My car has gone from running 14.4 @ 95 2.2 60's at the end of last season to 15.0 @ 90 if I'm lucky this season, same 60's. 5spd, VI, VAFC, etc. I bypassed the knocksensor today & no change in times. I cannot break back into the 14s and cannot trap high than 90mpg. Thought maybe the power rod is not actuating but I do feel the increase in top end after 5200RPM, at least by watching the tach... maybe wishful thinking. At this point not sure what it would be. I'm going to tear into the upper next weekend to see if the rod is loose from the cup. Can't really afford the dyno time to see where in the RPMs the loss is at.
Wondering if it could be something else?

 

like you said, check the VIAS, and check for any codes.

 

sounds like a vias problem to me... post back with results im interested in this..

your low trap speed seems indicative.

 

Check the flex section on your y-pipe.

I experienced similar power loss. It turned out to be the super cheap flex section used on my Warpspeed Y-pipe. My exhaust diameter been effectively reduced to about 1". Once that was fixed, the VQ30 was alive again.

 

you have an 02 sensor code or TPS issues?

 

Was kinda wondering that myself. I have the original version WS Y and the flex section is starting to look blown out. May check that 1st cuz I sure don't want to tear back into the upper.
A few more redline pulls on the interstate today & the ole butt seems to feel the VIAS kick in around 5200. I can hear the difference & see the RPMs climb pretty quick. When I got the VI it seemed to have the JB weld fix already. I can't find my original PMs from UNCd00d, who was selling it for a friend & they got it from I thought Tilley?

 

Well, the braided mesh is gone & I can see the coiled flex part of the flex section. Is that another pipe inside the coil part? Guess a new ypipe is on order soon. Didn't get a chance to check out the VIAS but I don't think that is an issue. Did manage to get my VAFC2 wired and wideband in though.

 

My Y-pipe had a mesh-coiled flex tube-mesh construction. There was discernable exterior mesh damage, but upon removal and inspection with a flash light, I could see the inner mesh clogging up.

Get a new flex (~$50 flex + $15 labor) instead of a new y-pipe.

 

We have a winner. Man that thing was collapsed like a beotch. Sorry for the thread revival, thought some might like to see. It was a warpspeed btw

inlet side


outlet side


Hope to get to the track tomorrow nite to verify but I'd say that was it. I'm kinda hoping it was partially collapsed when I ran my 14.4

 

do you have a pic from the outside?

 

 

This is a Warpspeed Y? My stock one looked identical to that when I replaced it a couple days ago with a Warpspeed one finally.

 

Damn that is ugly. Hope you replaced it with a 2 or 3ply flex.

 

seems to be a common problem for ws y pipes..

 

Yeah and I'd like to know how old his is to be in that bad of condition.

 

The guy I purchased the car from had installed the y-pipe & he told me it was a Warpspeed. He bought the car in fall of 01 with almost 30k miles. Not sure when he installed the ypipe but it WAS wrapped and it was his daily driver in KY. I bought the car in Jan 04 with 54k miles and it ran fine till at least this past winter with close to 80k miles. So I'm figuring the ypipe was exhaust wrapped in KY weather for roughly 4yrs/50k miles.

 

how did you bypass the knock sensor