Josh636 Member 65 Member For: 17y 4m 24d Gender: Male Location: Mount Isa Posted 20/04/08 11:24 AM Share Posted 20/04/08 11:24 AM So the title says I cant stop my over boost. I have a rapid cooler kit, 4inch dump cat back and just installed a modded housing and 12lb actuator. but still just over boosts. so a few details. I noticed on the 12lb actuator it has 10mm less travel than the stock one. has anyone else still had overboost even with a modded housing? I have the standard bov hooked up without the vac line connected and it opens at about 8psi and vents enough air to hold 11psi but without that set up it just overboost crazy mad. Link to comment Share on other sites More sharing options...
XR6 Turbo Developments Member 100 Member For: 17y 10d Gender: Male Location: Dandenong Posted 20/04/08 11:28 AM Share Posted 20/04/08 11:28 AM So the title says I cant stop my over boost. I have a rapid cooler kit, 4inch dump cat back and just installed a modded housing and 12lb actuator. but still just over boosts. so a few details. I noticed on the 12lb actuator it has 10mm less travel than the stock one. has anyone else still had overboost even with a modded housing? I have the standard bov hooked up without the vac line connected and it opens at about 8psi and vents enough air to hold 11psi but without that set up it just overboost crazy mad.Have you had the car tuned since you fitted the actuator and modified exhaust housing?? Link to comment Share on other sites More sharing options...
Josh636 Member 65 Member For: 17y 4m 24d Gender: Male Location: Mount Isa Posted 20/04/08 01:36 PM Author Share Posted 20/04/08 01:36 PM It hasn't been tuned yet but it still shouldnt run more than 12psi. I have the turbo boost straight into the actuator so no computer controlling boost. Before I changed the housing and the actuator I had the standard actuator hooked into boost and it would run 5psi up untill 3500rpm then start to overboost. now with the 12psi it spikes past 15 without even trying. it just seems like its still not passing enough gas through the wastegate hole. with the bov venting some of the boost it holds 12psi fine. Link to comment Share on other sites More sharing options...
XR6 Turbo Developments Member 100 Member For: 17y 10d Gender: Male Location: Dandenong Posted 20/04/08 01:55 PM Share Posted 20/04/08 01:55 PM I dont think that's its not venting enough gases I think your actuator is staying closed too long.How tight did you string the actuator up? Ive had 2 customers come to me with the same issue and when I pulled the turbo off to see how hard the actuator was adjusted they had almost taken up all the travel of the actuator. I have 14 cars running around with the same modification on the turbo as yours and not 1 has ever boost spiked. Call me in the morning so we can talk about it. Link to comment Share on other sites More sharing options...
XRDOSE BIGRED Donating Members 1,410 Member For: 17y 11m 4d Gender: Male Location: Sth East Melb Posted 21/04/08 03:56 AM Share Posted 21/04/08 03:56 AM ive got the same problem with my car. ive got the rapid kit and it overboosts on a cold night because I havent got my wastegate done yet its just too small to pass through all the gasses so in turn the gas that cant escape circulates in the turbo and causes it to spool faster making more boost. Porting the wastegate or getting a bigger one should fix the problem....anyone correct me if im wrong. Link to comment Share on other sites More sharing options...
veczar Gold Platinum Member Member 1,081 Member For: 20y 8m 1d Gender: Male Location: Victoria Posted 30/04/08 05:52 AM Share Posted 30/04/08 05:52 AM (edited) You are correct. It can be dangerous (for the engine) on a cold high going hard. Edited 30/04/08 05:53 AM by veczar Link to comment Share on other sites More sharing options...
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