I've been searching, but haven't found the threads that describe how to tell if the turbo is dead. I'd welcome anybody pointing me in the right direction.
I was pushing my '03 on track at Barber, heard a pop, and lost power. I got to a pull-off and opened the hood, half-expecting to find the hose had blown off the throttle body, because the car was acting they way it did when a local mechanic failed to tighten that down properly. I couldn't find any loose hoses or connections in the pressurized system. I had a five-hour drive to get home, and in the process, I learned what it could and couldn't do. It starts and idles as usual.
First, the engine sputters with no power if the throttle is used as usual. But, if it is applied VERY gently and progressively, the engine can gradually rev all the way past 4000 in the lower gears, but only holds 70 mph on flat or downhill in 5th. It gradually loses power and starts to stumble on long uphills, and if I try to push the throttle any more it "breaks up completely" so I have to downshift.
I bought it new in July '03 and it has the stock turbo and bov. It has a 3" tbe, buschur intake, and mail-in Dynaflash. I've had issues the past few years with the check eninge light coming on when cruising at 75mph and the car starts to stumble. It was doing that on the way to the track, and to a lesser extent on track. I put a new oem bottom end in over the summer after a rod bearing and main bearing went out. The head was redone a year earlier and I replaced all the valves, after timing belt failure (belt was only 15 months old, ~ 15k miles). It has 90,000 miles on it, and 17 track weekends.
A couple machanics at the track were consulted. The first said it sounded like it wasn't getting fuel, and sent me out to buy a boost guage and AFR guage. He was gone when I got back. The other said it sounded like the turbo was out. He pulled off the air filter and the throttle body hose and felt around. When he came up with some oil on his finger, he felt that was consistent with turbo failure.
I'm rural, and my local mechanic only knows evos from working on my car. I can get to the dealer, 60 miles away. Should I get the boost and AFR guages installed first off, to see what they show? Any advice on what else I or my mechanic should do to diagnose, or to determine if it is the turbo.
If it is the turbo, I'm thinking new oem. My car is faster than I am, so I don't feel like I need a big power upgrade (hence oem block), but if there are other more durable units in the same power range, I'd be interested in any suggestions. Cost is a huge factor; I put over $10k in this summer. If I got a boost controller, could I turn it down for daily driving to preserve the turbo and get better mpg, then turn it up for more power at the track. THANKS for your time.

UPDATE: SOOOOO...... when I got into it from below, I wasn't seeing any loose connectors, so I started feeling around and it felt like I had a long split in the top of the connector from the turbo to the LICP. I bought a MUSE LICP from Tiago V. at VR SPEED FACTORY (http://www.vr-speed.com) for a good price, and with good service. Got it installed and it is good to go. THANKS for all the replies. (I got the vac/boost gauge installed and I'm only getting 14 psi of boost. I'm about to go searchingand/or posting for help on that.)

 

If you bought the gauges I would go ahead and install them and see what's going on.
If your turbo is done I'd upgrade to an Evo IX turbo if you aren't going to go the aftermarket route. .

 

Have you checked the turbo itself, any shaft play ? As long as youre not boosting all the time when dd theres no need to lower the boost, maybe turn it up on race fuel or E85 when at the track.

 

I had the same issue as you did a few weeks ago with my Evo IX. The car would sputter at a certain psi when the turbo would spool. I thought my turbo had gone. Opened the hood checked all the hoses and everything. Then I went under the car and found out that the lower intercooler pipe had opened. Lifted the car, tightened the lower intercooler pipe, and voila, good as new. You should check your intercooler pipes before you decide that the turbo is done and replace it.

 

When my turbo broke the car drove like a lawnmower. I could barely get out of my own way. Besides that they were no miss fires, etc. I simply had no power.

 

Check the obvious lines- Lower Intercooler pipes are very deceiving especially if their stock, mine popped off the very first day I bought the car. I inspected it without jacking up the car 3-4times but- never saw anthing wrong until I actually jacked the car up. GL
Check LICP(cold side and hotside)
J-pipe
Wastegate boost vacuum lines

 

Yeah, you have a pipe disconnected somewhere. Just be thorough in checking.

The lower pipe likes to pop off the FMIC, my test for security on that one is to do a pull-up on it while lying under the car, but I only weigh in at 145 so it's up to you on that one.

Really though, you need to do a boost leak test, I've seen the rubber inside the the stock woven piping crack before and cause issues on throttle and unless you're taking it all apart to check a boost leak test will be easiest.