Here's the background of the problem:

The car is 02WRX and was dyno'd and ECU reflashed by Shiv at Vishnu. At time of reflash, the car had the stock muffler in place with Samco intercooler/radiator hoses in place. No other parts have been added/subtracted from the car since that time EXCEPT a straight-pipe muffler which was put on several thousand miles after reflash.
Last month I took off the straightpipe and put back the stock muffler. About a thousand miles later, I am now experiencing a major problem especially in 3rd gear, but also in 2nd to 5th gears as well. The car accelerates normally until around 4000RPM, at which time the tachometer needle shoots up VERY quickly to around 5000RPM, then drops down to around 4200RPM and (seems) to start accelerating as it should. This is at wide open throttle (1.2bar of boost) but also occurs with less boost/less throttle as well. Boost doesn't seem to be spiking, and stays at a steady 1.2bar.
I have now unplugged the battery to reset the ECU and the car is still performing the same.

What could be the problem and what are the possible solutions? Any advice would help before I consult Vishnu tuning. THANK YOU!

 

Clutch slipping?

 

Bye bye clutch!

 

And you're probably not running 17.4 psi on the stock turbo either.

Time to get a nice upgraded clutch!

 

Thank you for responses!

So you really think it's the clutch? I have 14K miles on the car and am getting an all new clutch this month as the "clutch judder" issue is very apparent and can be felt even when it's warmed up.

Could anything else be causing this? The turbo has gotten a good amount of water on it in the past, that wouldn't hurt it -right??

Thank you again !

 

The clutch is slipping...

cut down on those occasional street light runs

-Gagan

 

Good luck getting a new clutch from the dealer. Don't mistreat this one too

 

I already scheduled to get the "clutch judder" fixed this month and I'm bringing the Technical Service Bulletin information with me so I get an all new clutch assembly. The clutch feels like total BUTT even after warmed up, just like so many other early WRX's.

Once again THANK YOU ALL for your advice, I trust it and will update this thread when the new clutch is in.
Once again, BAIC is the BEST!!:banana:

 

It does sound like clutch slippage because the RPM range coincides with the peak torque range of your engine. That's when a slipping or worn out clutch is most likely to slip, not at lower RPM or peak HP.

--
0==WW==0
"…axles of evil…" - george w. bush

 

And the clutch judder always went away when warm on both my WRX's. I'm just scared they'll open it up, see a roasted clutch and hit you with the bill. Probably not though b/c SOA pays for the repair.

 

I'm not that hard on the clutch but then again, WRX owners have seen that you don't have to be hard on this clutch for it to have problems. I'm disappointed the clutch went out before 14K miles, it's a shame that Subaru should have to replace every clutch from the early WRX's. It's like turning a $25000 car into a $27000 car with Subaru spotting the extra two grand, but then again that was their decision to produce it and my decision to buy it. Subaru is still the best buy for the $