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Model specific boards => Golf mk4 => Topic started by: oceanic-green on 03 July 2012, 15:03

Title: No boost leaks but not 1oo% power
Post by: oceanic-green on 03 July 2012, 15:03
OK, I have eliminated all boost leaks, with a catch can and the usual silicone hoses, tip, charge pipe, 5 piece turbo boost hose kit ect ect. Plus I had a smoke test yesterday which suggested the dipstick, which I have now sealed up. I have a forge 007 dv, new N75 and new maf, ( both 5 months old) new coolant temp sensor. My boost gauge sits at 20-22 on idle.

I can feel that that it boosts but holds back in 2nd and 3rd. At a guess it is probably about 175-180 bhp, running a stage one r-tech remap, and as it is an Aum should be about 200+ bhp.

What should I check next? I have free version of vag com, but there are no fault codes showing!
Title: Re: No boost leaks but not 1oo% power
Post by: Rhyso on 03 July 2012, 15:05
Not 100% sure what you can log with the basic VAGCOM but try and log your boost / MAF values

Think the MAF is block 2/3
Boost is 110 / 115

If you can log your MAF you can do a crude calculation to work out your approx bhp
Title: Re: No boost leaks but not 1oo% power
Post by: oceanic-green on 03 July 2012, 15:09
Not 100% sure what you can log with the basic VAGCOM but try and log your boost / MAF values

Think the MAF is block 2/3
Boost is 110 / 115

If you can log your MAF you can do a crude calculation to work out your approx bhp

Thanks!

I think I can only log up to blocks 25, so I should be able to do the maf readings. So am I right in thinking I log blocks 2 & 3 or are saying it is 2 or 3.

Do I need to rev it and keep it at a certain rev, or do I need to drive it while doing it (with someone else of course logging it)
Title: Re: No boost leaks but not 1oo% power
Post by: oceanic-green on 03 July 2012, 15:25
Just found a file download with "instructions for logging with vagcom"  :smiley:
Title: Re: No boost leaks but not 1oo% power
Post by: Rhyso on 03 July 2012, 15:27
It is either Block 2 or 3  :smiley:

Full throttle run from 1500rpm to the red line in 3rd

What you should see from the MAF readings is a nice steady increase towards the peak BHP; take the highest figure and divide by 0.8 to give you a rough idea  :smiley:

If you have fluctuations in your MAF then its either your MAF or something, somewhere is causing it to read low
Title: Re: No boost leaks but not 1oo% power
Post by: oceanic-green on 03 July 2012, 15:31
It is either Block 2 or 3  :smiley:

Full throttle run from 1500rpm to the red line in 3rd

What you should see from the MAF readings is a nice steady increase towards the peak BHP; take the highest figure and divide by 0.8 to give you a rough idea  :smiley:

If you have fluctuations in your MAF then its either your MAF or something, somewhere is causing it to read low

Wonderful stuff! Nice one  :smiley:
Title: Re: No boost leaks but not 1oo% power
Post by: Dalo Harkin on 03 July 2012, 15:55
OK, I have eliminated all boost leaks, with a catch can and the usual silicone hoses, tip, charge pipe, 5 piece turbo boost hose kit ect ect. Plus I had a smoke test yesterday which suggested the dipstick, which I have now sealed up. I have a forge 007 dv, new N75 and new maf, ( both 5 months old) new coolant temp sensor. My boost gauge sits at 20-22 on idle.

I can feel that that it boosts but holds back in 2nd and 3rd. At a guess it is probably about 175-180 bhp, running a stage one r-tech remap, and as it is an Aum should be about 200+ bhp.

What should I check next? I have free version of vag com, but there are no fault codes showing!

In terms of being low on power, could be loads of things, actuator being one of them, MAF as you have said, exhaust system etc etc
Title: Re: No boost leaks but not 1oo% power
Post by: daz veedub on 03 July 2012, 15:59
ignition amp  :undecided:
Title: Re: No boost leaks but not 1oo% power
Post by: oceanic-green on 03 July 2012, 16:23

In terms of being low on power, could be loads of things, actuator being one of them, MAF as you have said, exhaust system etc etc

I hope it isn't the maf, as I only bought a new one from TPS about 3-5 months ago. I will get the logging done this week when i can get someone to help me with it, and when it is a bit dryer  :wink:

ignition amp  :undecided:

I just googled this , and apparently if it is this then it will miss fire badly. Is that correct? Mine does not miss fire at all, well not that I have noticed.
Title: Re: No boost leaks but not 1oo% power
Post by: oceanic-green on 03 July 2012, 22:59
OK, an update. After taking the car for a spin earlier, the boost only holds at 9psi  :huh: So I plugged in my hand held code reader (as I didn't have my vagcom or laptop with me) and I get a code  :angry: 17608. So after googling it I see it is either the diverter valve, or the N249 valve. So i guess it can't be the DV because that is a Forge 007 which is only about a year or so old. So it must be the N249 valve.

It seems to be one thing after the next with these cars!!! I get one thing fixed and then it finds the next weakest thing to go. arghhhhhhhhh :angry:

How much is an N249 going to set me back, and do I just get a normal vw one from TPS or dealers, or is there a better after market one?
Title: Re: No boost leaks but not 1oo% power
Post by: pickles on 03 July 2012, 23:02
can you not just delete you N249 and the other valve with the guides on here, less too worry about i suppose
Title: Re: No boost leaks but not 1oo% power
Post by: oceanic-green on 03 July 2012, 23:06
can you not just delete you N249 and the other valve with the guides on here, less too worry about i suppose

I am not too sure about deleting it, surely it has a purpose  :undecided:
Title: Re: No boost leaks but not 1oo% power
Post by: RTechUK on 03 July 2012, 23:09
Do the full N249 bypass  :wink: 
Title: Re: No boost leaks but not 1oo% power
Post by: oceanic-green on 03 July 2012, 23:13
Do the full N249 bypass  :wink: 

If I do that do I have to delete or by pass anything else ?
Title: Re: No boost leaks but not 1oo% power
Post by: rio_gti on 03 July 2012, 23:15
Just bypass it!!! Check maintenance section for the how to
Title: Re: No boost leaks but not 1oo% power
Post by: oceanic-green on 03 July 2012, 23:20
OK chaps! Thanks, I will attempt this tomorrow...hopefully  :cool:
Title: Re: No boost leaks but not 1oo% power
Post by: oceanic-green on 04 July 2012, 00:45
Just read Bav's guide to doing the N249 bypass, and looks fairly simple enough to do. If this doesn't work then I think I may just give up and save my money up from now on, and put it towards buying another more powerful but unmapped car!
Title: Re: No boost leaks but not 1oo% power
Post by: Dalo Harkin on 04 July 2012, 07:10
It should be done anyway really if nothing else its one less thing to go wrong, I used this guide here:-
http://forums.vwvortex.com/showthread.php?3111538

Title: Re: No boost leaks but not 1oo% power
Post by: oceanic-green on 04 July 2012, 07:40
It should be done anyway really if nothing else its one less thing to go wrong, I used this guide here:-
http://forums.vwvortex.com/showthread.php?3111538



Thanks mate  :smiley: I see in that link he shows how to remove the SAI, while Bav's he doesn't recommend that is done, as he put his back on after taking it off. Plus I have had the rivets in the pump changed to bolts, as recommended by Nick at R-tech when he remapped my car. As that apparently stops the thing from leaking.
Title: Re: No boost leaks but not 1oo% power
Post by: Dalo Harkin on 04 July 2012, 07:53
Yes it does stop it leaking if you do the bolt mod, I removed the SAI because the ribbed pipe that connects to it cracked and VW wanted something like £16 a section x 2 or 3 sections  :shocked:
I also use a CAI so didnt need to run the pipe into the Airbox

frees up loads of space in the bay, when I get round to it I'll do some pics  :nerd:

Bavs replaces all the standard tubing which is prone to breaking down and splitting with silicone tubing where as the link I posted removes the N249 and N112 and the hardlines are replaced with 2 sections of silicone tubing, one from the plenum to the DV and one from the plenum to the FPR

In short if it can go, on mine it goes  :grin:
Title: Re: No boost leaks but not 1oo% power
Post by: oceanic-green on 04 July 2012, 09:07
Yes it does stop it leaking if you do the bolt mod, I removed the SAI because the ribbed pipe that connects to it cracked and VW wanted something like £16 a section x 2 or 3 sections  :shocked:
I also use a CAI so didnt need to run the pipe into the Airbox


typical VW wanting £s for something that probably costs them  pennies.

I have just recently fitted a CAI, the pipercross Venom that I bought off someone else on here. they gave me a small foam filter too which I placed on the end of the SAI. Is that correct. My cold air feed goes behind the headlight, but I notice some people stick theirs down the hole by the battery to go behind the bumper, but I couldn't in any way fit my pipe down there!



when I get round to it I'll do some pics  :nerd:

 

cool, that will be interesting to see them  :smiley:


Bavs replaces all the standard tubing which is prone to breaking down and splitting with silicone tubing where as the link I posted removes the N249 and N112 and the hardlines are replaced with 2 sections of silicone tubing, one from the plenum to the DV and one from the plenum to the FPR

In short if it can go, on mine it goes  :grin:

I think I will just try Bav's for the moment, until I get more confident at knowing what I am doing.  :smiley: Although it probably won't be too long before I take your view and strip out all that goes LOL