666DAN

Yeah that's why it may be easier just to go to the bellmouth, equalize the exhaust and wastegate side and be done with it.....you really don't know how close I am to getting an EVO lol!!!! A greater spring tension is just going to see me pushing more boost than I want to with the current gearbox....aghghg why can't things be simple!!!! Yeah I went down to CES for a chat about it all. But maybe that's the issue, the setup is awesome for a fairly stock turbo, but once you get the exhaust pressures moving it's enough of a pressure difference to open the wastegate...we're only talking 15psi of load which in the scheme of things isn't much when you consider the pressure at the turbine. I'll put a bellmouth on, then we can reconvine and discuss

If you've got a stock R33 actuator...for a rough go try these numbers....a bit of playing wil be required keep any eye on the boost!!!! 55% 15% Gain 0.65 Set Gain Dan

Yeah but inlet restriction doesn't push open a free-boosting actuator, the pressure was enough to overcome the HKS actuator set at 15psi, currently I don't need to run any pressure lines to it to make it open...no boost control whatsoever. $1000 would be nice

Eactly dude, that's what I'm going with...see dodgy picture Equal pressure all the way! I think the split may be a good idea with a stock turbo, but my one is realy trying to push some serious gas out of it, the split just isn't working methinks.

Why not? It makes sense as the pipe running behind the actuator is at low pressure with respect to the exhaust side, that's the only way it can be pushed open. Bell mouth will equalize the pressure as there is no difference accross it then.

Really big emphasis on the term "hot plates"

If the bare block is the same as the Neo RB25DE I may be able to help out, all you'd need to do is swap over the vlaves, springs, cams etc etc I would presume.

All over it like a fat kid on a smarty! A CES HPC-coated stainless-steel split dump is coming to a "for sale" thread near you!!!!

New theory!!!! For the actuator to be forced open, there needs to be some pressure up against it ie one side is a much higher pressure than the other side. OK my dump pipe is 100% split, so the exhaust is about 2" in diamter and the dump has it's very own isolated 1" pipe....I'm thinking maybe the pressure across the actuator side is getting too high for the exhaust flow that the car is trying to push. If I just threw a bellmouth dump pipe on I'd probably be better off as there is no chance of a pressure difference across the internal actuator as it's also seeing the pressure from the exhaust flow (unlike now as it meets way down the pipe where the exhaust pressure pretty low in comparison) Feedback please

Well just got some more info, disconnected the wastegate pressure line. Car is free-boosting to 15psi (funnily enough what the actuator spring is set to) then boost tails off in much the same way. ie must be the actuator....next question wtf can I do, what other option do I have for an internally gated turbo?????

I've done and tried absolutely everything, it's definately not a fueling issue as well. Muffler has been off at the cat, boost still dropped-off. Actuator is setup correctly, it did the same thing on an R33 actuator and a R32 one, all at different psi settings, each one dropped off nastily. I'm currently running 15psi on the HKS actuator, no EBC connected. I'm getting annoyed with the bloody thing also

OK scratch the intake idea, just replaced the intake pipe with a reinforced one....same deal, boost drops off rapidly still :S If this had been a horse it'd be off to the glue factory by now!!!!!

FFS I drive an R34, what the hell am I going on about :S It's a very good condition Series II R33 type also

I found a post somewhere before which mimicked exactly what I was saying, their car held boost over 1.0bar, the second the engine came on full noise it started to drop-off to about 0.7bar.

Looks like I'll have to revisit this avenue again and put a reinforced pipe in as it's my last viable option before I take the car down the back paddock and shoot it. Anyone got an EVO 7 they want to give me??? Took the exhaust off, no improvement, if anything boost tapered-off quicker Blocked off BOV...doesn't look like it's leaking, boost still drops off Sat in the middle of a ring of mushrooms and prayed to the mechanical gremlins, boost still drops It only leaves some intake pipe collapso issue that I can't see.

I took this off my car today, it's roughly 2 years old, great condition (minor scrapes on the heat shield) just doesn't flow enough for my current setup. If you're chasing from stock to 400hp this will suit you down to the ground!!! $150

Ack!!! It's not the CAT, either way I stuck a 500hp rated one on, as if things do go the right way the 400hp jobbie will then cause me grief!!! Anyone want to buy a 3" Ceramic substrate CAT rated at 400hp? lol PM me

Sellout, ban ban ban ban!!!

TARDIS hands down

R34 intake pipe doesn't suck closed under boost, we watched it and the way it's designed is clever, it contracts and forms a rigid wall with the groves interlocking...the centre doesn't collapse at all contrary to myth. And yes everything else has been checked, ECU is fine etc etc My original feeling that the exhaust has never been flowing what it should still stands, for my car not to gain 0.1psi after getting a full turbo back is sus. Anyways should have answers in about 5 hours

Don't try and undo the star screw, will take more time than it's worth. You can see what way to turn it, there's a recess that the tab sits in, drivers side looking from the front of the car the tab pushes down over the screw turning anti-clockwise, they turn about 3cm then pop out.

Getting the same result with EBC, HKS actuator set to 15psi, turbotech, stock actuator, gypsy curse....you name it boost drops. Also another note, pressure measured before and after I/C is the same, no restriction there either

You turn the cover with one hand, keeping pressure on it, flip the plastic tab with your finger slightly and it'll jump over the screw. When you do it up, just don't force it past when you screw the cover back.

CES are taking the cat off tomorrow to check it for damage, most likely put a metal cat on as it was just a bigger ceramic jobbie they put in last time, also going to look at the resonator for collapse.

SOLD....maybe to robbo33's disgust???