Dibilas CAI maf issue.

[Al]

Mine was better

 

[-pseudonymous-]

Check this thread out here for the same issues:

http://www.golfmkv.com/forums/showthread.php?t=80189&highlight=ltft

Interesting reading. Being an american forum, take it how you will....

Interesting read that Dan. How much 'better' were your airflow readings after fitting the Dbilas Horace?

 

[Al]

Mine showed a 10g/s increase but the conditions were different between logs as was the spec of the car.

 

[wild willy]

The stock oval pipe has a csa of pi*(2/2)*(3/2) = 4.71 square inches
New intake is 3 inc round = pi*1.5*1.5 = 7.07 square inches.

New pipe is 1.5 times larger than the original.

therefore readings in new maff tube will be lower than the original figures even if good gains are realised.
your lambda sensors are confirming this within your fuel trims.

In theory at least your new maff reading will equate to 209 * 1.5 =313g/sec which is unlikely, in old money.

But since the original maff sensor does not sit in the center of the tube, its under reading to begin with.

What does this all mean, not much without a dyno, but i would speak to the company about your findings.
Don't forget to post up before and after logs of vagcom 118 to see if the improved air flow can be seen affecting the duty cycle.

 

[-pseudonymous-]

Hey Willy here are a couple of logs of block 118.....

Stock Intake in 3rd gear:

'118			
Engine Speed	Intake Air	Wastegate (N75)	Boost Pressure
	Temperature	Duty Cycle	(actual)
 /min	°C	 %	 mbar
1720	33	99.6	1010
1760	33	99.6	1060
1920	33	99.6	1170
2160	34	99.6	1290
2400	34	99.6	1430
2680	34	99.6	1650
2920	34	59.6	1930
3240	35	53.7	2190
3600	35	49.8	2250
3880	35	47.5	2120
4240	35	49.8	2070
4600	35	52.9	2110
4880	36	54.5	2130
5080	36	55.7	2160
5400	36	56.5	2140
5640	37	57.6	2130
5840	38	57.6	2120
6040	38	56.1	2040
6280	39	55.3	1950
6440	39	54.9	1930

Dbilas Intake in 3rd gear:

'118			
Engine Speed	Intake Air	Wastegate (N75)	Boost Pressure
	Temperature	Duty Cycle	(actual)
 /min	°C	 %	 mbar
1720	35	99.6	1050
1880	35	99.6	1170
2040	34	99.6	1260
2200	34	99.6	1350
2440	33	99.6	1510
2640	33	99.6	1710
2920	33	53.3	2030
3200	33	54.9	2280
3560	32	49	2240
3800	31	47.8	2090
4080	31	49	2080
4440	31	51.4	2120
4680	31	53.3	2110
4960	31	54.9	2130
5240	31	56.1	2140
5520	32	57.6	2120
5800	32	58	2110
6040	33	57.3	2040
6280	33	55.3	1980
6520	34	54.5	1910

Stock Intake in 4th gear:

'118			
Engine Speed	Intake Air	Wastegate (N75)	Boost Pressure
	Temperature	Duty Cycle	(actual)
 /min	°C	 %	 mbar
			
			
1960	39	99.6	1230
2040	38	99.6	1320
2160	38	99.6	1410
2280	38	99.6	1520
2360	38	99.6	1620
2480	37	99.6	1800
2680	37	57.3	2060
2800	37	61.6	2220
2920	37	57.3	2340
3080	36	53.7	2290
3200	36	51.4	2230
3360	36	49.8	2180
3520	36	48.6	2130
3680	36	47.1	2170
3760	36	47.1	2070
3920	36	49	2090
4000	37	49.8	2110
4120	37	50.2	2130
4280	38	51.4	2120
4400	38	52.5	2160
4520	39	53.7	2160
4640	39	54.5	2170
4720	39	54.9	2170
4840	39	55.3	2180
4960	40	55.7	2190
5080	41	56.1	2170
5160	42	56.5	2170
5280	42	56.5	2180
5400	43	57.3	2180
5480	43	57.3	2180
5600	44	57.6	2170
5680	45	58	2150
5760	45	57.6	2170
5840	45	56.9	2130
5960	45	56.1	2080
6040	45	55.3	2040

Dbilas Intake in 4th gear:

'118			
Engine Speed	Intake Air	Wastegate (N75)	Boost Pressure
	Temperature	Duty Cycle	(actual)
 /min	°C	 %	 mbar
			
			
1960	28	99.6	1250
2080	28	99.6	1350
2200	28	99.6	1470
2320	28	99.6	1590
2480	28	99.6	1760
2600	27	55.3	2000
2760	27	59.6	2270
2920	27	54.5	2380
3120	27	48.2	2270
3320	27	45.5	2120
3440	27	45.5	2060
3600	27	45.5	2070
3760	27	45.5	2070
3920	27	45.9	2050
4040	27	47.5	2070
4200	27	49	2090
4360	27	49.4	2120
4480	28	50.6	2140
4680	29	51.4	2130
4760	30	51.4	2130
4920	30	52.2	2120
5040	30	52.5	2140
5160	31	52.5	2130
5280	31	52.9	2120
5360	32	53.7	2120
5480	32	54.1	2120
5600	33	54.5	2120
5680	33	54.5	2120
5800	34	54.5	2090
5920	35	54.1	2060
6040	35	52.5	2010

Obviously its not really a fair test as the logs were done on different days and the ambient temperatures were slightly warmer when i logged the stock intake. If i get time over the weekend i will try and get some better logs of both the stock and Dbilas intakes under the same conditions, but looking at the logs above there doesn't appear to be a great deal of difference between the two.

While i was out logging i thought i may aswell check my airflow readings and funnily enough they have since risen from 209g/s to 218g/s. I think next week i may knock up a little spacer for the maf tube to bring the maf more central and re-log it.



Dbilas airflow log in 3rd gear:

'003			
Engine Speed	Intake Air Mass	Throttle Drive	Ignition
		Angle Sensor 1	Timing Angle
 /min	 g/s	 %	 °ATDC
1800	33.36	99.6	16.5
1960	38.56	99.6	15.8
2120	44.08	99.6	16.5
2320	56.67	99.6	12.8
2520	65.08	99.6	11.3
2760	85.58	99.6	6.8
3080	116.14	99.6	0
3360	135.11	99.6	-2.3
3680	130.11	99.6	6.8
3960	138.06	99.6	10.5
4240	147.03	99.2	12
4560	161.14	99.6	8.3
4840	170.56	99.6	10.5
5080	184.69	99.6	11.3
5360	189.75	99.6	10.5
5680	207.94	99.6	9.8
5920	211.97	99.6	11.3
6200	215.86	99.6	13.5
6400	218.17	99.6	15
6600	218.69	99.6	16.5

I've also noticed that since fitting the Dbilas intake my engine load values have gone to pot. Actual is no longer meeting the specified load whereas before fitting the intake it followed nicely. I assume this is down to false readings from the MAF sensor?