help an Audi driver with a boost question!

[landwomble]

Guys, I've got a 2004 225 Audi 1.8T.
I've been asking in the TT forums and got blanked, but you people seem to know your 1.8T engines.
Anyone able to help?

just fired up VCDS and did a quick log. This is measuing block 115, to look at requested vs actual boost.
I'm getting an intermittent N249 error, which might indicate a boost leak. Looking at these figures it looks like there might well be one. Could someone who knows what they're doing cast their eyes over this and see what they reckon?
2004, 225BHP model with APR stage 1 map, K&N filter and Forge 007P.

Extrapolated data (this wasn't all that clean a WOT run, you can see it's boot down from about 2000rpm or so, RPM on bottom axis.

Full log:

		Group B:	'115				Group C:
Lambda	Bin. Bits		RPM	Load	Absolute Pres.	Absolute Pres.	
		TIME					TIME
%		STAMP	 /min	%	 mbar	 mbar	STAMP
3.1	1001111	14.39	880	55.6	1000	1010	
0	1000011	15.4	1840	77.4	1690	1050	
2.3	1101001	16.21	2960	90.2	1000	1230	
0	1110101	17.01	2720	13.5	1000	1130	
0	1100001	17.92	2120	36.8	1000	1040	
-4.7	1101001	18.72	2240	27.1	1000	1050	
0	1000001	19.63	2480	88	2130	1100	
0	1001001	20.43	3000	112.8	2290	1320	
-0.8	1001001	21.23	3680	140.6	2420	1700	
-2.3	1001001	22.05	4520	163.9	2440	2040	
3.1	1001001	22.86	5360	164.7	2290	1960	
2.3	1001001	23.75	6240	172.9	2180	2040	
-1.6	1011001	24.55	5920	11.3	1000	1440	
1.6	1000001	25.35	4760	128.6	2260	1580	
2.3	1001001	26.26	5080	151.1	2320	1790	
1.6	1001001	27.06	5400	151.9	2220	1840	
0.8	1001001	27.88	5720	161.7	2180	1930	
2.3	1001001	28.68	6080	166.2	2130	2090	
0.8	1001001	29.48	6360	171.4	2130	2080	
0.8	1001001	30.29	5920	11.3	1000	1540	
0	1000001	31.09	4880	130.1	2200	1570	
1.6	1001001	31.9	5080	157.1	2260	1910	
-0.8	1001001	32.7	5240	157.9	2220	2000	
1.6	1001001	33.61	5480	177.4	2180	2130	
1.6	1001001	34.51	5720	184.2	2160	2210	
1.6	1001001	35.32	5960	176.7	2120	2170	
1.6	1000001	36.14	6120	168.4	2090	2110	
2.3	1010001	37.03	5200	12.8	1000	1210	
21.9	1010001	37.93	4400	12	1000	1130

Looks to me like I've got a fair leak somewhere. Was planning an N249 delete soon to take that out of the equation...

 

[cupra_mike]

hi mate welcome. im sure some one will help you on here

 

[LEE69]

Wrap the code tag around your logs

Group B:	'115	 Group C:
Lambda	Bin. Bits	 RPM	Load	Absolute Pres.	Absolute Pres.	
TIME	 TIME
%	 STAMP	 /min	%	 mbar	 mbar	STAMP
3.1	1001111	14.39	880	55.6	1000	1010	
0	1000011	15.4	1840	77.4	1690	1050	
2.3	1101001	16.21	2960	90.2	1000	1230	
0	1110101	17.01	2720	13.5	1000	1130	
0	1100001	17.92	2120	36.8	1000	1040	
-4.7	1101001	18.72	2240	27.1	1000	1050	
0	1000001	19.63	2480	88	2130	1100	
0	1001001	20.43	3000	112.8	2290	1320	
-0.8	1001001	21.23	3680	140.6	2420	1700	
-2.3	1001001	22.05	4520	163.9	2440	2040	
3.1	1001001	22.86	5360	164.7	2290	1960	
2.3	1001001	23.75	6240	172.9	2180	2040	
-1.6	1011001	24.55	5920	11.3	1000	1440	
1.6	1000001	25.35	4760	128.6	2260	1580	
2.3	1001001	26.26	5080	151.1	2320	1790	
1.6	1001001	27.06	5400	151.9	2220	1840	
0.8	1001001	27.88	5720	161.7	2180	1930	
2.3	1001001	28.68	6080	166.2	2130	2090	
0.8	1001001	29.48	6360	171.4	2130	2080	
0.8	1001001	30.29	5920	11.3	1000	1540	
0	1000001	31.09	4880	130.1	2200	1570	
1.6	1001001	31.9	5080	157.1	2260	1910	
-0.8	1001001	32.7	5240	157.9	2220	2000	
1.6	1001001	33.61	5480	177.4	2180	2130	
1.6	1001001	34.51	5720	184.2	2160	2210	
1.6	1001001	35.32	5960	176.7	2120	2170	
1.6	1000001	36.14	6120	168.4	2090	2110	
2.3	1010001	37.03	5200	12.8	1000	1210	
21.9	1010001	37.93	4400	12	1000	1130

 

[rk696]

Could it be a boost leak?

 

[Pyro]

From the graph I'd say leak not to sure how to read logs tbh are you getting any fault codes up? There's a guide on here for a DIY boost leak machine witch would br handy for you unless you can it booked in a tested by someone I'd check the 007 is in good working order and check every pipe for splits etc under the inlet manni is a reall weak spot on the leons so could also be on the TT so worth a look

 

[rsmith]

Post up the n249 error from vagcom, also log 003 & 020 together along with 115 & 118 logged together on a 3rd gear run from low rpm to redline on wide open throttle. Also if u could post the values in block 032 which are long term fuel trims it would give us a good indication.
As mentioned there is a guide on here for making a diy boost leak tester, hit up the search feature on here for it.

Did u have a look round the engine bay loose/split pipes?

If all this sounds like to much, bring it to your local vag specialist.

I hate flippin boost leaks.

 

[Pyro]

Don't you mean a 4th gear run Robbie?

 

[rsmith]

Don't you mean a 4th gear run Robbie?

Ideally 4th yeah as the run is longer, the log samples are better and more load is placed on the engine, but Sam 4th gear @ 7000rpm is just shy of 120mph, i know because i did one the other day, we always say do the runs on 4th gear but 99% of the time its not pratical unless you have access to a private road, i know alot of us say we do but

 

[Pyro]

Lol I personly do nice big runway up by me but I do see your point 4th is defo more fun tho.

 

[cupra_r_ick]

is there actually a runway by you sam, that you can get on ??

 

[Pyro]

Yea well some of it you can get on all day bit my mates dad runs security there and has let me on the past but can't do it very often there's about a 1/4 mile stretch that used to be open all the time as there's houses there but not been up in a while pretty sure you still can tho as there a bike test centre there

 

[CupraMVR]

I would check all the vacuum pipes under the inlet manifold. the 1 way valve aswell. any little split on a pipe can be a big leak under full boost while the engine is rocking back and forward. try the E pipe on the left hand side of the inlet manifold aswell. any soft pipes off the rocker cover to the TIP and breather pipes can have small splits and make a leak.

 

[landwomble]

Cheers guys, great advice. I'll get logging and report back. My first 1.8T engine so I'm not 100% sure what squishy pipes feel like, if you see what I mean. Will get looking under the bonnet...!

 

[landwomble]

back again

Hi all,
OK, sorry for the delay - but I've not been totally idle.
I did an N249 delete and in the process found that the T-piece from vac line into the N249 gubbins had been broken in the past and some numpty had used an inch of cut off brake line to join them up, which wasn't airtight...
I also serviced my Forge 007P with new O rings and piston, and cleaned the mucky K&N panel filter up and reoiled it.
Have tried the car with MAF disconnected and it feels the same so I don't think my MAFs knackered.

I've done a log in 3rd on WOT today:

	Group A:	'115				Group B:	'118				Group C:
		RPM	Load	Absolute Pres.	Absolute Pres.		RPM	Temperature	Load	Absolute Pres.	
	TIME					TIME					TIME
Marker	STAMP	 /min	%	 mbar	 mbar	STAMP	 /min	°C	%	 mbar	STAMP
	0.01	2320	13.5	1000	1020	0.4	2360	29	94.5	1070	
	0.8	2440	103	2140	1250	1.31	2640	29	94.5	1520	
	1.71	2800	155.6	2330	1830	2.11	3000	29	80	2320	
	2.52	3240	191.7	2410	2510	2.92	3520	29	83.1	2380	
	3.41	3800	191.7	2480	2420	3.83	4080	29	85.5	2540	
	4.23	4360	191.7	2470	2500	4.63	4640	30	87.8	2430	
	5.04	4880	191.7	2340	2390	5.42	5120	31	86.7	2390	
	5.84	5360	188.7	2250	2310	6.35	5640	33	86.3	2270	
	6.75	5800	180.5	2190	2210	7.15	6000	35	82.4	2250	
	7.55	6200	173.7	2150	2160	7.96	6360	37	85.1	2160	
	8.46	6560	164.7	2160	2080	8.95	6280	39	0	1880	
	9.37	5520	12.8	1000	1240	9.75	4920	36	0	1120	
	10.16	4760	12	1000	1060	10.56	4680	35	0	1050	
	10.96	4520	12	1000	1040	11.36	4360	34	0	1040	
	11.76	4200	12	1000	1040	12.17	4040	34	0	1040	
	12.57	3920	12	1000	1050	12.97	3840	34	0	1040	
	13.48	3760	12	1000	1050	13.98	3680	34	0	1040	
	14.38	3640	12	1000	1050	14.78	3600	33	0	1050	
	15.19	3560	12.8	1000	1040	15.59	3520	33	0	1030

and

Thursday	12	May	2011	12:37:29											
8N0 906 018 CB		1.8L R4/5VT     G   0003													
															
	Group A:	'003				Group B:	'020				Group C:	'032			
		RPM	Mass Flow	Load	Ign. Timing		Idle Stabilization	Idle Stabilization	Idle Stabilization	Idle Stabilization		Lambda	Lambda	Bin. Bits	Bin. Bits
	TIME					TIME					TIME				
Marker	STAMP	 /min	 g/s	%	 °BTDC	STAMP	 CF	 CF	 CF	 CF	STAMP	%	%		
	0.75	2200	12.69	8.6	30.8	0.01	0	0	0	0	0.35	0	-2.3	        	        
	1.96	2280	29.5	18.4	13.5	1.16	0	0	0	0	1.56	0	-2.3	        	        
	3.27	2720	78.58	100	12	2.36	0	0	0	0	2.77	0	-0.8	        	        
	4.48	3480	133.03	100	3.8	3.67	0	0	0	0	4.07	0	-0.8	        	        
	5.79	4400	175.94	100	9.8	4.88	0	0	0	0	5.28	0	-0.8	        	        
	6.99	5200	191.78	100	9.8	6.19	0	0	0	0	6.59	0	-0.8	        	        
	8.2	5920	200.92	99.6	11.3	7.4	0	0	0	0	7.8	0	-0.8	        	        
	9.51	6520	204.53	100	17.3	8.61	0	0	0	0	9.11	0	-0.8	        	        
	10.7	5920	6.36	7.8	6.8	9.92	0	0	0	0	10.32	0	-2.3	        	        
	11.92	4480	9.97	7.5	4.5	11.12	0	0	0	0	11.52	0	-2.3	        	        
	13.23	4080	9.56	7.1	4.5	12.32	0	0	0	0	12.71	0	-2.3	        	        
	14.44	3840	9.42	6.7	3.8	13.62	0	0	0	0	14.02	0	-2.3	        	        
	15.63	3720	8.97	6.3	3.8	14.84	0	0	0	0	15.24	0	-2.3

Car feels *massively* better since the N249 delete, with a real kick in the pants at 3200rpm or so.

How are these logs looking? I think they're a lot healthier than they were...

Any advice appreciated!
Ric

 

[rk696]

They look a lot better.

It could be that the dv was sticking open, or the pipe form the n249 was leaking.

 

[landwomble]

Cheers, good to hear. Reckon I need to worry about boost leaks, dodgy MAF, N75 etc or does this look decent? It's a 225 with stage 1 remap, panel filter etc...

 

[rk696]

That looks pretty decent to me.

Apparently if you divide your peak MAF reading by 0.8, it gives you a rough estimate of power.

In your case, 204.53 divided by 0.8 = 255.6 BHP.

On the first logs, most I could work it to be was aroun 215.

Still worth checking for leaks though.

 

[rsmith]

Logs look spot on now mate, 255/260bhp is on the money for a stage one.You can work out your projected torque from the g/s to, g/s / .8 * 5252 / rpm = lb/ft. i.e. 133/.8*5252/3480 = 250lbft @ 3480rpm, but it's only a guide, more bhp and torque ca be got from timing advance.

Good job on getting it sorted and updating the thread.

 

[landwomble]

Guys, should I worry that peak bar appears to be about 2.5 bar? Seems very high...?

 

[cupra_r_ick]

yes