Eyescream
01-02-2004, 07:42 AM
Hi all, been a long time.
I searched and wasn't really able to find anything that pertained to my question, so here it is:
My buddy's car (that I've been drafted to work on) is a 91 fastback with a red top, greddy VSPL front mount, greddy type S blow off valve, and a turbo-back exhaust. Aside from that, it's completely stock and in good running order. The problem we're having, though, is that the blow off valve isn't opening fully. I dunno if it's stuck or if it's not getting sufficient vacuum to open it enough, but at best we get this long, whistling sigh from the bov and some chatter from the turbo from the boost backing up into it when the throttle plate closes. This happens both when the car's stationary and when it's moving under load.
Right now we just have the vacuum port on the purple part of the blow off valve tee'd into the same vacuum hose that goes from the throttlebody (behind the plate) to the wastegate, where we were instructed to put it. Apparently the second port on the bov (right under the purple section) can be left open with no problems, but I'm curious if we should connect it (and if so, where's a good place? I tried connecting it to the hot pipe from the turbo to the intercooler, but that didn't help).
We hooked up a boost gauge and saw good vacuum numbers at idle (the needle sits between 19 and 20 on an Autometer boost gauge), and i tried another couple suggestions that Tony from Atlanta gave me, but I wanted to post and see if anybody else had run into this, and to get more ideas.
Thanks, guys.
I searched and wasn't really able to find anything that pertained to my question, so here it is:
My buddy's car (that I've been drafted to work on) is a 91 fastback with a red top, greddy VSPL front mount, greddy type S blow off valve, and a turbo-back exhaust. Aside from that, it's completely stock and in good running order. The problem we're having, though, is that the blow off valve isn't opening fully. I dunno if it's stuck or if it's not getting sufficient vacuum to open it enough, but at best we get this long, whistling sigh from the bov and some chatter from the turbo from the boost backing up into it when the throttle plate closes. This happens both when the car's stationary and when it's moving under load.
Right now we just have the vacuum port on the purple part of the blow off valve tee'd into the same vacuum hose that goes from the throttlebody (behind the plate) to the wastegate, where we were instructed to put it. Apparently the second port on the bov (right under the purple section) can be left open with no problems, but I'm curious if we should connect it (and if so, where's a good place? I tried connecting it to the hot pipe from the turbo to the intercooler, but that didn't help).
We hooked up a boost gauge and saw good vacuum numbers at idle (the needle sits between 19 and 20 on an Autometer boost gauge), and i tried another couple suggestions that Tony from Atlanta gave me, but I wanted to post and see if anybody else had run into this, and to get more ideas.
Thanks, guys.