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View Full Version : GTi Turbo Mk4 AUG - Many Questions!



twign
07-05-2008, 12:25 PM
Hi,

Long story short, i'm losing boost.

I need to know where to start in the process of trial and elimination...so I have a few questions. Any help anyone could offer would be greatly appreciated.

FYI...I had an N75J valve fitted when I had the remap. This coupled with the remap "should" run 20psi producing 200bhp.

Now...my first question...is the N75J valve also what's referred to as a 'Diverter valve'??? Majorly confused with this. Some people say it is....others say it isn't.

Second question...if this ISN'T the diverter valve....where is it? And what does it do??? Seen many forums where people refer to this as a possible point for losing boost, but I need to figure out what is is first!!!

Third question...Mass Air Flow (MAF). Is this the same as the Air Mass Meter? Again, seen some reference to both and I could do with determining if they're the same thing.

That's enough for now. More questions later i'm sure.

Thanks everyone (if I get replies).

Twign

Shleng
07-05-2008, 06:41 PM
Hi. The N75 valve is not the Diverter Valve. The diverter valve is located after the air filter and sometimes reffered to or replaced by a 'Dumpvalve'. It is a sort of 'L' shape, has two holes with pipes of about 20mm diameter and one on the 'top' that is 3mm.

People refer to the MAF as both the Mass Air Flow and the Air Mass Meter and yes they are both the same thing.

Can you hear the boost escaping? Is your ECU logging any faults? Im sure if you list these (if any) and what engine you have, people on here will be happy to help you.

twign
07-05-2008, 10:54 PM
Hi.

Thanks for confirming that. I thought as much. It's just tricky when everyones refers to things differently...and i'm pretty lost regarding turbos as this is my first!

AGU or AUG engine? Can't remember which way round it is. AGU i think?

Right, my dump valve 'was' originally a Baileys, but as of me discovering I was losing boost, I had that replaced for a Forge 007 (with the yellow spring - as when running correctly i'll be running appox 20psi). That set me back nearly £100...but it still didn't sort the problem...so I guess that can be eliminated.

Just quickly regarding the Forge....should you be able to hear it on acceleration? It gives off a very subtle 'whoosh' when letting off/chaning gear (which I believe from what I've read is correct - because it's recirculationg)...but it also makes a bit of noise when your foot's to the floor. Is that right? Not loads...but u can hear it.

Yes, u can hear boost escaping - almost a whistling sound when accelerating hard. In my opinion, it sounds like it's coming from infront of where i'm sat when driving. Am i right in thinking that's where the intercooler is? I hope it's just a split hose or something as apposed to being the intercooler.

Getting it looked at on saturday.

SO just want it sorting...for minimum cost lol.

twign