thebankman

iTrader: (7)

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!

KmanRuffian

Dude, didn't you post this problem like yesterday or something and we gave you an answer? Posting it in the engine management forum isn't gonna change our answers... Our best guess was your clutch is slipping, go find out if that's the case then come back and ask again if it is not.

thebankman

iTrader: (7)

General consensus seems to be the clutch which has major clutch judder.
And I posted once here and once in my local forum

thebankman

iTrader: (7)

It was the faulty stock clutch after all, all problems fixed after all clutch components replaced. Thanks for the help

KmanRuffian

Just so you know, your problems had NOTHING to do with the stock clutch being faulty. If you continue to drive in the same fashion it will happen again. The stock clutch has a cold clutch shudder problem which is different. What you had was a worn clutch from excessive slippage, etc. I think I saw you post somewhere else about your habits when launching your car and I thought to myself "No wonder his clutch is worn, he's lucky his tranny is still in one piece!" I can't remember for sure if it was you but yeah, it's not a faulty clutch, the new one will wear just as much if you don't change how you drive...

Edit: Actually that might not have been you, but yeah be more careful with this one...

meilers

Think of it this way. If he actually knew how a clutch functions and behaves, he would have diagnosed the problem himself immediately. He did not; thus he burned it. According to some of the horror stories on this site, I guess he's lucky they paid for the replacement.

BTW, it is "clutch shudder." NOT "shutter," "jutter," "judder" or the other many creative spellings I have seen on this and other message boards

Kevin M

iTrader: (12)

Actually, it is "clutch judder." Read the TSB and you'll see for yourself. I, however, prefer "shudder" as that's what it feels like. Whatever.

thebankman

iTrader: (7)

OK first off some of you need to get your facts straight and lay off the negative attitude...

I have never posted about my "driving habits" so lay off.

I do some spirited driving occasionally and have driven a manual transmission auto for the past six years so I think I know how to go easy OR hard on a clutch, and generally drive easy as I know the stock clutch is not designed for the power a WRX can make.

The stock clutch had "cold clutch judder" as stated in the Technical Service Bulletin on the subject, and began to experience clutch slipping just recently. I therefore can conclude that the original clutch was poorly designed for the WRX.

I'm not an expert but I'm learning more and more about the WRX and about cars in general as I continue to educate myself through shop manuals and personal experience. True I should have known it was the clutch, but I had never experienced such a problem and was merely looking for advice, not a smattering of passive-aggressive remarks. I hope to continue giving and receiving helpful information in the future on I-club.