Boost PSI vs Power??

[Quikie]

Hey all
Just a couple of questions about the boost psi reading, my car supposidly standard on the boost gauge is hitting about 16-18 flat out and leveling off at about 15, I have connected it into the manifold vac rather than before the dv which i read on here gives you a more accurate read out but i have noticed very little difference if any and im just wondering is the gauge I have kak or is there a possibility my car has a map on it and how could I find this out on vag-com, also when the car is stopped should the boost gauge point to 0?
On vac it reads 15/20 then stays at 0 crusing at about 55/60mpg then on boost will fly away up but the car does not feel fast as such?? Please give me your opinions...

Cheers
Paul

 

[Damoegan]

Is it a 1.8 20vt?
You can log boost with vag-com, that would tell you if your boost gauge is reading right.
If it is boosting right then it deffo has a remap of some sort as standard boost is ~10psi

 

[Quikie]

yeah mate, x reg cupra.. im not really vag-com friendly, can do the basics and im also waiting delivery of car computer so I can keep a constant eye on things and fault codes.. would this be a job for
vag scope??

 

[sparkie1984]

my boost guage site in the - side when idling im sure, but mines on the brake line thing if that matters?

 

[mr_D]

you defo have a remap. And when at idle the car causes negative vacuum which will sit the needle at -psi and when on boost it will be +psi. So everything sounds about right mate.

 

[Quikie]

cheers for info, as i said it still dont feel like it has but maybe im just expecting too much from it, think its time to start putting a bit of money in too the engine!

 

[__B3NNY__]

Log actual vs requested before you get to excited.

Could be a cheap inacurate gauge, what gauge is it?

 

[Robbie C]

As above, log block 115 for specified vs actual boost

 

[Quikie]

will do!
I dont know what the quality is like, called spitfire gauges?? About £25 each I think, got boost, oil temp and oil press..

 

[mr_D]

yeah but if it is a cheap crap gauge then it will still be near accurate and not off by that much

 

[Quikie]

Yeah I guess so MR D but as I said in original post it doesnt sit at 0 when the car is switched off, think its possibly had a knock at some stage... :S I will try and get some pics up tomorrow for yas to see what I mean.

 

[Quikie]

Well think I have done it right, logged block 115,can any body translate this????

Saturday	20	December	2008	21:20:47			
6K0 906 032 		1.8L R4/20VT SEA 01 0002					

	Group A:	'115				Group B:	 Not Running
		RPM	Load	Absolute Pres.	Absolute Pres.		
	TIME					TIME	
Marker	STAMP	 /min	%	 mbar	 mbar	STAMP	
	0.34	1720	30.8	1010	1020		
	0.84	1720	30.8	1010	1020		
	1.24	1720	35.3	1010	1030		
	1.74	1720	35.3	1010	1030		
	2.25	1680	34.6	1010	1030		
	2.65	1680	34.6	1010	1030		
	3.03	1680	35.3	1010	1030		
	3.43	1680	34.6	1010	1030		
	3.83	1680	34.6	1010	1030		
	4.23	1680	36.1	1010	1030
	4.63	1680	41.4	1010	1030
	5.03	1680	42.1	1010	1040
	5.43	1680	45.9	1010	1040
	5.83	1720	47.4	1010	1050
	6.23	1720	47.4	1010	1060
	6.63	1720	52.6	1010	1070
	7.03	1760	59.4	1010	1070
	7.43	1760	59.4	1010	1100
	7.94	1800	63.2	1010	1120
	8.34	1840	65.4	1010	1130
	8.74	1840	69.2	1010	1140
	9.14	1880	68.4	1010	1150
	9.54	1920	70.7	1010	1160
	9.94	1960	70.7	1010	1170
	10.34	2000	69.9	1010	1170
	10.84	2000	69.2	1010	1170
	11.24	2040	70.7	1010	1170
	11.73	2120	73.7	1060	1200
	12.13	2160	79.7	1060	1230
	12.53	2200	82	1070	1260
	12.93	2280	78.9	1020	1280
	13.33	2320	71.4	1010	1270
	13.73	2360	78.2	1080	1270
	14.13	2400	85	1090	1300
	14.53	2480	80.5	1050	1300
	14.93	2520	77.4	1040	1290
	15.33	2560	88	1150	1290
	15.73	2640	90.2	1140	1320
	16.23	2720	88.7	1150	1320
	16.63	2760	87.2	1130	1320
	17.03	2720	53.4	1010	1400
	17.43	2160	70.7	1210	1150
	17.83	2200	85	1320	1200
	18.23	2200	88.7	1440	1300
	18.63	2240	100.8	2010	1380
	19.03	2320	109	2090	1510
	19.43	2360	115.8	2090	1610
	19.93	2440	124.1	2090	1710
	20.33	2520	128.6	2090	1780
	20.84	2600	133.1	2090	1850
	21.24	2680	137.6	2070	1900
	21.64	2800	141.4	2080	1940
	22.04	2880	145.9	2070	1990
	22.44	3000	153.4	2060	2050
	22.82	3080	158.6	2070	2120
	23.22	3160	160.9	2070	2160
	23.62	3280	161.7	2060	2190
	24.04	3360	158.6	2080	2140
	24.53	3480	155.6	2080	2120
	24.93	3600	154.1	2080	2100
	25.43	3720	154.1	2080	2120
	25.83	3800	154.1	2070	2100
	26.23	3880	151.9	2070	2090
	26.63	4000	151.1	2060	2060
	27.03	3960	144.4	1010	2140
	27.43	3960	38.3	1010	1330
	27.83	3920	15	1010	1150
	28.23	3880	10.5	1010	1100
	28.63	3520	11.3	1010	1080
	29.03	2840	11.3	1010	1070
	29.43	3040	11.3	1010	1060

 

[mr_D]

when the car is turned on and your stationary where does the needle sit on the gauge?

 

[arron2004]

when mine is just on idle it never sits on 0 its like a minus 15 ! i really dunno if it helps mate but mine boost to 15psi and holds i all the way! mines not a good map at all but still brings a smile to my face and passengers

 

[-pseudonymous-]

Your gauge sounds as though its working as it should. On idle with engine running you should see a vac reading of around 20. With engine switched off should sit at 0.

Your car is definately mapped according to your vag-com logs. The map is requesting around 15.5 psi, and your actually peaking around 17 psi as your gauge shows.

One thing... ideally you need to do a run from around 2k rpm to redline in 3rd or 4th gear to get a clear and accurate log in vag-com.

Also copy and paste the results in

 tags, that way they are displayed correctly and easier 2 read. :)

 

[Quikie]

when the car is turned on and your stationary where does the needle sit on the gauge?

like -10/15 took pics earlier but aint able to upload them til tomorrow, ill take pics with power off and idling

when mine is just on idle it never sits on 0 its like a minus 15 ! i really dunno if it helps mate but mine boost to 15psi and holds i all the way! mines not a good map at all but still brings a smile to my face and passengers

Similar to mine, must be the sam cowboy map as yours

 

[Quikie]

Also copy and paste the results in

 tags, that way they are displayed correctly and easier 2 read. :)[/QUOTE]

Cheers big ears, problem sorted :D

I try and do the redline run tomorrow, also going to check for a dodgy vac pipes etc as the biatch went into limp mode when i planted it in 5th gear on the way back down my private road :) ??

 

[-pseudonymous-]

Cheers big ears, problem sorted

I try and do the redline run tomorrow, also going to check for a dodgy vac pipes etc as the biatch went into limp mode when i planted it in 5th gear on the way back down my private road ??

Any faults codes logged in vag-com? more than likely over boosting if going into limp mode in 5th due to higher load levels and higher boost spike....

 

[Quikie]

there was only one today before this happened and it was to do with the n249/n112 bypass i think, it said open circuit..
Whats the most common causes of over-boosting? I have replaced my n75 twice already, once with a J valve and then with the standard one as I thought it was sticking?

 

[Quikie]

VAG-COM Version: Release 409.1-S

1 Faults Found:
17695 - Boost Pressure Control Valve (N249): Open Circuit
P1287 - 35-00 - -

My boost guage sits in between 2-3 psi not 0 when engine off and at 14 InHg when idiling and on full boost is hittin 17psi on the gauge