Stupid Question

[S4NORICE]

I'm a bit confused because I seemed to have just fixed my car by beating the piss out it for 2 hours... No bullshit.

For the past few months or so I've been driving my car with a pretty light foot, in fact a really light foot, as I don't think I've boosted the turbo's past 5psi. My daily commute is about 40miles round trip and 95% of that is highway cruising. That said, I can practically make my entire commute without boosting past 5psi. (also like to add that since I've been pussy footing this thing around for 2 months, I went from getting 18-19mpg to 23-24mpg, lol...)

Anyway, yesterday I did a 1st-4th pull with a friend in the car and noticed the turbos would only spike 12.5 psi and hold 12psi. Not only that, but boost delivery just didn't seem right. I'd pin the pedal in 3rd at 45 and it seemed like it would take longer to spike than usual.

For discussion purposes, I have an apr 93 chip and can usually spike 18.5psi.

Probably just a leak, right? Nope, this morning I did a pressure test and the intake was holding 22psi without a problem. Maybe just a N75 valve preforming sluggishly allowing the wastegates to open up to soon, right? Nope...

After I did the pressure test I decided to take the car for a ride out on some back roads so I could do some pulls. I really wish I had logged some of these... But anyway, On the first couple pulls the car was running just like I mentioned above, spiking about 12.5 and holding just under that. Here comes the strange part, as time went on, the boost started getting progressively better. Seriously, every couple 1st-3rd pulls the boost would get slightly higher. Not only that, but the turbo's seemed to get more responsive the more I beat the piss out of it. After many many pulls, all my boost is back and the car rips again. WTF??

So my stupid question is this; Are the ECM's on these cars Adaptive??

Like I was saying before, I've been driving the car like a grandma for a while. Did things just need a wake-up call?

Anyone have any insight on this?

[lbs4]

i kinda had the same issue, after doing turbo the car had awsome power, and i drove it for about 2 weeks without boost, and the car wasnt peaking very low and the power took forever, instead of a jolt of boost it would gradually climb? i had no leaks but the wastgate was screwy so i fixed that i hope, and it seems to be going better but still the power isnt as responsive. when i first started getting on it,. there was awsome power in 3rd but it seemed like it wasnt comming like it should??? im a bit confused too.

[abccba]

; Are the ECM's on these cars Adaptive??

yes

[The_Jerbel]

You just needed to blow the carbon out of the exhaust

[Quattrocket]

I've heard of the n75 getting moisture in it and freezing causing them to stick. maybe it just needed some heat from the turbos to melt the ice? then again, I'm just talking out my ass.

[S4NORICE]

yes

Hm. It almost seemed as though the engine was in stuck in a mild form of limp mode. Strange...

[QWKDTSN]

I think it helps to boost now and then.... I know I have a very similar commute.. About 8 miles through town at about 30mph most of the way, almost never get into boost when commuting. If I go a couple of weeks without really boosting and then give it a 3rd gear pull to redline my car will blow smoke - and after that it seems to run a bit better. Gotta blow all the carbon out, I guess.

[S4NORICE]

I've heard of the n75 getting moisture in it and freezing causing them to stick. maybe it just needed some heat from the turbos to melt the ice? then again, I'm just talking out my ass.

eh - its actually been above freezing here the past few days. But I can see that happening on a 1.8t seeing that the n75 is mounted to the "ginseng root", or turbo inlet pipe and its a bit further away from the engine than on the 2.7. The N75 is certainly exposed to more cold air on the 1.8t than on the 2.7. The N75 on the 2.7 is right above the intake manifold so it should warm up pretty quickly.

Anyway, I just drove the car again and I still have all my boost. The Idea of burning off the carbon build up in my exhaust seems like a very good possibility, seeing that things haven't been glowing down there in a while. Maybe my pre-cats had a bunch of carbon build up, idk. This would make sense tho, because if the pre-cats were restricting flow, it would obviously reduce the velocity of the exhaust gas, thus restricting the turbine wheels from reaching full rpms.

The thing I find funny is that I've read/seen perhaps hundreds of guys posting that they can't get full boost, yet they have no leaks and N75 seems to be doing its job. Yet they also have no codes. This was my case yesterday. I wonder if they had a similar situation.

I typically drive this car pretty hard. However, some things have happened in the past few months, work has been letting people go left and right. My original snails have 180k on them, so I've put them in hibernation just in case things go bad at work... That said, stage 3 savings may end up getting used elsewhere.

knock on flpin wood...