Hybrid96EK

Alright. Here is the problem. Boost builds up and spikes to about 8psi BRIEFLY then settles to 5psi by 7,000rpms. I have a Greddy 19T kit. Custom 2.5" downpipe. I modified the elbow a little bit so it flows better then its orignal design. I have a boost controller on the car (turbo XS manual) and this doesn't do anything but raise the spiking point. I have a blitz dual SBC electronic boost controller but I am not able to get it to work properly, I think the solenoid is bad. Anyways, with no boost controller (straight to the wastegate) it spikes to 6psi or so, then settles to 5psi as rpms increase. I thought possibly a boost leak? but all pipes are tight with no signs of leakage. I have the BOC adjusted fairly tight, but perhaps this is the problem also and its leaking at higher rpms, although I can't see how. Does anyone have any suggestions on things to check? I know someone is going to tell me the turbo is too small, but I know people with the 15g kits that don't have these issues. It sucks because I can't get boost to increase and most of all, I don't want it spiking.

093turbo16

iTrader: (2)

Almost every car I have done with that kit does that exact same thing. I am not sure why it does that. I would like to know as well. I think an electronic controller might solve the problem though.

Soccerking3000

hmm this is odd because i would see it the other way lol and you'd get boost creep . When are you getting boost?

Hybrid96EK

Full boost seems to hit by 3,500rpms or so. Pulls well, just spikes then drops down..

Soccerking3000

i'm assuming you are using the port on the turbo for the boost source for the wastegate?

Hybrid96EK

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Soccerking3000 &raquo;</TD></TR><TR><TD CLASS="quote">i'm assuming you are using the port on the turbo for the boost source for the wastegate?</TD></TR></TABLE>

Yes. As it is right now, the manual controller is of course inline with this and the wastegate actuator...

When I got the turbo, the actuator rod was all the way tight and the car spiked to 8psi with no controller, then settled to 5psi. I loosened the rod some and got it better "controlled" where it would only spike to 6 and then settle to 5. Problem is I want to run more then 5psi, but I can't deal with the spikes..

Soccerking3000

i have no idea man, only thing i would suggest but not really suggest doing is unhook the wastegate line and see what happens... most likely it'll jsut boost to the max psi it could. Like i said i dont suggest it though lol. But if there is an issue with the wastegate such as binding or something to the regard you'll be able to see it. I did this but then again my motor isnt stock by anymeans

edit: i just realized how trully stupid this is dont do it lol

Hybrid96EK

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Soccerking3000 &raquo;</TD></TR><TR><TD CLASS="quote">i have no idea man, only thing i would suggest but not really suggest doing is unhook the wastegate line and see what happens... most likely it'll jsut boost to the max psi it could. Like i said i dont suggest it though lol. But if there is an issue with the wastegate such as binding or something to the regard you'll be able to see it. I did this but then again my motor isnt stock by anymeans

edit: i just realized how trully stupid this is dont do it lol</TD></TR></TABLE>

Yeah, I am pretty sure I know what it will do... but on a 100% stock Z6 with only ARP head studs, I also know that it won't last long enough to see if it holds. That and the fact that it would over rev the turbo makes it a very bad idea

With the blitz boost controller, it just hits the boost cut in the ECU, thats how I know its not working.

Soccerking3000

i would try and get another electronic boost controller, i dont know why the manual one isnt working correctly or the wastegate i dont know. When i had my greddy kit i used a a turboxs boost controller and it worked great...

i'm sure someone here will figure it out lol