You are correct. That's what I was attempting to say but my choice of wording was poor. The following edit might express my previous statement more clearly (I hope):

On a WRX, less restriction after the turbo is desirable. Properly tuned, you don't lose power with larger diameter tubing - you lose the backpressure which hinders turbo spool-up.

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

 

Gutting the up-pipe does not cause a CEL. The sensor on that pipe is to warn of
overheating caused by the cat getting to hot & possibly melting.
No cat, no overheating, = no CEL.

 

nawwwwwwwwws!!

:devil:

 

install an anti-lag control unit..... and dont forget the guage. DOA

;^)

 

From what I've read you may not want to reinstall the probe because it could break off and trash your turbo.

 

A full exhaust and tuning will help lag. And a ported and polished turbo will also help, I beleive. Gutting the stock uppipe can be dangerous because if its not done carefully a piece of the cat may fly into the turbine and then you'll be replacing the turbo. Good luck.

 

I think that it's just a safer idea to buy a helix than gutting an up pipe.

 

Gutting the uppipe is not a very good performance enhancer. The exhaust gases will tumble in the chamber instead of going straight and smooth through the pipe as it would if the catalytic converter were still in place, or if there were no chamber in the pipe. Don't do it unless you want an inefficient exhaust.

 

I agree, that every bit of the cat has to be removed, to prevent anything from hitting the turbo vanes. But I disagree withthe thought that it does not improve performance. That was one of the first things I did, along with installing a K&N flat intake filter, and it made a very noticable difference in spool-up. That lag used to drive me nut's! A high flow cat turbo-back made it even better.
Now at stage 2, I don't even think about lag any more.
Now if Cobb ever comes up with a map for a VF 35 turbo, I will go stg.2-1/2 - 93
I will say that the 4eat tranny gets better & better as the horsepower goes up, but it is a good idea to add an oil cooler if you do any amount of manual shifting.

 

Not to argue with you or anything, BIG GUN, but what I meant was that gutting the cat is not the best performance mod you can do. I didn't say that it does nothing, I just said that there are better alternatives that maintain better flow and overall efficiency. Of course, those alternatives cost money whereas cat gutting costs just a little time and effort. Different strokes for different folks