Recently, I installed a mechanical boost gauge in my car. On stock tune, I’m currently seeing spike of 15-16 psi and holding a solid 12-13. This is obviously an issue as I shouldn’t be seeing much more than 10, if at all past 10 for a stock tune.
So far, I’ve checked for boost leaks, swapped the n75 twice, checked all lines feeding to that, as well as checked the diverter valve to be thorough.
Could this be a waste gate issue? Sticking? Improperly adjusted? Broken?
Have you always owned the car and was the car ever serviced for a turbo related issue.
Possibilities
A broken wastegate as in snapped, or came loose will actually build minimal pressure.
A stuck wastegate would not allow for any kind of pressure loss and you say you lose 4 psi when you hold.
I’d be willing to bet its one of the three things listed above.
This is where I was going. There is the chance that service to the car could have resulted in a damaged waste gate possibly a pinched line. If you had a vw I would tell you the last guy who owned your car did a waste gate preloaded.
Thanks for the input guys. When I get home I think I’m going to try to adjust the waste gate.
Did you check to see if the lines that go from the n75 to the waste gate have an tears or cracks in it? That can cause an over boost because it can’t actuate the WG.
Yes, they seem to all be a-ok.
Figured I’d update this. The wastegate has been adjusted twice so far and I’m debating wether to do it again. I’m much closer to target boost. The hardest part for me was overpowering the OEM threadlock goo stuff that has been on the turbo since birth. Other than that, it is very much a DIY thing and I didn’t even need to make any fancy boost thing to relieve pressure on the adjustment nut.
I don’t understand your issue?
Is the car running like crap or something?
What if you have a tune and now your screwing with the waste gate?
I’m not well versed on the newer 2.0T, but I know that the 1.8T would go into limp mode if you “over boosted” past the stock limit. The way around this was soldering diodes to the MAP sensor to “trick” the ECU. These ECUs are pretty damn smart and if you shouldn’t be making 16psi…the ECU will usually shut you down.
The way I see it is you shouldn’t be screwing with the waste gate unless you think there is truly an issue. What if you boost gauge is screwed up…is it analog (not the most accurate) also is it a $25 gauge or a $200 gauge? See where I’m going there.
He has our tune. However, his replacement turbo’s waste gate was modified for more boost, so he is trying to bring it back to “stock” so to say.
I’m confused then…
Title says “over boosting on stock tune”
So it doesn’t make sense to me and I’ll let you guys work it out.
Piggybacking on what Jake said… When I replaced my turbo with another unit, the previous owner of the new-to-me unit turned the boost up mechanically (using the wastegate adjustment built in to every k03). This creates problems with putting things out of efficiency range and overall making my experience worse. So what I’ve done is undone the previous owner’s doing, thus bringing me back to an OEM adjustment to the wastegate.
He was stock tuned initially.
Lol glad I wasn’t the only one who was confused
Summary. Car was stock now has jhm tune
Wastegste was modified by previous owner. Who added more pretension than it came from factory.
Result: Ktish has to adjust wastegste to factory preload
Mec me and you called it. Ktish I would continue to adjust the waste gate till it’s where it should be. The waste gate mod is great if your a kid with a GTI that has a mashed together car. Now that you have a JHM tune you don’t need any tricks stuff like that is only going to cause issues.
Yep! We’re just the diagnostics tag team duo!
Also I seem to recall someone building a tool that you could pump up with a bike pump and that had a silicone hose that you could connect to the wastegate.
So the idea is. You connect the hose to the wastegate, fill the tool (it was PCV glued together with JBweld) with air, and you could see at what pressure the wastegate was opening and closing, so then you could adjust it to perfection without having to drive the car, and then put it back on jack stands and wait for it to cool down. Kind of like a one stop fix.
Look up “Jimrobbington Wastegate mod” on audizine…something like that sounds familiar.
edit found it.
http://www.audizine.com/forum/showthread.php/420536-Wastegate-Adjustment
I’ve read that thread before. The guess and check method I’m using right now is working better than the ‘shop’ that tried to fix it with fancy tools and what not that tried to fix it for me this past weekend.
what you really should do is just srap that k03, buy a big turbo with a top mount manifold…that way you could adjust the wastegate super easy.
This is the obvious solution.
“I don’t care how much it costs! I just want to adjust my wastegate easier!”