Greddy Type S problem - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

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.

Steeles · 01-02-2004, 08:09 AM

hey scream... Bragleman brought this up on the lisyt the other day since he has the same BOV on his KAT... Dennis reminded us that the type R is for higher boost applications. 18-30psi range so it may be that your not running enough boost for it. might have to step back to the type S BOV to get it working right. I meant to call you back after reading that. but well.. damn ADD kicked in

Eyescream · 01-02-2004, 08:23 AM

It is a Type S, dude. Says so in the thread title.

I've not heard about that difference between the two BOVs, though that makes sense I guess. The only people that I know IRL that have experience with them are DSM guys, and they haven't really been able to help me.

I'm confused as to what other vacuum line I could tee into for the bottom section port, though. Apparently we do need to use it in this case, but I'm afraid to go cutting into lines in case the ones I'm cutting don't help, because then we'll be stuck having to buy new vacuum lines.

Bolo · 01-02-2004, 12:11 PM

The type-s can be used as a push/pull design. Just connect the smaller nipple to a boost source (hotpipe). I had mine setup like that but I didn't like the part throttle response. It wouldn't really build boost until you were at WOT. But it did make the bov respond a lot quicker.

01-02-2004, 07:42 AM	#1
Eyescream Leaky Injector Join Date: Aug 2003 Location: Knoxville, TN Age: 45 Posts: 103 Trader Rating: (0) Feedback Score: 0 reviews	Greddy Type S problem 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.

01-02-2004, 08:09 AM	#2
Steeles Post Whore! Join Date: Sep 2002 Location: 7th layer of hell, special pit of anger Age: 48 Posts: 3,785 Trader Rating: (0) Feedback Score: 0 reviews	hey scream... Bragleman brought this up on the lisyt the other day since he has the same BOV on his KAT... Dennis reminded us that the type R is for higher boost applications. 18-30psi range so it may be that your not running enough boost for it. might have to step back to the type S BOV to get it working right. I meant to call you back after reading that. but well.. damn ADD kicked in __________________ Keeping it Godzira bishes. So I murdered another turbo

01-02-2004, 08:23 AM	#3
Eyescream Leaky Injector Join Date: Aug 2003 Location: Knoxville, TN Age: 45 Posts: 103 Trader Rating: (0) Feedback Score: 0 reviews	It is a Type S, dude. Says so in the thread title. I've not heard about that difference between the two BOVs, though that makes sense I guess. The only people that I know IRL that have experience with them are DSM guys, and they haven't really been able to help me. I'm confused as to what other vacuum line I could tee into for the bottom section port, though. Apparently we do need to use it in this case, but I'm afraid to go cutting into lines in case the ones I'm cutting don't help, because then we'll be stuck having to buy new vacuum lines.

01-02-2004, 12:11 PM	#4
Bolo Leaky Injector Join Date: May 2002 Location: Bay Area Posts: 69 Trader Rating: (0) Feedback Score: 0 reviews	The type-s can be used as a push/pull design. Just connect the smaller nipple to a boost source (hotpipe). I had mine setup like that but I didn't like the part throttle response. It wouldn't really build boost until you were at WOT. But it did make the bov respond a lot quicker.