chur

Thanks brother it turned out to be the pod filter without it, it holds boost perfectly... I still would have expected different symptoms but I guess if your not learning then your probably dead! The guy that sold me the filter(and specifically assured me it would flow enough) is going to get a kick in the nads. Cheers for your time

13thracer thanks for the link it got me thinking, went to the garage in anger determend not to sleep till I found the problem coz it just didn't add up. Then it dawned on me that the idiot who assured me that the pod filter would flow more than enough air for my application may have been talking out of the wrong hole. Set the wastegate up as it should be,Yanked the poddy off and in a fit of foot stomping anger wheeled out of the garage, freaken thing is holding boost perfectly!!! Somehow I new this problem was going to end up making me look like a total tool my experience with cars is that 90% of the time it's something simple. Bad news is it probably doesnt have super awsome internals, damn it! Thanks for all the advice guys

Its cause I'm special I'll take it for a longer squirt with the wastegate wired open tomorrow, I agree it should be impossible! thanks

Cheers lineskee Na your right, I need to start again at the basics, thanks for your input

Yup I know what your saying, the flapper was definetily wired fully open, infact further than the actuator would normally throw it. Hmm I had the dump pipe completely out of the car the other day all seemed to be in order, maybe I will need to dig deeper. I know it sounds impossible, seems impossible to me too

Thanks zebra I wish it was a dodgy gauge, that would be easy lol I have two, one is a blitz mechanical, and the other is an HKS digital, both reading about the same. I think I'll just drive it into a wall thanks brother.

No no I have. Infact at the moment it is connected directly to the port normally used for the BOV. I have proved that the actuator is getting boost pressure and that the actuator is moving. As Cubes pointed out if you wire the flapper open then it definitely should not overboost.

I actually had one of these turbos on my L28 powered 280zx, It went really well and certainly never had any problems like this. Thanks for your time fellas and if anyone has ever seen anything like this please let me know, cheers Special thanks to cubes :laughing-smiley-014:

Hmm thats what I thought. A blocked exhaust would cause slow spooling, then again I havnt driven another r33. Dump pipe is a factory dog.

Hi recce This all started because while doing the cooler I also went to install an HKS evc4. I put a nipple into the right angle pipe off the top of the compressor. After it failed to work I took the controller out of the equation and plumbed the actuator directly to the plenum (to the nipple below the factory blow off valve line normally used for the carbon canaster, with a brand new length of pipe) I have also swapped them around and even put the boost gauge in line so I'm fairly sure now that the actuator is actuating. Now that I have showen that even with the wastegate wired open its still overboosting I think there is something else amiss

Flapper is nice and free and I wired it fully open for this test. I had the dump pipe off in the weekend everything looked fine. What I'm now wondering is if the cat has fallen to bits, could the extra back pressure cause overboosting... Yes I am totally grasping at straws Thanks

Ok before I was stumped, now I'm just totally confused. I've completed 2 more tests tonight. 1. using compressed air and a regulator I emulated boost to the actuator, It worked perfectly. Around .5 bar it actuated and moved the the flapper effortlessly. 2. As suggested by Cubes I disconnected the actuator and wired the flapper open........it's still overboosting!! I only took it up to .70bar however I am fairly certain it would have kept going if I hadn't of buttoned off. Any other ideas, Could a blockage in the exhuast system cause this kind of issue? I'm kinda hoping somebody will point out the obvious cause, I'm lost!

Interesting, I brought a complete fmic kit, none of the bends seemed too harsh however I will bear it in mind. 6 months of not understanding whats going on may cause me to drive it off a cliff (whilst overboosting) Thanks for your input

Good call, I will give it a try, that should prove it! Thanks Cubes

Praying to the skyline gods for help. I'm having issues with the boost on my rb25det, it has me totally stumped. Mods: Factory turbo/wastegate Front mount Intercooler. Pod filter 2.5" exhuast from turbo to cat, 3" from there back Problem: Overboosting To diagnose the problem I am running a line directly from the plenum to the actuator (no boost controller). The wastegate flapper is moving freely (I have had the down pipe off and inspected the internals). I took the wastegate actuator off and had it tested by a local shop who told me it is holding pressure. Some people have told me that adding the exhuast and pod filter could make it boost higher however I fail to see how this is possible as my boost gauge (1 of 2) is reading off the same port running as the actuator. Today I let it boost up to .90 bar and it definetly did not level off. Finally it seems that everything is pointing towards the actuator being faulty, It isnt obviously jambing as I can pull it open by hand but somethings going on. If anybody can add anything I've missed it would be much appreciated.