost and engine load trailing from specified after 4600 to 4700 rpm, wich is usually where I actually see power pick up. why would this be.. I also see that before and arond this point that engine load has exceeded specified, so maybe when engine load comes down to specified or below, its adding back timing or something?

MAFs - 430 combined, I would say that this is the WHP? 20% loss is 537 crank HP. overall not bad.. but again, I am just trying to sort out my un-smooth power delivery. Or am I a complainer?

Duty cycle on N75 is reacing 98% - is this a concern? need replacement?

Another observation.. 191.7% is max readable engine load %

[ttboost]

I told my tuner that my N75 was ONLY at 95%. he said that is good, any higher and you risk burning it up, it needs a break too...it's relatively normal for MAF's to lead and lag a little...My MAF's read anywhere between 400-430 combined..and my car made 400/460 on an AWD Mustang dyno....so pretty close...

[Brav]

"Ghost-" sent me a PM about his car - also REVO/MTM. he said he has requested boost/actual matching when engine is cooler, and then actual trailing behind a bit more like my later logs after the engine gets hotter. I dont know if the correlation with oil temp is relevant or its something else getting hotter..

I also forgot to mention... that last log - I ran it without my foot pegged.. just against the kick down button. Wanted to see if it made a difference.

[Ghost-]

Hello, in the last post of this thread: http://www.rs6.com/showthread.php/23...ble-boost-leak I try to explain what happens with the boost after the engine gets hotter. I notice a +/- 300mbar of boost lost after the engine is hot, so my mechanic and me are wondering what could cause this. We have been looking for info on the internet and the most similar I have found is what Brav is saying and that sometimes, boost hoses tend to "inflate" or develop what is named a "hot fissure" which opens when the hose is hot...

[Brav]

I am pretty sure my DVs are stock - I guess I should be upgrading mine some way?

[Ghost-]

I am pretty sure my DVs are stock - I guess I should be upgrading mine some way?

You dont need to replace them if they are working as they should. To make sure they are working as intended go take a look at page 2 of this "how-to": http://www.forgemotorsport.co.uk/valve_service.pdf

Cheers!

[4everRS]

You dont need to replace them if they are working as they should. To make sure they are working as intended go take a look at page 2 of this "how-to": http://www.forgemotorsport.co.uk/valve_service.pdf

Cheers!

That might work on a spring type DV, but the stockers are a diaphragm type.

[Ghost-]

That might work on a spring type DV, but the stockers are a diaphragm type.

Oops, you are right. Im sorry about that :S

[Brav]

So the stock DVs will either work or not work.. not be "overboosted "?