Confirm My Exhaust Restriction :(

[Munkyb0y]

he's having the same result without the ebc. so it's not that

i reckon your highflow cat doesnt flow too high. alot of these so called highflows are crap. i had an xforce 3" hf cat on mine, it ran like crud, so i put the 2.5inch back on, much better. now i'm looking around for a magic cat or metal cat stainless type with the big 5" body.

have you checked that your cat hasnt collapsed?

[666DAN]

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.

[Quigga]

seen this kinda thing before, melted cat baffle/muffler/resonator = zuast blocked and poo results

also if ur using a bleed type bc they tend to drop boost out at higher rpms

[666DAN]

seen this kinda thing before, melted cat baffle/muffler/resonator = zuast blocked and poo results

also if ur using a bleed type bc they tend to drop boost out at higher rpms

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

[Quigga]

unbolt the zuast from closest place to turbo (after dump before cat would be best nothing in the system but pipe) run the car see if it feels the same,

take off the snorkel or watever infront of the turbo and give it a visual inspection (check blades ect)

have u got a tuneable ecu or anything (has it reset)

best way to work out a problem is by excluding the possiblities

good luck Quigga

[Haines]

Have you got the standard induction pipe ??

could that be sucking closed and causing restriction ???

[666DAN]

Have you got the standard induction pipe ??

could that be sucking closed and causing restriction ???

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

[Haines]

let me know how you go with it

I have full 3 " and i can stand beside it and not hear it running (keeps the Po Po away ,but not very manly)

[666DAN]

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

[VB-]

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.

make sure, because it does happen, i've seen it, i've got it on DVD and it ahppened at about 14psi from memory, with a hi-flow, so similar to your setup

Edited July 25, 2007 by VB-

[666DAN]

make sure, because it does happen, i've seen it, i've got it on DVD and it ahppened at about 14psi from memory, with a hi-flow, so similar to your setup

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.

[Haines]

ive never seen it happan

I only just read about it when i bought that intake pipe off bass junky

but the more i think about it if that pipe gets some heat soak in it it would go pretty flexible and may even colapse the reinforcing rings

ive heard of ppl putting zipties in the grooves to stop it happening ,does this work ????

[666DAN]

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.

[666DAN]

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!!!!!

[nissan_gtr35]

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!!!!!

Ok so im gonna throw an idea out there, feel free to shoot it down everyone!!!

Instead of concentrating on the possibility of a "mechanical" restriction, is it possible that the soul source of power, i.e. the fuel, is being restricted??? Just seems strange that without any major internal restictions that the boost isnt steady. Trust me i know all about internal flow restrictions as i spent last year designing an intake system which had to pass all engine air through a 20mm circular restrictor (ahh good old Formula SAE ). I know how painful finding the right balance can be!!!

Anywho, just a thought, maybe the injectors are clogged or shot, not enough "hot" exhuast gas to expnad to provide the boost level desired?

Maybe its time for some Wynns Spitfire

[BAMR33]

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!!!!!

So did you test taking off the rear muffler like you said your were going to do originally. Could still be the wastegate actuator, I too have a HKS one and they're substantially smaller and lighter the standard item, maybe they're not up to the job...

[T04GTR]

he's having the same result without the ebc. so it's not that

thats my point.

[T04GTR]

untill you set it up PROPERLY its still gonna drop off. have you try doing what is sugested ealier?

[666DAN]

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

[Munkyb0y]

have you considered the turbo itself, or intercooler, may not be performing as it should?

Edited July 28, 2007 by Munkyb0y