dyno'd a week ago...my tuner pushed the car relatively hard up to about 4000rpm and I was only seeing -2.9 in*hg of vacuum where my 18g should be well into boost...

a boost leak somewhere but nothing is jumping out at me ... nothing obvious. If I'm expecting 12psi to 15ps around 4k rpm and I'm seeing -2 in*hg of vac the air has to be going somewhere.

No clear/obvious broken couplers/loose connections from the turbos to the TB.

the tuner suggested I check my waste gate valve seats - which I got the drivers side off last night (early this morning) and it's in place. Going to pull the passenger side next. Going to replace the diaphragms and hopefully install a waste gate relocation pipe (if I can find a kit).

Has anyone experienced something like this? known of a solution? or have any insight?

My tuner is Nick over at Mac

any help is appreciated -

 

Get some soapy water and get to dabbing your whole kit. When you see bubbles that's it.

I'd also start with the waste gate, then pipes then connections and on from there.

Happy hunting.

 

sounds like wastegate is open, bypassing the turbo

un install any EBC/MBC and just run WG first to check spool/boost. You should be able to hear the turbos spool up.

Tuan had his wastegates fail open (disc on end of rod broke rod end, stayed cocked)

 

^I appreciate the posts guys...it turns out I made a dumb mistake ... at first blush my impeller spins freely as I get closer to it I believe the blower has to be rebuilt it's got a good amount of play in it...fairly sure this is on me and if it's not, it's still on me...

two mistakes - first & foremost - I think I hooked the waste gates up wrong - used the top port rather than bottom side - I thought that's how they were supposed to be while not using a boost control solenoid and I didnt have the where-with-all to have someone with more experience review my setup.

second was not rebuilding my waste gates and having them sticky - the diaphragms look fine but I'll spend the $30 for new diaphragms, I'll replace my plunger valve seats($30) and do very good job cleaning the mechanics of the waste gate before it goes back on...

dumb dumb dumb...a $1500 to $2000 mistake...

I'll be digging into the passenger side here soon...

 

you can get CHRA for 500.

top port is only when you run a boost controller. If thats how you plumbed it, then your turbos should have spooled well beyond 25psi or so. Leave the top port open.

 

yeah...lessons learned...I didnt over-boost like that...I'll be a little smarter once I get it buttoned back up...

 

continue to the build thread...

https://my350z.com/forum/forced-indu...n-build-5.html